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 indite that the product can be recycled.

Download Plastics Spec Sheet (83kb - Adobe Acrobat file)