Novel approach to the measurement of the visual perceptibility of sink marks on injection molding parts

作者：Gruber Dieter P^*; Berger Gerald; Pacher Gernot; Friesenbichler Walter

来源：Polymer Testing, 2011, 30(6): 651-656.

DOI：10.1016/j.polymertesting.2011.04.013

• Injection molding
• Sink marks
• Machine vision
• Visual perception
• Simulation

The visual perceptibility of sink marks is a deciding criterion for the quality of a variety of injection molded parts and, due to highly functional part design, the formation of sink marks is inevitable in many cases. The aim of this work is to present a novel mathematical model that allows for quantifying and predicting the visual perceptibility of sink marks appearing on the surface of injection molded parts. The model was implemented in an inspection system and tested by using an injection molded part that exhibited sink marks caused by ribs of varying thickness located on the back side of the part. Tests were processed by incrementing the holding pressure while other processing parameters were kept constant. The machine vision system was used to evaluate the visual perceptibility of four different sink marks. A study in which human assessors were asked to rate the perceptibility of sink marks was carried out to prove the significance of the proposed model in terms of correspondence to the human vision. Results show strong correlation with the human vision and confirm the capability of the newly developed machine vision system.

• 出版日期2011-9