What is the difference between PP sheet and PVC?

PP is polypropylene plastic, English Polypropylene

Specific gravity: 0.9-0.91 g/cubic centimeter Molding shrinkage: 1.0-2.5% Molding temperature: 160-220℃

It has low density, strength and stiffness, and can be used at around 100 degrees. It has good electrical properties and high-frequency insulation and is not affected by humidity, but it becomes brittle at low temperatures, is not resistant to molds and is prone to aging. It is suitable for making general mechanical parts. Corrosion-resistant parts and insulating parts

Molding properties 1. Crystalline material has low hygroscopicity, is prone to melt rupture, and is prone to decomposition in long-term contact with hot metal.

2. Good fluidity , but the shrinkage range and shrinkage value are large, and shrinkage cavities, dents, and deformations are prone to occur.

3. The cooling rate is fast, the pouring system and cooling system should dissipate heat slowly, and attention should be paid to controlling the molding temperature. The material temperature is low The directionality is obvious. It is especially obvious at low temperature and high pressure. When the mold temperature is lower than 50 degrees, the plastic parts are not smooth and are prone to poor welding and leaving marks. Warping deformation is easy to occur above 90 degrees.

4. Plastics The wall thickness must be uniform to avoid lack of glue and sharp corners to prevent stress concentration.

PVC, polyvinyl chloride, English Poly (Vinyl Chloride)

Specific gravity: 1.38 g/cubic centimeter Molding shrinkage: 0.6-1.5% Molding temperature: 160-190℃

Mechanical properties, excellent electrical properties, strong acid and alkali resistance, good chemical stability, but low softening point. Suitable for making thin plates , wire and cable insulation layer, seals, etc.

Molding performance 1. Amorphous material, small moisture absorption, poor fluidity. In order to improve fluidity and prevent bubbles, the plastic can be pre-dried. The mold pouring system should be rough Short, the gate cross-section should be large, and there should be no dead ends. The mold must be cooled and the surface should be chromium-plated.

2. It is extremely easy to decompose, and is more likely to decompose when in contact with steel and copper at a temperature of 200 degrees. Corrosion will escape during decomposition. . Irritating gas. Small molding temperature range.

3. When using a screw injection machine nozzle, the hole diameter should be large to prevent dead corners from stagnating material. It is best not to use inserts. If there are inserts, they should be preheated< /p>