Abstract
This paper deals with a technique for improving the shape quality of injection-molded polymer products by controlling the heat transfer within the mold. In this paper, the authors tried to find a refined technique for improving the sink-mark problem, and examined the mechanism governing the sink-mark generation on an asymmetrically cooled polystyrene strip from the standpoint of thermal engineering. Sink-marks due to the shrinkage are considered to be controlled by both the cohesion between the molten polymer and the mold wall, as well as the stiffness of the frozen layer which gradually develops within the molded polymer adjacent to the mold wall. Although limited to polystyrene strip, the results obtained in the present study showed that the cohesive power of the molten polymer increases rapidly when the mold wall temperature exceeds the thermal deformation temperature of the polymer, and that the thickness of the frozen layer, which dominates its stiffness, monotonously increases with increasing time elapsed after the shot and decreasing with the mold wall temperature.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
