Extruded polystyrene insulation foam or XPS foam like blue foam is manufactured through an extrusion process which involves melting together the plastic resin and other ingredients. The liquid formed is then continuously extruded through a die and expands during the cooling process. This produces a closed cell rigid insulation.

Expanded polystyrene insulation foam or EPS foam like fruit and veg boxes is manufactured using a mould that contains small foam beads. Heat or steam is then applied to the mould, which causes the small beads to expand and fuse together. This manufacturing process does not form a closed cell insulation as there can often be voids between each of the beads where they are not touching one another.

We use XPS foams for modeling because you can create a smooth surface without voids. It’s easier to shape and sand. There is several different types of XPS foam available and it usually comes down to personal preference.

XPS foam is commonly used for model making because it is easily shaped with simple tools. It's a really useful for quick form studies. Making a tangible item in 3D helps you to understand the look and feel of a product.

In the built environment foam can be used for quick massing models to help you quickly understand the mass/form of the building you are designing or how it fits into it's environment.

Foam also makes quick and easy moulds for casting and forming.

Here's some other resources we've found on youtube that you might find helpful.

Some useful websites

Check out our Pinterest pages for more examples of XPS foam models

Get yourself trained!

If you want to learn and/or increase your skills in forming foam don't hesitate to come and chat to a friendly Makerspace staff member. Make sure you complete the Badges that the UNSW Makerspace Network has for you!