Polypropylene (PolyPropylene, PP for short) is a semi-crystalline thermoplastic. It has high impact resistance, strong and tough mechanical properties, and is resistant to various organic solvents and acid and alkali corrosion. It has a wide range of applications in the industry and is one of the common polymer materials. The molecular structure of polypropylene is a typical main body regular structure, which is a crystalline polymer with a molecular weight of 10 to 500,000. Specific gravity: 0.9 to 0.91 g/cm3 Molding shrinkage: 1.0 to 2.5% Molding temperature: 160 to 220oC Use around 100 degrees. 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. Forming characteristics: 1. Crystalline material, low hygroscopicity, easy to melt and rupture, and easy to decompose after long-term contact with hot metal. 2 . The fluidity is good, but the shrinkage range and shrinkage value are large, and shrinkage holes are prone to occur. Dent, deformation. 3. The cooling speed is fast, the pouring system and cooling system should slowly dissipate heat, and pay attention to control the molding temperature. The material temperature is easy to orient at low temperature and high pressure. When the mold temperature is lower than 50 degrees, the plastic parts are not smooth, and it is easy to produce poor welding, flow marks, and warping deformation above 90 degrees. The thickness of the plastic wall must be uniform to avoid lack of glue and sharp corners to prevent stress concentration.
Polypropylene (PP) foaming material has good heat insulation, cushioning, flotation and high cost performance, so it is widely used in the field of application. In the current process, chemical foaming agents are used to prepare foaming functional masterbatches, and then pass Polypropylene (PP) sheets are prepared from foamed functional masterbatches, but the chemical foaming agent has problems such as suddenness, large cells, and stress concentration; therefore, the prepared foamed functional non-particles have poor compatibility and dispersion with PP. Poor performance, resulting in the problems of stress concentration and poor mechanical properties of the prepared PP sheet. Although the existing technology can modify polypropylene, it is necessary to add AC, cross-linking agent, etc. in the process of preparing functional masterbatches , the preparation process of the polypropylene foam sheet is complicated, and the AC and the cross-linking agent are not environmentally friendly, difficult to recycle and cannot meet the existing production capacity.
Application of polypropylene in environmental protection equipment
Polypropylene is widely used and can be processed into polypropylene sheets, PP air ducts, PP dampers, polypropylene anti-corrosion water tanks, PP wet scrubbers, polypropylene blowers, and polypropylene PP ventilation duct systems.
