SFT, which has a high glass fiber content, is one of the effective methods to replace metal and secure weight reduction and price competitiveness. Also, paintless injection molding in which a functional pattern is applied to the mold surface can eliminate the cost of painting. In this study, three types of SFTs were manufactured by adding round glass fibers measuring Φ7 and Φ10 μm and flat glass fiber measuring 27 × 10 μm for the experiment. DOE (Design of Experiment) was conducted to confirm the change in the warpage of the product and the gloss of the micro pattern due to the cross-sectional shape of glass fibers and the major injection conditions. Based on the results, it was identified that the flat SFT had a very small warpage compared to the round SFTs, and the holding pressure was the main factor in the warpage of all three SFTs. The Φ7 μm SFT had the largest gloss value, and the Φ10 μm SFT and the flat SFT had similar average values. All SFTs demonstrated an enormous change in gloss according to the change in mold temperature. The flat SFT had the smallest standard deviation in both warpage and gloss.

With the development of 3D printing technology, its applications are expanding. However, 3D printed parts present a challenge in achieving high-quality surface roughness because of stair stepping problems. With the recent application of 3D printing in electronics and the visibility of flow in microfluidic systems, high-quality surface roughness is needed. Chemical mechanical polishing (CMP), one of semiconductor fabrication processes, has the longest planarization length in terms of productivity among existing planarization methods. In this study, we investigate friction characteristics of polishing of ABSLike resin material printed by the Stereolithography Apparatus (SLA). At the polishing of ABS-Like resin, the friction force has a high value at the beginning of polishing, but it stabilizes as processing progresses because of the effect of waviness on the printed material. The surface roughness (Sa and Sz) reduction and the glossiness of ABS-Like resins after polishing appear to be related to the reduction of the Shore D hardness resulting from the rise in the polishing process temperature caused by friction during polishing.