Enhancing Surface Temperature Uniformity in a Liquid Silicone Rubber Injection Mold with Conformal Heating Channels

Abstract

To enhance the productivity and quality of optical-grade liquid silicone rubber (LSR) and an optical convex lens simultaneously, uniform vulcanization of the molding material is required. However, little has been reported on the uniform vulcanization of LSR in the heated cavity. This paper presents a conformal heating channel to enhance the temperature uniformity of the mold surface in the LSR injection molding. The curing rate of an optical convex lens was numerically investigated using Moldex3D molding simulation software. Two different sets of soft tooling inserts, injection mold inserts with conventional and conformal heating channels, were fabricated to validate the simulation results. The mold surface temperature uniformity was investigated by both numerical simulation and experiment. In particular, both a thermal camera and thermocouples were employed to measure the mold surface temperature after LSR injecting molding. It was found that the uniformity of the mold surface for LSR injection mold with the conformal heating channel was better. The average temperature of the mold surface could be predicted by the heating oil temperature according to the proposed prediction equation. The experimental results showed that the trend of the average temperature of five sensor modes was consistent with the simulation results. The error rate of the simulation results was about 8.31% based on the experimental result for the LSR injection mold with the conformal heating channel.

Development of a Silicone Rubber Mold with an Innovative Waterfall Cooling Channel

“…A specific observation is that molds or dies with the WCC, produced through selective laser melting [ 37 ], may encounter issues such as cooling water leakage at connection points. A notable advantage, however, is that the WCC’s molds or dies exhibit no cooling water leakage during plastic injection molding when utilizing a one-process fabrication approach with rapid tooling technology [ 38 , 39 ]. This study utilized silicone rubber [ 40 ] to produce the injection molds with a WCC and CCC [ 41 ].…”

Optimizing heat source distribution in sintering molds: Integrating response surface model with sequential quadratic programming

“…Numerous studies have successfully attained enhanced temperature uniformity by optimizing the structural design of mold heating systems. Kuo et al [ 11 ] presented a conformal heating channel to enhance the temperature uniformity of the mold surface in the LSR injection molding. Baris et al [ 12 ] design a plastic injection mold with conformal cooling channels by metal additive manufacturing and achieved up to 62.9 % better cooling performance with a better thermal uniformity on the mold surface.…”

Enhancing the Cooling Efficiency of Aluminum-Filled Epoxy Resin Rapid Tool by Changing Inner Surface Roughness of Cooling Channels

“…Surface topography of the cooling channel was evaluated by laser scanning confocal microscope [25]. Effects of surface roughness of the inner wall of cooling channel on the cooling efficiency of aluminum-filled epoxy resin rapid tool [26] were investigated.…”