plastics

What are the general advantages and disadvantages of plastics?

Advantages:

• ductile

• Low cost

• Lightweight

• Easily moulded

• High strength-to-weight ratio

• Resistant to corrosion, chemicals

• Electrical and thermal insulators

• Can be coloured or transparent

Disadvantages:

• non-biodegradable → environmental issues

• Difficult and costly to recycle

• Some may release toxins or microplastics

Key properties and uses of polyethylene (PE, HDPE, LDPE, PET)

• versatile, high chemical and water resistance, ductile, impact resistant, recyclable

• Low heat resistance, can deform under load

• Plastic containers and bottles

• Water and gas pipes

• Cable insulation

Key properties and uses of Polypropylene (PP)

• corrosion and chemical resistant, waterproof, good electrical insulator, high tensile strength, malleable, lightweight

• Weak under UV and heat, poor bonding, flammable

• Laboratory equipment

• Electronics products

• Automobile products

Key properties and uses of ABS

• strong, rigid, tough, and impact-resistant, easily moulded

• UV sensitive,

• Automotive body parts

• Household electronics and electrical appliances

• Business equipment

• Hard hats, wall sockets

Key properties and uses of polylactic acid (PLA)

• biodegradable (made from cornstarch), eco-friendly, high tensile strength and ductility

• Slow to degrade in nature, expensive, low melting point, not water resistant

• Automobile interiors

• Medical implants (screws, plates, rods, mesh)

• 3D printing

Key properties and uses of PVC

• rigid or flexible, chemically resistant, long lifespan, low cost

• May release harmful plasticizers, brittle in cold

• Automobile parts

• Electronics and electrical equipment

• Water/waste drainage pipes

• Furniture

What are the key properties and uses of nylon?

• very high wear and abrasion resistance, high tensile and compressive strength, self-lubricating, durable

• Absorbs moisture (hygroscopic), poor UV resistance, melts easily

• Gears

• Rollers and guides

• Bearings

• Wear pads

How do plastics compare overall to metals in engineering?

• lower density → lighter components

• Corrosion and chemical resistance → good for electrical applications

• Less strength and stiffness → not suited for heavy structural loads

• Easier to mould → ideal for mass-produced consumer and automotive parts