Design of conformal cooling channels for an automotive part

Abstract

The cooling system plays a crucial role in determining the productivity and quality of an injection molding process. With the current growth of Solid Freeform Fabrication (SFF) techniques, mold designers have been striving for not only improvement in cooling system performance but also for a method to do so automatically. In this paper, a method is proposed for developing a conformal cooling system that facilitates uniform cooling over the entire mold surface with minimum cycle time. Based on the temperature distribution after the filling stage, the mold surface is split into zones which will be cooled by optimized subconformal channels obtained from the optimization process. The optimization process in which the objective function is stated as minimization of the cooling time with boundaries ensuring a realistic design will optimize the cooling system layout in terms of cooling channel size and location. Finally, all subcooling channels are combined to generate the entire conformal cooling system for the injection mold. NOMENCLATUREQ KS : heat flux from molding, kJ/m Q E : heat exchange with the environment, kJ/m Q C : heat exchange with the coolant, kJ/m t C : cooling time, s s : part thickness, mm a : distance between two cooling channels, mm b : distance from the mold surface to the center of the cooling channel, mm d C : diameter of cooling channel, mm T M : mold temperature, o C T E : demolding temperature, o C i m : latent heat of fusion of polymer, kJ/kg c p m : specific heat of the melt, kJ/(kg o C) ρ m : melt density, g/cm 3 λ m : thermal conductivity of the melt, W/(m o C) T water : temperature of coolant, o C T W : mold wall temperature, o C λ ST

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.…”

Design and simulation-based optimization of cooling channels for plastic injection mold

“…This technique has some benefits such as being easy to connect to simulation program, to render a view of entire design space as well as computational efficiency (Papalambros, 2002;Park, 2007;Wang & Shan, 2007;. The systematic procedure of metamodel-based optimization technique applied to injection molding is depicted in Fig.…”

“…Solid free-from fabrication (SFF) or rapid prototype (RP) techniques have been applied to build this complex cooling system. It was reported that cooling quality is better than that of conventional cooling channels (Sachs et al, 2000;Xu et al, 2001;Ferreira & Mateus, 2003;Dimla et al, 2005;Au & Yu, 2007;Rännar et al, 2007;Park & Pham, 2009;Safullah et al, 2009). Prototyping technologies with metal powder that can make the mold with conformal cooling channels include selective laser sintering (SLS), 3D printing (3DP), electron beam melting, and laser engineered net shaping.…”

Different Methods in Analyzing Roll Forming Process of Automotive Component

“…On the contrary, with general analysis it is hard to apply this technique to the simulation of RF. Therefore, in most studies, the computational mesh in general analysis has fine elements over the entire sheet (Park & Pham, 2009). …”