Low softening point glass - for temporary fixing sheet metal to platens of a heated press

摘要

A low melting glass, esp. suited for use as an adhesive layer for fixing metal sheets temporarily to the platens of a hot press, consists of a fluophosphate glass contg. more than 50 wt.% P2O5 and 14-45 wt.% alkalis (calculated as oxides). The pref. compsn. is (wt.%) P2O5: 50-80; Li2O: 0.5-4% Na2O: 0-24; K2O: 0-38; (Li2O + Na2O + K2O): 1 W-45; (MgO + CaO + SrO + BaO): 0-6; Al2O3: 0-0.8; WO3: 0-1.0; F2-O: 2-12. There is better thermal contact between the sheet metal and the platens. The glass is easily removed due to high coefft. of expansion and high solubility. The parts are easily removed from the press.