Abstract
<title>Abstract</title> <p>Injection molds with conformal cooling channels (CCC) produced by selective laser melting (SLM) are widely reported to reduce cycle time in thin-walled applications, yet their comparative economic performance for thick-walled geometries has not been experimentally quantified. This study presents the first three-way experimental comparison of mold concepts for thick-walled PP-R injection molding (wall thickness up to 8.8 mm): conventional 316L stainless steel, copper-beryllium (CuBe) alloy produced by conventional machining, and 316L with SLM-manufactured CCC incorporating lattice-structure optimization. The evaluation combines two-stage finite element simulation (Moldflow), real-process trials with embedded pressure and temperature sensors, part characterization, and a financial sensitivity analysis based on real ERP cost data. CuBe reduced the injection cycle by 18% and product cost by 12%, at a 10% mold investment premium and an 8-fold demand growth requirement for 3-year payback. The SLM-CCC mold achieved 11% cycle reduction and 7% cost saving, but required 142% longer fabrication time (2.42× the conventional duration), a 46% investment premium, and 18-fold demand growth for equivalent payback. All three mold concepts produced parts meeting full functional qualification for pressurized hot-water hydraulic systems. For this geometry class, CuBe alloy molds outperform SLM-CCC across every economic metric examined. The 18-fold demand growth threshold, rather than the observed 11% thermal gain, constitutes the critical variable for evaluating SLM adoption in thick-walled injection molding.</p>