Use of a Holistic Design and Manufacturing Approach to Implement Optimized Additively Manufactured Mould Inserts for the Production of Injection-Moulded Thermoplastics

Abstract

Injection moulding is one the most familiar processes for manufacturing of plastic parts by injecting molten thermoplastic polymers into a metallic mould. The cycle time of this process consists of the phases of injection, packing, cooling, and ejection of the final product. Shortening of cycle time is a key consideration to increase productivity. Therefore, in this manuscript the adoption of additively manufactured mould inserts with conformal cooling channels by means of selective laser melting (SLM) with the aim to reduce process cycles is presented. The design and manufacture of a mould insert with conformal cooling channels for producing pressure fitting thermoplastic parts is described. Numerical analysis of the injection process and simulation of shape distortions after SLM were conducted providing useful results for the design and manufacture of the mould insert. The results of the numerical analyses are compared with experimental 3D geometrical data of the additively manufactured mould insert. Temperature measurements during the real injection moulding process demonstrating promising findings. The adoption of the introduced method for the series production of injection moulded thermoplastics proves a shortening of cycle times of up to 32% and a final product shape quality improvement of up to 77% when using mould inserts with conformal cooling channels over the conventional mould inserts.

Optimization to Assist Design and Analysis of Temperature Control Strategies for Injection Molding—A Review

“…On the other hand, some researchers exploited numerical tools, such as Moldflow Insight or Moldex 3D, to perform thermo-mechanical analysis, aiming to gain an insight into plastic part quality before producing a mold insert. Papadakis et al [28] studied the importance of a holistic design approach, applied to additive manufactured inserts with CCCs. They compared the performance of two different configurations (conventional cooling channels and crown cooling channels), and to better understand the potential of the proposed solution (crown cooling channels) in terms of the cooling enhancement, a transient thermomechanical FEA was performed in Moldex 3D software.…”

Occupational Safety Analysis for COVID-Instigated Repurposed Manufacturing Lines: Use of Nanomaterials in Injection Moulding

“…Stoffenmanager Nano is a supportive control-banding tool for nanomaterial risk assessment developed by the TNO-Netherlands Organization for Applied Scientific Research (The Hague, The Netherlands) and Arbo Unie (Nijmegen, The Netherlands), and it is available as a web-based tool. Stoffenmanager Nano allocates five bands for hazard (A, B, C, D, E) and four bands for exposure (1,2,3,4) on the basis of material and process characteristics, which are provided by the user. Task-and time-weighted exposure bands are derived based on the frequency and duration of a given process.…”

“…Injection moulding (IM) is one of the most common manufacturing techniques because of the large variety of different feedstocks, including polymers, metals, ceramics and composites, it allows, as well as the low production costs it entails [1]. There has been continuous optimization for the processing of thermoplastic polymers [2,3], while recent advancements have led to the manufacturing of nanocomposite parts and products [4]. Among the species of nanomaterials that have been used for additives in IM manufacturing case studies are multiwalled carbon nanotubes (MWCNTs) in polypropylene (PP) nanocomposites for tuning electrical properties [5] and TiO 2 nanoparticles in high-density polyethylene (HDPE) nanocomposites for modifying thermal and mechanical properties [6].…”

Condition Monitoring of Additively Manufactured Injection Mould Tooling: A Review of Demands, Opportunities and Potential Strategies

“…Conformal cooling channels can follow the external geometry of the parts, providing more effective and consistent heat transfer. AM offers faster cycle times of up to 30% [ 8 , 9 ] and improvements in shape quality of the parts [ 9 ] compared to conventional cavities, as shown in Figure 2 .…”