Follow the part mentioned last time. What I share with you today is: the basic characteristics and uses of the main plastic varieties.
1. Polyethylene–Polyethylene has good flexibility, excellent dielectric properties and chemical resistance, molding processability, but poor rigidity.
Its use is generally in chemical corrosion-resistant materials and products, small load gears, bearings, etc., wire and cable sheathing and daily necessities.
2. Polypropylene–Polypropylene has excellent corrosion resistance, mechanical properties and rigidity exceeding polyethylene, fatigue resistance and stress crack resistance, but the shrinkage rate is large, and the low temperature brittleness is large.

It is generally used in medical appliances, household kitchen supplies, home appliance parts, chemical corrosion-resistant parts, medium and small containers and equipment. For example, our plastic spoons and plastic funnels are made of food grade PP materials.
3. Polyvinyl chloride-excellent chemical resistance and electrical insulator performance, good mechanical properties, flammability, but poor heat resistance, easy to degrade when the temperature rises.
Its general use is in hard and soft pipes, plates, profiles, films, etc., and wire and cable insulation products.
4. Polystyrene-Polystyrene resin is transparent, has certain mechanical strength, good electrical insulation performance, radiation resistance, good molding processability, but it is brittle, poor impact resistance and heat resistance.
Its general use is in non-impact transparent instruments, instrument shells, covers, daily necessities such as bottles, toothbrush handles, etc.
5. Acetonitrile-butadiene-styrene copolymer (ABS)-ABS has excellent mechanical properties of toughness, hardness and rigid phase balance, electrical insulation properties, chemical resistance, good dimensional stability, and good surface gloss , Easy to paint and color, but not strong heat resistance, poor weather resistance.
Its uses are generally automobiles, electrical instruments, mechanical structural parts (such as gears, blades, handles, dashboards), our speaker shell uses ABS material.
6. Acrylic resin–Acrylic resin has good light transmittance, excellent weather resistance, good plasticity and dimensional stability, but low surface hardness.
Its general purpose is in optical instruments, requiring transparent and certain strength parts (such as gears, blades, handles, dashboards, etc.)
7. Polyamide–Polyamide has excellent mechanical properties, good impact toughness, excellent wear resistance and natural lubricity, but it is easy to absorb water and has poor dimensional stability.
It and other general purpose wear-resistant and stressed parts in machinery, instrumentation, automobiles, etc.

See you next time.