Metal Additive Manufacturing of Plastic Injection Molds with Conformal Cooling Channels

Abstract

Conformal cooling channels (CCCs) are widely used in the plastic injection molding process to improve the product quality and operational performance. Tooling that incorporates CCCs can be fabricated through metal additive manufacturing (MAM). The present work focuses on the MAM of a plastic injection mold insert with different CCC types that are circular, serpentine, and tapered channels with/without body-centered cubic (BCC) lattices. The entire manufacturing process of the mold insert is explained from the design step to the final printing step including the computational thermal & mechanical simulations, performance assessments, and multiobjective optimization. Compared to the traditional channels, conformal cooling channels achieved up to 62.9% better cooling performance with a better thermal uniformity on the mold surface. The optimum mold geometry is decided using the multiobjective optimization procedure according to the multiple objectives of cooling time, temperature non-uniformity, and pressure drop in the channel. Direct Metal Laser Sintering (DMLS) method is used for manufacturing the molds and the quality of the printed molds are analyzed with the X-ray Computed Tomography (X-ray CT) technique. The errors between the design and the printed parameters are less than 5% for the circular and tapered channels while the maximum deviation of the strut diameters of the BCC is 0.06 mm.

Characterization of Epoxy-Based Rapid Mold with Profiled Conformal Cooling Channel

“…An alternative coolant such as compressed gas, ultrafine bubble, or cold stream can also be employed to investigate the difference in the cooling performance. It should be noted that the fabricated injection mold can also be employed to plastic injection molding [ 26 , 27 ]. The heat transfer was affected significantly by the deposition of the limescale in the wall of the cooling channel during mass production using injection molding.…”

Application of New Conformal Cooling Layouts to the Green Injection Molding of Complex Slender Polymeric Parts with High Dimensional Specifications

“…From the perspective of increasing productivity, an efficient cooling design is critical, since the cooling phase takes up a large part of the cycle time. Designing adaptative channel geometries capable of maintaining a constant distance between the part surface and the cooling channels, even in those difficult areas where material accumulation occurs, can dramatically decrease cooling time and increase the uniformity of temperatures at the surface of the molded part [ 22 ]. In the same way, a uniform distribution of temperatures on the surface of the part helps to not only reduce the cooling time, but also helps to improve the quality of the part in terms of metrology [ 23 ].…”

“…Unfortunately, currently, the application of green conformal cooling channels for the cooling of injection molds is a complex procedure from initial design to the final manufacturing process of the mold. Despite previous literature and relevant review articles, unfortunately, there are still significant gaps in the research and application of conformal cooling layouts [ 22 ].…”

Experimental Study on the Characterization of Orientation of Polyester Short Fibers in Rubber Composites by an X-ray Three-Dimensional Microscope

“…As shown in Figure 1 , An X-ray three-dimensional microscope (micro-CT) [ 9 , 10 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ] is mainly composed of a micro-focus ray source system, a precision sample stage system, a high-resolution optocoupler detector, and a flat panel detector system. An X-ray three-dimensional microscope is an instrument developed based on the CT imaging principle.…”