Technical Description

epe (ethylene polyolefin) film is often used for encapsulating both hjt (heterojunction technology) and topcon (tunnel oxide passivated contact) solar cells, particularly in glass-glass modules, due to its superior water vapor barrier and anti-pid (potential induced degradation) properties. 

 

epe advantages:

enhanced water vapor barrier: epe offers better protection against moisture ingress compared to eva (ethylene vinyl acetate), which is crucial for the long-term performance of solar modules. 

superior anti-pid: epe is more resistant to pid, a phenomenon that can degrade solar cell performance, making it suitable for high-efficiency cells like hjt and topcon. 

flexibility for bifacial modules: epe can be used on both sides of glass-glass modules, which are commonly used for bifacial solar panels. 

hjt and topcon specific considerations:

tco surface adhesion: due to the special surface structure of tco (transparent conducting oxide) in hjt cells, earlier epe products may have had issues with adhesion. however, advancements in epe materials have addressed this problem. 

epe with uv-dc: some epe formulations are designed to incorporate  technology, which can improve the efficiency of hjt cells by converting harmful uv light into visible light. 

epe for topcon: epe is increasingly used for topcon modules, especially in glass-glass designs, where the epe is often placed on the cell side to maximize performance. 

alternative to poe: while poe (polyolefin elastomer) is considered the best encapsulant for hjt in terms of performance, epe can be a cost-effective alternative, especially given potential poe supply issues. 

other considerations:

epe + eva: some companies recommend using epe on the front side and eva on the back side of glass-glass modules, particularly for topcon. 

epe with mesh: epe can be combined with mesh films to reduce silver paste consumption and facilitate the development of busbar-free hjt cells. 

in summary, epe is a viable and increasingly popular encapsulation material for both hjt and topcon solar cells, offering advantages in terms of water vapor barrier, anti-pid performance, and flexibility for different module designs

 

special materials like epe and poe are used to help connect solar cells without needing metal bars. these materials also keep out water vapor and work well for amorphous silicon based hjt solar cells

cybrid and hangzhou first created a new film that turns uv light into energy in hjt cells, increasing module power by 7w and potentially lowering costs with widespread use

with hjt technology getting popular, new ideas like light conversion films are expected to make solar panels work better.

for hjt, given the hydrophobic nature of the deposited amorphous silicon layers, the encapsulation material needs to be carefully selected to have high water vapor barrier properties. the optimization of encapsulation materials from a tco compatibility standpoint is equally important. encapsulation solutions supporting busbar-less interconnection with integrated film is also top of the agenda for major suppliers.

according to cybrid's international marketing director eric yang, a reliable encapsulation solution is only available with the glass-glass structure, while not yet for the glass-backsheet configuration, and the choice could be between poe and epe on the front and rear sides. however, hiuv's peng says that epe can meet the requirements of the hjt, and thus is the most widely used solution.

encapsulation material makers have developed a somewhat disruptive solution specifically for hjt. the uv also causes degradation in tco layers of hjt cells. one way to overcome this issue is to use ub cutting film, but this reduces the efficiency. to mitigate these losses, 2 leading encapsulation material suppliers, cybrid and hangzhou first in a cooperative effort, have developed a wavelength transfer film that improves the optical absorption of the module. it is a photoelectric conversion film that converts uv light with a low photon response for hjt solar cells into blue light or red light with a higher photon response. the film increases the power of a 60-cell m6 hjt solar module by more than 5w, and with larger modules, it can go up to 7w. 

 

eva poe solar encapsulation film extrusion line

short description:

eva poe epe encapsulation film has excellent durability such as weather resistance,high-temperature resistance,humidity resistance,and ultraviolet resistance. it has excellent additional force on glass, metal, plastic pet, and tpt, and maintains long-term additional force.excellent light-absorbing rate and transparency. solar cells are deactivated and harmless during processing. high cross-linking rate after lamination. good encapsulation performance.

 

 

features of eva film

excellent durability such as weather resistance, high-temperature resistance, humidity resistance, and ultraviolet resistance.

it has excellent additional force on glass, metal, plastic pet, and tpt, and maintains long-term additional force.

excellent light-absorbing rate and transparency.

solar cells are deactivated and harmless during processing.

high cross-linking rate after lamination.

good encapsulation performance

 

topcon solar cells have a special alunimum oxide layer on the front that needs strong defense against pid and moisture related corrosion

poe film used in encapsulation may encounter issues like busbar slipping and additive migration, prompting the need for anti-slip solutions and strategies to prevent additive flow

as topcon technology gains traction and major players invest significantly on improving encapsulation materials like poe and epe to match its growing demand.

the first impression of topcon cells on a general note is that the passivation and metallization schemes are inverse to that of perc, which means the aluminum oxide passivation is on the front so, the front side requires the highest degree of protection from pid. the metallization paste used on the emitter side of the cells is aluminum doped, thus is more prone to corrosion, requiring high barrier from moisture ingression. this is also applicable for the rear side of the topcon structure as it features a complex passivation stack of amorphous silicon and tunneling oxide, which are also moisture sensitive. thus, it also requires some optimized solution for the rear side.

according to cybrid's international marketing director eric yang, the choice is between poe or epe on the front side and epe or eva on the rear side in glass-glass modules. for the glass-backsheet structure, it mainly depends on the wvtr barrier properties of the backsheet. with a standard backsheet, the choice is only pure poe film, as only such modules are able to pass the testing protocols, according to yang. however, using the latest generation of high barrier backsheets recently developed by several backsheet suppliers or employing backsheets inserted with an additional aluminum film may enable the use of eva or epe. however, yang emphasizes that the industry is not willing to use aluminum backsheets, one for bad processing, and then also for higher costs

anti-slip solutions for poe

nevertheless, the current practice is to use pure poe film, at least on the front side. addressing the common problems with poe, slipping of busbars, cybid has developed an anti-slip solution by adjusting the process of mixing and film making, improving the embossing, and method for inhibiting the precipitation of auxiliaries, the latter being the ultimate,

since basically all top tier companies are investing heavily in topcon and the leaders of the segment such as jinkosolar have already installed 2-digit capacities, the market share of the pure poe film was a little higher in 2022 compared to 2021. the pure poe films still suffer from the sliding issue due to the fact that the additive is flowing out of the film. there are some solutions under development to block the additive flowing out of the film, according to cybrid's yang. there are even more burning issues because of which the industry is seriously evaluating other options. as it is, the poe resin is quite a bit expensive. then there are looming fears of poe being pushed into short supply. there is an industry-wide belief that the current supply of the poe resin can cater to less than 100 gw, especially when using the pure poe film, and several marketresearch firms as well as the industry are quite upbeat about the topcon technology and expect it to exceed 80 gw already in 2023

 

the leading suppliers of polyolefin resins are dow, mitsui chemicals and lg. segment leader dow's manager grand, while not revealing the production capacity for its poe resin, says that solar is definitely a priority for the company. grand further emphasized that the advantage of the company is in its ability to serve different markets locally, with production facilities in asia, europe and north america.

the first obvious approach to poe resin consumption is to again employ the epe structure. a few companies have started r&d efforts in this direction. however, according to hiuv's senior marketing manager peter peng, the standard epe structure used in perc modules is not sufficient in itself to pass the reliability tests for damp heat and pid. hiuv, on the other hand, has found a solution that is also based on coextrusion but with a little tweak. peng says the solution involves using only 2 layers of eva+poe instead of epe called exp, where the 'x' layer is for strengthening the bonding between coextruded eva and the poe stack. the solution is based on the analysis that when poe is working but the epe isn't, it indicates that the stack should have more poe content over the epe level. peng says that the ratio is currently a secret, but emphasizes that the poe content can be reduced in the future through further optimization.

as mentioned above, since the topcon uses aluminum pastes, the poe side faces the cell side and the eva side is attached to glass. the structure would become the mainstream for topcon 

the long-term reliability and durability of topcon cell technology-based pv modules depend on the optimal combination of front and rear side encapsulants to balance cost and quality. these modules are available in either a glass-glass or glass-backsheet configuration. the former, though largely accepted in the pv market, has been reported to have several potential reliability risks in the field under several environmental stresses. multiple pv material companies are addressing these challenges through advancements in encapsulant technology.

