Expanded polystyrene foam, also called EPS, is an extremely durable material used in a wide variety of consumer products. These can be found almost everywhere, at your local grocery store (plates, cups, food containers, etc.) and at your local electronics store (insulation for refrigerators, cooler boxes, etc.), plastic plates made of styrene, boxes CDs, and cloth hangers are all made of styrene. It is also an excellent insulating material.
EPS foam starts with very small balls, which are also known in texture as sand-like grains.
To make EPS foam blocks from these small raw beads, they must be "blasted" into larger beads, about 50 times their original size. This is known as the pre-expansion process. Depending on the desired density, the pearls are blown with the help of steam in a machine called an expander or steam. You can also take advantage of EPS foam in Hawaii through various web sources.
An expander can be a simple manual machine in which workers place raw materials and then ignite steam. Or it could be a machine that automatically removes the material. At this stage, the beads – up to 50 times their original size – are called pellets and are ready to print.
The pre-expander continuously works without pressure and is equipped with an open agitator tank at the top, through which raw materials are continuously fed from below via an adjustable screw conveyor. Steam is also continuously directed into the pre-expansion chamber through an opening located directly above the tank.