GB679704A - Improvements in the manufacture of articles of multicellular glass - Google Patents

Abstract

679,704. Glass manufacture. SOC. ANON. DES MANUFACTURES DES GLACES ET PRODUITS CHIMIQUES DE ST.-GOBAIN, CHAUNY, ET CIREY. Oct. 9, 1950 [Oct. 10, 1949] , No. 24636/50. Class 56. Multicellular glass articles are moulded in a mould which is charged to such an extent that the expanding glass fills the mould completely, the articles thus requiring no squaring or like operation subsequent to the moulding. The charge is calculated to produce an ultimate pressure of about 100 grams per square centimetre on the mould walls. A composition of a suitable glass frothing-mixture is described. The charge is subjected to a temperature of about 800‹ C. for about 30 minutes and then the temperature is lowered to 650‹ C. for about 15 minutes in order to stop' the frothing. This may be effected in a continuous furnace and cooling lehr. After removal from the mould, the articles are annealed in the usual manner. The mould, shown in plan in Fig. 2, comprises two L-shaped parts 1, 2 with abutting flanges which are pressed together with U- shaped clamps. The bottom and top plates are likewise held in position by U-shaped clamps. In a modification, a half-cylindrical mould has tangs projecting through slots in the end plates, the tangs being apertured to receive wedges which engage the outsides of the end plates and hold the mould parts together. In Fig. 8, a mould part 8 for making a half-cylindrical pipe lagging is strickled by a template 17 to distribute the charge 18 before the inner halfcylindrical mould part is applied, and secured by U-shaped clamps, to the mould part 8.