 

transition of encapsulation materials & structures from eva to alternative technologies

with the rise of new solar cell technologies, encapsulation materials are shifting beyond traditional eva, introducing advanced multilayer solutions and new suppliers.

the rise of bifacial and advanced solar cell technologies has led to the adoption of alternatives to eva, like poe and multilayer structures

co-extruded films, such as eva-poe-eva (epe), are being used to combine the benefits of both materials, addressing the limitations of single-layer encapsulation

he number of non-eva products has increased to 36, with materials like non-crosslinking polyolefin (po) being developed by suppliers such as hiuv, enrich, and sinopont

discussing different materials and structures, the encapsulation segment would have been irrelevant  just a few years ago. ethylene vinyl acetate (eva) has been the material of choice for encapsulation, likely since the inception of solar modules. over time, eva became so dominant that it was synonymous with encapsulation, enjoying a market monopoly for over 3 decades. however, the limitations of eva began to show, particularly with the wider adoption of bifacial technology based on the perc cell platform. the emergence of new cell architectures such as topcon, hjt, and xbc further raised the performance requirements for encapsulation materials, prompting the industry to look beyond eva. in response, polyolefin (poe) has evolved as a prominent alternative. while poe offers significant advantages, it is not without its drawbacks, such as longer process times, costly resin, and the tendency for busbars to slip during laminatio

 

until a few years ago, encapsulation materials were limited to single-layer constructions. the industry has adopted a multilayer co-extruded structure to overcome the limitations of eva and poe while combining the benefits of both worlds. a typical configuration involves a poe film sandwiched between 2 eva layers (epe). at the same time, eva has seen continued optimization, resulting in improved variants with superior anti-pid properties and low acid formation. another notable innovation is white eva, which enhances reflectivity on the rear side, making it particularly beneficial for monofacial modules

 

eva v/s poe: a comparative study of solar panel encapsulants

in the solar energy sector, encapsulants play a vital role in protecting photovoltaic (pv) cells and enhancing the performance of solar modules. among the various encapsulant materials available, ethylene vinyl acetate (eva) and polyolefin elastomer (poe) are two of the most prominent choices. this blog will explore the properties, advantages, and drawbacks of both encapsulants, providing insights into their suitability for different solar applications.

understanding eva

eva is a copolymer made from ethylene and vinyl acetate. its chemical formula can be represented as:

 

c2h4n c4h6o m

where n and m represent the number of repeating units of ethylene and vinyl acetate, respectively. eva is known for its excellent optical clarity, strong adhesion to glass and solar cells, and good weather resistance. it creates a hermetic seal around the solar cells, protecting them from moisture, dust, and physical damage.

 

eva solar encapsulant

understanding poe

poe, a newer encapsulant option, is composed of polyolefin elastomers. the general chemical structure of poe can be represented as:

 cnh2n m

​

this structure indicates that poe is derived from olefins (alkenes), which contribute to its unique properties.

 

the specific chemical formula can vary based on the composition and molecular weight of the poe, but it typically includes long-chain hydrocarbons with varying degrees of branching depending on the type and amount of comonomer used.

 

for example, when 1-octene is used as a comonomer, the resulting structure may include branches that enhance flexibility and impact resistance:

c2h4+c8h16→poe

this polymerization process creates a network where ethylene units provide strength while the octene branches contribute to elasticity and toughness.

poe encapsulants offer enhanced moisture resistance, thermal stability, and potential for extended lifespan compared to eva.

poe encapsulants are particularly beneficial for high-efficiency solar cells and modules exposed to harsh environmental conditions.

structural model of polyolefin elastomer (poe)

key comparisons between eva and poe

 

eva vs poe

successful poe deployment during the manufacturing process is essential. poe is more susceptible to bubble formation during the lamination process if proper manufacturing techniques are not followed. therefore, it is essential to work with reliable and experienced partners who can ensure a smooth manufacturing process and deliver maximum results.

both eva and poe have their unique advantages and drawbacks when it comes to solar encapsulation. eva remains a reliable choice for many manufacturers due to its cost-effectiveness and established track record. however, as the demand for high-efficiency solar modules increases—especially those designed for harsh environments—poe is becoming an increasingly preferred option.

 

in summary, when selecting an encapsulant for solar panels, considerations such as environmental conditions, expected module lifespan, and budget constraints should guide the decision-making process. as technology continues to evolve, both eva and poe will play critical roles in shaping the future of photovoltaic systems.

for those interested in exploring high-quality encapsulation solutions or learning more about renewsys' offerings in this space, consider visiting our website for detailed information on our products.

 

 

1.applicable materials: eva+auxiliary for solar encapsulation film, poe+auxiliary
2. the production line width of silver cylinder: 3000mm
3. die width: one pair of 2600mm; one pair of 3000mm (can be customized according to customer requirements, and the product can be cut into multiple pieces online according to requirements)
4.eva product gsm: 300-530g/m2
5.extruder direction: from back to front (easy to disengage production debugging)
6.max line speed: 20m/min (actual production speed depends on raw material process and working conditions)
7.thickness deviation: t ds 3%, mds 2%
8.installed capacity: about 550kw (working capacity about 300kw)
9.water supply temperature 7-20°c, water pressure 4-6bar, circulating water volume 40-50m3/h
10.supply air source pressure z7bar air pressure 0.9 m3/h

 

combined control thickness measurement/automatic thickness measurement provides a guarantee for high-quality production and establishes a three-dimensional map of products through networking with defect detection, so as to analyze and predict problems intuitively and quickly. high-precision intelligent control maximizes the stability of the production line, and at the same time efficiently and scientifically assists in the establishment of the production process, and quickly forms data analysis to escort production.

the latest far-infrared tempering process, precise temperature control, stainless steel, and special insulation materials to achieve heat preservation and energy saving. online eva scrap recycling technology saves the cost to the greatest extent for customers.

mature eva film making machine equipment solutions, optimal shrinkage rate, minimum grammage error, fast machine adjustment response, and intelligent control to establish an all-around control system for product quality.

provide on-site layout and public works solutions, and provide customers with a full set of engineering support and one-stop solution to customers’ project construction problems.

what is eva？

eva is an ethylene-vinyl acetate copolymer, which is produced by the copolymerization of ethylene (e) and vinyl acetate (va) and is referred to as eva, or e/vac. compared with polyethylene, eva has reduced crystallinity and improved flexibility, impact resistance, filler compatibility, and heat sealing performance due to the introduction of vinyl acetate monomer in the molecular chain. generally speaking, the performance of eva resin mainly depends on the content of vinyl acetate on the molecular chain. because the composition ratio can be adjusted to meet different application needs, the higher the content of vinyl acetate (va content), its transparency, softness and toughness will be relatively improved.

eva characteristics

1. durability
premium eva film is known for its outstanding durability, even under harsh weather conditions such as high temperature and high humidity.
2. bonding
under the right conditions, eva film has excellent adhesion to solar glass (not standard glass, which has a rough surface). eva also bonds very well to the backsheet.
3. optical
eva is known for its excellent transparency. this means that light transmission is acceptable and doesn’t block too much sunlight trying to reach the solar cell. today, several manufacturers in asia use transparent backing, so there is transparency between the cells. this type of module is called a translucent module.

what is eva film？

in the solar industry, the most common encapsulation is the use of cross-linkable ethylene vinyl acetate (eva). with the help of a laminator, the cells are laminated between eva films in a vacuum, in compression. the process takes place at temperatures up to 150 °c. one of the disadvantages of eva film is that it is not uv resistant, so a protective front glass is required to shield it from uv rays.

polymerization methods include high-pressure bulk polymerization (for plastics), solution polymerization (pvc processing aid), emulsion polymerization (adhesive), and suspension polymerization. emulsion polymerization is used for vinyl acetate (va) content higher than 30%, and high-pressure bulk polymerization is used for low vinyl acetate content.

the eva solar film making machine extrusion production line uses eva resin (va content 30-33%) as the base material to produce eva film for solar photovoltaic cells. this production line can also produce hot-melt adhesive eva inter layer film by changing the formula and process.

in the solar industry, the most common encapsulation is the use of cross-linkable ethylene vinyl acetate (eva). with the help of a laminator, the cells are laminated between eva films in a vacuum, in compression. the process takes place at temperatures up to 150 °c. one of the disadvantages of eva film is that it is not uv resistant, so a protective front glass is required to shield it from uv rays.

polymerization methods include high-pressure bulk polymerization (for plastics), solution polymerization (pvc processing aid), emulsion polymerization (adhesive), and suspension polymerization. emulsion polymerization is used for vinyl acetate (va) content higher than 30%, and high-pressure bulk polymerization is used for low vinyl acetate content.

the eva solar film making machine extrusion production line uses eva resin (va content 30-33%) as the base material to produce eva film for solar photovoltaic cells. this production line can also produce hot-melt adhesive eva inter layer film by changing the formula and process.

what is poe film?

poe is better than eva anti-pid (potential-induced attenuation), which is also the main advantage of poe. fourth, the water resistance effect of poe is better, and it can be widely used in the water surface power stations and other links.

poe film is mainly used in double-sided modules, which replaces the backplane with photovoltaic glass, with high power generation, strong stability and long service life, so as to improve the efficiency of the module.

what is epe film?

