What sealant to choose for windshield installation?

Polyurethane sealant replaces the traditional assembly process and improves the safety factor of the vehicle. According to statistics, at present, 100% of the bonding of domestic car windshields is made of polyurethane sealant. More and more passenger cars, especially high-end luxury passenger car manufacturers, are also promoting this technology for bonding and sealing windshields and side windows. , in order to improve the overall performance of the vehicle, the utilization rate of polyurethane sealant in the windshield bonding of the entire automobile industry can reach 95%.

The bonding and sealing of automobile windshields is a very important process in general assembly, and the requirements for the use of glue are also very strict. The sealant is required to have high strength, tear resistance, and excellent sealing performance, which can improve the overall rigidity of the car body. Excellent weather resistance and durability are also required in the process. (be sure to test the adhesion between the sealant and the substrate before use, to determine the bonding effect of the sealant and the substrate, to select the appropriate cleaning agent and primer, etc.)

The windshield has very strict requirements on the sealant to ensure the overall rigidity of the car body. Its design requirements can be divided into the following five aspects:

(1) High strength, tear resistance

(2) Weather resistance, durability

(3) Excellent sealing performance

(4) The construction process is simple and the displacement time is short

(5) Meet the overall rigidity of the car body and increase the rate of change when the glass is broken

Polyurethane windshield glue sizing method

When sizing polyurethane sealants for windshields, we pay attention to "three parts of materials and seven parts of construction". Good construction is an important guarantee for sealant products to fully exert their excellent performance. Be sure to carry out the adhesive test between the sealant and the substrate before sizing, to determine the bonding effect between the sealant and the substrate, and to select the appropriate cleaning agent and primer.

Sizing process:

(1) Surface cleaning: improve the adhesion between polyurethane sealant and substrate.

(2) Apply primer: improve the adhesion between polyurethane sealant and substrate.

(3) Glue sizing and installation: Before gluing, the glue nozzle should be cut flat into a triangular opening with a knife, and the inner diameter (R) of the glue nozzle should depend on the width of the bonding design. Conventional: 6mm−8mm for side windows; 10mm−12mm for front and rear windshields. The height (H) of the triangle is twice the thickness (h) of the bonding design.

(4) Other operations and requirements:

The window glass should be assembled immediately after gluing, and it should not exceed 20 minutes at the latest to be assembled on the window. The work of gluing and bonding generally takes 8-12 hours to reach a certain strength. Before that, it is strictly forbidden to apply other deformation forces to the workpiece.