What are the applications of polyurethane sealant in automobile windshields?

Polyurethane sealants are widely used in the automotive industry, mainly used for automotive windshield sealing, caulking/weld sealing, structural sealing, interior bonding, floor bonding and sealing, air conditioning luggage compartment bonding and sealing, and Other bonding seals, etc.

Polyurethane windshield adhesive is a very important variety in the automobile assembly process. It is used for bonding and sealing windshields, side windows, etc., replacing traditional assembly processes and improving the safety factor of the entire vehicle. According to statistics, currently 100% of domestic car windshields are bonded with polyurethane sealants. More and more passenger cars, especially high-end luxury bus manufacturers, are also promoting this technology for windshield and side window glass bonding and sealing. , in order to improve the overall performance of the vehicle, the usage rate of polyurethane sealant in windshield bonding in the entire automotive industry can reach 95%.

Car windshield design requirements:

Ordinary glass cannot be used in automobile glass due to safety considerations, so there are generally only two types of common automobile glass, tempered glass and laminated glass. According to the GB 9656-2003 'Automotive Safety Glass' standard, the windshield must have good visibility and sufficient strength. When a vehicle accident occurs, the windshield can protect the driver and passengers.

Design requirements for sealant for automobile windshields

The bonding and sealing of windshields is a very important process in the automobile assembly process, and the requirements for the use of sealant 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 automobile body, and in Excellent weather resistance and durability are also required during use.

The automotive industry standard QC/T 1024-2015 of the People's Republic of China 'One-component polyurethane sealant for automobiles' requires that single-component polyurethane sealant for automobiles used for bonding must meet the tensile strength ≥6.0MPa and must be heat-resistant. aging performance tests such as resistance to moisture and heat, artificial climate accelerated aging , and water resistance.

Polyurethane sealant application process

'Thirds of materials, seventy of construction', good construction is an important guarantee of quality. Before gluing, be sure to conduct an adhesion test between the sealant and the base material to determine the bonding effect between the sealant and the base material, select appropriate cleaners and primers, etc.

Gluing process:

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

Pour an appropriate amount of the matching cleaning agent into a clean and dry special container, dip it in the cleaning agent with clean absorbent cotton and other materials, clean the grease, dust, etc. on the surface of the adhered part, and then dry it fully.

(2) Apply primer: Improve the adhesion between the polyurethane sealant and the base material.

Shake the primer thoroughly and pour an appropriate amount into a special container. Use a soft brush such as wool to apply a thin layer of primer on the cleaned adhered parts and let it dry thoroughly.

(3) Gluing and installation:

sealant can be applied in dots or strips as needed. After the sealant construction is completed, the bonding positioning and trimming of the windshield and the car body need to be completed within the operational time of the sealant.