b'TECHNICAL DATAWhat is Expanded Polystyrene (EPS) DryingEPS is a closed cell lightweight cellular plasticsTo provide dimensionally stable dry blocks it is material produced from polystyrene. The material hasnecessary to pass them through a temperature been modified by the addition of flame retardantcontrolled oven. This process also ensures that any additives. residual blowing agent has been removed.Polystyrene literally translated is polymerisedFinishingstyrene. That is, the single styrene molecules areFor most customers the manufacturing process is not chemically joined together to form a large moleculecomplete until the EPS blocks have been cut into which is called the polymer. Styrene is produced fromvarious shapes. This process is mainly carried out using benzene and ethylene, and polymerisation isa hot wire cutting machine that gives a fine finish to the accomplished in the presence of catalysts, usuallyproduct and enables very fine cutting tolerances to be organic peroxides. The expandable form is producedachieved. as small beads containing a blowing agent.Australian StandardThe Manufacturing Process Australian Standard1366, Part 31992 Physical Pre-Expansion Properties of Rigid Cellular Polystyrenesets out The small expandable beads are subjected to steam,minimum properties for six classes (see table 1) and which causes the thermoplastic polystyrene to soften.methods for determination and compliance. Flexibility in Increasing vapour pressure caused by the blowingproduction allows EPS to be produced to this standard agent causes the beads to expand to up to 40 timesor to other requirements that specialized applications their original volume. It is this prefoam stage whichmay demand.determines the final density of the expandedpolystyrene block. Quality Control To ensure compliance with customer requirements our Aging Quality Assurance process monitors and tests various After pre-expansion the prefoam is transferred via tokey properties.fluidized drying bed to large silos for aging. Thisprocess is designed to allow for the replacement ofAcoustic Properties expanding agent by air in the cells of the bead. AgingAs EPS has a closed cell structure it offers only a also allows for stabilization and cooling of thelimited absorption of airborne sound. Structure borne prefoam. sound, transmitted though such structures as walls,may be effectively isolated by the use of floating floor Mouldingsystems. For this type of insulation EPS with the Once conditioned by aging, the prefoam is blown intorequired dynamic stiffness can be obtained by a mould where further steaming causes the expandedcompressing the sheets by 50 to 60 percent and then beads to fuse into a block. allowing them to recover to 80 or 90 percent of their original thickness. Table 1Physical Properties of EPS, according to AS 1366, Part 31992ClassPhysical PropertyUnit Test MethodL SL S M H VHNominal Density (kg/m3)11 13.5 16 19 24 28 N/aCompressive stress at 10% deformation (min) kPa 50 70 85 105 135 165 AS2498.3Cross-breaking strength (min) kPa 95 135 165 200 260 320 AS2498.4Rate of water vapour transmission (max)g/m2s 710 630 580 520 460 400 AS2498.5measured parallel to rise at 23CDimensional stability of length, width, thickness (max) at 70C, dry condition 7 days % 1.0 1.0 1.0 1.0 1.0 1.0 AS2498.6Thermal resistance (min) at a mean temperatureM2K/W 1 1.13 1.17 1.20 1.25 1.28 AS2464.5 or of 25C (50mm sample) AS2464.6Flame propagation characteristics: -median flame duration; max S 2 2 2 2 2 2-eighth value; max S 3 3 3 3 3 3 AS2122.1-median volume retained; % 15 18 22 30 40 50- eighth value; min. % 12 15 19 27 37 47Delta Insulation SystemsPage 2 of 4 P: +61 07 3271 2170 E: info@deltainsulationsystems.com W: www.deltainsulationsystems.com.au A: 49 Bernoulli Street, Darra Qld. 4076 ABN: 12 122 760 552'