Types of automotive seals
1, epdm rubber
Ethylene - propylene diene diene rubber (EPDM) is synthesized by adding ethylene and propylene monomers to a small amount of nonconjugated diolefins.Its structure is characterized by saturated double bonds on the main chain of polymer molecules and unsaturated double bonds on the branch chain.Therefore, it has excellent weather resistance, heat resistance, ozone resistance, uv resistance, good processing performance and low compression permanent deformation, and is the preferred material for the production of sealing strip.At present, most of the sealing strip materials are made of EPDM.According to the different parts and functions of the sealing strip, in the practical application, the EPDM material is added with vulcanization, protection, reinforcement, operating system materials and special entraining materials (such as colorant, foaming agent) to form the compact adhesive (including black adhesive and color adhesive) and sponge adhesive.
2. Polyvinyl chloride
Polyvinyl chloride (PVC) is a traditional universal plastic, through the modification of its aging resistance and rubber feeling greatly improved, but because of its poor elasticity, mainly used in the sealing strip inside and outside and some sealing strip clamping position material.PVC is also commonly used as the door frame seal strip on trucks and agricultural vehicles, and it is often combined with EPDM for light-colored accessories on cars.
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, is to the vehicle and seal the system designer's attention.However, due to its poor elasticity, large compression permanent deformation, at the same time in the production of sponge technology is not mature, and the price is high, so its usage is greatly limited.At present, the main part is used in the manufacture of window side strip and window guide groove.With the improvement and improvement of TPE manufacturing technology, its application scope will be further expanded.