TPR has the following advantages: (1) It can be processed by general thermoplastic molding machines, such as injection molding, extrusion molding, blow molding, compression molding, and mold transfer molding; (2) It can be vulcanized with rubber injection molding machine, and the time can be shortened from about 20min to less than 1min; (3) It can be molded and vulcanized by a press, with fast pressing speed and short vulcanization time; (4) The wastes generated in the production process (escaping burrs and extruding waste rubber) and the final waste products can be directly returned for reuse: (5) The used TPR old products can be simply recycled and reused to reduce environmental pollution and expand the source of resource regeneration; (6) No vulcanization is required to save energy. Take the energy consumption of high-pressure hose production as an example: 188MJ/kg for rubber and 144MJ/kg for TPR, which can save more than 25% of energy; (7) The self reinforcement is great, and the formula is greatly simplified, so that the influence of the compounding agent on the polymer is greatly reduced, and the quality performance is easier to master; (8) It opens up new ways for the rubber industry and expands the application field of rubber products. The disadvantage is that the heat resistance of TPR is not as good as that of rubber, and the physical property decreases greatly with the increase of temperature, so the scope of application is limited. At the same time, the compression deformation, resilience and durability are inferior to that of rubber, and the price is often higher than that of similar rubber. However, in general, the advantages of TPR are still outstanding, while the disadvantages are constantly improving. As a new type of energy-saving and environment-friendly rubber raw material, TPR has a promising development prospect.
Polyurethane (PU), the full name is polyurethane, is a polymer compound. It was made by Otto Bayer in 1937.Polyurethane is divided into two categories: polyester type and polyether type. They can be made into polyurethane plastics (mainly foamed plastics), polyurethane fibers (called spandex in China), polyurethane rubbers and elastomers.
Soft polyurethane is mainly a thermoplastic linear structure, which has better stability, chemical resistance, resilience and mechanical properties than PVC foam materials, and has less compression deformation. It has good thermal insulation, sound insulation, shock resistance and anti-virus performance. Therefore, it is used as packaging, sound insulation, filter material.
Rigid polyurethane plastic is light in weight, excellent in sound insulation and thermal insulation, chemical resistance, good electrical properties, easy processing, and low water absorption. It is mainly used in construction, automobile, aviation industry, thermal insulation structural materials.
The performance of polyurethane elastomer is between plastic and rubber, oil resistance, wear resistance, low temperature resistance, aging resistance, high hardness and elasticity. Mainly used in shoe industry and medical industry. Polyurethane can also be used to make adhesives, coatings, synthetic leather, etc.
Polyurethane appeared in the 1930s. After nearly 80 years of technological development, this material has been widely used in the field of home furnishing, construction, daily necessities, transportation, and home appliances.
Advantages: Rigid PVC is one of the most widely used plastic materials. PVC material is a kind of non crystalline material.
In actual use, PVC materials are often added with stabilizers, lubricants, auxiliary processing agents, pigments, impact agents and other additives.
PVC material has non flammability, high strength, weather resistance and excellent geometric stability.
PVC has strong resistance to oxidants, reducing agents and strong acids. However, it can be corroded by concentrated oxidizing acids, such as concentrated sulfuric acid and concentrated nitric acid, and is not suitable for contacting aromatic hydrocarbons and chlorinated hydrocarbons.
Disadvantages: The flow characteristics of PVC are quite poor, and its process range is very narrow. In particular, PVC materials with large molecular weight are more difficult to process (such materials usually need to add lubricant to improve flow characteristics), so PVC materials with small molecular weight are usually used.
The shrinkage of PVC is quite low, generally 0, 2 — 0, 6%.
PVC is easy to release toxic gas in the molding process.
Nylon Advantage:
1. High mechanical strength, good toughness, high tensile and compressive strength. The specific tensile strength is higher than that of metal, and the specific compressive strength is comparable to that of metal, but its rigidity is less than that of metal. The tensile strength is close to the yield strength, more than twice as high as ABS. The absorption capacity of impact and stress vibration is strong, and the impact strength is much higher than that of ordinary plastics, and better than that of acetal resin.
2. The fatigue resistance is outstanding, and the parts can still maintain the original mechanical strength after repeated bending. PA is often used in situations where the periodic fatigue effect of common escalator handrails and new plastic bicycle rims is extremely obvious.
3. High softening point and heat resistance (such as nylon 46, high crystalline nylon has a high thermal deformation temperature, which can be used for a long time under 150 ℃. After glass fiber reinforcement, PA66 has a thermal deformation temperature of more than 250 ℃).
4. Smooth surface, small friction coefficient, wear-resistant. It is self-lubricating and has low noise when it is used as a movable mechanical component. It can be used without lubricant when the friction effect is not too high; If lubricant is really needed to reduce friction or help heat dissipation, water, oil, grease, etc. can be selected. Therefore, as a transmission component, it has a long service life.
5. It is resistant to corrosion, alkali and most salt liquids, weak acid, engine oil, gasoline, aromatic hydrocarbon compounds and general solvents, inert to aromatic compounds, but not resistant to strong acids and oxidants. It can resist the erosion of gasoline, oil, fat, alcohol, weak alkali, etc. and has good anti-aging ability. It can be used as packing material for lubricating oil, fuel, etc.
Disadvantages:
1. Poor water absorption and dimensional stability.
2. Poor resistance to low temperature.
3. The antistatic property is poor.
4. Poor heat resistance.
Post time: Feb-04-2023