EVA Resistant Silicone Membranes For Solar Panel Lamination: A Beginner’s Guide

EVA Resistant Silicone Membranes For Solar Panel Lamination

Table of Contents

Why we mentioned “EVA Resistant” at the beginning of the title?

The main two points are as follows:

Firstly, we add the definite article “EVA resistant” in front of “Silicone membranes”. This narrows today’s topic to a special silicone product, which is not a common silicone rubber sheet on the market, but a lamination material connecting with the solar industry.

Secondly, it starts with the construction of the solar panels.

Mainly made of six components in detail below, solar panels are carefully assembled in state-of-the-art facilities with precision and accuracy.

Six main components of a solar panel

Six main components of a solar panel

Extruded aluminium frame – Protects the edge of the laminate section containing the solar cells.

Toughened glass (3 to 3.5mm thick) – Protects the solar panel from falling debris and makes it waterproof.

Encapsulation (EVA film layers) – Ethylene vinyl acetate (EVA), a highly transparent plastic, protects solar cells from external impacts, temperature, moisture and dirt.

Solar photovoltaic cells – Made from silicon semiconductors converting sunlight into electricity through the photovoltaic effect.

Polymer rear backsheet – The rearmost part of the panel, provides mechanical protection and electrical insulation.

Junction box (diodes and connectors) – Interconnect all the solar cells, and houses external cables for connecting to other PV modules.

In today’s blog post, we are going to explore more details about this unique membrane silicone, including its characteristics, applications and best companion.

I am sure you will learn something useful, summarized by professionals based on years of work experience.

Well, here we go!

What Are Solar EVA Films?


solar cell encapsulation EVA film

EVA, which stands for ethylene vinyl acetate, is a thermoplastic polymer known for its excellent radiation transmission and low degradation when exposed to sunlight. It is widely used as an encapsulating adhesive in solar modules. When subjected to heat during the assembly process, EVA forms a sealing and insulating film around the solar cells, providing protection and enhancing the overall performance of the modules.


(1) Maintaining excellent durability in high temperature and high humidity circumstances.

(2) Exhibiting strong adhesive bonding capabilities to both solar glass and the backsheet.

(3) Allowing for optimal optical transmission and minimal blocking of sunlight, enabling efficient solar cell performance.

Cross-linkable EVA films are the most commonly used encapsulation material in the solar industry. Through the process of lamination, solar cells are sandwiched between EVA films in a vacuum environment under compression in a lamination machine. This process typically takes place at temperatures of up to 150°C.

However, one drawback of EVA films is their lack of UV resistance, necessitating the use of protective front glass to provide UV screening for the solar panels.

Why You Need Quality Membranes For Solar Panels Lamination?

It’s obvious that EVA films are a key encapsulation material used for traditional solar panel lamination. During the heating and pressurization process, the gases released due to the melting of EVA films are very corrosive to rubber and plastic products.

To achieve long-lasting and reliable results in production, pressing technology is essential.

Conventional membranes can be negatively affected by EVA volatilization during the lamination process, leading to their decomposition. This, in turn, blocks the proper joining of the single layers in solar panels, resulting in a higher wear rate of membranes.

This highlights the importance of EVA-resistant silicone membranes in the production of solar panels, particularly during the pressing of single layers. The quality of these membranes in the laminator is a key factor in ensuring the success of the manufacturing process.

That’s why we require silicone membranes with EVA resistance.

A Buyer’s Concerns Prior To Choosing Silicone Diaphragms

Why silicone?

Silicon is a natural chemical element. Silicone is a man-made polymer derived from silicon. The two words are often used interchangeably but there are important differences.

Compared to other rubber materials, silicone stands out due to its exceptional ability to withstand high temperatures, harsh weather conditions, and corrosion.

THK 4mm or 3mm?

The regular thickness available in the market is 4 mm (±0.2mm). However, customized services are also offered for special solar laminating machines, and in such cases, a thickness of 3 mm is commonly used.

