EVA Film Interlayer for Laminated Glass(1)

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EVA Film Interlayer for Laminated Glass(1)

1. Spreading EVA FILM

Hi everybody, i am peter shin from China. I have been in EVA FILM industry for decades. As many
glass related workers still not believe in EVA FILM, they don’t believe that EVA FILM can replace
PVB FILM in many fields.
In the same time, EVA FILM has many advantages than PVB FILM.
So i think it’s my job to spread EVA FILM knowledge to more people.
Welcome to join our group in yahoo.com, even though you are not in PVB , EVA FILM industry.
Only if you are in glass industry, please join in us and discuss with us .
If you want to learn more, go to our EVA FILMS’ INFO blog.
If you are a totally new about EVA FILM, please go to wikipedia. to learn the basic knowledge of

2. Introduce of EVA FILM
Laminated Glass with EVA Film is much important one in the series of laminated glass in glass
industry .The processing principle of EVA laminated glass is similar to most of the laminated
glass . Furthermore, using EVA film to laminating glass does not require autoclave. All laminating
processing will be finished and completed in one vacuum laminator. EVA Film for glass has
excellent transparency, outstanding adhesion and aging-resistance (more than 20 years), can be
used for architectural glass, decorative glass with fabric.

EVA film:

EVA stands for ethylene vinyl acetate, a copolymer resin used in the production of laminated
glass as the interlayer sandwiched between two pieces of glass. The main function of the
interlayer is to hold the two piece of glass together, thus making them safer and more secure.
EVA film is translucent and has a light pattern on the surface before heating. After heating, it
becomes completely transparent, offering good visibility. In the production of laminated glass
with EVA interlayer, no autoclave, roller press, air bag, or vacuum rubber ring is required. As EVA
interlayer can be handled under normal climatic conditions, no clean room with climatic control
is required.

EVA Film
is made out of macromolecule material and it performs excellent in bonding strength,
heat resistance, cold resistance, humidity resistance and tensile strength in laminated. It has
been partly taking the places of PVB film in laminated safety glass, laminated art glass, laminated
color glass.

Advantages of EVA film :

- High tensile strength
- Excellent transparency

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- Outstanding adhesion
- UV protection
- High wind resistance
- Good temperature withstanding
- Water proof
- Humidity durable
- Long-term reliable
- Sound barrier

EVA Gilm for Safety Glass:
1. Extremely high transparency .The transmittance rate can reach 92.1%.
2. Outstanding heat, humidity and ultraviolet ray durability and long-tem reliability
3. Superior low moisture ingression than PVB, can fit for side-naked processing in high
humidity environment.
4. Widely use in more fields than other internal EVA films, which only laminate silk and
films with glass.
5. Highest interlayer laminating strength and security characteristics can avoid ungluing and
air bubble caused by low-quality film.
6. Superb compatibility with polymers and other insert media, such as PET,PC ,PVC, glass,
wood cloth, paper liquid crystal sheet, solar cell ,etc
7. Easy handling, using low-cost small vacuum-kiln equipment.
8. Highest productivity, low waste.
-Display cases
-Bnaking facilities
-Solar control requirements
-Glass floors
-Sound control
-Entrance doors
-Funiture and home decoration
-hotel hall
-Office decoration
-Commercial and residential glazing
-Safety glazing
-In the processing of EVA laminated glass, owing the ordinary glass with its green color, it
will influence the original design effect. However, using ultra-clear glass can have a excellent
performance, it can make the interlayer fabric more clear.

3. China’s EVA FILM compared to Japan’s EVA FILM

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Yes, EVA FILM was first implied in Japan, like Bridgestone. At that time, no other countries had
used EVA FILM to laminate glass(Maybe i am wrong, welcome to correct me). Yes EVA has been
used in others fields, like slipper and insider of cloth etc.
Not many years later, EVA FILM was introduced to China. but the quality is not very good.
The EVA FILM is only used in decorative glass. Which mens the safety of EVA FILM is not trusted.
But now in China, the EVA FILM after modified by lots of times, are in good quality.
And some European customers change the suppliers of EVA FILM to China suppliers, because EVA
FILM in China is inexpensive but at the some quality of EVA FILM in Japan.
As we have compared EVA FILM in China and Japan.
The visible light transmission and ultraviolet light blocked rate are as good as EVA FILM in Japan.

4. EVA FILM Category

Based on the UV Blocked rate, the EVA FILM can divided into :

Indoor EVA FILM and Outdoor EVA FILM.
Indoor EVA FILM, of course, the UV blocked rate is lower than 30%. So they can only be used
inside building.
But how is it going to happen, if I put the indoor EVA FILM laminated glass in outdoor using?
That is a great question. And the answer is that the indoor EVA FILM laminated glass will turn
yellow in short period, maybe two years, and bubbles will come out inside the laminated glass,
and the EVA FILM will break away from the glass.
For outdoor EVA FILM, the most advanced EVA FILM can absorb 99% of the UV radiation.
But at least the UV radiation should be absorbed more than 85% percent that the EVA FILM can
be used for outdoor.
It’s logical that more UV radiation absorbed by EVA FILM, more years the laminated glass with
will survive.
Yes, it’s not necessary to say but I want to mention that you can use the outdoor EVA FILM for

Based on the transparence, the EVA FILM can divide into:

Ordinary transparent and super transparent.
Ordinary transparent, of course, means the transparence is good but less than super transparent.
Most ordinary transparent EVA FILM is used in laminating with fabric and papers.
And generally speaking, the ordinary transparent EVA FILM are INDOOR EVA FILM. And super
transparent EVA FILMs are outdoor EVA FILM.
But some people also used super transparent EVA FILM to laminate with fabric and papers.
But because some people need the super transparence but not the UV blocked rate, some EVA
FILM manufacturer make the INDOOR super transparent EVA FILM.

