Fabrication of Rotary Hook for Embroidering Machine by Metal Injection Molding

Embroidery process is the last stage of manufacturing textile products by sewing thread mechanism. The rotary hook that is manufactured by several stages of precision machining is a key part of completing the knot in embroidery. The rotary hook was manufactured by applying MIM (metal injection molding) techniques techniques, which combine the advantages of injection molding and metal powder sintering technologies, to obtain high productivity and dimensional accuracy. The sintering of injection product was performed at a temperature between $600^{\circ}C$ and $1,275^{\circ}C$ in an atmosphere of Argon with a relative density of 99% at $1,275^{\circ}C$ to 99% at the sintering temperature. A product with a hardness of 700 HV was manufactured by heat treatment. All the prescribed patterns were completed without obtaining a prescribed pattern for the developed prototype. Further, the wear test of the hook body carried out using gold thread also showed a similar decrease in size compared to that of the existing product. In this study, the manufacturing method was developed by applying MIM techniques to replace the manufacturing process of the rapidly executed rotary hook that entails various stages of machining. The developed manufacturing process is expected to boost the competitiveness of Korea's embroidery industry by replacing imports and contributing to more than 30% cost savings.

금속분말 사출성형법을 이용한 자수기용 로터리 훅 제조 연구