Chemical Name: Polypropylene, features: density, strength stiffness, hardness and heat resistance are superior to low-pressure polyethylene, can be used at 100 degrees. Has good electrical properties and high-frequency insulation from humidity, but the low temperature brittle, do not wear, easy to aging · suitable for production of general machinery parts, corrosion-resistant parts and insulating parts a drying process editor: If you store proper drying process is not required. Melting temperature: 220 ~ 275C, be careful not to exceed 275C. Mold temperature: 40 ~ 80C, recommended 50C. Degree of crystallinity determined by the mold temperature. Injection pressure: can be as large 1800bar. Injection speed: Typically, high-speed injection molding can make the internal pressure is reduced to a minimum. If the product surface defects, so you should use low-speed injection molding at higher temperatures. Runners and gates: For cold runner, the typical flow channel diameter range is 4 ~ 7mm. Recommend the use of whole body circular sprue and runner. All types of gates can be used. Typical gate diameter range is 1 ~ 1.5mm, but can also be used as small as 0.7mm gate. For the edge gate, the minimum gate depth should be half the wall thickness; smallest gate width should be at least twice the wall thickness. PP materials can use hot runner systems. Forming properties of crystalline materials, moisture absorption, prone to melt fracture, long-term contact with the hot metal decomposition. 2. Liquidity is good, but the contraction range and large shrinkage, shrinkage prone to dents, deformation. 3. Cooling speed, gating system and cooling system should be slow to heat, and pay attention to controlling the molding temperature low temperature and high pressure feed easy orientation, the mold temperature is below 50 degrees, the plastic is not smooth, easy to produce poor welding, flow marks, 90 degrees prone to warpage. 4. Plastic wall thickness shall be uniform to avoid the lack of rubber, sharp corners to prevent stress concentration. 2 Performance Editing physical properties of polypropylene is non-toxic, odorless, tasteless milky highly crystalline polymers, density of only 0. 90 -. "0 91g / rm, is one of the lightest of all plastic varieties of it. particularly stable in water, the water absorption in water is only 0. O1%, a molecular weight of about 8 in case of 150,000. moldability is good, but the shrinkage rate is high (1% to 2.5%). thick-walled products easy to depression, for Some high dimensional accuracy of the parts, but also difficult to meet the requirements, the product surface gloss, easy coloring. high crystallinity [4] mechanical properties of polypropylene, regular structure, which has excellent mechanical properties. absolute value of the mechanical properties of polypropylene high polyethylene, but still in the plastic material at a low species, its tensile strength reaches 30 MPa or only slightly higher level and other large isotactic index of polypropylene has a high tensile strength, but with like improve the regulatory index, the impact strength of the material decline, but then decreased to a certain value does not change temperature and loading rate on a great impact toughness of polypropylene. When the temperature is higher than the glass transition temperature, impact damage showed toughness fracture, below the glass transition temperature of brittle fracture and impact strength values ??fall significantly. improve the loading rate, can rise to the fracture toughness of brittle fracture transition temperature. Polypropylene has excellent resistance to bending fatigue resistance, and its products at room temperature 106 can be bent without damage. However, at room temperature and low temperature, due to the molecular structure of regular high itself, so poor impact strength properties of polypropylene is the most prominent anti-bending fatigue resistance, commonly known as the pleated plastic thermal performance Polypropylene has good heat resistance, the article can be sterilized at a temperature above 100 ℃, without being subject to external conditions, 150 ℃ are not deformed. brittle temperature of -35 ℃, will be lower than -35 ℃ embrittlement, cold resistance than polyethylene. For the reported value of polypropylene has a glass transition temperature 18qC, OqC, 5 ℃, etc. This is because people with different samples, which contained crystal phase and amorphous phase in different proportions, No molecular chain of the chain length due to different amorphous polypropylene melting temperature higher than about 40 to 50% polyethylene, about 164 a 170 ℃, 100% isotactic polypropylene having a melting point of 176 ℃. Chemical stability chemical stability of polypropylene well, except be concentrated *, concentrated nitric acid erosion, but for a variety of other chemical reagents are relatively stable; but the low molecular weight aliphatic hydrocarbons, aromatic hydrocarbons and chlorinated hydrocarbons such as polypropylene soften and make swelling, and it also improved chemical stability increases with the degree of crystallinity, so suitable for the production of various chemical polypropylene pipes and fittings, anti-corrosion effect is good. It has a higher electrical properties of the dielectric constant with temperature rise, can be used to produce heating of electrical insulation products. It is also very high breakdown voltage, suitable for electrical accessories. Anti-voltage arc resistance, static high contact with the copper and easy to aging. weathering poly Propylene is very sensitive to ultraviolet light, adding zinc oxide, thiodipropionate dilaurylthiodipropionate, carbon black or similar creamy white fillers such as to improve its anti-aging properties of the hydrophobic parameter calculation reference value (XlogP):. 3.32, the number of hydrogen bond donor : 03, the number of hydrogen bond acceptors: 34, rotatable bond number: 15, the number of tautomers: 6, topological molecular polar surface area (TPSA): 29.5 Avoid strong oxidizing agents, chlorine, potassium permanganate closed, cool dry place to ensure that there is good ventilation [1]. PP sheet / polypropylene / Gaelic German import / domestic / wear resistance, impact /