PP physical properties
Polypropylene is a non-toxic, odorless, tasteless, milky white high crystalline polymer with a density of only 0.90--"0. 91g/cm3, which is one of the lightest varieties of all plastics. It is particularly stable to water. The water absorption in water is only 0.01%, the molecular weight is about 811,000. The moldability is good, but the shrinkage rate is large (1%~2.5%). The thick-walled products are easy to be sunken, and some dimensional precision is high. Parts, it is difficult to meet the requirements, the surface of the product is shiny and easy to color.
PP characteristics
Non-toxic, odorless, low density, strength, stiffness, hardness and heat resistance are better than low-pressure polyethylene, can be used at around 100 °C. It has good electrical properties and high-frequency insulation and is not affected by humidity, but becomes brittle at low temperature, not wear-resistant and easy to age. Suitable for making general mechanical parts, corrosion resistant parts and insulating parts. Common organic solvents such as acids and bases have little effect on it and can be used in food utensils.
Polypropylene has many excellent properties:
1. The relative density is small, only 0.89-0.91, which is one of the lightest varieties in plastics.
2, good mechanical properties, in addition to impact resistance, other mechanical properties are better than polyethylene, molding processing performance is good.
3. It has high heat resistance and the continuous use temperature can reach 110-120 °C.
4, good chemical properties, almost no water absorption, and does not react with most chemicals.
5, the texture is pure, non-toxic.
6, electrical insulation is good.
7. The transparency of polypropylene products is better than that of high density polyethylene products.
PP has many advantages but also has disadvantages:
1. The product has poor cold resistance and low temperature impact strength.
2. The product is susceptible to aging by the action of light, heat and oxygen during use.
3. Poor coloring.
4, easy to burn.
5, poor toughness, high static, poor dyeability, printability and adhesion
