Patent ID: 8991213
Filing Date: 2015-03-31
Classification: C03B,C03C,Y02P

Abstract:
1. A method for producing closed cell borosilicate glass comprising steps for: a) selecting a batch of glass particle sizes ranging from −80 mesh to +350 mesh; b) maintaining a content of B c) adding a foaming agent to the batch; d) determining a softening point for the batch; e) heating the batch to a cellulating temperature in the range of around 100° C. to 250° C. above the determined softening point; f) allowing the batch to cellulate at the cellulating temperature; g) ensuring that cells formed within the batch maintain a closed cell structure with no interconnecting pores between the cells; and h) decreasing the heating of the charge to a temperature to permit annealing of the charge; whereby the borosilicate cellular glass achieves a coefficient of expansion in the range between 33×10