Foam glass having crust layer and method of producing same

摘要

The invention relates to a foam glass having a foam layer and a crust layer which covers at least one major surface of the foam layer. The crust layer is formed so as to have a thickness of from 1.5 to 20 mm and an apparent specific gravity of from 0.8 to 1.7, whereas the foam layer has an apparent specific gravity of from 0.3 to 0.6. The powder materials of the foam layer and the crust layer are respectively granulated prior to firing operation. This foam glass has good impact resistance, flexural strength and machinability including cuttability. By dispersing 15-30 vol % of glass grains 0.5-5.2 mm in diameter in the crust layer the foam glass is improved in surface hardness and flaw resistance. When the foam glass is reinforced by embedding therein a metal material such as wire netting, the metal material is pretreated with either a mixture of a silica based glass powder and an adhesive liquid binder or a dispersion of a silicon alkoxide optionally together with another metal alkoxide in a liquid medium to ensure firm adhesion of the metal material to the glass matrix and enhance mechanical strength and fire resistance of the foam glass.