The materials of automobile seals are mainly as follows, and the specific analysis is as follows:

1. Epdm rubber

Ethylene propylene diene rubber (EPDM) is formed by the polymerization of ethylene and propylene monomer with a small amount of non-conjugated dienes. Its structure is characterized by unsaturated double bonds on the main chain of the polymer molecule but unsaturated double bonds on the branch chain. Therefore, it has excellent weather resistance, heat resistance, ozone resistance, uv resistance, good machining performance and low compression permanent deformation, which is the preferred material for the production of sealing strip. At present, most of the automotive sealing strip materials are using EPDM as the main raw material.

According to the different parts and functions of the sealing strip, in practical application, vulcanization, protection, reinforcing, operating system materials and special materials (such as coloring agent, foaming agent) are added to EPDM material to form dense glue (including black glue and color glue) and sponge glue.

2. PVC

Polyvinyl chloride (PVC) is a traditional general plastic, by modifying its aging resistance and rubber sense is greatly improved, but because of its poor elasticity, in the sealing strip is mainly used as the inside and outside of the strip and some sealing strip clamping parts of the material. In trucks and agricultural vehicles, PVC is also commonly used as body door frame sealing strip, and in cars, IT is often combined with EPDM as light color accessories.

3 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 interest to vehicle and seal system designers. However, due to its poor elasticity, large compression permanent deformation, and in the manufacturing of spongy 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 bars and window guide slots. With the improvement and perfection of TPE manufacturing technology, its application scope will be further expanded.

4. Supporting materials

Skeleton: Skeleton plays a role of supporting and clamping fixed in the sealing strip, 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, the development of lightweight and good following skeleton is rapid.

Flocking: usually 3-4D filament polyester and polyamide fiber, mostly black in color. In recent years, colored fluff has also been favored and applied.

Coating materials: coating materials are divided into polyurethane and silicone, has a good effect of reducing wear, most of the traditional coatings are organic solvents, pollution to the environment, just launched water based coating not only good appearance, but also can partially replace fusing, has a good role in reducing friction coefficient, is the development direction of coating materials.

Self-adhesive: it is a butyl glue without vulcanization system, which can maintain plasticity and bonding force for a long time. It plays an auxiliary sealing role in the clamping part of the door frame and trunk sealing strip. Nitrogen filled hot melt adhesive sealing effect is good, can be used in some special requirements.