Context & Aim
Additive manufacturing offers a geometry freedom that allows to integrate new functionalities in the design. As well as producing products, additive manufacturing can support existing manufacturing processes by being used for tooling production. This case study covers the production of mould for injection moulding.
Challenge
Trend Technologies intends to improve the productivity of their injection moulding process. This study aims to optimise the heat dissipation of the insert allowing a reduction of the cycle time of the injection moulding process and limiting the defects due to uneven cooling gradient within the mould.
Solution
The use of conformal cooling channels has been proven to be one way to answer this challenge in previous studies across the AM field. The mould is produced using a Laser Powder Bed Fusion process, which can process several materials; thus, an assessment of the efficiency of conformal cooling mould produced with maraging steel (thermal conductivity ~ 25 W/mK) and aluminium AlSi10Mg (thermal conductivity ~ 100 W/mK) is of particular interest considering the cost of a conventional beryllium copper insert (thermal conductivity ~ 130 W/mK).
Results
The study comprised five design iterations of a conformal cooling mould moulds, from which the Revision 2 (V2) and Revision 5 (V5) were tested on the production line. Measurements of the surface temperatures of these inserts confirmed the efficiency of the additive manufactured moulds. The first conformal cooling maraging steel insert (V2) performed similarly to the beryllium copper bubbler insert, set as a reference. With a higher thermal conductivity than maraging steel, the conformal cooling aluminium insert (V2) outperformed the reference. The second design (V5) maraging steel insert is the most efficient, with cooling channels closer to the surface. The previous results correlate for a promising and optimum solution using a V5 aluminium insert.
Impact
The conformal cooling channels were proven to improve the thermal dissipation and the homogeneity in the mould.
- Reduced cycle time
- Uniform cooling resulting in less part warpage
- IMRAM Programme enabled Trend to develop a predictive model that can be used to determine viability of conformal cooling inserts vs traditional machining methods.
“The program to date has proven best in class technology, process and people skills. The process to date has been symbiotic with open knowledge sharing across Trend, IMR and the participating companies. The current open projects with Trend and the IMR are progressing well with promising results to date (Conformal Cooling + A.M Workflow). Trend are excited to be working with IMRAM team and the wider IMR on future developments. The IMR are an essential part of Trend’s R&D and Innovation initiatives.”
(Stephen Lynam, Engineering Manager, Trend Technologies)
THEMATIC PILLAR
Design for Manufacturing
