EPS(Expandable Polystyrene) is a lightweight, rigid, plastic foam insulation material produced from solid particles of polystyrene. Expandsion is achieved by virtue of small amounts of pentane gas dissolved into the polystyrene base material during production.The gas expands under the action of heat, applied as steam, to form perfectly clesed cells of EPS.
How do we classfiy EPS Material?
Regular Grades - High Expansion, Medium Grade, Fast Cycling, Colorful beads
Flame Retardant - High Ratio Flame Retardant, Low Pentane Flame Retardant.
Fast cycling grade EPS confers excellent processing and product properties
Consistent raw beads and good fluidity of foamed bead.
No harmful odors in pre-expansion and moulding
Short maturing time
Characteristically rapid cooling in automatic molding machines and better performance with vacuum system
Uniform cell size, beautiful and flat surface appearance
Good integration inside, high resistance
Use in contact with food
Recommended 40-60 expansion ratio.
Recommended Processing Condition
Material Selection
Select proper bead diameters according to the required shape and density of the final product. Large articles in medium and low density (less than 16g/l) require D-104 or D-103. Continuous pre-expanders require D-104 or D-105 while batch pre-expanders require D-105/D-106/D-107.
Pre-expansion
Steam Pressure: 0.15Mpa-0.30Mpa
Pre-expansion Temperature: 96-108℃
Conditioning Time: 4-24 Hours
Moulding
Steam Pressure of Stationary Mould: 0.7-1.2kgf/cm²
Steam Pressure of Moving Mould: 0.7-1.2kgf/cm²
Health and Safety
Fast cycling grade totally meets food contact safe requirements as is less than 0.2%wt/wt. The total content of aromatic hydrocarbon impurities are far lower than the one in similar competitive products.
During storage, transportation and processing, low levels of pentane blowing agent will be present, which will have an explosive range in air between 1.1-6.0%. The raw material and products must therefore be well ventilated and kept far away from sources of ignition including static electricity.
Flame retardant EPS grades confer excellent processing and product properties
Consistent raw bead and good fluidity of foamed bead
Rapid expansion
Relatively low density in second-time expansion.
Excellent flame retardation with the US UL Product Security Certification.
Wide range of operation and suitable for various block machines, automatic machines and manual presses.
Fine cell, beautiful and flat appearance.
Low shrinkage rate of block in molding.
Recommended 40-70 expansion ratio to increase as per several-time expansion.
FlameRetardant Property of Block Molding
Our company flame retardant EPS has passed the ecaluation of the US Underwriters Laboratories Inc. (UL) and the approval mumber is E212192. Improper processing will, however, reduce the flame retardant coalings in expansion or blendingwith general grade EPS will in both cases reduce the flame retardant properties. In order to ensure flame retardantproperties, products must be left to age to allow residual blowing agent to dissipate. The aging period is mainly determined by the content of residual blowing agent, apparent density and product size. For block, the following data is procided from experience. (Under well ventilated conditions)
15kg/m³ 20 mm thickness At 1east one-week shelf life
50 mm thickness At 1east two-week shelf life
30kg/m³ 20 mm thickness At 1east two -week shelf life
50 mm thickness At 1east three-week shelf life
Correct understanding of self-extinguishing of flame retardant EPS
Flame retardant EPS product is not never-burned material, even it’s named “flame retardant”. Actually international standed defined EPS foam building product as “flammable bulding material”, it’s just more flame retardant compared with regular EPS material.
GB8626 China National Standard “lgnitability of building products measurement” stipulates that the sample tested should be stored at least 14 days with temperature 23±2℃ and the relative humidity 50±5%.
GB8624-2006 China National Standard “Fire classification of construction products and building elements”, equal to Europe Union Standard “en13501-1:2002”. The new version of GB8624 has been changed a lot and expanded the understanding to the parameters of burning release rate, burning heat release quantity, burning smoke density and burning smoke density and burning result toxicity. The classifications of self-extinguishing levels are related with the final uses of the products. If the same product has different final uses, it will have different levels of self-extinguishing.
According to EN13238-Conditioning procedures and general rules for selection of substrates and ENISO11925-2:2002- lgnitability of building products subjected to direct impingement of flame-part 2: single-flame source test, the flame retardant EPS with the brand SUNCHEM has passed the tests.
Recommended Processing Conditions
Material Selection
Select the bead diameter as per the required density of block. Low density(10-13g/l) requires C-102, C-103 or C-104. When required density is in the range of 12-16g/l, the required grade will be C-104 or C-105. When density is 16-24g/l, the required grade will be C-104, C-105 or C-106. With higher density, over 25g/l, the requirement is C-106, C-107.
Pre-expansion
Steam pressure: 0.2Mpa-0.4Mpa
Pre-expansion temperature: 96-106℃
Maturing time: 4-10 hours interval between two pre-expansions.
The density in first pre-expansion is usually 1.5-1.6 time that of the second pre-expansion.
Block Molding
Packaging
Steam Pressure of Stationary Mould: 0.8-1.2kgf/cm²
Steam Pressure of Moving Mould: 0.8-1.2kgf/cm²
Block
Main Heatingf: 0.55-0.80 kgf/cm²
Cooling Time: around 300-800 seconds, related to density of block and property or machinery.
