| 摘要 |
Cellular polystyrene is made by charging a perforated mould with sufficient partially but incompletely expanded polystyrene particles-containing residual amounts of an organic liquid expanding agent b.pt. 10 DEG -80 DEG C.-to form an expanded product filling the mould having a density of 0,4-0,8 lbs./cu. ft.; passing saturated steam into the mould to purge the mould of air, to achieve a steam pressure of 13-20 lbs./sq. inch and to cause the particles to expand and fill the mould; venting the steam pressure in the mould; removing the expanded product from the mould at a temperature of 200 DEG -220 DEG F. to allow the demoulded product to continue to expand outside the mould; and finally cooling the resulting product.ALSO:Cellular polystyrene is made by charging a perforated mould with sufficient partially but incompletely expanded polystyrene particles-containing residual amounts of an organic liquid expanding agent b.pt. 10-80 DEG C.-to form an expanded product filling the mould having a density of 0,4-0,8 lbs./cu. ft; passing saturated steam into the mould to purge the mould of air, to achieve a steam pressure of 13-20 lbs./sq. in. and to cause the particles to expand and fill the mould; venting the steam pressure in the mould; removing the expanded product from the mould at a temperature of 200-220 DEG F. to allow the demoulded product to continue to expand outside the mould; and finally cooling the resulting product. Expanding agents mentioned are methyl alcohol, methyl chloride, dichloroethane, low boiling chlorofluoroalkanes, pentane, hexane, heptane, cyclopentane, cyclohexane, cyclopentadiene and petroleum ether and mixtures. |
