PP Plastic Plates Bowls edible material properties analysis
PP is a semi-crystalline materials.
(1) Physical properties: Polypropylene is non-toxic, odorless, tasteless milky white highly crystalline polymers, density of only 0.90 ~ .091g / cm3, it is one of the lightest of all the plastic variety. It particularly stable water, water absorption in water 24h of only 0.01%, from about 8 to 150,000 molecular weight. Moldability is good, but the shrinkage, thick-walled products easy to depression. Product surface gloss, easy coloring;
(2) The mechanical properties: high crystallinity polypropylene, regular structure, which has excellent mechanical properties, its strength and hardness, elasticity than HDPE, but at room temperature and low temperature, since regular molecular structure itself is high, so the impact strength is poor, when the molecular weight increases, impact strength also increases, but the molding processability is deteriorated. The most outstanding performance PP is bending fatigue resistance, as with a living hinge integrally PP injection, can withstand 7 × 107 times opening and closing folding bending without signs of damage, dry friction coefficient and nylon are similar, but in oil lubrication, as nylon;
(3) Thermal properties: PP has good heat resistance, melting point 164 ~ 170 ℃, articles can be sterilized at a temperature above 100 ℃, without outside in, 150 ℃ not deformed. Brittle transition temperature of -35 ℃, below -35 ℃ embrittlement occurs, cold resistance than polyethylene;
(4) Chemical stability: Chemical stability of polypropylene well, in addition to be concentrated sulfuric acid, concentrated nitric acid erosion in addition, a variety of other chemical reagents are relatively stable, but low molecular weight aliphatic hydrocarbons, aromatic hydrocarbons and chlorinated hydrocarbons to make PP soften and swell, while its chemical stability also improved with increasing degree of crystallinity, so suitable for the production of polypropylene pipes and fittings of various chemical, anti-corrosion effect is good;
(5) Electrical performance: excellent high-frequency insulation properties of polypropylene, because it almost does not absorb water, so the insulation performance is not affected by humidity. It has a high dielectric constant with increasing temperature, the heat can be used to produce electrical insulation products, it is also high breakdown voltage, suitable for electrical accessories. Anti-voltage arc resistance, static high copper contacts easy to aging;
(6) Weather resistance: Polypropylene UV-sensitive, adding zinc oxide, dilauryl thiodipropionate, carbon black or similar creamy white fillers to improve its anti-aging properties.
Edible food grade PP plastic bowls plastic What kind?
China currently allows for the production of food contact utensils, food containers, tools, equipment, plastic packaging materials, there are four main categories: polyethylene, polypropylene, polystyrene, and melamine. Although the use of PVC allows the production of food containers and purity monomer limit, but must meet the provisions of qualified materials to produce, prohibit the use of separately.
Edible food grade PP plastic bowls common plastics pp main properties are as follows
1. Good heat resistance, a melting point of 164-170 degrees, the water can be boiled and steam sterilization, but also long-term use is not deformed at a temperature of 100 degrees.
2. General Plastics pp surface gloss transparency, good mechanical strength, odorless, tasteless, non-toxic, in line with national health standards.
3. Excellent corrosion resistance, oxidation resistance slightly worse than polyethylene.
4. Low prices, wide range of applications.
5. Good resistance to bending fatigue performance, at 0 degrees can be bent back and forth more than one million times without damage.