Plc Modification for Fill and Close Stopping Sequence Improvement

Abstract

From November 2020 to January 2021, an analysis was made looking for the best way to increase the yield of the machines in charge of the dry process when making a contact lens. In this analysis, it was discovered that there was overwhelming evidence that the biggest offender was curing losses. Curing losses are defined as all molds out of the curing ovens divided by the amount picked up by the CUA (Control Unit Acquisition). An analysis of the PLC code that corresponded to the affected areas determined that best course of action to save the greatest number of molds possible and reduce or possibly eliminate curing losses. After implementation of only a plc code modification an expected improvement on the curing losses should be between 1-2%. Key terms ⎯ contact lenses, fill & close, PLC, SCADA