Composition and structure
Composition
![]() |
Finnfoam’s primary material is crystal clear polystyrene. |
Finnfoam is a cellular plastic whose primary material is polystyrene. Polystyrene is not hazardous to health. Polystyrene is widely used as packing material for foodstuffs. Polystyrene is a thermoplastic material that can be melted down and reused.
Another important raw material used in the production of the Finnfoam expanded polystyrene is carbon dioxide, which is sourced, among other things, from industrial emissions, and is thus environmentally friendly. The carbon dioxide escapes from the panels and is replaced with air within few weeks from manufacturing. Polystyrene and carbon dioxide amount to approximately 96–98% of the raw materials used. In addition, Finnfoam includes various additives such as coloring agents, process stabilizers, and modifier regulators for the cell structure.
No CFC, HCFC or HFC gases or fire retardants that contain hazardous bromine compounds are used in the manufacturing of Finnfoam. Neither do any gases, particles or fibers that are hazardous to health evaporate or release from Finnfoam. Finnfoam has been rated M1 for emissions, which stands for the best quality of indoor air.
Structure
PS Lattia 100 (styrofoam) 18 kg/m3) |
FINNFOAM (F-300 32 kg/m3) |
![]() |
Finnfoam consists of extruded polystyrene, which is internationally referred to as XPS thermal insulation. The remarkable properties of Finnfoam are based on its cell structure. Finnfoam's cell structure is completely consistent and closed. It is substantially different to the cell structure of expanded polystyrene, i.e. EPS.
Finnfoam's completely consistent cell structure is achieved by using a production method in which carbon dioxide is dissolved into molten polystyrene under high pressure. The carbon dioxide is gasified as it is released into regular air pressure from the jet nozzle.
![]() |
The surface of Finnfoam is covered by a solid skin. (Cell diameter less than 0.1 mm) |
Using cell structure modifier regulators and the settings of the machine, the cells are formed into the desired size and shape. In the extremely sturdy panels that can withstand more than 70,000 kg/m2 the cells are in a slightly vertical position. More than 23 billion cells can be produced per second.
The manufacturing process also creates a consistent skin on the surface of the panel, which consists of a solid layer of polystyrene instead of cells. The solid skin repels water. The skin on both sides of the panel combines with the cell structure in the middle to create a sandwich structure, which further increases the sturdiness of the panel.