DETERMINING THE PROBABILITY OF THE VISUAL DETECTION OF SINK MARKS ON DIFFERENTLY TEXTURED INJECTION MOLDED PRODUCTS

This doctoral dissertation studied the effects surface texture and color have upon the visual detection of sink marks. Human observers evaluated a series of injection-molded parts exhibiting various sink marks dimensions as well as various textures. Data were collected in the Plastics Processing Laboratory at Western Michigan University’s Parkview Campus and at various plastics companies located in western Michigan. The results of the research confirmed industry-held beliefs in the effectiveness of surface texture to conceal minor sink marks. The color of the sample plaques was found to be a significant contributor to the probability of the perception of a sink mark. The research also found that the environment surrounding a sink mark could influence the probability of visually detecting the sink mark. Factors essential for predicting sink mark visibility were identified, allowing the development of models for designers to use to eliminate the visibility of problematic sink marks.