HOW TO MAKE PVB LAMINATED GLASS WITH PVB FILM POLYVINYL BUTYRAL
By Peter Shin
www.HelloGlass.com
The storage and protection of PVB film when laminating safety glass
with Polyvinyl Butyral PVB film
Warehouse condition:
Indoor, Normal temperature, humidity lower than 65%
Storage period:
To be stored in buyer's warehouse less than 24monthes after the producing date
Don't open the package if it's not used immediately.
Prevent the package from getting wet.
Put the PVB film into the combining room for at least 24 hours before use.
The rest PVB film must be stored in a room with temperature and
moisture control.
======================================================
Glass cleaning and requirement when laminating safety glass with
Polyvinyl Butyral PVB film
Purpose:
Erase any oil or dust on the glass surface
Enhance adhesion capacity
Basic condition and requirement:
Clean the glass. City-water is available
Rinse the glass with treated water only.
Water quality requirement: <30 uS or >1M Ω，Hardness <10ppm，Water
temperature 40-60℃
The glass must be dried completely. Both hot wind and cold wind are
workable, but the wind should be filtered first so as to prevent
contamination.
=========================================
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: uc@ucolin.com / www.ucolin.com
umewe360@gmail.com/ umewe360@hotmail.com
===========================================
Requirement for combining room when laminating safety glass with
Polyvinyl Butyral PVB film
Basic condition and requirement：
Temperature: 20-25℃
Humidity: 23% +/- 2%
Double doors
Indoor air must pass through the filter
A carpet able to suck up the dust should be put between the double doors.
It's necessary to keep clean the indoor floor and devices.
Operating workers must wear clean overalls that will not be dehairing,
and also wear glove and cap to prevent causing contamination.
=============================
Glass combining when laminating safety glass with Polyvinyl Butyral PVB film
Note: glass surface temperature: 20-40 ℃,
Suggest control temperature: 25-30 ℃
If temperature is higher than 40℃:
The PVB film will get shrink;
PVB film wrinkle will appear;
The film will get sealed earlier than expected;
The PVB film will get soft and adhere to the glass;
There will be lots of air inside the film.
If temperature is lower than 20 ℃:
The PVB film surface will be too smooth to get fixed;
It will be very difficult for the glass and the PVB film to get adhered;
It will be difficult to get rid of the gas and trim the edge of the
laminated glass;
There may be flaw on the edges.
PVB film temperature: 20-25℃
Combining process:
The PVB film should be 5-10mm bigger than the glass;
The PVB film is put on the glass on level stage;
The PVB film can not be pull when its edge is being trim;
2-5mm PVB film should be left on the edge after trimming.
The four edges of the upper glass should be aligned with that of the down glass.
Check carefully whether there's any contaminating stuff on the glass
or the film.
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Prepressing and air expelling when laminating safety glass with
Polyvinyl Butyral PVB film
Purpose:
To get rid of the air leaving between the glass and the film
To pre-combine the glass and the film before it's put into the autoclave
To seal up the edge in order to avoid the air permeating into the
laminated glass again.
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.
=================================================================================
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
====================================================
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
====================================
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: uc@ucolin.com / www.ucolin.com
umewe360@gmail.com/ umewe360@hotmail.com
=====================================
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℃
=================================
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.
===========================================
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: uc@ucolin.com / www.ucolin.com
umewe360@gmail.com/ umewe360@hotmail.com
