How to produce laminated Glass with PVB Film

1. Glass Preparation

Cutting glass precisely and cutting tolerance must be less than 2mm to avoid bubbles. Polish the glass edges and wash the glass with softened water, then dry the glass and put it into the laminating room.

2. Lamination

The laminating room should be clear and dust-free, and the operator should wear it neatly. The room temperature should be 15-25°C and the humidity 18-40%. The full laminating process is as follows:

a. Lay one piece of clean glass on the table.

b. Place the PVB film on the glass, the edge of cutting the PVB film should be 2- 5mm more than the edges of the glass. Do not touch the glass when cutting PVB film.

c. Lay another piece of clean glass on PVB film.

3. Pre-pressure Exhaust

In order to get a well-sealed edge, the air between the film and the glass needs to be pressed out. As normal, there are two methods below:

a. Rolling De-airing

The pre-laminated glass to heat up to 25-40°C on the glass surface and put into the first roll by the space of roll is 1mm less than the thickness of laminated glass with a pressure of 0.2-0.5 MPa. And also enter into a thermostatic container to heat up to 60-80°C. Then through the second roll, the space of the roll is 2mm less than the thickness of laminated glass with a pressure of 0.3-0.5 MPa. After finishing to the second roll, seal the four sides of laminated glass with clear tape to avoid bubbles.

b. Vacuum De-airing

Put the pre-laminated glass into a vacuum bag or vacuum rubber gasket, then use the cool or heat pump to expel the air. Recommend: the decompression vacuum degree is exceed 650 mmHg. The cool pumping temperature should be lower than 25°C and keep it for 30-40 mins; while in the period of heat pumping, the temperature should be 70-120°C and keep it for 30-60 mins.

4. In Autoclave

Put laminated glasses into the autoclave and note the space between two pieces of laminated glass is exceed 5mm. Then sealing the autoclave door to raise the autoclave temperature up to 80°C and then raise the rate to 5°C per minute after the temperature of 80°C, and also the pressure in 0.06MPa per minute. When it is up to 120-140°C and 1.0-1.5MPa, keep the temperature and pressure for 30-60 minutes. After that, keep the pressure and lower the temperature to 80°C， at the same time， lose the pressure to the atmospheric pressure. After finishing the high-pressure molding process, we can have the final laminated glass for usage.