1. Polyvinyl chloride Polyvinyl chloride (PVC) is a tra […]
1. Polyvinyl chloride
Polyvinyl chloride (PVC) is a traditional general-purpose plastic. Its aging resistance and rubber feel are greatly improved by modification. However, due to its poor elasticity, it is mainly used for the inner and outer strips and the clamping of some sealing strips. Part material. In trucks and agricultural vehicles, PVC is also often used as body door frame sealing strips, and in cars, it is often combined with EPDM as light-colored accessories.
2. EPDM rubber
Ethylene propylene rubber (EPDM) is polymerized by adding a small amount of non-conjugated diene into ethylene and propylene monomer. The characteristic of its structure is that there are no unsaturated double bonds in the main chain of the polymer molecule, but unsaturated double bonds are introduced in the branch. Therefore, it has excellent weather
resistance, heat resistance, ozone resistance, ultraviolet resistance, good processing performance and low compression set. It is the first choice for the production of sealing strips. At present, most of the
automotive sealing strip materials use EPDM as the main raw material.
According to the different parts and functions of the sealing strip, in actual applications, vulcanization, protection, reinforcement, operating system materials and special imparting materials (such as colorants and foaming agents) are added to the EPDM material to form a dense glue (including black Glue and color glue) and sponge glue.
3. Thermoplastic elastomer
Thermoplastic elastomer material (TPE/TPV) is a material that has been developed in recent years. The two-phase structure is characterized by plastic and rubber, so to a certain extent, the characteristics of plastic and rubber can be easily realized without vulcanization during processing. The precise control of the cross-section, the material can be recycled at the same time under certain conditions, and the environmental pollution is small. Therefore, it is the concern of the vehicle and sealing system designers. However, due to its elasticity and permanent deformation, it is not mature enough to produce sponges, and the price is very high, so its amount is very limited. At present, it is mainly used in the manufacture of window side rails and window guide grooves. With the improvement and improvement of TPE production technology, its application scope will be further expanded.