Expanded polystyrene (EPS) is made from a spherical "sugar-like" substance called expandable polystyrene.
There are three stages in the conversion process of expandable polystyrene into expanded polystyrene.
The first stage involves using steam to heat expandable polystyrene beads.
The steaming process causes the beads to expand to about 40 times their original size.
A blowing agent called pentane (a colourless flammable liquid used as a solvent) boils when heated by the steam and creates the closed cell honeycomb structure in the expanded beads.
The second stage involves leaving the the expanded polystyrene beads to cool and to stabilise for about 12 - 24 hours.
The third stage involves transferring the beads to a mould and reheating them. The beads expand a further 10% and fuse together to form a rigid moulding. The expanded polystyrene moulding consists of about 98% air and 2% polystyrene.
The structure of expanded polystyrene makes it very light, shock absorbent, compression resistant and a good thermal insulator. This makes it an ideal material for protective packaging, for personal safety equipment such as cycle helmets and as an insulating material in countless applications but especially in the building industry where it is used under concrete floors and on walls etc.
Learn about Plastics
We use animations and supporting technology notes to describe plastics and plastics processes.
Animations illustrate plastics processes in probably the most clear way possible, making plastics processes easy to understand, easy to learn and easy to remember.
Our plastics technology notes and animations describe all the major processes including:
Our new Plastics Module developed from the work in the KS3 and KS4 D&T packages. It is a complete package that includes:
- plastics technology notes
- animations of plastics processes
- a range of exercises that include design and make assignments (DMAs), focused practical tasks (FPTs) and technology questions.
To make teaching easier, the technology theory notes and exercises are in digital format, making them suitable for computers and whiteboards; and in PDF format, which makes it simple to print and duplicate A4 theory notes and worksheets.
Comprehensive and economical D&T software bundle
Three great software products covering the design aspects, the resistant materials aspects and product design aspects of KS3 and KS4 D&T courses.
Our new D&T software bundle includes:
The three packages contain a wealth of technology theory notes, animations of D&T processes, design exercises, design analysis exercises and technology exercises.
Download links will be emailed to you/your school within 24 hours of receipt of your order.
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Plastics Module + KS3/KS4 D&T software bundle