HOW TO MAKE PVB LAMINATED GLASS WITH PVB FILM POLYVINYL BUTYRAL(2-2)
By Peter Shin
www.HelloGlass.com
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【Product 1】CNC-Force EVA INERLAYER FOR ARCHITECTURAL LAMINATED GLASS [email protected]
【Product 2】CNC-SmartSMART FILM FOR PRIVACY SWITCHABLE GLASS [email protected]
【Product 3】CNC-Shield PVB INTERLAYER FOR AUTOMOTIVE WINDSHIELD GLASS [email protected]
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SILICONE LAMINATE BAG FOR EVA LAMINATING MACHINE [email protected]
SILICONE BAG FOR PVB AUTOCLAVE VACUUMING [email protected]
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If the air is not expelled completely:
Bubbles may appear;
It may cause delamination;
The laminated glass’ thermal stability is not good;
The glass may get cracked inside the autoclave.
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Air expelling, prepressing and edge sealing when making PVB laminated glass
Two ovens and two times of roll extrusion
Clean the glass
Temperature: 20-25℃, humidity:25%+/- 2%
Prepressing oven
Prepressing oven
Combining room:
The first oven’s temperature:
the pre-laminated glass may get crack if the temperature is too low
The pre-laminated glass edge will get sealed earlier than expected if the temperature is too high
The second oven’s temperature:
If temperature is too low, the pre-laminated glass edge can not be sealed smoothly and the adhesion is not good;
If temperature is too high, bubbles will be produced.
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Conditions for prepressing and expelling air when laminating glass with PVB Film
Roll extrusion way on the flat layer:
The first roller: the glass surface temperature is about 35℃, with pressure 5-7 bar; and the gap between two rollers is about 10% smaller than the glass total thickness.
The second roller: the glass surface temperature is 65-75℃，with pressure 5-7bar; and the gap between two rollers is 15% -20% smaller than the glass total thickness.
Vacuuming way on the curved laminating layer:
Vacuum ring: silicone vacuum bag
Cold pumping:
Temperature : 20-30℃; 22℃ is suggested.
Vacuum degree: 550 -660mm HG;
Time: About 5-20 minutes.
Heat pumping:
Glass surface temperature: 95-105℃
Time: less than 25 minutes
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Air expelling when laminating safety glass with PVB Film
Factors affecting normal air expelling:
Temperature required for glass is lower than 25℃, and for PVB lower than 18 ℃。
Cold pumping time is at least 5-20 minutes, with temperature 22℃.
Vacuum degree: absolute vacuum 80% (latm/100kPa)
Vacuum ring’s temperature: lower than 30 ℃. 20-25 ℃ is recommended.
Rheology and the grains on PVB Film’s surface
Glass’s thickness
Each glass is not matched very well to the other glass after hot bending
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UCOLIN SILICONE TECH
(1)-Silicone Vacuuming Bag for EVA Glass Laminating Machine/Privacy Glass Laminating
(2)-Silicone Sheet for EVA Glass Laminating Machine
(3)-Silicone Bag for PVB Glass Laminating Auto-clave
(4)-Silicone Rubber Sheet for Solar Cell Module Laminating Machine
(5)-Silicone Sheet for Wood Door Vacuum Laminating Machine Vacuum Press Machine Vacuum Filming Machine
Contact Us: [email protected] / www.ucolin.com
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Autoclave when laminating safety glass with PVB interlayer film
Purpose:
Dissolves the residuary air inside the PVB film
Allows PVB film flows and combine with the glass
Obtain required performance and transparency
Basic condition and requirement:
Temperature and pressure can get increased simultaneously, but the pressure can not get increased to quickly.
Pre-laminated Glass’s constant temperature: 135-145℃
Pre-laminated Glass’s pressure under constant temperature: 12-14 bar
Time for constant temperature and pressure: at least 20 minutes
Temperature for releasing pressure: under 50℃
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Autoclave’s working principle when laminating safety glass with Polyvinyl Butyral PVB film:
PVB film:
shapeless polymer
Appears adhesive under low temperature
Appears flowable under high temperature
Temperature: enable the PVB film to flow and get shaped permanently
Pressure: enhance the adhesion between PVB film and glass
Time: allows PVB film to become flowable
Notes: the thicker the glass, the longer time for the autoclave’s cycle.
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Common problems for autoclave when laminating safety glass with Polyvinyl Butyral PVB film
=Pressure get increase too quickly: the PVB film stays cool inside the autoclave; and it will cause the air running through if the glass edge was not sealed well or hot bending did not go well.
=Pressure get increase too slowly: the air rest inside the PVB film will get expanding if the temperature increases too fast, and becomes bubbles that will rift the glass edge.
=the time for constant temperature and pressure is too short:
The PVB film does not flow completely, and so it can not got contact with the glass completely
The adhesion becomes worse;
The glass clearness will get reduced consequently
=the temperature is too high when releasing pressure:
The PVB film is still too hot and soft at the meantime;
The high pressure air get together inside the glass edge, and get saturation;
If the pressure reduce too suddenly, the air under high pressure will get expanded inside the soft film and becomes bubbles;
The air under high pressure will diffuse from the glass center to the glass edge and later becomes bubbles because the pressure in the edge is lower.
All Rights Reserved By:
UCOLIN SILICONE TECH
(1)-Silicone Vacuuming Bag for EVA Glass Laminating Machine/Privacy Glass Laminating
(2)-Silicone Sheet for EVA Glass Laminating Machine
(3)-Silicone Bag for PVB Glass Laminating Auto-clave
(4)-Silicone Rubber Sheet for Solar Cell Module Laminating Machine
(5)-Silicone Sheet for Wood Door Vacuum Laminating Machine Vacuum Press Machine Vacuum Filming Machine
Contact Us: [email protected] / www.ucolin.com
[email protected]/ [email protected]