plastic hollow  ball,PP Ball

English name: Polypropylene
:0.9-Weight 0.91 grams / cubic centimeter molding shrinkage rate 1.0-2.5% molding temperature :160-220 drying conditions: ---
Polypropylene is the second after the development of nylon resins another fine varieties, it is a high-density, non-side-chain, high-crystalline Bi-linear polymer, with excellent comprehensive performance. When not colored translucent white, waxy; light than polyethylene. Transparent than polyethylene, and rigid than polyethylene. Material properties of density, strength stiffness, hardness heat resistance are superior to low-pressure polyethylene, can be used at 100 degrees Celsius. Has a good performance and high-frequency electric insulation from humidity, but brittle low temperature, impatience mode Easy aging. suitable for the production of general machinery parts, corrosion-resistant parts and insulating parts
Forming properties 

 1. Crystalline material, hygroscopicity small, easy to melt rupture happened, long-term contact with hot metal easy decomposition.
2. Mobility, but the scope of contraction and shrinkage of values, and prone to shrinkage. Dents, deformation.
3. Cooling speed, gating system and cooling system should be slow heat, and attention to control of molding temperature. Expected direction directional low temperature significantly. Hypothermia is particularly evident when high-pressure, mold temperature is below 50 degrees, the plastic parts is not smooth, easy have a bad weld, leaving marks, 90 degrees above the prone Warpage
4. Plastic wall thickness shall be uniform to avoid the lack of glue, corner to prevent stress concentration.