What are wooden seal materials and chemical composition

1.PVC resin
It is the main body of sealing material, all the materials can account for 65% -75% from the conditions of use and the seal life considerations should be used in suspension polymerization of a high molecular weight resin in order to ensure adequate tensile and excellent flexibility. However, with the increase of the average molecular weight PVC resin, processability of the resin is deteriorated. Therefore, in the selection of suspension PVC resin, comprehensive consideration product performance and processing performance two factors.metal security seals

2.rubber toughening component
It is blended with PVC resin elastic material, typically accounting for 10% -15% of materials, polymer blends based on principle, to use with PVC resin solubility parameter of similar types of plastic or elastomer, such as nitrile rubber (powder like powder), chloroprene rubber, polyurethane, and ELVALOY i.e. E-VA-CO (ethylene - vinyl acetate - polar monomer terpolymer), etc. These rubber or elastic body made in PVC resin is added, not only gives seal good flexibility, can also play the role of PVC plasticizers permanently, so the cost of allowing case, consider increasing the content of the rubber composition. In the rubber toughening component antioxidant and other additives are also added to ensure there is enough product life.

3.thermal stabilization system
PVC resin is a heat-sensitive resin, the thermal stability is poor, such as the PVC resin to 100 ℃, the decomposition will generate more than 1 50 ℃, the decomposition quickly, a large amount of hydrogen chloride gas. The decomposition of the resin processing temperature is below its flow temperature (170 ℃ or so) that can not be processed. To do this, consider the formulation add enough effective heat stabilizers. Which is characterized by absorption of hydrogen chloride can, therefore called the hydrogen chloride acceptor, usually of metal soaps and lead salt heat stabilizer. The former such as calcium stearate, lead stearate. The latter, such as dibasic lead phosphate, tribasic lead sulfate. Because each of the heat stabilizer is a synergistic effect between, it should be matched with each other, to receive reliable thermal stabilizing effect, but also to minimize the cost and reduce the dosage. PVC resin and its total usually about 5% -7%. pull tite seals