Based on colors, EVA FILM can divide into:

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-no color transparent
-colored transparent (standard 8 colors in China)
-colored translucent (standard 7 colors in China)
-colored opaque
-Black (transparent, translucent, opaque)
-white (transparent, translucent, opaque)
The standard colors are:
Some companies can customize the color you need it (not included in the standard colors), you
offer the samples, and they will adjust the color film samples for you to check. But of course, the
cost would be higher. It’s different from the quantity of the color you want to customize.

Based on thickness, the EVA FILM can divide into:

0.25 mm
But some companies produce the same thickness with the Japan’s common standard:
Also, the EVA FILM manufacturer can customize the thickness for you, but for this customizing,
the added cost would be very low, some EVA FILM manufacturer may not charge for it.
If you have different views, please communicate with me in the comments. You are warmly

5. Common problems of EVA FILM

Maybe you have already faced the following problems of EVA FILM,
-Gluing of EVA,

- Mosquitoes

- Black spots

- Holes on EVA FILM
-for colorful EVA FILM, the color is not even.
- Knocked marks

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- Yellowing of EVA and etc. …
Gluing of EVA
Which means the two layer of EVA FILM stick together, three reasons can cause it:
(1) The EVA FILM is ultra-transparent film; they are easy to show adhesives. In this situation,
put membranes between the two layers of EVA FILM.
(2) The temperature is too high, like the temperature in the container is too high (maybe over 65
degree), which will lead the EVA FILM to melt, and stick together.
(3) The film is to0 tight when was produced, this is factory’s problem, they should loosen the EVA
FILM when they are circle to be a roll.
This is about the environment of EVA FILM factory; they should kill pests in workshop, and avoid
other mosquitoes to come in.
Black Spots
This is also about producing procedure in EVA FILM factory, the workers should wear gloves or
wash hands often, to make sure when they touch the EVA FILM, and their hands are clean.
For colorful EVA FILM, the color is not even
It’s about the procuring procedure of EVA FILM; maybe the procedure of mixing the colorant is
not good enough.
Knocked marks
This is caused in the transportation. The carrier is not carefully or the EVA FILM is not packaged
by wooden boxes.
Yellowing of EVA
It’s about the formula of EVA FILM, which means the quality of the EVA FILM. So you buy little
trial order before you make big quantity order.

6. EVA FILM Processing Procedure Notes

1.) Activate vacuum pump for 2-3min till the vacuum value reach 0.095Mpa, then start heating.
2.)The temperatures and times for processing based on 1Pc 5mm Glass +1Layer EVA Film + 1Pc
5mm Glass
3.)For thicker glass or more layers of EVA Film, the heat-holding-time should be longer, please
check with “The Processing Parameter of Different Glass Thickness and EVA Film Layers” or
consult us.

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1.) The plainness of the glass is poor (especially the tempered glass). Make sure the inserted film
is thicker than the deformation scale of the two overlapping glasses.
2.) The film has not completely melted. Please raise the temperature or increase the time of
3.) Stop the vacuum pump two early. Don’t stop the vacuum pump until the temperature bellows
4.) The Silicon Bag is leaking. Please replace the Silicon Bag to unsure that the vacuum value
reaches 0.095Mpa.
Please fully confirm the corrosive and permeability of the edge sealing reagent and glass glue
before using, for those may lead to films breaking away from glasses!

7.Bubbles Solution for Laminated Class with EVA Film

When some customers processing laminated glass, bubbles appear inside the glass is the big
problem they have to face.
People always think is this way:
1. the EVA Film you sent to us last time, don’t have bubbles problem, why this time the bubbles
is coming out, that’s definitely the reason of the quality of your EVA Film.
2. Some customers face this situation. Maybe they don’t use EVA Film very much, so they don’t
finish the one roll of EVA FILM in a short period. They used two thirds of the roll of EVA film, and
after several weeks, they go back to use the left part of the roll. But this time the bubbles coming
out, they are very confused. How come the same roll has different quality?
3. Some customer may just change the new EVA FILM supplier and the bubbles comes out.Even
their new supplyer tell them it’s all about the processing , they would not believe him, they
would think it’s of course the problem of the quality of your EVA film, because my older supplier
don’t have this bubbles problem.
Many Laminated glass producer have misconception of the reasons of the bubbles problems.
Here is the real why:
1. First situation: the temperature is too high, maybe more than 180 degree, which will cause
the compound to break down and create gas. In this way, it’s just reducing your temperature, and
everything would just be fine.
2. Second situation: the temperature in the oven is not average, which means some part of the
glass, is hotter than others. So some part of the EVA film will melt and finish the crosslink
reaction while other parts of EVA Film is still no t melted, which will interrupt the vacuuming and
cause the bubbles. For this situation, we suggest you use the wind blowing heating machine.
3. Third situation: the Vacuum machine is old or the vacuum ability is not good enough. If the

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vacuum machine is old, renew it. If the vacuum ability is not powerful enough try to buy a new
4. Four situation: the air moisture is high. Much moisture in the air in your place is changed,
which will easily cause the EVA film wet when it expose in the air. Moisture in the EVA FILM
would cause the bubbles. Although the EVA FILM is less sensitive to moisture compared with PVB
FILM. But if the moisture is too high, the bubbles will also come out.
Some customer open the packaged of one roll, and don’t use it up at one time. And the left part
of the EVA film will absorb the moisture in the air and cause the bubbles.
5. Five Situation: Different EVA FILM supplier has different formula for EVA FILM, so if you
change the EVA FILM supplier, you need to adjusting the processing parameters according to the
supplier’s EVA FILM property.

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To be continued.