Effects of different cooling channels on the cooling efficiency in the wax injection molding process

Abstract The manufacturing of Conformal cooling channels (CCC’s) is now easier and more affordable, owing to the recent developments in the field of additive manufacturing. The use of CCC’s allows better cooling performances than the conventional (straight-drilled) channels, in the injection molding process. The main reason is that CCC’s can follow the pathways of the molded geometry, while the conventional channels, manufactured by traditional machining techniques, are not able to. Using CCCs can significantly improve the cycle time, allow to obtain a more uniform temperature distribution, and reduce thermal stresses and warpage. However, the design process for CCC is more complex than for conventional channels. Computer-aided engineering (CAE) simulations are important for achieving effective and affordable design. This article presents important results regarding molds with new conformal cooling channels geometries. The aim is to assess the maximum pressure that the parts can be subjected to in a real injection molding application. Linear structural analyses are carried over in the Finite Element Method Software ANSYS Workbench 2020 R2, in order to analyze both the resistance and stiffness behavior of the studied geometries. The results are analyzed according to several metrics. The results were discussed and it could be concluded that some of the structures are suitable for the typical operating conditions of the injection molding process.

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Dynamic conformal cooling improves injection molding

The International Journal of Advanced Manufacturing Technology ◽

10.1007/s00170-021-06794-0 ◽

2021 ◽

Vol 114 (1-2) ◽

pp. 107-116

Author(s):

Andreas Kirchheim ◽

Yogeshkumar Katrodiya ◽

Livia Zumofen ◽

Frank Ehrig ◽

Curdin Wick

Keyword(s):

Additive Manufacturing ◽

Injection Molding ◽

Injection Molding Process ◽

Layer By Layer ◽

Mold Surface ◽

Molding Process ◽

Conformal Cooling ◽

Cooling Channels ◽

Heating And Cooling ◽

Conformal Cooling Channels

AbstractTo achieve a certain visual quality or acceptable surface appearance in injection-molded components, a higher mold surface temperature is needed. In order to achieve this, injection molds can be dynamically tempered by integrating an active heating and cooling process inside the mold halves. This heating and cooling of the mold halves becomes more efficient when the temperature change occurs closer to the mold surface. Complex channels that carry cold or hot liquids can be manufactured close to the mold surface by using the layer by layer principle of additive manufacturing. Laser powder bed fusion (L-PBF), as an additive manufacturing process, has special advantages; in particular, so-called hybrid tools can be manufactured. For example, complex tool inserts with conformal cooling channels can be additively built on simple, machined baseplates. This paper outlines the thermal simulation carried out to optimize the injection molding process by use of dynamic conformal cooling. Based on the results of this simulation, a mold with conformal cooling channels was designed and additively manufactured in maraging steel (1.2709) and then experimentally tested.

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Analysis of multi-cavity molding of parts with different geometries

Advanced Technologies & Materials ◽

10.24867/atm-2020-1-004 ◽

2020 ◽

pp. 1-8

Author(s):

Saša Ranđelović ◽

Mladomir Milutinović ◽

Vladislav Blagojević ◽

Srđan Mladenović ◽

Dejan Tanikić

Keyword(s):

Injection Molding ◽

Cooling System ◽

Critical Issue ◽

Injection Molding Process ◽

Uniform Temperature ◽

Molding Process ◽

Cooling Channels ◽

Simple Geometry ◽

Temperature Filed ◽

Uniform Temperature Field

In the industrial processes of injection molding, one of the basic requirements is a uniform temperature filed within workpiece and the mold cavities. In the case of simple geometry of workpiece and mold with single cavity achieving a uniform temperature field is not a critical issue. However, if one deals with parts of complex geometries, multi-cavity molds and asymmetric layout of different forms in the mold additional analyses of the runner and cooling system are necessary in order to obtain the required quality and accuracy of end the products. Disposition and dimensions of both runners and cooling channels are directly related to the geometry of finished parts and material properties. In that sense, virtual models and numerical simulations of injection molding processes based on the finite element method are very effective tool which enable accurate prediction of potential problems and significant reduction of trial and error procedure. In this paper, FEM software package Moldex3D was employed for simulation and analyses of injection molding process in which pipe fittings Ø75/45o and Ø75/90o are produced using a mold with two asymmetric cavities.

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