 

it combines two advantages of both eva and poe:is a variant of poe products. because of the price gap between poe and eva is large, poe is 13 yuan / square meter, eva7 yuan / square meter, one square meter price difference is 6 yuan, a 2 square meter component needs two, the price difference is as high as 24 yuan / component.

poe is slippery in performance, and it is easy to make the battery deviate when laminating. lamination takes 30% longer than eva, which is one of the main reasons for the lower capacity of double glass components than single glass components. therefore, the industry put forward the co-extrusion structure of eva / pose / eva, that is, sandwich type, the external contact surface is eva, reduce the probability of wrong pieces, reduce the cost, and the poe in the middle plays a barrier role.

it is not a polymer or resin by it self but a blend of two polymers /resins namely eva & poe, which when extruded multilayer method & from t die layer/sheet is formed in ratios normaly 33/33/33 & additives etc are added to make perfect epe film/sheet.

solar panel encapsulation: important part of solar panel

 

what is a solar panel encapsulation? what does it do?

solar panel encapsulation mainly include eva, poe, pvb (polyvinyl butyral) encapsulation film.

solar panel encapsulation adhesive film is placed between the glass of the solar panel module and the solar cell or the back sheet and the solar cell to encapsulate and protect the solar cell, and is one of the key materials of the solar panel module.

 

how many kinds of solar panel encapsulation films?

eva: eva resin is used as the main raw material, modified by adding cross-linking agent, silane coupling agent, light stabilizer, antioxidant, ultraviolet absorber and other additives, and formed by melt processing.

it has excellent light transmittance and wide process window, and because eva resin and additives are polar materials, it has good compatibility and absorption effect.

 

poe: poe resin is used as the main raw material, modified by adding crosslinking agent, silane coupling agent, light stabilizer, antioxidant, ultraviolet absorber and other additives, and formed by melt processing.

it has excellent water vapor barrier and anti-pid performance, but because poe is a non-polar resin, it is easy to cause additive precipitation.

 

pvb: pvb resin is used as the main raw material, modified by adding plasticizers, silane coupling agents, light stabilizers, antioxidants, ultraviolet absorbers and other additives, and formed by melt processing. has excellent mechanical strength.

 

epe: eva and poe co-extrusion melt-processed film.

 

transparent film: including high-transparency type and uv cut-off type. the high-transparency type can pass through the full-band sunlight to maximize the conversion efficiency of solar energy. the uv cut-off type has the ability to absorb ultraviolet rays, which can effectively improve the aging of materials caused by ultraviolet rays.

 

white film: including non-woven composite structure and pre-crosslinked white film, mainly colored by titanium dioxide. the non-woven composite structure white film has good cushioning effect, anti-spill glue effect, and zero depth reflection improves power gain.

 

the pre-crosslinked white film can control the whitening, wrinkling and good reflectivity of overflowing glue by adjusting the initial degree of crosslinking.

 

single-layer structure adhesive film: refers to pure eva, poe, pvb adhesive film.

 

multi-layer composite structure adhesive film: refers to the white film and epe co-extruded adhesive film made of eva, poe and non-woven fabric.

 

frosted film: the front and back sides are frosted film with irregular patterns, anti-sticking and non-slip.

 

prism-shaped film: the surface of the steel roller is a film with regular prismatic patterns, which is anti-sticking and non-slip, and is suitable for high-weight film.

 

casting film: the film is processed and formed by casting. at present, the solar panel encapsulation film is mainly processed and formed by casting. the cast film has good softness, high fluidity, small internal stress and low shrinkage.

 

calendered film: a film formed by calendering. the calendered film has high mechanical strength, high hardness, large internal stress and good flatness.

 

thermosetting adhesive film: under a certain temperature and time, a network structure is formed through a chemical cross-linking reaction to produce an adhesive film with mechanical strength and bonding and sealing effect. eva is a thermosetting film, and poe has two types: thermosetting and thermoplastic. the thermosetting adhesive film is mainly suitable for the encapsulation of conventional crystalline silicon solar panel modules.

 

thermoplastic film: a non-chemically cross-linked, hot-melt film without added peroxides. it has the characteristics of recyclable utilization and repeated processing. pvb is a thermoplastic film, mainly suitable for bipv (building integrated solar panel) solar panel modules. thermoplastic poe is mainly suitable for thin film solar panel modules.

for which different types of pv modules are different encapsulation suitable?

ordinary crystalline silicon modules often use eva film as the main encapsulation. the front of single-glass modules uses high-transmittance eva film, and the back panel uses uv-cut eva film.

 

both the front and back of the double-glass module use high-transparency poe film. thin-film modules commonly use pvb film, uv cut-off poe film and thermoplastic poe film as the main encapsulations. maysun’s double glass products are applied with poe film, you can click on the product for more details.

why is solar panel encapsulation important?

solar panel encapsulation adhesive film, as the core material of solar panel modules, is very important to the encapsulation process and performance of modules.

 

the working environment of solar panel modules is mainly outdoors, exposed to sunlight, rain, ice and snow for a long time, and the warranty period of solar panel modules usually requires more than 25 years.

 

therefore, encapsulations are constantly improving technology in terms of characteristics and material matching, process adaptation, performance requirements, and reliability assurance.

how does the solar panel encapsulation ensure the excellent  operation of the solar panel?

keeps the ability to pass light and electricity by keeping wetness out: moisture and dust that accumulate on solar cells can block sunlight and disrupt the flow of electricity. encapsulation prevents moisture and dust from causing damage by providing a protective cover.

 

keeps the solar panel‘s structure in good shape: encapsulation helps protect the solar panel from deformation and maintains its integrity. it prevents damage and degradation of the delicate solar cells over time.

 

to keep solar panels working: ensuring proper encapsulation is crucial for the performance and lifespan of a solar panel. it serves as a protective layer for the sensitive solar cells and electrical components, helping them maintain optimal performance.

 

ensure the reliability of solar panels: the warranty of modules for more than 25 years has strict requirements on performance degradation and material aging.

 

the pid effect causes the power attenuation of the module, and the entry of water vapor easily causes the hydrolysis reaction of the eva film to generate acetic acid, which reacts with the alkali precipitated on the glass surface to produce a large number of freely mobile na ions, which move to the surface of the cell under the action of an external electric field. and enriched to the anti-reflection layer to produce pid effect.

 

note: what is the pid effect?

pid effect: water vapor and high temperature will cause the volume resistivity of the adhesive film to decrease and accelerate the corrosion of the battery ribbon, which will further lead to pid attenuation and component aging.

eva (ethylene vinyl acetate) film: composition and application

dricus de rooij

materials

   

eva is the abbreviation for ethylene vinyl acetate. eva films are a key material used for traditional solar panel lamination.

what are ethylene vinyl acetate(eva) films?

in the solar industry, the most common encapsulation is with cross-linkable ethylene vinyl acetate (eva). with the help of a lamination machine, the cells are laminated between films of eva in a vacuum, which is under compression. this procedure is conducted under temperatures of up to 150°c. one of the disadvantages of eva films is that it is not uv-resistant and therefore protective front glass is required for the uv screening.

