, 2 performance of polypropylene (PP)
the main characteristics of polypropylene is density is small, its mechanical performance is better than that of low pressure polyethylene, and has the very outstanding rigidity, good heat resistance. It can be used above 100 бу C. Basically does not absorb water, and has good chemical stability, in addition to concentrated sulfuric acid, concentrated nitric acid, almost are very stable. High frequency electrical performance is excellent, and not affected by temperature, easy to form. The disadvantage is that the wear resistance is not high enough, the forming shrinkage is large, the low temperature is brittle, and the hot deformation temperature is also low.
purpose: to do all kinds of machinery parts, flange, gear, coupling, pump impeller, such as car parts. Chemical pipeline and container equipment. And can be used as lining, surface coating, tape, medical instruments and surgical instruments.
, 3 performance of polyvinyl chloride (PVC)
soft and hard polyvinyl chloride (PVC) points of two kinds: Hard polyvinyl chloride, high mechanical strength, excellent electrical performance, strong resistance to acid and alkali, good chemical stability; Disadvantages: low softening point. Soft polyvinyl chloride tensile strength, bending strength, impact strength, impact toughness, etc. are hard polyvinyl chloride is low, and the elongation when broken is higher.
use: rigid polyvinyl chloride products have tubes and rods, plate, rod, centrifugal pump, fan, round tubing, acid and alkali pump valve and container, etc. Soft PVC products are storage tank, sheet, film, wire insulation, window cover, acid and alkali resistant hose.
has a certain mechanics Strength, chemical stability and electrical properties are better, good light transmittance, good coloring, and easy to form, it is characterized by almost complete resistance to water, lack of heat resistance is low, brittle, and its products due to internal stress easy to fracture, can only be used at low load and not high temperature (60 ~ 75бц).
use: All kinds of instrument shell, skeleton, instrument indicator light, lampshade, automobile lampshade, chemical acid storage tank, acid conveyor tank (especially such as hydrofluoric acid), chemical instrument parts, telecommunications parts, because of good transparency, can be used as optical instrument parts and lenses.