Cat Scratch Defects In Glass Containers And Tableware: New Approach In Evaluation

Catscratch defects in container and tableware glass products are frequently observed at the external surface at a depth of 50-100um. Typical electron microprobe analytical results show an enrichment in alumina and zirconia. The high level of alumina renders the cord material viscous and of lighter density than the soda-lime glass. Consequently, the cord material does not settle at the bottom of the furnace, contrary to common belief. Density calculations were made by using computer programs readily available to glass scientists.