Not long ago, a German client sent us a beautiful housing for quotation.
- Premium curved ABS + PMMA (scratch-resistant like glass)
- Horizontal louvered vents with downward-facing openings (classic dust/rain-proof style)
- The vents run continuously from the curved front/back walls onto the side walls, wrapping perfectly around the four corners
Renderings looked straight out of a Beurer or Stiebel Eltron heater, or a air purifier.
Our toolmaker immediately found a designing flaw at the corner of the housing, which made the housing unfeasible for injection molding:
Horizontal louvered vents on 2 plates at a 90-degree angles are too close to each other. Vents on each plate need a set of sliders to be made. 2 sets of sliders coming from 90-degree directions – they physically collide.
I believe the wrapping-the-four-corners louvered vents design were copied from stamped aluminium appliances where the wrap-around geometry is cheap and easy. A typical approach to enhance design, probably for cost saving or aesthetics improvement, by replacing materials. It works perfectly in stamped aluminium, starting with pressing the horizontal louver slots in the flat sheet to simply bending the sheet 90-degree at the corner.
However, the designer overlooked the manufacturing feasibility when the process was changed from metal stamping to injection molding. 2 sets of louvered slots require 2 sets of sliders. When they are adjacent at the corner, it causes space collides.
Our suggestions for housing design modification are to split the right-angled-shape plate to 2 parts or to remove side-wall vents. Not only making the housing moldable, the modification also cut down the mold cost significantly.
That was not the first time we met a gap between an aesthetically good design concept from a design company and a manufacturable and cost-effective production for a mold factory. Only factories with hands-on manufacturing experience understand the gap.
To close the gap, mold factories should stop quoting blind or obey clients’ requirement unconditionally. And, for brand owners, it costs nothing to consult a factory and pre-validate production features for injection molding by a toolmaker before final design approval.
#InjectionMolding #IndustrialDesign #DFM #ProductDevelopment #Manufacturing #DesignForManufacturability
Post time: Nov-20-2025