Principle of plastic

Definition:

Plastic raw material is composed of high polymer synthetic resin (polymer) as the main ingredients penetrate into various shop help materials or additives, plastic and liquid under certain temperature and pressure, can be molded into a certain shape, and under certain conditions keep unchanged shape material.

Most of plastic raw materials from some of the oil extracted, the most familiar part of the PC material is refined from the oil, PC material at the time of burn of petrol, had a ABS are derived from coal, ABS in burn off when rendering soot, derived from natural gas, POM POM at the time of burn down there will be a very smelly gas smell.

Classification:

Plastic raw materials according to the molecular structure of the synthetic resin thermoplastic and thermosetting plastic main points: the thermoplastic plastic refers to the repeated heating still has plasticity plastic: mainly include PE/PP/PVC/PS/ABS/PMMA/PC/PA commonly used raw materials, thermosetting plastic refers to heat hardening statue made of synthetic resin, like some phenolic plastic and amino plastics are not commonly used.

According to the main application range points are general plastics such as PE/PP/PVC/PS, engineering plastics such as ABS/POM/PC/PA several, there are some special plastic, such as resistance to high temperature humidity and corrosion resistance and other modification of plastics for special use.

Features:

A. heat expansion of plastic raw materials, the linear expansion coefficient is a lot bigger than metal.

B. general plastic material stiffness of one order of magnitude lower than the metal.

C. the mechanical properties of plastic raw materials will be significantly lower under heat for a long time.

D. general plastic raw materials at room temperature and below the yield strength under the stress of stress for a long time, there will be a permanent deformation.

E. plastic raw material is sensitive to damage of gap.

F. the mechanical properties of plastic raw materials are usually less than metal, but some than strength and modulus of the composite material is higher than metal, if the product design is reasonable, will be more to play up the superiority.

G. generally improving plastic raw materials mechanics performance is all members of the opposite sex.

H. some plastic raw material moisture absorption, and lead to change size and performance.

I. some plastic is flammable.

J. fatigue data of plastic raw material is very few, need to be used according to the requirements into consideration material use and color processing.

1, most of plastic raw materials can be recycled, but due to the double plastic (material floolwing) than the general material brittle, so only can be used mixed with new material (raw material), the largest proportion is not more than 25% is more appropriate, at the request of customer standards for the principle, the various types of plastic because of the melting point is different, injection pressure of different, must not be confused in production.

2, because want to cooperate with color plastic products, plastic raw materials can be divided into: therefore aggregate, color material, toner and recently appeared to add liquid coloring in the plastic raw materials, grain of raw material is already mixed the pigment into the raw material, every grain of plastics have been shaded, so the formation of product color uniform stability, color pigments and kind of material is mix color or toner raw material use, low cost, and need not store large amounts of non-ferrous materials, but the color is not stable, more difficult to control in the production of unity.

Environmental issues:

Since its launch, the plastic is widely used, but also create serious environmental problems at the same time, plastic garbage to natural decomposition, lead to the increase of solid waste, if into the sea, also can lead to ingestion of Marine organisms, suffocation, poisoning, etc., affect the Marine ecological Vatican plastic garbage will also cause air pollution, plastic parts, spirit such as poly (vinyl (PVC) and polycarbonate (Polycarbonates) in certain conditions or will release harmful substances or in the distribution of interferon, harmful biological reproductive function, therefore, to use less plastic become very important in the environmental protection work.