Below to introduce the characteristics of several kinds of the most common type of plastic.
A: PVC (polyvinyl chloride)
Heat-sensitive plastic, generally can be divided into hard and soft, add the amount of plasticizer, the difference is that raw material is less than 10% of the hard, more than 30% were soft.
Features: (1) no obvious melting point, soften 60℃, 100 ℃ ~ 150 ℃, viscoelastic state 140 ℃ melting, decomposition at the same time, the 170 ℃ decompose rapidly, softening point close to the decomposition, decomposition in HC1 gas release.
(2) thermal stability is poor, temperature, time will lead to decompose, liquidity is poor.
Second, PC (polycarbonate) material
Features: (1) an amorphous plastic, no obvious melting point, glass transition temperature of 140 ° ~ 150 ℃, the melting temperature of 215 ℃ ~ 225 ℃, molding temperature 250 ℃ ~ 320 ℃.
(2) the viscosity, is more sensitive to temperature, in the normal processing temperature range and internal stability is good, basic does not decompose, 300 ℃ long stay when more than 340 ℃ starts to break down, is influenced by shear rate viscosity is smaller.
(3) water imbibition is strong
Three, PMMA (organic glass)
Features: (1) the glass transition temperature of 105 ℃, melting temperature is greater than 160 ℃, the decomposition temperature of 270 ℃, forming temperature range is very wide.
(2) the viscosity, liquidity is poor, good thermal stability.
3. Strong water imbibition.
Four, PA (nylon)
Features: (1) crystalline plastics, sort is more, different species, its melting point is different also, and the melting temperature range is narrow and general used PA66 its melting point is 260 ℃ ~ 265 ℃.
(2) low viscosity, good fluidity, have obvious melting point, thermal stability is poor.
(3) water imbibition.
Five, PET (polyester)
Features: (1) melting point 250 ℃ ~ 260 ℃, blow molding grade PET molding temperature is a little wide, approximately 255 ℃ ~ 290 ℃.
(2) blow molding grade PET high viscosity, temperature has great effects on viscosity and poor heat stability.
