PPS General - purpose polystyrene is a thermoplastic resin that is a colorless, odorless, tasteless, glossy, transparent bead?or?granular solid. The density is 1.04 to 1.09, the transparency is 88% to 92%, and the refractive index is 1.59 to 1.60. Under the stress action, the birefringence is produced, that is, the so-called stress optical effect. The melting temperature of the product is 150~180 C, the thermal decomposition temperature is 300, the thermal deformation temperature is 70~100, and the long-term use temperature is 60~80. At the lower temperature of 5~6, the stress can be eliminated and the thermal deformation temperature can be improved. If a little alpha methylstyrene is added to the production process, the heat-resistant grade of the general polystyrene can be improved. It can be dissolved in aromatic hydrocarbons, chlorinated hydrocarbons, aliphatic ketones and esters, but it can only swelling in acetone. Resistant to certain mineral oil, organic acid, alkali, salt, lower alcohol and water solution. The water absorption rate is low, and its mechanical properties and dimensional stability can still be maintained in the wet environment. The optical properties are second only to acrylic resin. The electrical properties are excellent, both the volume resistivity and the surface resistivity are very high, and are not affected by the changes of temperature and humidity, and are not affected by corona discharge. The radiation resistance is also good. Its main shortcomings are brittle, brittle, low impact strength, poor heat resistance, and can not resist boiling water. It can only be used under low temperature and low load. The resistance to sunlight is poor and flammable. Black smoke and special odor when burning. System of law General - purpose polystyrene is made of styrene as a monomer through free radical polymerization?or?ionic polymerization. The methods of production include bulk polymerization, solution polymerization, suspension polymerization and emulsion polymerization. The main methods used in industrial production are suspension polymerization and bulk polymerization. 1., the bulk polymerization method was used to feed styrene monomer into the prepolymerization kettle, then add a small amount of additives and initiators, and then heat up and stir at 95~115 degrees to prepolymerized. After the conversion rate reached 20% ~ 35%, it was then sent into a tower reactor with stirrers for continuous polymerization. The polymerization temperature is raised to about 170 degrees C, so as to achieve complete conversion. A small amount of unreacted styrene is released from the top of the tower and can be reused. The polymer is discharged from the bottom of the tower continuously, and the finished product is obtained by the extrusion granulation. The process is as follows. 2. suspension polymerization with styrene as monomer, water as medium, with gelatin?or?starch, polyvinyl alcohol, hydroxyethyl cellulose protective glue?or?magnesium carbonate, magnesium silicate, calcium phosphate and other insoluble inorganic salt as dispersing agent, maleic anhydride styrene copolymer two sodium help dispersing agent, benzoyl peroxide as the initiator that was initiated polymerization at about 85 DEG C. It can also be polymerized at high temperature at high temperature above 100 C in high pressure polymerizer without initiator. The polymer has been washed, separated and dried to obtain a colourless and transparent bead like resin. Molding process PVC PVC protective wall panel is mainly used to replace the aluminum protection wall panel. In addition to a part of PVC resin, the rest components of PVC floor tiles are recycled materials, adhesives, fillers and other components. They are mainly applied to the hard ground of airport terminal buildings and other places. 8. PVC daily consumer goods Luggage is a traditional product made of PVC, PVC is used to make all kinds of imitation leather, used for luggage bags, sports products, such as basketball, football and rugby. It can also be used to make belts for uniforms and special protection equipment. Clothing with PVC fabric is adsorption fabric (without coating), such as a poncho, baby pants, leather jacket and boots. PVC is used in many sports and entertainment products, such as toys, records and sporting goods, PVC toys and sporting goods grow a lot, because of its low production cost and easy forming. 9.PVC coating products The artificial leather with a substrate is applied to the cloth?or?paper with PVC paste, and then plasticized above 100 degrees C. It is also possible to extend the PVC and the auxiliaries to the film, and then combine with the substrate. No artificial leather substrate is soft sheet directly into a certain thickness by the calender, then press the pattern can be. Artificial leather can be used to make suitcases, leather bags, book covers, sofa and car cushions, as well as floor leathers, used as floor materials for buildings. 10.PVC foam products When the soft PVC is mixed, a suitable amount of foaming agent is added to make the sheet. After foaming, it is made into foam plastics, which can be used as foam slippers, sandals, insoles, and shockproof cushioning packaging materials. The extruder can also be used as a new type of building material, which can be used as a low foaming hard PVC plate and special-shaped material, which can be used instead of wood. 11.PVC transparent sheet PVC added shock modifier and organotin stabilizer, and became transparent sheets by mixing, plasticizing and calendering. The use of thermoforming can be made into thin wall transparent containers?or?vacuum plastic packaging. It is an excellent packaging material and decorative material. 12. other The doors and windows are made of hard and special-shaped materials. In some countries with wooden doors and windows aluminum doors and windows market share etc.; wood materials, building materials (steel, North Sea); hollow container. The virtual circuit is one of the services provided by the network packet switching (another datagram service), simply said, is through the internal control mechanism of the network, the establishment of virtual logical connection between the host and the user, ensure correct transmission packet with the sequence of communication, before and after establishment and removal of virtual circuit. The perpetual virtual circuit is a virtual circuit that is set up at the initialization of the network, and the virtual circuit is kept. Both the X.25 network and the B-ISDN provide PVC services. PVC bags are generally forbidden. Research on new materials EVA(4) toys. EVA resin also has more applications in toys, such as children's wheels, cushions and so on. (5) hot melt adhesive. Hot melt adhesive with EVA resin as the main component, because it does not contain solvents, no environmental pollution and high safety, is very suitable for automated production lines, so it is widely used in books, furniture, wireless binding of automobiles and home appliances assembly, footwear, carpet coating and metal anticorrosion coating. (6) others. EVA resin is also widely used in the fields of ink, bag, bottle cap and so on. It is estimated that the consumption of EVA resin in these areas is not less than 15 kt. Material description of part specification level of hot melt appearance and color The use of compound, extrusion, adhesive, sealant and wax Notes on heat stabilizers: antioxidants in BHT Processing conditions for processing conditions Technical data of raw materials Performance project test condition [state] test method test data unit Physical performance density ASTM D-792/ISO 11830.957 g/cm3 Melt flow rate 190/2.16kg ASTM D-1238/ISO 113343 g/10min VA content 32% Thermal performance melting point (DSC) ASTM D-3418/ISO 314663 (145) C (F) VEKA softening point ASTM D-1525/ISO 30636 (97) C (97) C (F) Physical property table