Foam Board Insulation is based on covering indoor or outdoor surfaces of building in order to prevent heat losses to the surrounding.
There are several material used for the production of these foam core boards, of which Polystyrene is the most widely used.
Polystyrene is an aromatic polymer made from styrene monomer. Polystyrene is among the most used types of plastic for general use. Chemically, polystyrene is a long-chain hydrocarbon, with every other carbon molecule connected to a phenyl group. Discovered in 1839, polystyrene became ubiquitous, being used in the production of a variety of objects both for general and industrial use.
Polystyrene, in its foam form proved to be a very good thermal insulator and damping material. This quality made it well suited for the production of foam core boards used in foam board insulation, and also for the construction of non-weight bearing structures.
The foam boards made from polystyrene foam are of two main types, differenting by manufacturing process and by the properties they exhibit.
The one most widely used form of polystyrene foam core board is Molded Expanded Polystyrene.
Molded Expanded Polystyrene is a closed-cell material, which, molded in desired shapes is used for making various items. The most common use of Molded Expanded Polystyrene is packaging material, taking advantage of its excellent damping qualities.
Making foam boards from MEPS, implying mixing unexpanded polystyrene beads with a blowing agent and pouring the mixture into a container which is heated to allow the beads to expand. The expanded beads are injected into a pressurized mold, transforming them to foam. The foam is then shaped to make the boards, which is used for the foam board insulation.
The second type of boards is those made from Extruded Expanded Polystyrene, or XEPS. While similar to MEPS, XEPS is made by liquefying polystyrene pellets mixed with several chemicals and then adding a blowing agent which forms gas bubbles. This thick liquid is then extruded trough a die, and after cooling is cut and shaped as needed.