External plasticizing, refers to the inside of the product as an additive-plasticizer, to improve the toughness and elongation of the product.
The outer plasticizer
can significantly improve the initial elongation of the product, but only temporarily. Because the outer plastic is simple and product mix, no chemical reaction, so the additional stuff eventually ran out from the product (volatilized), resulting in greatly decreased elongation, and because the surface is always oily, sticky dust, so sometimes, you see some company paint appearance like being spit"phlegm".
American ASTM D 6083 requirements, products do accelerated aging test 1000 hours, the elongation must be>100%, is to prevent the addition of the outer plasticizer
in the product.
Within the plasticizer is the use of changing the molecular structure of the polymer/molecular weight of the polymer to increase the elongation/softness, such as polyethylene-vinyl acetate copolymer.
The inner plasticized, and the outer plasticized contrary, after adding the product, and the product chemical reaction, will not run out, so it is permanently plasticized.
Specific assessment, is to test the model after accelerated aging elongation, from the table below our roof mate Gold-Class Performance test, you can see our advantage.
Currently internationally more popular single-layer membrane has PVC class. Because PVC-polyvinyl chloride, is a rigid plastic (we should all know that PVC pipe, the polymer is plastic), so the PVC membrane must be added to have the flexibility of plasticizer, although there is a DuPont can provide plasticized PVC plasticizer, but PVC membrane currently on the market, because of the cost reasons, some still use plasticized. And when the plasticizer
ran, is the end of the life of PVC membrane, because the elasticity will be completely lost.