The problems of EVA film in glass lamination processing

1.Laminated Glass Delamination

EVA Film do not have enough Adhesion performance

There is delamination after edging or naturally delamination

The test method is to do adhesion test

When the EVA film was processing in Glass laminating machine,one side of film is adhesion to glass,and the other side is stick to a layer of fabric or paper.

After Glass laminating process,cool down the laminated glass and take it out of laminating oven.

After the glass is completely cooled,please tear the fabric or paper,if the film could not tear out or the film seriously deformed because of tear,

which indicating the EVA film have good ahesion.

2.The EVA film thickness is seriously uneven

Because the EVA film thickness is seriously uneven,During processing in the furnace,the EVA film could not fulfill the uneven of glass when the EVA film is not enough thick,

at this place,the laminated glass is very easy to have bubbles.

3.The EVA film tension is too big

Due to the tension is too big during the production,the EVA film is too tight when in roll,the EVA film was stretch,after glass lamination,it would happened the EVA film shrink at the edge.

Which result in the edge of glass without EVA Film fulfill.

4.The oil of Glass edge do not clean enough when cutting the glass

The oil would affact the EVA film adhesion to glass.

Method:the oil of glass edge should be clean enough before glass lamination

5.Glass process temperature is too low

The EVA film could not happened chemical reaction with glass totally,which would happened delamination problem.

Method:When making glass processing,it must use the indicated glass processing temperature range,the temperature surface should reach the temperature manufacturer indicated.

Because the Glass laminating machine have some temperature difference,customers could adjust your temperature setting when processing.

6.Glass process temperature is too high

When the processing temperature is too high,the EVA Film flowing is active,it would be over flowing at the glass edge when processing in the glass laminated furnace,than the EVA film would become thinner,which is easy to happened the glass edge delamination.

Method:When making glass processing,it must use the indicated glass processing temperature range,the temperature surface should reach the temperature manufacturer indicated.

Because the Glass laminating machine have some temperature difference,customers could adjust your temperature setting when processing.

7.The difference between positive temperature and negative temperature is too large

The actual temperature in the furnace and the temperature displayed on the thermometer have too large difference between the positive and negative temperature,which results in the actual processing temperature is too high or too low.

Method:It is recommended that customers check the positvie and negative temperature difference of the furnace and improve or replace the temperature control system.

If the customer is unwilling to do this,we should advise him to adjust the temperature value to balance,unitl the surface of glass temperature could reach the temperature we suggested.

8.The constant temperature time is not enough in the glass laminating furnace

Due to the not enough constant temperature time in the glass laminating furnace,the adhesive in the film can not fully react with the glass,and the adhesive force is weak and easy to delaminated.

Method: Strictly follow the process steps during glass lamination process,please do not reduce the processing time because of the tight engineering time.

For example,5mm Glass+0.38mm EVA film+5mm Glass sandwich,(1)If the temperature we test is glass surface,when the glass surface reach the indicating temperature,than we keep this constant temperature for 20minutes(The constant temperature time is calculating from the glass surface reach the indicating temperature.)(2)If the temperautre we test it hot air,it is necessary to keep constant temperature for 40minutes (When the temperature reach the indicating temperature,than we start to make calculations).

When we face with the following conditions,we should adjust the temperature and extend the constant temperature time in the Glass laminating machine.

(1)Glass is thicker

(2)EVA Film is thicker

(3)The Insert materials is thick

(4)Multi-structure Glass lamination

9.Excessive humidity during Glass lamination processing

While in Glass lammination process,excessive humidity during processing will hydrolyze the adhesion in the film,which would reduce the adhesion of EVA film.

Method: we suggest customer should laminated the glass in dry workshop,it is better that it could be processed in constant conditioner room.

If the humidity is over 65%RH,please do not process the laminated glass under this condition.

Especially under the raing season,we should be pay much more attention to the humidity to reduce the delamination complaints.

