Design of U-shape milled groove conformal cooling channels for plastic injection mold

Abstract

Besides the solid free-form fabrication technology, milling operation is an alternative applicable method to make complex cooling channels conform to the surface of the mold cavity. This paper presents the U-shape milled groove conformal cooling channels and proposes the design optimization process in order to obtain an optimal cooling channels' configuration and target mold temperature. The relation between the cycle averaged thermal behavior of the mold cavity and the two-dimensional configuration of cooling channels was first investigated thoroughly by an analytical method. Design of experiment and 2D simulation were done to obtain the mold wall temperature and to check the feasibility of the analytical method. The optimization process of the free-form conformal cooling channels is based on the combination of both analytical method and 3D CAE simulation. The analytical step relies on explicit mathematic formulas, so it can approach the neighboring optimal solution quickly. Subsequently, the three-dimensional heat transfer simulation is applied to fine-tune the optimization results. A case study for a plastic car fender was investigated to verify the feasibility of the proposed method. The results show that conformal cooling channel gives a uniform cooling, reducing the cooling time and increasing the molded part's quality with less effort of plastic designers and high computational efficiency.

Milled Groove Square Shape Conformal Cooling Channels in Injection Moulding Process

“…That's the reason why the temperature increases. The results from analysis are in good agreement with other previous findings [4,5,10,13] where conformal cooling channels can offer a better thermal distribution and shorter cooling time. However, the percentage of reduction varies because of differences in a shape and size of the part analyzed, different type of plastic and mold material used, different coolant temperature, and layout of cooling channels.…”

“…Dang and Park [13] introduced U-shape milled groove conformal cooling channels on a car fender parts molded from Noryl GTX979. Steel P20 was used as a mold insert, and Moldflow Software was employed to simulate the warpage (deflection) on molded parts with cooling time set at 6.3 s for both type of cooling channels and normal water at 25 C as a coolant.…”

“…It is worth to highlight that the U-shape groove conformal cooling channels proposed by Dang and Park [13] is difficult to design, fabricate, and assemble, and it is costly due to the extra inserts needed. Thus, MGSS conformal cooling channels presented in this article have several advantages which include easier design, fabrication, and assemble processes.…”

Potential of Conformal Cooling Channels in Rapid Heat Cycle Molding: A Review

“…Therefore, it is a great challenge for mold designers and tooling engineers to come out with a proper design of an efficient cooling channels system to improve both productivity and quality of the plastic-molded parts. 41,42 To overcome this problem, researchers have introduced conformal cooling channels which are designed to follow the shape of the products. To achieve it, mold designers and tooling engineers have to understand the rate of heat transfer between the plastic injection and mold.…”

Additive manufacturing–assisted conformal cooling channels in mold manufacturing processes

“…The efficiency of the conventional straight drilled and CCC was compared with results such as warpage and cooling time using Moldflow software. 10,12,36 Blow molding Blow molding is a process to produce hollow-shaped parts. The cooling stage takes up approximately twothirds of the complete blow molding cycle.…”