3DP-MOLD

The duration of production of injection molds and their development cost for the production of parts by polymer injection are significant and are only interesting for large-scale productions. The 3DP-mold collaborative project, initiated by the Swiss Plastics Cluster, offers an innovative, flexible and low-cost process for the production of small series by polymer injection using impressions made by Additive Manufacturing. This project meets the requirements of Industry 4.0 with the transformation from mass production to mass customization.

Currently, the processes used to manufacture plastic injection molds are as follows:

• Machining by removing material and/or electro-erosion in steel blocks is expensive and is only profitable for mass production. The geometry of the parts will be subject to the limits of the machining of the mold and the time required to produce impressions can reach several weeks at a cost of several thousand francs.

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• The 3D printing of resin impressions reduces the time required to produce injection molds to a few days, and therefore the costs. However, the size of the series produced is limited to a few hundred pieces and current proposals are limited to simple pieces made from commonly used polymer materials.

The rapid evolution of 3D printing technologies, in particular SLA (Stereolithography) and LFS (Low Force Stereolithography), allows the partner companies of the 3DP-Mold project to acquire new flexible production skills and maintain their competitiveness. The various resins available on the market (SLA and LFS) with a selection of polymers used by the partner companies (biopolymers, consumer, technical and high-performance polymers, filled and unfilled, elastomers, etc.) are tested and evaluated in order to optimize the design of molds with 3D printed impressions and the injection process parameters for representative injected parts in terms of shape complexity, dimensional requirements and surface quality.

The 3DP-mold project started in June 2024 and will end in December 2025.