 

for standard modules that use eva encapsulation, for the backing usually a layer of tedlar composite (tedlar polyester tedlar (tpt)) is used, which is a thin, opaque film. tedlar is the dupont tradename for a film of polyvinyl fluoride, pvf, poly ethylene terephthalaye (pet) or metal.

long term encapsulation and protection

once the eva sheets have been laminated, the ethylene vinyl acetate sheets play an important role in preventing humidity and dirt penetrating the solar panels. also with the help of the eva, the solar cells 'are floating' between the glass and backsheet, helping to soften shocks and vibrations and therefore protecting the solar cells and its circuits

ethylene vinyl acetate (eva) properties

durability

quality eva film is known for its excellent durability, also in difficult weather circumstances, such as high temperature and high humidity.

bonding

under the right circumstances, eva film will have excellent adhesive bonding to solar glass (not standard glass, solar glass has a rough surface). also eva bonds very well to the backsheet.

optical

eva is known for its excellent transparency. this means that the optical transmission is acceptable and doesn't block too much of the sunshine trying to reach the solar cells. nowadays, several manufacturers in asia use a transparent backing, which has transparency between the cells as a result. this type of module is known as semi-transparent.

solar panel encapsulation film extrusion line takes eva and poe as raw materials. the process includes materials handling, heating, extruding, calendaring, cooling and winding. the production line can be specially made by customer’s requirements. the film product is a new type of thermosetting hot melt film, anti-adhesive at normal temperature, easy for operation. it is fully shaped and adhesive after heating and laminating. it can make the silicon wafer, glass, backplane multi-layer material firmly bonded into the whole one. excellent heat and humidity resistance, uv resistance, fully realize the long-term use of solar modules in outdoor requirements.

to understand the application of eva film in solar cells, it is necessary to first understand the structure of the cell. generally, the cell structure consists of five layers of "glass + eva + silicon solar cell + eva + tpt/tpe" from top to bottom. different structural layers play different functions and roles according to their material characteristics: tempered glass, whose function is to protect the main body of power generation (such as cells), its selection requirements are: high light transmittance (generally more than 91%), ultra-white tempered deal with. eva film is used to bond and fix the tempered glass and the main body of power generation. the quality of the transparent eva film directly affects the life of the module. the eva film exposed to the air is easy to age and turn yellow, thus affecting the light transmittance and power generation of the module. quality, in addition to the quality of eva itself, the lamination process of component manufacturers is also very influential. for example, the cross-linking degree of eva is not up to standard, and the bonding strength of eva to tempered glass and backplane is not enough, which will cause eva to age prematurely and affect the service life of components.

features

excellent mixing and plasticizing effect of extruder

eliminate thermal stress and solve the problem of thermal shrinkage

unique design to solve the problem of sticky layer and peeling of adhesive film

 

 

in the last two decades, the continuous, ever-growing demand for energy has driven significant development in the production of photovoltaic (pv) modules. a critical issue in the module design process is the adoption of suitable encapsulant materials and technologies for cell embedding. adopted encapsulants have a significant impact on module efficiency, stability, and reliability. in addition, to ensure the unchanged performance of pv modules in time, the encapsulant materials must be selected properly. the selection of encapsulant materials must maintain a good balance between the encapsulant performance in time and costs, related to materials production and technologies for cells embedding. however, the encapsulants must ensure excellent isolation of active photovoltaic elements from the environment, preserving the pv cells against humidity, oxygen, and accidental damage that may compromise the pv module’s function. this review provides an overview of different encapsulant materials, their main advantages and disadvantages in adoption for pv production, and, in relation to encapsulant technologies used for cell embedding, additives and the interaction of these materials with other pv components.

 

1. introduction

a new energy-consuming society requires more and more energy, and renewable sources become imperative. therefore, the need to provide green energy is related not only to the growth request for energy but also to growing socio-political concerns and the need for urgent action, on a global scale, to limit climate change. the requests to replace fossil-based resources and to reduce co2 emissions could be met through the decarbonization of the energy secto

the worldwide capacity in green energy production has increased by up to 650 gw in the last 10 years, leveraging solar energy, which is the cleanest and fastest-growing renewable energy source the capture of solar energy, and its transformations in electricity and heat, required the development of advanced devices and technologies. in all cases, the formulation of innovative and more efficient materials for solar energy capture and conversation is essential

in the last two decades, in order to convert efficiently the sun’s energy into electrical energy, pv module design and production have been significantly advanced, and the growth trend in this field is mainly oriented towards producing lighter and low-cost pv modules. the key factors for the development and market penetration of pv modules are their conversion efficiency, durability, and stability. the current operating life of a pv module is less than 25 years, while the latest generation of double-sided heterojunction photovoltaic panels, produced by 3sun (enel green power, rome, italy), can maintain high properties and performance for about

crystalline silicon (c-si) pv modules are the most produced and commercially available photovoltaic devices. they consist mainly of glass–encapsulant–cells–encapsulant–backsheet. the encapsulant sheets, based on polymer materials treated to obtain resistant structures, are extremely important components in pv modules. they are able to provide mechanical stability, electrical safety, and protection for the cells and other module components against environmental impacts

although this review mainly addresses encapsulant polymeric materials that are used in making the pv module, it is also relevant to mention the manufacturing sequence for crystalline silicon wafers, which constitutes the substrate of most solar cells today. the manufacturing sequence for crystalline silicon wafers can be divided into three steps: (i) silicon feedstock, (ii) crystallization, and (iii) wafering. however, the refinement processes for the hyper-pure silicon material were developed to enable the semiconductor industry. although the silicon feedstock comes with more than sufficient purity for solar cells, the morphology of the micrometric-sized silicone crystals must be changed because of their extremely high brittleness. for this reason, the silicon material must be melted and recrystallised under controlled conditions in order to generate larger crystal grains that are bonded, to minimize the crystal defects that could limit and compromise the solar cell’s performance. the transformation of silicon ingots to thin layers is carried out using slicing technologies, that are changed overtime, in the presence of some colling media

the crystalline silicon (c-si) pv modules consist mainly of glass–encapsulant–cells–encapsulant–backsheet, and, currently, the backsheet is substituted by glass or plastic sheeting to increase the solar capture efficiency, as shown in . based on information available everywhere, as summarized in , the evolution of si-pv module technologies and devices develops toward lighter and lower-cost efficient pv modules, through the use of innovative and high-performance materials. thin-film pv modules are designed similarly to c-si modules, and thin-film pv modules also use encapsulants, which are imperative to ensuring the efficient isolation of the pv components from exterior impacts

 

figure 1. evolution of si-cell pv module technologies/devices.

however, as discussed accurately in international technology roadmap for photovoltaic (itrpv)— the encapsulant and backsheet/cover are key component materials, and both are also major cost contributions in pv manufacturing. obviously, the balance between production costs and insurance of the module service lifetime must be established. based on data available in the itrpv report, eva is the most considered and most widely used encapsulant material, as shown in  eva is expected to keep a quite constant market share of about 10% over the next years. it is important to note that polyolefins are one incoming alternative to eva, especially when considering tow-face plastic–plastic modules and si-heterojunction pv modules. as shown in , the market share for polyolefins is expected to increase by 20 times in the next 10 years, while other encapsulant materials are estimated to keep a low market share for these specific niche applications.

 

figure 2. world market share for (a) different encapsulant materials and (b) glass and foil as front and back cover materials. based on data from international technology roadmap for photovoltaic (itrpv)

it is worth noting that the foils will stay mainstream as back coverings, although, for bifacial c-si modules, it is expected that the glass will gain a significant market share as backsheet cover materials, and it is estimated to obtain ca. 45% share in the next 10 years, as shown in 

however, over time, different polymer materials have been considered for use in the production of pv modules, and, currently, the most popular encapsulants are based on (i) elastomers, such as poly-ethylene–vinyl–acetate (eva) and silicones, (ii) thermoplastics, such as polyvinyl butyral (pvb) and ionomers, (iii) thermoplastic elastomers, such as thermoplastic silicone elastomers (tpse), thermoplastic polyolefins (tpo), and polyolefin elastomers (poe). therefore, this review provides an overview of the aforementioned different encapsulant materials, their main advantages and disadvantages in adoption for pv production, and, in relation to encapsulant technologies, additives and the interaction of these materials with other pv components.

2. encapsulant materials for si-cell pv module

the encapsulant polymer-based materials in pv modules must provide proven mechanical stability, electrical safety, and protection of the cells and other module components from environmental impacts. therefore, the most considered materials for encapsulants at the industrial scale are: (i) elastomers, such as poly-ethylene–vinyl–acetate (eva)], (ii) thermoplastics, such as polyvinyl butyral (pvb) (iii) thermoplastic elastomers, such as thermoplastic silicone elastomers (tpse) thermoplastic polyolefins (tpo) and polyolefin elastomers (poe) because of their good balance between performance and costs. to achieve even better performance in pv protection, all of these polymer encapsulants must be processed by appropriate technologies to ensure accurate cells embedding and ribbons protection, and they must be treated with suitable additives, such as crosslinkers, stabilizers, and adhesion promoters. the main technical specifications of encapsulant polymeric materials include melting and glass transition temperatures, volume resistivity, moisture transmission rate, light absorption, and elastic modulus.

figure 3 shows a classification of the encapsulant polymeric materials. based on their chemical structures and bonds, they form the chemical or physical crosslinking structures of encapsulant films. all of these encapsulant polymeric materials are discussed, and  summarizes the main physical properties of the pv modules encapsulant materials, along with their advantages and disadvantages in adoption as encapsulant protection films.

