SCONAPOR™ expandable polystyrene (EPS) from Styron is available as beads. SCONAPOR EPS can be used to manufacture flame-resistant moulded foam parts, as well as blocks and plates.
SCONAPOR EPS contains a low-boiling blowing agent that causes the beads to expand 60-fold in volume with the application of saturated steam in the prefoaming process (first processing step). After interim storage of the prefoamed beads (second processing step) they are fused in closed moulds by a further application of steam (third processing step).
The foam comprises up to 98% air and, due to the cell structure, is pressure resistant and elastic. Due to its low thermal conductivity, foams produced from SCONAPOR are particularly suitable as insulating material in a variety of applications and also for packaging.
All end products manufactured from SCONAPOR EPS and labelled with an 'F' contain flame retardant. Foams manufactured with SCONAPOR EPS are assigned to Category B1 - flame-resistant building materials - as per DIN 4102.
Chemical Resistance of Rigid Foam made from SCONAPOR EPS
Foams made with SCONAPOR™ EPS are resistant to construction materials such as cement, lime, anhydrite and almost all aqueous media including hydrated acids. In addition they are resistant to water-soluble alcohols and silicon oils.
Foams made with SCONAPOR EPS are also conditionally resistant to paraffin oil, vegetable oils and diesel fuel. Long-term exposure to these substances can affect the surface of the foam and cause deformation due to shrinkage.
Foams made from SCONAPOR EPS are not resistant to organic solvents such as hydrocarbons, chlorinated hydrocarbons, ketones and esters. Dehydrated acids such as glacial acetic acid, fuming sulphuric acid or concentrated nitric acid will also destroy the foam.
After any possible contact of the foam with adhesives, a potential solvent sensitivity must be considered.
Guidelines and Safety Precautions
Due to vaporisation of the blowing agent contained in SCONAPOR™ EPS flammable solvent-air mixtures can form even at room temperature. For safe processing it is therefore recommended to ventilate storage and workrooms well, preferably at ground level. For storage and interim storage silos a dedicated ventilation system is recommended. Open flames, sparks and other sources of flames and heat must be kept well away from rooms used for processing, handling and storage. The ban on smoking must be strictly adhered to.
For example, friction in conveying ducts can cause EPS raw beads, prefoamed particles and completed parts to become electrostatically charged. Sparks resulting from possible discharge must be avoided using suitable measures.