Investigation of foamed glass using natural waste materials as foaming agent




Glass, Waste, Foaming agent, Thermal conductivity


The use of high-quality thermal insulation materials to improve the energy efficiency of buildings is strongly increasing. Foam glass, a durable and porous material that is resistant to almost all substance effects, is one of the best thermal insulation materials. Glass foaming is a complicated process that is affected by the types of foaming agents used in the initial composition of the mixture and the mode of foaming. The influence of all components of the mixture - glass matrix and foaming agent - is discussed in this paper. Three types of glass powder (alkali frit, soda-lime silicate and borosilicate) were determined to be the matrix material. The foaming agents generate a gas phase via thermal decomposition of eggshell or a chemical reaction with the oxygen in the molten glass via SiC and coffee ground waste. The powder compacts  fired at 900 °C for 10 minutes with a foaming agent content of 2 wt %  presented excellent thermal insulation properties by using soda-lime silicate glass with SiC and eggshell foaming agents mixtures. The coffee ground waste-glass mixtures show inferior thermal insulation properties with each different glass powder.