The main chemical composition of plastic extrusion profile is PVC, so it is also called PVC profile.
It is a new type of building material widely used in recent years. It has excellent properties, convenient processing and wide use. Because of its physical properties such as rigidity, elasticity, corrosion resistance and excellent aging resistance, it is usually used as a good substitute for non-ferrous metals such as copper, zinc and aluminum.
Properties of Plastic Extrusion PC Lens:
Specific gravity: 1.18-1.20g/cm3 molding shrinkage: 0.5-0.8% molding temperature: 230-320 ℃ drying condition: 100-110, 4-5 hours can be used in - 60 ~ 120 ℃ for a long time.
Material properties: high impact strength, good dimensional stability, colorless and transparent, good coloring, good electrical insulation, corrosion resistance and wear resistance, but poor self-lubricating, stress cracking tendency, high temperature hydrolysis, poor solubility with other resins. Suitable for making instrument small parts, insulating transparent parts and impact resistant parts.
1. Amorphous material, good thermal stability, wide molding temperature range, poor fluidity. Moisture absorption is small, but it is sensitive to water and must be dried. The forming shrinkage is small, and it is easy to melt crack and stress concentration, so the forming conditions should be strictly controlled, and the plastic parts must be annealed.
2. For plastic parts with high melting temperature, high viscosity and more than 200g, the heated extension nozzle should be used.
3. The fluidity of the plastic is poor. The mold pouring system is based on the principle of rough and short. It is suitable to set up a cold well, the gate should be large, and the mold should be heated.
4. If the material temperature is too low, it will cause material shortage, plastic parts will be lusterless, too high material temperature will easily overflow the edge, and plastic parts will bubble. When the mold temperature is low, the shrinkage, elongation, impact strength, bending, compression and tensile strength are low. When the mold temperature is more than 120 ℃, the plastic part cools slowly and is easy to deform and stick to the mold.
5. The wall of plastic parts should not be too thick, and should be uniform, avoiding sharp corners and notches.
Properties of plastic PMMA lens:
1. High transparency, light weight, not easy to deform, good optical conductivity
2. PMMA is difficult to ignite and can burn slowly
3. Not resistant to alcohol, ketone, strong base, soluble in aromatic hydrocarbon and oxidized hydrocarbon (trioxyethane can be used as adhesive)
4. Easy forming and stable size
5. Impact resistance and surface hardness are slightly poor, easy to scratch, so the packaging requirements are high