How to use glass laminated autoclave: standardized process from heating to pressure reduction
The preparation work before starting the machine directly affects the subsequent production. First, check the sealing performance of the kettle: after closing the kettle door, start the inflation device, raise the pressure to 0.1MPa and maintain the pressure for 5 minutes. If the pressure drop does not exceed 0.02MPa, it means that the sealing is qualified. At the same time, set the parameters according to the glass specifications: for ordinary laminated glass of 5mm+5mm, the recommended pressure is 1.2MPa and the temperature is 130℃; for thick glass of 8mm+8mm, it needs to be adjusted to 1.4MPa and 140℃, and the insulation and pressure time is extended to 60 minutes.
The heating stage needs to follow the principle of "uniform heating". After starting the equipment, increase the temperature in the kettle at a rate of 2-3℃ per minute to avoid glass shattering due to excessive temperature difference. When the temperature is close to the set value (such as reaching 125℃ at 130℃), the heating rate needs to be reduced to 1℃/minute to accurately control the final temperature. A glass factory once had 30 pieces of glass cracked at the edges due to rapid heating. After following this process, no similar problems occurred.
The heat preservation and pressure holding stage is the key to film melting. At this time, the pressure gauge and thermometer need to be closely monitored. If the pressure fluctuation exceeds ±0.05MPa, it should be adjusted in time through the air supply valve. The operator records the data every 10 minutes to ensure that the temperature and pressure are stable in the set range. At this stage, the PVB film will gradually penetrate into the tiny lines on the surface of the glass to form a strong bond.
The "step-by-step pressure reduction" in the pressure reduction link is the core of reducing glass stress. After reaching the set time, the pressure is first reduced to 0.8MPa and maintained for 10 minutes; then reduced to 0.4MPa and maintained for 15 minutes; finally, slowly exhaust until the pressure returns to zero. The whole process should avoid sudden pressure reduction, otherwise it may cause the glass and film to separate. While reducing the pressure, the temperature in the kettle will naturally drop. When it drops below 60℃, the kettle door can be opened to take out the product.
From sealing detection to parameter setting before starting, from precise control of uniform heating to meticulous monitoring of heat preservation and pressure maintenance, to patient operation of step-by-step pressure reduction, every step of the glass laminated autoclave process hides the ultimate pursuit of "precision" and "patience".
This series of standardized operations seems to be a strict constraint on the equipment, but in fact it is an "invisible line of defense" to ensure the quality of laminated glass - it ensures the perfect fit between PVB film and glass, eliminates the hidden danger of bubbles, and gives the composite glass sufficient strength and safety. For production, keeping these process details is to keep the qualified rate of the product; for enterprises, only by implementing each step of the operation can they gain a firm foothold in the quality track of laminated glass. After all, behind a flawless laminated glass is the awe of "a slight difference leads to a thousand miles of error" in countless links.
