CNC Glass Interlayer(China) www.cncglass.com [email protected][email protected]http://cnc.glass/ Too High Temperature Causing Bubbles in EVA Film Safety Laminated Glass Glazing (Practical Case Study) By Peter Lin We have helped a safety glazing laminator solve the bubbles problem in EVA interlayer film safety laminated glass glazing. We would like to write the case here to help other laminators. Here is the background: The EVAfilm is made in China, but not our CNC Glass Interlayer EVA film products. 10 mm tempered glass + 0,76 Eva Film (the combination of 2 layers 0.38EVAFilm)+ 10 mm tempered glass The size of the pre-laminated glass is about 5 square meters. Heating till 70 degrees within 30 minutes, then keep stable in 70 degree 5 minutes, after that heating till 140 degrees during 40 minutes, keeping stable in 140 degrees 55 minutes. There were big bubbles in the laminated glass. The laminator sent us some photos:
6
Embed
Too high temperature causing bubbles in eva film safety laminated glass glazing (practical case study)
Here is the background: The EVA film is made in China, but not our CNC Glass Interlayer EVA film products. 10 mm tempered glass + 0,76 Eva Film (the combination of 2 layers 0.38EVA Film)+ 10 mm tempered glass The size of the pre-laminated glass is about 5 square meters. Heating till 70 degrees within 30 minutes, then keep stable in 70 degree 5 minutes, after that heating till 140 degrees during 40 minutes, keeping stable in 140 degrees 55 minutes. There were big bubbles in the laminated glass. The laminator sent us some photos:
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
(our process is as follow : heating till 70 degrees within 30 minutes, keep stable in 70 degree –15 minutes, heating up to
130 degrees within 40 minutes , keeping stable at 130 degrees during 50 minutes)
2-Could the reason be low vacuuming ? ( the vacuum is in maximum stage. I mean 0,01. There is no way to go down in the
scale)
3-Can be the reason of bad cooling. After the alarm rings we take out the rack fully out and blow the air by the additional
fans.
Peter, Please help us with this problem.”
Peter’s Suggestion:Since the bubbles problem in the body of laminated glass was because the temperature is too high. The too hightemperature will always cause the bubbles around the edges (the edges of pre-laminated glass absorbing highertemperature than the center of pre-laminated glass), we suggest you reduce the second stage temperature from130 degrees to 125 degrees C.
Test result:On next day, the laminator sent us an email to tell us that all the bubbles problem is solved: The laminated glass is perfect
now.
Here is the email from the laminator:
“Dear Peter,
I would like to let you know that we finally today solved the problem. It was exactly the problem that you guessed. The
temperature 135 and 130 was too high for our oven.
I reduced it till 122 C degrees which is the best temperature for our machine and the EVA film. And it is perfect now.”
Peter ‘s tips:When we face bubbles in EVA film safety laminated glass glazing, there are many factors that may cause the bubbles, such
as, leak vacuuming, too high temperature, too thin EVA Film, tempered glass, too much humidity, too many layers
pre-laminated glass at one time, bad EVA film quality, etc. Some times, if we can not find the reason easily, we should do
small quantity test to exclude the possibility one by one.
And also, please don’t hesitate to contact us if you need any help from us, my email is [email protected] , and you