SYNTHETIC PARTING MATERIAL FOR SHAPING GLASS SHEET DOUBLETS

摘要

The number of bent laminated glass windshields having bull's-eyes that adversely affect its optical properties is reduced by using amorphous precipitated silica particles such as is used as flatting agents for paints, as a parting material between a pair of glass sheets during bending. The particles form relatively soft agglomerates that are milled and classified to produce a narrow distribution of particle sizes as compared to the distribution found in untreated silica, such as diatomaceous earths previously used as a parting material.