Plastic
Plastics – An Overview
- Plastics are a broad group of synthetic materials made from polymers that show a wide variety of properties.
- They are commonly derived from petroleum or natural gas but can also be manufactured from renewable resources such as corn or sugarcane.
- Plastics can be thermoplastic and thermosetting in nature; thermoplastics can be heated and reshaped multiple times, whereas thermosets retain their shape once formed and cannot be remoulded.
Properties of Plastics
- Plastics are generally lightweight, yet possess good strength and durability.
- They are resistant to moisture, chemicals and UV radiation while being electrical and thermal insulators.
- Depending on the type, plastics can show high levels of transparency or opacity.
- Plastics can be engineered to have varying levels of flexibility, from rigid plastics like PVC to flexible ones like polyethylene.
Design Applications of Plastics
- Plastics are used in an expansive range of design applications due to their versatile properties.
- They offer great advantages in terms of mouldability and complex shapes can be achieved with relative ease using injection moulding and other methods.
- Certain plastics are food-safe, which makes them suitable for packaging and kitchenware.
- Their light weight and strength make plastics apt for use in repeat load structures such as chairs.
Working With Plastics
- Techniques for working with plastics include injection moulding, extrusion, and vacuum forming.
- Finishing techniques include painting, polishing and the application of adhesives.
- Safety aspects to consider when working with plastics include potential harmful fumes during processing.
Environmental Impact of Plastics
- Most plastics are non-biodegradable and can contribute to environmental problems when not disposed of properly.
- Some plastics can be recycled, but the process is complex and not always economically viable.
- The production of plastics can be energy intensive and contributes to greenhouse gas emissions.
- Sustainability is an increasingly significant factor when considering use of plastics, taking into account the full lifecycle of the product from manufacture to disposal.