Thermoplastics are one of the most common materials in the modern world, having replaced metal in everything from packaging to safety equipment. A thermoplastic is defined as a polymer that can be heated, moulded and welded together. It can also then be remelted and formed into another shape without weakening the material. These properties make thermoplastics an incredibly useful material.
Polythene is one of the most common plastics encountered everyday. It is used mainly for packaging in everything from cosmetic bottles to plastic shopping bags. As it is easily moulded and colorized it is also a very popular material for making children's toys.
Polyvinyl chloride is resistant to fire and water and so is commonly used for raincoats, indoor plumbing and vinyl floors. It remains fire proof as the compound still contains chlorine. Although the majority of PVC is the wet-look flexible material, it can also be turned into hard sheets which can be used as unbreakable protective barriers.
Polystyrene comes in two main forms, the expanded version, used for protecting products in boxes, and the compounded version, used for moulded parts such as pens and radio dials. It is used to make both the white foam cups for hot drinks and the clear plastic variety for cold drinks.
Polyester is a manufactured fibre rather than an actual plastic. On its own it is not very useful, but as it comes in this fibrous form it can be woven into materials and still retain its plastic properties. This means the material it is woven into become very strong while still flexible. Polyester does not take to colouring very well so it must always be combined with another material to make it into clothing.
Nylon is arguably the most famous of the thermoplastics and revolutionised the clothing industry after its discovery in 1939. It comes in a similar fibre form to polyester, but unlike polyester is was easier to make cloth out of. This was because the cloth could be easily dyed, washed and was still very hard wearing. Clothing is actually made from nylon, whereas polyester is added to improve the material.
Acrylic is an impact and heat resistance thermoplastic used most commonly for plastic household fittings where it is likely to come into contact with heat, for example the dials on an oven or the casing of a toaster. Its other advantage in this area is when it does burn it does not release harmful smoke or gases like some other plastics. Its uses are limited due to poor resistance to solvents.