Smooth finish or textured?

A membrane has two surfaces.

(1) Smooth/Smooth: one side smooth, the other side smooth.

(2) Smooth/Textured: one side smooth, the other side textured (also called cloth impression).

Some customers believe that placing the rough or textured side of the silicone sheet in contact with solar cells is beneficial. However, industry experts state that there is no scientific basis for this practice.

The recommended approach is to consult the supplier when purchasing silicone sheets to determine the appropriate orientation.

Fabric inserted or not?

A ply of fabric inserted between two layers of silicone(rubber) is very common. Because there is a reinforcement skeleton, which provides this kind of silicone membrane with high strength, small deformation, and long service life.

For solar panel lamination, silicone sheets without cloth inserts are less commonly utilized in the present day.

What should you do if a membrane gets a crack?

In cases where the crack is significant and affecting lamination results, it is advisable to replace the sheet membrane immediately. Continuing to use a damaged membrane can lead to poor lamination quality and potential damage to the solar cells encapsulation.

Or reach out to the supplier or manufacturer of the silicone membrane to report the issue. They can provide guidance on the best course of action based on the type of membrane and the severity of the crack.

Punching or not?

In certain cases, customers may have specific requirements to punch small sequential holes along the edges of the silicone membrane. If you have such a requirement, it is crucial to communicate with your supplier beforehand to determine if they can accommodate this service.

Recommended Solar Silicone Membranes

Based on research within the solar industry, three types have gained significant popularity over the past decade. They are S2, S5 and S5+. These solar membranes ensure superior encapsulation for PV modules in the lamination equipment.

The S2 Generation Silicone Membrane

The S2 Gen version, featuring gray silicone on both sides, offers a cost-effective solution and is particularly suitable for smaller module manufacturing plants.

The S2 Generation EVA-Resistant Silicone Membrane

Key features:

Standard thickness4mm
ReinforcementA ply of aramid fabric inserted
Surface finishSmooth/Smooth or Smooth/Textured surface for your selection
Lamination timesMore than 4,000 life cycles under normal operating conditions

The S5 Generation Silicone Membrane

The S5 Gen silicone sheet is a remarkable rubber membrane, engineered with a silicone backing material and a distinctive black covering layer. This unique combination of black covering and gray silicone provides exceptional EVA resistance and outstanding performance throughout demanding applications.

The S5 Generation EVA-Resistant Silicone Membrane

Key features:

Standard thickness4mm
ReinforcementA ply of aramid fabric inserted
Surface finishSmooth/Textured
Lamination timesOver 10,000 life cycles under normal operating conditions

The S5+ Generation Silicone Membrane

The S5+ Gen is an exceptional type of rubber sheet, expertly crafted with a silicone backing material and FKM hybrid material covering. This unique layer exhibits exceptional resistance to outgassing and the related decomposition processes of EVA films. As a result, our rubber sheet offers outstanding durability, significantly extending your machine’s running times.

The S5+ Generation EVA-Resistant Silicone Membrane

However, the S5+ is now replaced with the S5.

How many cycles do they withstand?

This is one of the most asked questions by customers.

Commonly our data shows that The S5 Gen upto 10,000 cycles. Good life cycle performance under controlled environments, such as humans, temperature, laminating machines, etc. As there are a number of variables beyond our direct control, it is very difficult to “guarantee” an exact cycle life.

Applicable solar laminators

Our silicone membranes are specially designed to fit many brands of solar module laminators like Spire, Burkle, NPC, Meier, 2BG, Ecoprogetti, 3S, Komax, Electro Solar, Spaleck-Stevens, Nisshinbo, P-Energy, Mondragon, Boostsolar, Orient, ZST, etc.

Why Teflon Sheet Is Necessary For Solar Module Laminator?

The above three types of solar diaphragms are designed to resist the deterioration that results from EVA outgassing.

