| 摘要 |
PURPOSE:To obtain the titled lightweight foamed grains, having a hollow part therein and an outer layer consisting of a foamed glass layer, and suitable for heat insulating materials and aggregates, etc., by heating a coated core material prepared by coating a specific combustible core material with a mixture of glass powder with a decomposition type foaming agent. CONSTITUTION:The titled almost spherical foamed grains 1, obtained by wetting a core material consisting of spherical combustible plastic (foam) particles having >=0.3mm. particle diameter with a water-soluble high polymer binder, e.g. polyvinyl alcohol (PVA), by spray, etc., coating the resultant particles with a mixture of 100pts.wt. glass powder passing through a 100-mesh screen with 0.5-10pts.wt. decomposition type foaming agent, e.g. CaCO3, heating the coated core material at 700-900 deg.C for 1-10min to burn the combustible (foam) particles, and melt foaming the glass particles, and having a hollow part 2 having a diameter of about 20-90% outside diameter and outer layer consisting of a foamed glass layer 3, 1-25mm. grain diameter, narrow grain diameter distribution and 0.05- 0.6g/cc bulk density. |
