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How do plastic products manufacturers classify plastic materials?

How do plastic products manufacturers classify plastic materials? The fluidity of thermoplastics can be analyzed from a series of indices such as molecular weight, melt index, Archimedes spiral flow length, apparent viscosity and flow ratio. Mold processing wholesalers pointed out that the molecular weight is small, the molecular weight distribution is wide, the molecular structure is poorly regularized, the melt index is high, the snail flow length is long, the performance viscosity is small, and the flow ratio is good. The plasticity of the same product name must be checked. Determine whether its fluidity is suitable for injection molding.

According to the mold design requirements, the fluidity of common plastics can be roughly divided into three categories: 1 good fluidity, PA, PE, PS, PP, CA, polymethyl decene: 2 fluid medium polystyrene series resin, PMMA, POM Polyphenylene ether;

3 poor fluidity PC, hard PVC, polyphenylene ether, polysulfone, polyarylsulfone, fluoroplastic.

The fluidity of various plastics also changes due to various molding factors. The main factors affecting the following are: pfh mold alliance network

1 When the temperature of the material is high, the fluidity increases, but different plastics also have differentities. The fluidity of PS, PP, PA, PMMA, modified polystyrene, PC, CA and other plastics varies greatly with temperature. For PE and POM, the temperature increase and decrease has little effect on the fluidity. Therefore, the former should adjust the temperature to control the fluidity during molding.

2 When the pressure injection pressure is increased, the molten material is subjected to large shearing action and the fluidity is also increased, especially PE and POM are sensitive. Therefore, the molding pressure should be adjusted to control the fluidity during molding.

3 The form, size, arrangement, cooling system design, flow resistance of the melt, etc. of the mold structure casting system directly affect the actual fluidity of the molten material in the cavity. Where the molten material is lowered in temperature and the fluidity resistance is increased, Liquidity is reduced. The mold processing wholesaler pointed out that the mold design should be based on the fluidity of the plastic used, and choose a reasonable structure. When molding, it can also control the material temperature, mold temperature and injection pressure, injection speed and other factors to properly adjust the filling to meet the molding needs.

Crystalline thermoplastics can be classified into two types: crystalline plastics and amorphous plastics according to the fact that they do not crystallize when condensed. The mold processing wholesaler pointed out that the so-called crystallization phenomenon is that when the plastic is from the molten state to the condensation, the molecules move independently, completely in a disordered state, and the molecules stop moving freely, at a slightly fixed position, and have a molecular arrangement A phenomenon of the tendency of a formal model. As the standard for judging the appearance of these two types of plastics, it is considered that the transparent material of the thick plastic part of the plastic is generally opaque or translucent, and the amorphous material is transparent. However, there are exceptions. For example, polymethyl decene is a crystalline plastic with high transparency, and ABS is amorphous but not transparent.

How do plastic products manufacturers classify plastic materials?