 

figure 3. the encapsulant polymeric materials in pv modules and their characteristics.

table 1. encapsulant materials for pv modules production, their main physical properties, and their main advantages and disadvantages.

 

elastomers as encapsulant materials

poly-ethylene–vinyl–acetate (eva)

eva has been the most considered encapsulant material in the last twenty years, but although its formulation has been significantly improved, it shows drawbacks related to discolouration and yellowing eva degradation phenomena have been extensively studied and described, and, according to the literature, it degrades by deacetylation, hydrolysis, and photothermal decomposition moreover, the photothermal degradation of eva could be accelerated because of the photothermal degradation of additives such as uv absorbers, stabilizers, and antioxidants.

however, the degradation of eva and its additives is also accelerated by the formation of hot spots due to the presence of some si-cells defects, which cause a local temperature increase of up to ca. 350 °c   unfortunately, this causes an uncontrolled acceleration of eva and additives thermal degradation/decomposition and acetic acid formation. as documented in the literature, the thermal degradation of eva, although in a reduced way, could be slightly slowed down by introducing polyolefin constituents   

to be a good encapsulant, eva must be transformed in elastomer by adding suitable crosslinking agents and being subjected to prolonged thermal treatment and high pressure. the peroxide radical crosslinking of eva is a random process, and its occurrence must happen during the lamination process, considering the high volatility of low molecular weight crosslinkers.

therefore, eva is considered to be a good encapsulant material because of the good balance between performance and costs. unfortunately, easy degradation of eva, with the formation of acetic acid, discolouration, and yellowing, compels the producers of pv modules to search for other encapsulant materials with a good balance of performance and costs.

. silicones

there are inorganic–organic materials based on silicon, hydrogen, and oxygen atoms (-si(x,y)-o-) they are very promising materials, but due to their high cost and the need for highly specialized equipment for their lamination process, silicon materials are not considered for large-scale applications. these encapsulant materials are more suitable for special conditions applications, for example, for encapsulation of devices for extra-terrestrial use and applications. as is widely known, the silicones show excellent chemical inertia and resistance to oxidation and heat, good transparency in the uv range, and very low water uptake. unfortunately, due to the nature of silicone, these encapsulant materials require specific processing conditions and equipment. their use could be justified, even considering high costs, in high-performance applications. moreover, these materials show very low mechanical resistance, and the use of suitable reinforcement additives, that could penalise the optical properties is imperative.

. thermoplastics as encapsulant materials

1. polyvinyl butyral (pvb)

the second-most considered encapsulant material is pvb, which has costs similar to that of eva the first-considered formulation of pvb for encapsulants required high pressure and temperature during the roll-to-roll lamination, combined with an autoclave. currently, upon accurate correction of the pvb composition, pvb can be laminated in bland conditions, under lower temperatures, and in less time using vacuum lamination. that makes pvb encapsulants mostly easy to process.

pvb shows good thermo- and photo-oxidative resistance in comparison to eva, although the use of different additives is absolutely requested in order to have low pressure and temperature processing. additionally, pvb shows a high hydrolysis tendency due to its water uptake, and, obviously, this represents a limit issue for its large-scale use.

ionomers

there is a new high-cost class of pv module encapsulants that are based on ethylene and unsaturated carboxylic acid co-monomers, such as ethylene–methacrylic acid copolymer ionomers have high production costs for synthesis, which, in the last ten years, due to their good uv stability, have been considered suitable materials for different wire and cable applications. the ionomers form physical-crosslinked structures, due to their polar nature, and there is no necessary chemical crosslinking. the chemical nature of the considered co-monomers, in some specific cases, could require prolonged processing time in order to ensure good adhesion between the encapsulant sheets and cells. ionomers show good mechanical performance and resistance, and they have been considered for thin-film solar modules, but there are other promising encapsulants for c-si modules.

. thermoplastic elastomers as encapsulant materials

thermoplastic silicone elastomers (tpse)

these relatively new kinds of encapsulant materials combine good silicone performance and easy thermoplastic processability until now, their synthesis and production costs have been relatively high, and, for this reason, they are not considered for large-scale applications, but they could be considered promising candidates for special pv module applications. tpse could form physical crosslinking structures, and controlling the sequence and length of the plastic and elastomer units could allow them to obtain excellent mechanical performance, water permeability, and electrical insulation. by including more silicone units, it is possible to synthesize materials having a good resistance to large temperature ranges.

2.3.2. thermoplastic polyolefin (tpo)

as an alternative to eva encapsulant, thermoplastic polyolefins (tpo) are newly developed non-crosslinking or crosslinking materials for photovoltaic (pv) module lamination according to the literature, tpo shows a lower discolouration tendency and better optical and thermal properties degradation before and after artificial weathering this makes these encapsulant materials very attractive, although some problems, related to good adhesion between the encapsulant sheets and cells during lamination, have been encountered. tpo encapsulants are copolymers based on ethylene–propylene rubber and ethylene–octene rubbers, and their synthesis and production are cheaper than other encapsulant materials. tpo shows good mechanical properties and uv resistance, and, according to the literature, the discolouration of tpo is around nine times slower than that of eva. in 50 days of weatherability tests, the transmittance of eva significantly reduced while that of tpo remained almost unchanged. unfortunately, tpo shows significantly higher water permeability than eva. some crosslinking tpo shows better adhesion properties, and, similarly to eva, they show discolouration and reduced ageing resistance. fortunately, the degradation pathways do not develop volatile by-products, such as acetic acid, that could cause the corrosion of metal ribbons.

2.3.3. polyolefins elastomers (poe)

the poe are copolymers of ethylene and other alpha-olefins, such as butene or octene, and they are very promising encapsulant materials  poe could be synthesized using metallocene catalysis, and controlling the ethylene/comonomer sequence and comonomer content could produce polymers with tailored elasticity. the presence of comonomer units disrupts the polyethylene crystallinity while the macroscopical mechanical behaviour of poe could be controlled by manipulating the molecular weights. additionally, poe shows very good resistance to uv ageing and no discolouration upon exposure to sunlight, but, unfortunately, the use of adhesion promoters to improve the adhesion between the glass and the embedded cells is required.

the main physical properties of the above-discussed pv module encapsulant materials, and their advantages and disadvantages in adoption as encapsulants, are listed below in 

as mentioned before, in case of accidental “hot spot” formations due to incorrect pv module function, local temperatures rise to up to ca. 350 °c. this issue is an enormous problem for all organic encapsulant materials, and especially for eva. this problem is exacerbated due to the favourable conditions for acetic acid formation and volatilization, which causes sheet delamination and ribbon corrosion.

3. technologies for pv cells embedding

the solar cells can be embedded between encapsulant sheets using different technologies, such as the vacuum lamination process, roll lamination combined with autoclave, and the casting process, as summarized in 

table 2. currently adopted technology for pv cells embedding.

 

therefore, the most considered processing technology is the vacuum lamination process, which has been adopted successfully for almost all encapsulant materials, such as poly-ethylene–vinyl–acetate (eva), polyvinyl butyral (pvb), thermoplastic silicone elastomers (tpse), thermoplastic polyolefins (tpo), polyolefin elastomers (poe), and ionomers. the processing conditions, such as temperatures and time for treatment during the vacuum lamination process, are chosen considering the chemical nature of the encapsulants. they are usually tprocessing = 140–170 °c and tprocessing = 7–20 min.

the roll-to-roll lamination process combined with autoclave, which is very similar, in concept, to glass lamination, is suitable for the processing of polyvinyl butyral (pvb) and thermoplastic silicone elastomers (tpse). the processing conditions are similar to that of the vacuum lamination process, i.e., tprocessing = 140–170 °c and tprocessing = 7–20 min.

the casting process is adopted for pv assembling when silicones are considered efficient encapsulant materials. it consists of a dispersion of silicones on components. the silicones form three-dimensional structures upon thermal or ultraviolet treatment. usually, this process is considered lower temperature, i.e., ca. 80 °c, with a treatment time of about 20 min.

regardless of the considered encapsulant materials and adopted technologies for embedding the cells, the encapsulants must provide mechanical stability, electrical safety, and protection of the cells and other components from environmental impacts.

4. additives for pv module encapsulants

to achieve good stability and protection, the polymer-based encapsulants must be mixed with different additives that play different roles, for example: (i) crosslinking agents help the formation and structuration of 3d crosslinked sheets   (ii) stabilizers, such as antioxidants, that prevent the thermal degradation of encapsulant materials during the lamination process and in service, along with uv absorbers and stabilizers that protect the sheets against uv irradiation in service conditions [26,37,38], and (iii) adhesion promoters to ensure good adhesion between cells and other pv components   all of these additives have specific and unique tasks for the formulation and use of encapsulant materials in pv modules.

