Polyurethane Sealant, the Key to Car Windshield Safety

Polyurethane windshield adhesive is a very important variety in the final assembly process of the automobile, which is used for the bonding and sealing of the windshield, side window glass, etc., replacing the traditional assembly process and improving the safety factor of the whole vehicle. Due to safety considerations, ordinary glass cannot be used, so there are generally only two kinds of common automotive glass, tempered glass and laminated glass. The windshield must have a good line of sight, sufficient strength, and when the vehicle has an accident, the windshield can protect the driver and passenger.

The bonding and sealing of the windshield is a very important process in the final assembly process of the automobile, and the rubber requirements are also very strict, requiring the sealant to have high strength, tear resistance, excellent sealing performance, and can improve the overall rigidity of the car body, and it also requires excellent weather resistance and durability during use."Three points of material, seven points of construction", good construction is an important guarantee of quality. Before sizing, it is necessary to test the adhesion of sealant and substrate, determine the bonding effect of sealant and substrate, select the appropriate cleaning agent and primer.

The windshield has very strict requirements for 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 and 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

The common sealing materials of windshield glass mainly include traditional rubber strip, polysulfide sealant, silicone sealant and polyurethane sealant. The characteristics and application scenarios of various materials are compared as follows:

(1)Conventional rubber strip: 

Low sealing performance, easy deformation; suitable for commercial vehicles and rail vehicles are partially used

(2)Polysulfide sealant: 

High viscosity, heavy odor; no longer applicable

(3)Silicone sealant:

Good weather resistance and durability, wide adhesion, low tensile strength;this parameter is applicable only to scenarios with low security

(4)Polyurethane sealant:

With a variety of materials have excellent chemical glue relay; It can be heated and cured at room temperature, and has good wear-resistant, water-resistant, oil-resistant, ozone resistant, solvent resistant, chemical resistant, anti-mold and other properties. At high temperature and high humidity, it is easy to hydrolyze and reduce the bonding strength. 

High strength bonding and sealing of various vehicles and vehicle bodies