Comparison of feedstocks for optical glass and optical plastic

Abstract

The raw materials for optical glasses and optical plastics are very different. The plastic feedstocks are volatile liquids, petrochemicals, which are highly refined by industrial distillation. The feedstocks for inorganic glasses are minerals, purified by solid processing methods. The optical plastic resin is always virgin stock; "regrind" is never used for high-quality optical plastics. In contrast, the inorganic optical glass feedstock is improved by adding "cullet", which is the recovered waste from breakage and trim during glass part production. This paper discusses the sources and refinement of feedstocks for both glass and plastic, including consideration of cost, recycle and ramifications for optical part production, and anticipated future trends. A snapshot summary of current marketplace conditions is given.