10.Glass is too thick, and the EVA film we used for lamination is too thin

It would happened delamination problem because the adhesion of EVA film is not enough to handled such heavy glass

Method:Glass is thicker,we should use thicker EVA film for Glass lamination

11.The EVA Film is expired

Along with the stock time is too long,the adhesion of EVA film would be loss and result in delamination

Method:It is necessary to use the EVA film in the valid period,If the EVA film already stock for long time,we should do adhesion test to check if there is enough adhesion force for glass lamination.

Otherwise,If the EVA film could be stock in low temperature low humidity surrounding,the valid period of EVA film would be extend.

12.The gap of insert material is too big and the EVA film we choose is too thin

When the EVA film processing in Glass laminating machine,the EVA film is melt,but the EVA film flow and could not fulfill the big gap because of not enough thick EVA film,it would happened delamination

Method:If the insert materials is thick and the gap is big,we should increase the thickness of EVA film for lamination

13.Excessive waterjet cutting pressure

Too much pressure on the processed laminated glass with waterjet cutting would easily case delamination.

The laminated glass with insert materials,such as fabric,silk,cloth,paper,all these kinds of materials would cause delamination due to water absorption.

Method:Please avoid the waterject to cut the laminated glass

14.The insert materials happened water absorption

Eding the laminated glass with insert materials would happened EVA adhesion is seriously reduce,which would affact the adhesion of EVA film.

15.Sealants,paints and coatings corrode the EVA film

In many applications,safety laminated glass usually needs to use sealant to join the seams.

Practice has proved that some types of sealants will have adverse reactions to EVA laminated glass film,which cause delamination,bubbles or blackening around the laminated glass.

Both methanol volatilized from neutral sealant and acetic acid volatilized from acid sealant will corrode the EVA film.

Even some paints and coatings will have the above-mentioned adverse reaction to the EVA film.(The toluene and xylene gas volatilized from paint and coating are solvents for EVA film)

Method:It is recommended that when choosing a sealant,it is best to conduct quality consultation and necessary inspections on the sealant used.

After confirming that the sealand used has no adverse reaction to the laminated glass,than we could put it into batch production

It is recommended that customers use special glue for laminated glass or glass glue that has not corroded with the EVA film after testing.

Paint and coating is completely dry and there is no smell volatilizes before installing the glass.

16.EVA Film and Insert materials are not compatible

The EVA Film can not be adhesive to all materials,it would be delaminated when it is adhesive to insert materials,backing film,inks and other materials.

Method:It is recommended that customers do adhesion test before mass production to reduce the risk of mass production.

17.The anti-mold powder on the glass surface is not cleaned

The anti-mold powder on the glass surface is assembled without cleaning,and the glass is easy to delamination after glass processing production.

Method:It is recommended that customers could clean and wipe the glass before combining the EVA films.It is better to processing the glass in glass washing machine and drying machine.

18.The characteristic of EVA Film itself

For example,the pigment in sandblasted white film is easy to absorb water,it is easy to open the glue when edging.

Method:Please try to edging the glass before sandwich the EVA Film and glass.

19.Wipe the glass and EVA film with water or water containing alcohol when sandwich the EVA film and glass

Wipe the glass and the film with water or water containing alcohol before they are dried when the film is combined,and the adhesive in the EVA Film is hydrolyzed,which affacts the adhesion of the EVA Film.

Method:It is recommended that customers use absolute ethanol(alcohol content greater than 99%) to wipe the glass and film,or have glass drying equipment and material dehumidificatioon measures.

20.Glass bounce

The glass will be flattened under vacuum pressure,especially the edge of the glass will have curvature that is invisble to the naked eyes.

Once the vacuum is removed,the glass will be rebound.If the adhesive force of the EVA Film is not enough to withstand the rebound force of the glass,it would be delamiantion.

This phenomenon mainly occurs in tempered glass and thicker glass.