Thermoplastics and thermosetting polymers are types of plastic that undergo different production processes and yield a variety of properties depending on the constituent materials and production method.
The main physical difference is how they respond to high temperatures. When heated to their melting point, thermoplastics soften into a liquid form. Therefore, the curing process is reversible, which means that they can be remoulded and recycled. On the other hand, thermoset polymers form a cross-linked structure during the curing process, preventing them from being melted and remolded.
Think of Thermosets like concrete, once they have set you can never go back to the liquid form (irreversible process). While Thermoplastics are like water, they can transition between ice and water with the application or removal of heat (reversible process).
Thermoplastics generally provide high-strength, flexibility and are resistant to shrinkage, depending on the type of resin (the polymer in melted liquid form). They are versatile materials that can be used for anything from plastic carrier bags to high-stress bearings and precision mechanical parts.
Thermosetting polymers generally yield higher chemical and heat resistance, as well as a stronger structure that does not deform easily.
Weak molecular bonds in a straight-chain formation
Strong chemical molecular bonds that are cross-linked
Melting point lower than the degradation temperature
Melting point higher than the degradation temperature
Flexible and elastic. High resistance to impact (10x thermosets)
Inelastic and brittle.
Strong and rigid
Repolymerized during manufacture (before processing)
Polymerized during processing
Comprised of hard crystalline and elastic amorphous regions in its solid state
Comprised of thermosetting resin and reinforcing fibre in its solid state
Recyclable and reusable
Highly chemical resistant
Heat and chemical resistant
Cracks can be repaired easily
Difficult to repair cracks
Thermoplastics can be processed in a variety of methods including extrusion moulding, injection moulding, thermoforming and vacuum forming.
Granular material is fed into the mould, usually in the form of spherical granules of approximately 3 mm diameter. These granules are then heated to melting point, which requires very high temperatures.
As thermoplastics are highly efficient thermal insulators, cooling during the curing process takes longer than other plastics. Therefore, rapid cooling is undertaken to achieve a high output rate, usually by spraying with cold water or plunging into water baths. To cool thermosplastic plastic films, cold air is blown onto the surface. The plastic shrinks upon cooling, varying between a shrinkage rate of 0.6% to 4% depending on the material. The rate of cooling and shrinkage has a distinct effect on the crystallisation of the material and internal structure, which is why the shrinkage rate is always specified for thermoplastics.
Thermosetting resins are processed in their liquid form under heat. The curing process involves adding curing agents, inhibitors, hardeners or plasticisers to the resin and reinforcement or fillers, depending on the required outcome.
The most commonly used thermosetting resins include:
Thermosetting polymer composites are made using a laminating process, which binds together resins such as epoxy, silicone, melamine, etc. with reinforcement base materials such as glass, linen and graphite.
Prior to curing, the reinforcement substrate is dipped into the resin binder in its liquified form. Once bound, the sheets of material are passed through an oven to partially cure them. Several sheets are then piled to the required thickness, heated and pressed together to form a laminate. Alternatively, the sheets may be wrapped together and heated to create rods.
Polyamide (nylon) – Tough and relatively hard material used for power tool casings , curtain rails, bearings, gear components and clothes.
Polymethyl Methacrylate (PMMA, acrylic) – Stiff, durable and hard plastic that polishes to a sheen, used for signage, aircraft fuselage, windows, bathroom sinks and bathtubs.
Polyvinyl Chloride (PVC) – Tough and durable material that is commonly used for pipes, flooring, cabinets, toys and general household and industrial fittings.
Polypropylene – Light, yet hard material that scratches fairly easily, with excellent chemical resistance, used for medical and laboratory equipment, string, rope and kitchen utensils.
Polystyrene (PS) – Light, stiff, hard, brittle, waterproof material used mainly for rigid packaging.
Polytetrafluoroethylene (PTFE, Teflon) – Very strong and flexible material used for non-stick cooking utensils, machine components, gears and gaskets.
Low-density Polythene (LDPE) – Tough, relatively soft, chemical resistant material used for packaging, toys, plastic bags and film wrap.
High-density Polythene (HDPE) – Stiff, hard, chemical resistant material used for plastic bottles and casing for household goods.
Epoxy resin – Hard material that is brittle without extra reinforcement. Used for adhesives and bonding of materials.
Melamine formaldehyde – Hard, stiff and strong, with decent chemical and water resistance, used for work surface laminates, tableware and electrical insulation.
Polyester resin – Hard, stiff and brittle when unlaminated. Used for encapsulation, bonding and casting.
Urea formaldehyde – Hard, stiff, strong and brittle used primarily in electrical devices due to its good electrical insulation properties.
Polyurethane – Hard, strong and durable material used in paint, insulating foam, shoes, car parts, adhesives and sealants.
Phenol formaldehyde resin (PF) – Strong, heat and electrical-resistant material used in electrical items, sockets and plugs, car parts, cookware and precision-made industrial parts.
Types of thermoplastics:
Types of thermosetting polymers:
Hazy Biaxially Oriented Polyester Film 250µm (ES301232)
Polyamide Nylon 6
Epoxy Resin TO200
Epoxy Resin T20-60
Epoxy Resin TK123
General Polyethylene, low density (PE-LD)
General Polyethylene, high density (PE-HD)
General Polystyrene (PS)
General Polyvinyl chloride, plasticized (PVC-P)
General Polytetrafluoroethylene (PTFE)
General Polymethyl methacrylate (PMMA)
General Phenol-formaldehyde (PF+WD35+MD15), Type 31
General Polyurethane, rigid foams (PUR-R)
LGBA BOPP (Biaxially Oriented Polypropylene) Label Film
HGFL BOPP (Biaxially Oriented Polypropylene) Transparent Film
Polystyrene (PS) for Extrusion
High Density Polyethylene (HD PE) for Injection Molding
Plastics & Rubber Insulation
Equipment For Chemical Industry
Environment Health Safety
Resins For Composite Materials
Gas & Steam Turbines
Sports Equipment & Facilities
Cans & Tins
Containers & Tanks
Thermal Insulation Of Buildings
Wires & Cables
Cookware, Cutlery & Flatware
Optical Storage Devices
Optics & Imaging
Road Vehicle Systems
Car Interior Components
Agricultural Machines & Equipment
Plant Care Equipment
Lamps & Related Equipment
Lamp Caps & Holders
Miscellaneous Domestic & Commercial Equipment