4.1. crosslinking agents

the crosslinking agents, usually organic peroxides, help the formation and structuration of crosslinked encapsulants, improving the adhesion between the cells and other pv components and ensuring the isolation of pv modules from the environment   the formation of crosslinked structures is usually completed during the vacuum lamination process or during the roll-to-roll lamination process. therefore, the formation of crosslinked structures proceeds through radical random reactions, and its completion occurs upon heat of uv exposure.

4.2. stabilizers: antioxidants and uv absorbers and stabilizers

thermal stabilizers, such as phenolic antioxidant derivatives, are usually added to protect the polymer-based encapsulant against thermal degradation during the prolonged lamination process and during thermal shock in the case of the occurrence of accidental “hot spots” [26]. unfortunately, since the antioxidants are organic molecules, in the cases of hot spots occurrence they degrade and/or decompose quickly, and their degradation products could react with the degradation products of the encapsulant sheets.

the addition of uv absorbers and stabilizers in the composition of encapsulant materials is absolutely imperative. the presence of both adsorbers and stabilizers helps to slow down the thermo-/photo-induced degradation of the encapsulants through uv adsorption, radical capture, and/or hydrogen donation. the uv adsorbers are able to attract and adsorb the uv rays, transforming the energy into non-harmful energy and avoiding the macromolecule chain scission. the uv stabilizers are multi-functional. first, they perform radical capture, and second, they perform hydrogen donation, avoiding the propagation of radical development upon exposure to uv rays. there are different uv stabilizer classes, such as classical benzophenones, hindered amines, etc. none of these additives change the encapsulant transparency and colour, and they must be able to extend the lifespan of the encapsulants in service conditions.

4.3. adhesion promoters

adhesion promoters, usually based on silanes, help the adhesion and encapsulation of cells and other components [61,62]. unfortunately, the presence of adhesion promoters, in some cases, could cause slight hazing of the encapsulant, and this could hinder the correct function of the pv modules. moreover, according to the literature, silanes could catalyse the formation of acetic acid in eva encapsulants, leading to premature ribbon corrosion. currently, the opportunity to replace the silanes-based adhesion promoters with polar waxes containing different functional polar groups has been proposed in the scientific literature  

the main advantages and disadvantages of different encapsulant additives are summarized in table 3.

table 3. additives of encapsulant materials for pv module production and their main advantages and disadvantages.

 

5. encapsulant materials for organic and perovskite solar cells

although this review is mainly focused on the encapsulant materials for si-cell pv modules, encapsulant materials for organic and perovskite solar cells have also been briefly mentioned. pv module development towards new devices is related to the formulation of organic and perovskite solar cells, but, as is well-known, these devices show poor stability [  therefore, the poor stability of the devices must be well addressed before the large-scale industrial production and commercialization of organic and perovskite solar cells. as documented, the power conversion efficiency for organic solar cells has surpassed 14% for single junction and 17% for heterojunction devices, while the efficiency for perovskite solar cells is ca. 23%, similar to that for traditional silicon solar cells  

according to the literature, the encapsulant materials for both organic and perovskite solar cells are essential for correct pv device function, preventing the permeation of water vapour and oxygen, and achieving stability and the desired lifetime for these solar cells. the probable encapsulant materials for organic and perovskite solar cells are ethylene vinyl acetate (eva)   or europium (eu3+) doped eva  polyvinyl butyral (pvb)   thermoplastic polyurethane (tpu)   ethylene methyl acrylate (ema)   and polyisobutylene (pib)   although these materials do not offer suitable stability for the devices. currently, prosed encapsulant materials for organic and perovskite solar cells are uv-cured epoxy resins, and these materials could offer good device stability, but the regular disposal and distribution of the active elements is not an exactly easy matter. therefore, the most considered encapsulant material for both organic and perovskite solar cells is eva, although it does not offer desired stability for the device.

the roll-to-roll technology for layer assembling results in the most considered technology to produce organic and perovskite solar cells. the use of additives, such as crosslinkers, stabilizers, and adhesion promoters, is imperative in order to further improve performance and to ensure the durability and desired properties of these encapsulant materials.

6. conclusions and future perspectives in module design

pv module development is related to the formulation of more and more performance devices with a power increase of more than 1%. the main direction for silicon pv device development is towards lighter and lower-cost devices, and, obviously, this requires higher-performance materials for next-generation pv modules.

regarding the encapsulant materials, improving the uv cut-off to below 350 nm for pv encapsulant materials is desirable, and this could be obtained by using specific additives to ensure the cut-off effects.

currently, eva is the most considered encapsulant material for si-cells, although it shows some drawbacks and the research for new encapsulants continues. eva degradation pathways allow for the formation of acetic acids, which cause ribbon corrosion and compromise the use of this encapsulant material. other encapsulants based on tpo, poe, silicones, and ionomers have also been developed, and all of these materials show lower degradation tendencies in comparison to eva, with less discolouration and opacity in service conditions. therefore, encapsulants are very important components in pv module production and assembly, and their failure could cause the failure of pv devices, significantly lowering energy recovery and conversion.

eva or modified eva is also the most considered encapsulant material for organic and perovskite solar cells, although these applications require materials that can prevent the permeation of moisture and oxygen and offer stability to devices.

to sum up, the research for novel encapsulants is related to the formulation of materials having a favourable cost-performance balance, an improved uv cut-off to below 350 nm, and an easy lamination process for pv cell embedding, in terms of reduced curing times and lower process temperatures and pressures.

 

production method of poe film

 

the production of poe film involves the following stages:

 

polymerization: poe film is made by polymerizing ethylene and an alpha-olefin, such as propylene, butene, or hexene, using a metallocene catalyst. the catalyst is used to control the polymerization process, resulting in a specific molecular weight and composition. the polymerization is carried out in a reactor at high temperature and pressure.

 

extrusion: the polymerized poe is then extruded into a thin film using a blown film process or a cast film process with the help of an automatic blow molding machine. in the blown film process, the extruded material is inflated like a balloon to form a tube, which is then flattened and wound onto a roll. in the cast film process, the extruded material is cooled on a chilled roller to form a flat sheet, which is then wound onto a roll. this stage is crucial and requires reliable machinery, which can be found among top film extruder suppliers.

 

coating: the poe film is then coated with a layer of adhesive to improve its adhesion to the solar cells. the adhesive layer can be made of eva (ethylene vinyl acetate), which is the most common material used in solar pv modules, or other materials such as tpu (thermoplastic polyurethane) or silicone. for related processes and machinery, exploring options like a plastic film washing line might be beneficial for understanding the complete lifecycle and treatment of various films.

 

lamination: the poe film is then laminated onto the solar cells using a hot press. the lamination process involves heating the solar cells and the poe film under pressure, which activates the adhesive layer and bonds the two together. the lamination process also helps to remove any air pockets or wrinkles that may have formed during the assembly process.

 

2.applications of poe film in solar pv modules

 

poe film manufactured by the film extruder is used in solar pv modules as a backsheet, which is the outermost layer of the module that faces the environment. the backsheet protects the solar cells from moisture, uv radiation, and mechanical damage, and also provides electrical insulation. poe film is an ideal material for backsheet applications due to its excellent weather resistance, impact resistance, and electrical properties.

 

poe film is also used as an encapsulant in some types of solar pv modules. encapsulants are materials that surround and protect the solar cells, providing both electrical insulation and mechanical support. eva is the most common material used as an encapsulant, but poe film has some advantages over eva, such as better weather resistance and lower water vapor transmission rate.

 

poe / eva solar film production line

our poe/eva film extrusion line can produce lower shrinkage solar cell encapsulation film.

green energy is the most talked-about topic at present. undoubtedly, solar energy becomes an outstanding one of the. global solar energy products has developed by over than 45% annually in the past decade. the development and investment of solar energy of china exceeded the world average.

 

we will deliver dozens of poe film production lines. if you want to invest in the solar cell encapsulation film industry, choosing our equipment is an option to maximize the return on investment.

