Plastic Cutting page

P J Bowers Pty Ltd

The Foam Factory

Plastic Cutting & Shaping

Plastics

There are many different types of plastics used for a wide range of purposes. Plastics can be moulded into almost any shape with any number of characteristics.

Alexander Parkes first invented plastics in 1860, however mass production has only occurred in the past few decades. Plastics production world wide now exceeds 80 million tonnes a year. In Australia, plastics production is about one million tonnes a year.

The sources of plastics today are mainly crude oil, gas or coal. According to the Plastics and Chemicals Industries Association, Much of the raw material for plastics comes from waste in petroleum refining - some of which would otherwise be flared off and wasted.

Types of Plastic

Plastics are polymers, that is long chain molecules, made from smaller molecules called monomers. The polymers are made in large vessels under special conditions of temperature and pressure, using catalysts. At this stage, the polymers are in the form of resin pellets or powders.

Plastic products are made in three stages:

The resin pellets or powders are heated to soften them;
The softened material is formed into a certain shape; and
The product is cooled, retaining the shape.

To help identify different plastics, manufacturers stamp a Plastics Identification Code on their products. This code is a number inside a triangle with chasing arrows. These codes are only to identify the product. They do not indicate that the product can be recycled.

Some uses for plastics and recycled plastics in Australia.

Plastic Identification Code	Name of plastic	Description	Some uses for virgin plastic	Some uses for plastic made from recycled waste plastic
	polyethylene terephthalate PET	Clear tough plastic, may be used as a fibre.	Soft drink and mineral water bottles, filling for sleeping bags and pillows, textile fibres.	Soft drink bottles, detergent bottles, clear film for packaging, carpet fibres, fleecy jackets.
	High density Polyethylene HDPE	Very common plastic, usually white or coloured.	Crinkly shopping bags, freezer bags, milk and cream bottles, bottles for shampoo and cleaners, milk crates, plastic furniture	Compost bins, detergent bottles, crates, mobile rubbish bins, agricultural pipes, pallets, kerbside recycling crates.
	Unplasticised Polyvinyl chloride UPVC	Hard rigid plastic, may be clear.	Clear cordial and juice bottles, blister packs, plumbing pipes and fittings.	Detergent bottles, tiles, plumbing pipe fittings.
	Plasticised polyvinyl chloride PPVC	Flexible, clear, elastic plastic.	Garden hose, shoe soles, blood bags and tubing.	Hose inner core, industrial flooring.
	Low density Polyethylene LDPE	Soft, flexible plastic.	Lids of icecream containers, garbage bags, garbage bins, black plastic sheet.	Film for builders, industry, packaging and plant nurseries, bags.
	Polypropylene PP	Hard, but flexible plastic - many uses.	Icecream containers, potato crisp bags, drinking straws, hinged lunch boxes.	Compost bins, kerbside recycling crates, worm factories.
	Polystyrene PS	Rigid, brittle plastic. May be clear,glassy.	Yoghurt containers, plastic cutlery, imitation crystal “glassware”.	Clothes pegs, coat hangers, office accessories, spools, rulers, video/CD boxes.
	Expanded polystyrene EPS	Foamed, lightweight, energy absorbing, thermal insulation	Hot drink cups, takeaway food containers, meat trays, packaging.
	Other	Includes all other plastics, including acrylic and nylon.