So what can be done to prevent EVA deterioration in these diaphragms?

One effective method to enhance the diaphragm’s lifespan is by using a layer of Teflon sheet placed between the module and the diaphragm.

Teflon Sheet For Solar Module Laminator

Teflon sheet, known for its water resistance, anti-corrosive properties, and high heat resistance, offers substantial advantages when added to the solar laminator. This not only extends the diaphragm’s life but also provides various production benefits.

In a word, Teflon sheets are the perfect companions for solar silicone membranes. Thickness 0.25mm and 0.35mm are the most frequently ordered from our factory.

Such as:

0.25mm * 2500mm * 25M

0.25mm * 2200mm * 42M

0.25mm * 2280mm * 5910mm

0.35mm * 2350mm * 50M

0.35mm * 2200mm * 2200mm

0.35mm * 2300mm * 6070mm

Solar Laminator Sealing Strip

Solar Laminator Sealing Strip - Red Color

Silicone sealing strip for solar panel laminator is used to seal the lamination chamber. The silicone sealing strip has the characteristics of high temperature resistance, corrosion resistance and not easy to deform.

Item NO.Diameter
(shore A)
Tensile Strength
≥ (Mpa)
≥ (%)
Temperature ≥ (°C)Color
DH-01066709400220White, Red
DH-01088709400220White, Red
DH-0112H12709400220White, Red
DH-0114H14709400220White, Red
DH-011515709400220White, Red
DH-0116H16709400220White, Red
DH-0118H18709400220White, Red
DH-0118.2H18.2709400220White, Red
DH-012020709400220White, Red
Solar Laminator Sealing Strip - White Color

So, if you also need the sealing strips, please can you advise the diameter and quantity(length) you want.

Before ending today’s post, I also would like to share the extension about a solar cell.

Differences Between A Solar Panel, A Solar Module, And Solar Arrays

A solar module is a single unit that converts sunlight into electricity. A solar panel is a group of solar modules that are connected together to increase the overall power output. A solar array is a collection of solar panels that are connected together to generate even more power.

Differences Between A Solar Panel, A Solar Module, And Solar Arrays

In summary, a solar module is a single unit, a solar panel is a group of pv modules and a solar array is a collection of panels.

Solar module – complete and environmentally protected assembly of interconnected PV cells.

Solar panel – PV modules mechanically integrated, pre-assembled and electrically interconnected.

Solar array – assembly of mechanically integrated and electrically interconnected PV modules, PV panels or PV sub-arrays and their support structure.

Actually, The term “solar panel” should basically never be used.

What Is Your Sample Policy?

While our silicone membranes are well-established products, we understand that some customers may prefer to test samples before making a purchase.

Well, we are very happy to offer samples for your review. Samples are free of charge and we also pay the shipping cost, no matter wherever you are!

Normally sample size is A4 and the total weight will be about 1-2kgs.

But, when we encounter such a case as below, we usually suggest that they place a trial order directly.

Sample Policy For EVA Resistant Silicone Membranes

So, why not order the whole size for a test? For we also offer 1pc only at a moderate price.


EVA resistant silicone membranes play a vital role in ensuring the success of solar panel lamination. Their ability to withstand extreme lamination conditions and provide durable, reliable performance makes them an essential component in the solar manufacturing process.

When selecting EVA-resistant membranes, consider factors such as size, thickness, temperature resistance, and compatibility with your lamination equipment.

By choosing the right membranes and working with a reputable supplier, you can optimize your solar panel production and enhance the efficiency and longevity of your lamination process.

Now, I want to hear from you.

Does this post help you learn about the process of laminating solar modules?

Are you considering to replace your current solar silicone membrane with a new one from Deer Hunter?

Let me know by leaving a quick comment. Or contact our mobile/WhatsApp number +86-13823789007, or email us at sales@cndeerhunter.com

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