What are the materials of the automobile sealing strip

The material of automobile sealing strip

1. Epdm rubber

Ethylene propylene diene diene (EPDM) is synthesized by polymerization of ethylene and propylene monomers with a small amount of non-conjugated diolefin. The structure of the polymer is characterized by unsaturated double bonds in the main chain and unsaturated double bonds in the branch chain. Therefore, it has excellent weather resistance, heat resistance, ozone resistance, uv resistance linear as well as good processing performance and low compression permanent deformation, so it is the preferred material for the production of sealing strips. At present, the majority of automotive sealing strip materials are using EPDM as the main raw material.

According to the different parts and functions of the sealing strips, in practical application, vulcanization, protection, reinforcement, operating system materials and special given materials (such as colorant, foaming agent) are added to EPDM materials to form dense adhesive (including black adhesive and color adhesive) and sponge adhesive.

2. PVC

Polyvinyl chloride (PVC) is a traditional universal plastic, through modification of its aging resistance and rubber sense is greatly improved, but because of its poor elasticity, in the sealing strip is mainly used as the inner and outer strip and some sealing strip clamping parts of the material. PVC is also commonly used as the sealing strip of body door frame on trucks and agricultural vehicles, and often combined with EPDM as light color accessories on cars.

Thermoplastic elastomers

Thermoplastic elastomer (TPE/TPV) is in recent years the development of the material, the structure characteristics of two phase composition is made of plastic and rubber, so to some extent, the characteristics of both the plastic and rubber, without sulfide in the machining process, easy to implement in the cross section of the precise control, material under certain conditions can recycle at the same time, the environmental pollution is small, therefore, It is of great concern to vehicle and seal system designers. However, due to its poor elasticity, large compression permanent deformation, at the same time in the manufacture of spongy body technology is not mature, and the price is high, so its consumption is greatly limited. At present, the main part is used for the manufacture of window side strip and window guide groove. With the improvement and perfection of TPE manufacturing technology, its application scope will be further expanded.

4. Auxiliary materials

Skeleton: Skeleton plays a role of supporting and clamping fixed in the sealing strip, the most commonly used skeleton have metal frame and steel wire frame, which can be divided into the cutting metal frame, plate rolling peace, material is low carbon steel, aluminum and magnesium alloy, etc., on the structure is divided into single bridge, build, stretching, symmetric and asymmetric model, in order to meet the manual, hammer and rolling tools such as the needs of different assembly process. In recent years, lightweight and good tracking frames have developed rapidly.

Flocking wool: polyester fiber and nylon fiber with 3-4D fineness are usually used, and the color is mostly black. In recent years, colored fluff has also gained favor and application.

Coating material, coating material was divided into classes and class of silicone, polyurethane has good antifriction effect, most of the traditional coatings for organic solvent, there is pollution to the environment, the latest of water-based coating not only look good, but also partly replace flocking, good reduce the effect of friction coefficient, is the development direction of coating material.

Self-adhesive: it is a butyl glue with no vulcanization system, which can keep plasticity and adhesive force for a long time. It plays an auxiliary sealing role in the clamping part of door frame and luggage sealing strip. Nitrogen filled hot melt adhesive sealing effect is good, can be used in some special requirements.