In the production process of double-pass sealed insulating glass, the success of butyl rubber coating as a seal directly affects the quality and service life of insulating glass. However, in the actual production process, the butyl rubber coating sometimes encounters the phenomenon of bubbles. The harm caused by the consequences of the bubbles phenomenon is mainly two:

(1) Interrupt the normal coating of the rubber strip and affect the coating efficiency.

(2) Due to the large number of tiny air bubbles, the brightness of the surface of the rubber strip is affected, and a burr phenomenon is generated, which seriously affects the appearance of the aluminum spacer before the film is not laminated. Therefore, the elimination of air bubbles is particularly important in the production process of insulating glass.

There are many reasons for air bubbles in the process of coating butyl rubber, which can be roughly divided into the following aspects:

(1) There are air bubbles inside the finished butyl gum. Because butyl gum is a semi-solid viscous self-adhesive, if air bubbles are mixed in the production process without treatment or incomplete treatment, the air bubbles will remain in the colloid. During the coating process, the air bubbles can be discharged from the glue head with the colloid. Thus affecting the coating quality.

(2) The butyl rubber in the rubber tank is not drained off, so replace it with a new butyl rubber. If the piston is withdrawn in the presence of butyl rubber in the rubber cylinder, the butyl rubber with excellent adhesion will form a mountain peak at the bottom of the rubber cylinder and the piston. After the new butyl rubber is pushed, the rubber cylinder There will be a lot of air bubbles between the peak-shaped butyl rubber bonded to the piston and the new butyl rubber. The difference is that there is less air bubbles at the piston than at the bottom of the rubber cylinder. Therefore, during the glue application process, there is a large bubble and more burrs immediately after changing the glue, and at the end, there are fewer bubbles.

(3) The difference between the diameter of the butyl colloid and the diameter of the rubber cylinder is too large. If the diameter of the butyl rubber is much smaller than the diameter of the rubber cylinder, there is a large space between the butyl rubber and the inner wall of the rubber cylinder and it is flooded with a large amount of air. Part of the air is squeezed and sealed between the colloid and the cylinder wall. 'Although some air will be discharged from the gap between the piston and the cylinder wall during the extrusion process, the closed air cannot be discharged due to the obstruction of butyl rubber. As a result, bubbles will be generated at a certain interval in the butyl rubber coating process.

(4) The temperature of the rubber cylinder and the rubber head is too high. Due to the existence of macromolecular organic substances in the butyl rubber, if the temperature is too high, the organic substances will be cracked to produce small molecular substances, some of which exist in a gaseous form at high temperatures. If the butyl rubber is coated at this time, the rubber head is discharged Later, the gas under high temperature and pressure suddenly drops pressure, and its volume will expand rapidly, generating a large number of micro-bubbles, making the rubber strip appear as a burr phenomenon.