 

full-automatic contiuously gravimetric feeding system

not only is this system able to keep accurate feeding continuously, but it is flexible while the recipe would be changed as per the market demand or technical upgrade.

intelligent and precise feeding system is a good beginning of a high quality product.

twin screw extrusion system

direct extrusion technology is one the most important characteristics of this line. the successful employment of twin screw extruder makes poe / eva resin and a number of additives in-line compounding a reality.

this meaningful improvement is a result of our profound understanding of twin screw extruder and wealthy practices. this innovation is more than technical advantages, but reducing operating costs substantially.

the excellent mixing effect of twin screw extruder is playing a leading role in poe / eva film production, because it involves a great number of additives, and it requires good compounding.

unique screw elements and screw profile are designed according to the physical and chemical nature of poe / eva resin. it keeps each ingredient mixing homogeneously while avoiding pre-crosslinking. it is a basis of high productivity as well.

special cooling calender design

special cooling channel of calenders keeps the temperature of calendar surface uniform. peculiar silicon coated calendar can remove the stress of poe / eva film effectively so that lower
the shrinkage rate significantly.

german-made gear pump ensures melt entering into -die with constant quantity and stable pressure. the close-loop can keep the system stable running intelligently.

calibration system

peculiar eva-use / poe-use t-die designed as per extrusion rheology of solar cell grade poe / eva resin makes sure the stable extrusion at low temperature.

this is one of the givens which guarantee the lower shrinkage and high light transmittance.

full automatic in-line thickness tester log and report the thickness in time. the full automatic constant tension winding system is designed refer to the mechanical nature of eva film. less margin waste, higher rate of finished products stem from continuous optimizing of each unit during long-term practice of production. these optimizations help reducing operating cost substantially.

intelligent control system

from relay to industry computer, we have more options available. the logic setting between each functional modules makes precise control simple. safer production is a result of considered mechanical and electrical protection. the precise sync and synergetic control of each unit guaranteed the high quality final product at ease.

excellent quality of poe / eva film

the pursuit of each detail leads to a world class poe / eva solar cell encapsulation film.

we can guarantee the shrinkage less than 3%, and the line speed reach at 5~12m/min.

turn-key project

for some customers, a high-quality machine is not enough. the high quality of poe / eva film is a combination of production processing and stable line.

we not only deliver machines, but transfer value. from technical consulting of project proposal to production quality control, from processing to staff training, we provide you total engineering solution and a turn-key project so that you will be more confident when execute your project.

according to the report published by market research, the global solar encapsulation market size was valued at usd 4.94 billion in 2023 and is predicted to reach usd 10.91 billion by the end of 2032. the market is expected to grow with a cagr of 9.20% during the forecast period. the report analyzes the global solar encapsulation market’s growth drivers, restraints, and impact on demand during the forecast period. it will also help navigate and explore the arising opportunities in the solar encapsulation market industry.

 

global solar encapsulation market  overview

solar encapsulation is used to protect the solar panels and they are used in various equipment. in order to protect solar panel, various solutions are used. solar encapsulation enhances the efficiency of solar panels and prevents them from external hazards. good quality of solar panels and other solar equipment are susceptible to adverse environmental and physical threats. the associated risk can be reduced with the help of solar encapsulations. the materials that are selected for solar encapsulation should be flame retardant and corrosion resistant.

this selection of materials depends on the requirements of the consumer. encapsulation requires significant energy and material resources. the trend of solar encapsulation is growing in multiple  construction and others. encapsulation in the solar pv modules ensures safe working and reduces maintenance costs.

global solar encapsulation market: growth factors

growing acceptance of the solar encapsulation and the increasing awareness towards renewable energy are reinforcing the demand for solar pv modules. many government agencies are ensuring higher adoption of the solar encapsulation technology which is positively impacting the global solar encapsulation market. escalating demand for solar pv modules and the rising government initiatives will boost the global market growth. immense proliferation of technology and the increasing energy requirements contribute to the market growth.

high investments in the r&d by pv module manufacturers encourage the development of newer encapsulants. the emergence of the innovative organic solar technology will enhance the investments in the global market. there is a hike in demand for electricity owing to the rapidly increasing population which in turn will result in a rise in demand for the solar equipment. it is expected that economic solar equipment will be available in the future. conversely, the high cost of solar equipment may restrain the global solar encapsulation market growth to some extent.

 

 

eva solar panel encapsulation film machine: efficient and reliable technology

introducing the eva solar panel encapsulation film machine, a cutting-edge solution for efficient and high-quality solar panel manufacturing. a leading supplier, and company in the industry, this advanced machine showcases our commitment to delivering innovative and reliable manufacturing solutions. designed to enhance the durability and performance of solar panels, the eva solar panel encapsulation film machine ensures precise encapsulation of solar cells using high-quality ethylene vinyl acetate (eva) film. with its state-of-the-art technology and meticulous engineering, this machine guarantees optimum lamination, effectively protecting solar modules from external elements and extreme weather conditions. manufactured under stringent quality control standards, our eva solar panel encapsulation film machine not only ensures superior performance but also offers seamless integration, easy operation, and minimal maintenance requirements. it is the perfect choice for solar panel manufacturers seeking to enhance production efficiency and yield remarkable results. choose solar techmach llp india. as your trusted partner and experience unparalleled expertise in solar cell,panel ,epe encapsulation ,recycling & many other machinerys for manufacturing. embrace the future of sustainable energy with the eva solar panel encapsulation film machine – a testament to our dedication to crafting reliable and innovative solutions for the renewable energy industry.

 

ntroduction:

eva poe epe film can be used for solar cells, crystalline silicon cells, thin film photovoltaic cells and

other components within the packaging material. the content of 30% -33% of the eva resin

as main raw material, made through a special process, with strong bonding, high light

transmission, anti-aging characteristics.

epe film is three layer flim, combined by eva/poe/eva three layer, the ratio of each layer is 1/2/1, or 1/1/1, 

poe is better in water and air barrier performance, but due to poe cost is higher than eva, market 

still mostly using the eva, not poe, but epe is a kind of alternative solution, to find a middle point, 

epe cost is in the middle between eva and poe, also the quality is better than eva.

feature of eva/poe/epe film:

1) excellent durability, such as weather resistance, high temperature and high

humidity resistance, uv light resistance.

2) excellent adhesion to glass, metal and plastics pet, tpt maintaining long term adhesion

3) excellent light and transmittance and transparency.

4) inactivation and harmless in solar cell during processing.

5) have a high cross linking rate after lamination.

6) good encapsulating property

poe / eva solar film production line

film extrusion is the first step towards ready-to-use packaging solutions. the extrusion process is always the basis for efficient printing and converting and is therefore a fundamental prerequisite for high-quality products. typical cast film line applications include stretch, cpp or barrier applications, which offer high productivity and consistent quality.
our cast film portfolio offers you the right machine for your individual production requirements: from basic solutions for standard products to highly customisable solutions for the production of demanding products. with our unique cast film extrusion technology, we are happy to support you in selecting the ideal machine for your specific needs!

applications of poe / eva solar film production line

the poe/eva solar film production line plays a crucial role in the overall efficiency, durability, and performance of solar modules, contributing to the widespread adoption of solar energy as a clean and sustainable power source.

 

eva poe epe solar film extrusion line

functions

eva poe epe packaging film is mainly used for solar cell encapsulation. the eva/poe/epe solar film, in terms of adhesion and durability, has superior optical characteristics; it is more and more widely used in the electric cell module and many optical products

gwell developed new type of eva/poe/epe solar film extrusion line, with high output, by two or three extruder co-extrusion, line speed 2x13m/min, and automatic winder, 

 

pv module encapsulant film market size was valued at usd 3.07 billion in 2024 and the total pv module encapsulant film revenue is expected to grow at a cagr of 4.9% from 2025 to 2032, reaching nearly usd 4.50 billion.

 

pv module encapsulant film market overview

a photovoltaic (pv) module encapsulant film is an acute component used in the construction of solar panels. it acts as a protective layer that encapsulates and seals solar cells, ensuring their durability and longevity in several environmental conditions. the encapsulant film enhances the reliability, efficiency and overall performance of solar panels. the encapsulant film offers a barrier that shields the mild solar cells from environmental factors including moisture, dust, dirt and mechanical impacts. this protection supports to prevent damage to the solar cells and other internal components. advancements in photovoltaic technologies, technological innovations in encapsulation materials and increasing awareness of climate change are the driving factors for the pv module encapsulant film market growth. the report includes historical data, present and future trends, competitive environment of the pv module encapsulant film industry. the bottom-up approach was used to estimate the market size. for a deeper knowledge of pv module encapsulant film market penetration, competitive structure, pricing and demand analysis are included in the report. the qualitative and quantitative methods are included in the report for the analysis of the data of the pv module encapsulant film industry.

