Styrofoam is foam and expanded Polystyrol. For this producing you need water, styrene and pentane.
Styrene is a liquid, which is tending to the polymerization when it is room- temperature. You get styrene when you dehydrogenate ethyl benzol.
The additive substance is pentane, which must be present at the polymerization. When you want get a poly sterol with propellant. You get pentane from oil, when the oil is distilled.
Through the polymerization when pentane is present, you get a poly sterol which propellant is in it. At this chemical process monomer transformed to polymers, as well form macromolecules. This process happens in two steps. The first part is the polymerization. The monomers are added. At first these are transformed in a radical or ion condition. It forms macro- molecules or ion, which are like a chain, because they store the active molecules together. When the chain brakes of, then the polymerization is finished. The ends of the chain are in a solid form. Now the poly condensation is start. At this process the monomer combine and form three-dimensional cross linked macromolecules.
Picture II.11: Forming of poly sterol
Now the raw stuff is process. This is dividing in 3 parts: the before-foam, the temporary storage facilities and the out- foam.
Picture II.12: The forming of Styrofoam
The before-foam happens with 90° C hot steam. At this process the pearls swell up because the steam and the propane. The volume enlarges till the fifty fold from the beginning volume. Now a compact structure in the pearls is form. The gross density of the Styrofoam is depended on the time, how long the steam weaves.
The foamed Styrofoam is storage in ventilated silos, because the steam and the propellant condense. So it become an under pressure, which is compensation through the diffuse of fresh air. Only so the pearls can be compact.
The last step is out-foamed of the Styrofoam. It is producing block material or finished forms. Now the block foam is described. The pearls are filling in the block-form. This is a metal box with steam nozzles. The steam is between 110°C till 120°C hot. Now the material is sticky. In this state the foam- pearls weld with each other. After it cold out, the block can take out of the form after a short time. Now you can work with the Styrofoam.