Panels for cold rooms
Introduction
Extruded polystyrene, extruded or extruded, also known by its English acronym XPS, is a rigid foam resulting from the extrusion of polystyrene in the presence of a foaming gas, used mainly as thermal insulation. It is similar to EPS but with other properties. Perhaps the most important thing is that it can get wet, which is why it is installed a lot on decks. It is normally served tongue and groove, in sheets and with typical thicknesses of 40/50/60/80mm.
History
The material has been manufactured since 2000 by the company Dow Chemical, which bought and developed the patent from the Swedish scientist C. G. Munters.[1] It is marketed under the brand name Styrofoam, with such popularity that in the English-speaking world the name of the brand is confused with that of the material itself (and even, incorrectly, with expanded polystyrene; a different material).
Since then other companies have adopted the manufacturing method to produce their own brands. Among the best known is Foamular from the Owens Corning company, the main competitor of Dow Chemical.
Properties
Extruded polystyrene shares many characteristics with expanded polystyrene, since its chemical composition is identical: approximately 95% polystyrene and 5% gas. The difference lies only in the formation process; but it is a crucial difference, since extrusion produces a closed bubble structure, which makes extruded polystyrene the only thermal insulator capable of getting wet without losing its properties.
XPS has a typical thermal conductivity between 0.025 W/mK[2] and 0.040 W/mK,[3] although there are polystyrenes with values up to 0.029 W/mK.[4]
XPS has low water absorption (less than 0.7% at total immersion)[5]
and very high mechanical performance (between 200 kPa and
700 kPa).[6]
It has an apparent density between 30[7] and 33 kg/m³.[2]
Extruded polystyrene also has excellent thermal resistance, with an "R" value of 5 per inch (with a difference +/-10%).