Thermoforming Polymers

Thermoforming Polymers

• Can be heated and shaped repeatedly
• Are recyclable

Types of Thermoforming Polymers

Acrylic

• Hard with good plasticity when heated
• Used for car headlights, protective visors, and baths

Polypropylene (PP)

• Lightweight, strong, and tough
• Applications include computer game cases, patio chairs, children’s toys, and food wrapping film

Polyvinyl Chloride (PVC)

• Low-cost polymer with flexibility
• Used for window and door frames, guttering, and building cladding

High-Density Polythene (HDPE)

• Stiff and lightweight with excellent chemical resistance
• Ideal for buckets, bottles, pipes, and washing up bowls

Polystyrene (PS)

• Inexpensive sheet or foamed polymer
• Used in schools for vacuum forming

Thermosetting Polymers

• Formed once and cannot be recycled

Examples and Applications of Thermosetting Polymers

Melamine Formaldehyde

• Excellent resistance to heat, moisture, scratching, and staining
• Used for kitchen worktops and tableware

Epoxy Resin

• Consists of resin and hardener, creating a strong adhesive
• Used for various applications with good chemical and heat resistance

Urea Formaldehyde

• Hard, stiff polymer with excellent electrical insulation
• Suitable for switches, plugs, and electrical fittings

Polyester Resin

• Formed with a reaction of acids and alcohol
• Commonly used in sheet molding compound and toner of laser printers

Sources of Polymers

• Can be made from natural and synthetic resources
• Synthetic polymers are made from crude oil
• Natural polymers are made from materials like silk, wool, cellulose, and proteins

Properties of Polymers

• Selection depends on factors like cost, resistance to corrosion, strength, conductivity, elasticity, stiffness, or malleability

Finishing of Polymers

• Some polymers formed in a mold are self-finishing
• Cut edges may need finishing
• Additional finishes include paint spraying, rubberizing sprays, heat transfer printing, decals, detailing, vinyl cut graphics, flocking, and laser etching

Availability of Polymers

• Available in various forms such as pellets, granules, foams, films, filaments, sheets, rods, and bars

Differences between Thermoforming and Thermosetting Polymers

• Thermosetting polymers strengthen when heated and cannot be remoulded
• Thermoplastics can be reheated and remoulded without a chemical change