No abstract

Rapid heat cycle molding (RHCM) can eliminate the weld line, increase flow length, and improve surface quality of the molded parts. However, the cycle time is much longer as compared to the conventional injection-molding process due to the time taken to heat up and cool down the mold. This paper reviews the applications of conformal cooling channels to reduce the cycle time in rapid and hard tooling for the conventional injection-molding process. The performance of conformal cooling channels in reducing the cycle time has been proven; however, the full potential of conformal cooling channels in RHCM is yet to be explored. fects on the plastic parts such as paintings is a renowned solution by manufacturers. However, this method requires additional secondary processes and definitely increases the costs. In addition, the painting process also contaminates the environment and sometimes harmful to the operators. Weld line is one of the defects that totally impairs on cosmetic appearances of plastic products. It normally appears like scuffing on surface of parts and forms when the parts have a hole or intricate shapes that require more than one gate.

In designing molds for injection molding process, it is very difficult to achieve efficient cooling with uniform thermal distribution. To overcome these issues, the uses of conformal cooling channels with the uniform distance between the center of the cooling channels and the mold surfaces have more advantages, offering a better thermal distribution and reducing the cooling time. This article presents Milled Grooved Square Shape (MGSS) conformal cooling channels which have a more effective cooling surface area and are more efficient in cooling compared to circular and other types of cooling channels with similar cross-sections. A case study on front panel housing is investigated, and the possibility of fabricating the conformal cooling channels on hard tooling for injection molding process, which is easier to design, fabricate, and assemble compared to other methods, is presented. The performance designs of straight drilled are compared with two types of MGSS conformal cooling channels by using Autodesk Mold flow Insight (AMI) 2012. The results show that the variations of thermal distributions were improved within 12 to 50%, and cooling time was shortened within 6 to 8%. Thus, the capabilities of MGSS conformal cooling channels should not be underestimated by molding industries.