 

pv module encapsulant film market dynamics

drivers increasing demand for solar energy to boost pv module encapsulant film market growth as more solar panels are expanded for commercial, residential and utility-scale projects, the requirement for encapsulant materials to keep and improve the performance of these panels also raises. many countries are employing motivated renewable energy targets and policies to minimize greenhouse gas emissions and combat climate change. these policies encourage the solar energy industry growth, thereby enhancing the encapsulant film market. solar energy is a hygienic and environmentally friendly source of electricity generation. compared to conventional fossil fuels, solar energy provides substantial cost savings. as the cost of solar installations becomes more individual, more competitive and businesses choose solar solutions which contribute pv module encapsulant film market's growth. increasing awareness of the advantages of solar energy such as its long-term economic benefits and favorable environmental impact, promotes more people to invest in solar panel installations, thereby raising the requirement for encapsulant materials. ongoing advancements in solar technology including higher efficiency solar cells and improved panel durability, also boost greater adoption. these advancements often need higher-performing encapsulant films to match the improved properties of solar panels. the growth of urban populations and increasing energy demand in rapid swift search for sustainable energy solutions. solar energy, with its potential to be coupled within urban areas, experiences higher demand increasing the use of encapsulants. as china goals to increase its solar power capacity, there is a sophisticated demand for solar panel installations. this directly boosts the demand for pv module encapsulant films, which are crucial materials used to enhance the performance of solar panels and drive the pv module encapsulant film market growth.

 

pv module encapsulant film market trend

advancements in materials and formulations new materials and formulations have led to encapsulant films that are more resistant to degradation from uv radiation, humidity, temperature fluctuations and other environmental stresses. enhanced durability have been extend the lifespan of solar panels and minimized maintenance needs. uv resistance is essential to prevent the yellowing and degradation of encapsulant films over time. advanced materials have been better uv protection, ensuring the long-term optical clarity and efficiency of solar panels. solar panels have been experiencing temperature variations that impact their efficiency and performance. encapsulant films with enhanced thermal stability have been supporting panels to maintain their effectiveness under stimulating thermal conditions. strong adhesion between encapsulant films and solar cell materials is crucial to prevent delamination and ensure the structural integrity of the panels. advancements in adhesion technology have led to more reliable and long-lasting encapsulation which boost pv module encapsulant film market growth. optimized materials have reduced the loss of solar energy due to light reflection and absorption within the encapsulant film itself. this has been resulting in higher energy conversion efficiency and improved overall panel performance. advanced materials have been offering encapsulant films with increased flexibility without sacrificing robustness. this flexibility is vital to accommodate the expansion and contraction of solar cells due to temperature changes without causing stress or damage to the panel.

pv module encapsulant film market restraint

volatility of raw material prices to hamper pv module encapsulant film market growth sharp and unpredictable fluctuations in the prices of raw materials including ethylene-vinyl acetate (eva) or other polymer materials utilized in encapsulant films, have led to uncertainty in production costs. manufacturers have struggled to accurately estimate their costs, affecting pricing strategies and profit margins. when raw material prices increase substantially, manufacturers face higher production costs without the capability to immediately pass those costs onto customers. this has consumed profit margins and impacted the financial health of companies in the encapsulant film market. if raw material prices increase for some manufacturers but not for others, those facing higher costs have become less competitive in the market. this has been resulting in market share shifts and potentially impedes the growth of some companies. as a result, the volatility of raw material prices hamper pv module encapsulant film market growth.

pv module encapsulant film market regional insights

asia pacific held the largest pv module encapsulant film market share in 2024 and is expected to have the highest cagr during the forecast period. the increasing energy demand, favorable government policies, and efforts to minimize carbon emissions are the boosting factors for the growth of solar energy installations in the asia pacific. the requirements for encapsulant films to secure and enhance the performance of solar panels has grown increasingly with this expansion. developing economies in the asia pacific, especially china are global manufacturing cores for solar panels. the high production volume of solar panels in this region directly translates to a significant demand for encapsulant films. many countries have implemented supportive policies and incentives to encourage solar energy adoption. feed-in tariffs, tax advantages and renewable energy goals create a conducive environment for solar installations, fuelling the encapsulant film market. the region has some of the world's most populous countries with growing energy requirements. solar energy, maintained by encapsulant films, provides a clean and renewable solution to meet this demand. asia-pacific countries have been enthusiastically involved in advancing solar technology. this involves developments in encapsulant film materials, enhancing the efficiency, durability and overall performance of solar panels. rapid growth in urbanization and infrastructure development in the region creates a requirement for sustainable energy solutions which boosts the pv module encapsulant film market growth. solar panels with encapsulant films have been incorporated into buildings, factories, and other structures to produce clean energy. some asia-pacific countries are key exporters of solar panels and related products. this export-oriented method contributes to the demand for encapsulant films to meet domestic as well as international market needs. increasing awareness of environmental concerns and the need to minimize carbon emissions boost the adoption of renewable energy sources including solar power. encapsulant films ensure the efficiency and reliability of solar installations. the region attracts significant investment in solar energy infrastructure. this investment helps the growth of the encapsulant film market as solar projects are developed and expanded.

pv module encapsulant film market segment analysis

based on material type, the market is segmented into ethyl vinyl acetate (eva), polyolefin elastomer (poe), thermoplastic polyolefin (tpo) and polyvinyl butyral (pvb).  ethyl vinyl acetate (eva) dominated pv module encapsulant film market in 2024 and is expected to continue its dominance over the forecast period. eva has admirable adhesion properties, allowing it to bond well with both solar cell materials and the back sheet. this strong adhesion supports protecting the solar cells from moisture, dust and other environmental factors. eva is optically transparent, which means it allows sunlight to pass through with minimal reflection or absorption. this property supports maximizing the amount of sunlight that reaches the solar cells, improving energy conversion efficiency.

 

eva is flexible and capable of accommodating solar panels' expansion and contraction as they heat up and cool down. this flexibility helps minimize stress on the solar cells and prevents delamination. eva is easy to process and laminate, making it suitable for large-scale manufacturing of solar panels. its relatively low processing temperature minimizes the risk of damaging elusive solar cell materials during encapsulation. they have historically been cost-effective compared to some other encapsulant materials. this has contributed to its adoption, especially in utility-scale solar installations where cost considerations are essential and drive pv module encapsulant film market growth. due to its long history of utilization, eva has a well-established supply chain, ensuring a reliable source of material for manufacturers. by application, the market is segmented into the monoficial pv module and bifacial pv module. monoficial pv module held the largest pv module encapsulant film market share in 2024 and is expected to have the highest growth rate over the forecast period. monofacial pv modules are a well-established and extensively adopted technology in the solar industry. they have been in use for periods and are familiar to manufacturers, installers, and consumers. monofacial modules are typically more cost-effective to produce and install than bifacial modules. the simplicity of design and the absence of additional features such as rear-side transparent materials contribute to lower manufacturing costs. monofacial modules are versatile and have been installed in a variety of locations and orientations. they do not need specific ground conditions or structures to capture rear-side sunlight, making them suitable for a wide range of applications. manufacturers, engineers, and installers have extensive experience working with monofacial modules, which streamline design, installation, and maintenance processes. monofacial modules have well-established performance metrics and standards that make it easier to predict their energy output and integrate them into existing solar energy systems. much of the solar energy infrastructure, such as mounting systems and tracking technologies, has been optimized for monofacial modules. this makes the transition to bifacial modules more multifaceted and potentially costly. monofacial modules have a strong market presence and are widely adopted by consumers, investors, and regulatory bodies. this market adoption contributes to their dominance in installations and fuel pv module encapsulant film market growth.

pv module encapsulant film market competitive analysis

the market's competitive analysis includes the pv module encapsulant film market size, growth rate and key trends. the report provides information about the key companies, such as their size, pv module encapsulant film market share, and geographic presence. the report provides such type of competitive landscape of all pv module encapsulant film key players to assist new market entrants. some of the key players are 3m(us), borealis(austria), hangzhou betterial film technologies co., ltd.(china), jiangsu sveck photovoltaic new material(china), hangzhou first applied material(china), shanghai hiuv new materials co(china), mitsui chemicals company(japan), arkema(france), cybrid technology(taiwan), coveme(italy), h.b. fuller (us), guangzhou lushan new materials co., ltd.(china), dupont de nemours, inc.(us), first solar, inc(us) and others. many companies conducted research and development activities to increase their product portfolio. for instance, in changzhou betterial film technologies co., ltd. (china) 2024, the company announced the development of a new pv module encapsulant film which is known as billirial.  it is a thermoplastic polyolefin (tpo) film that is designed to be more resistant to pid than traditional eva films. billirial is made from a new kind of tpo polymer that has been precisely designed for use in pv modules. billirial is also easier to process than eva films, which has been helping to minimize the cost of solar modules.