| abstract |
| Background Before 1980s, Korean jewelry industry used gold and silver as the main ingredient of jewelry and prioritized spot and material value of jewelry as the wealth. Such social perception gradually changed in 1980s through business expansion of jewelry shops and marketing promotion. Such change was brought by domestic business condition extended by economic growth. urthermore, in early 1980s, color television became popular in South Korea and various beautiful colors captivated consumers. As a result, jewelry in harmony with color and design became necessary. In addition, Asian Game in 1986, Iksan Jewelry Business Valley establishment in 1987, Olympic in 1988, liberalization of jewelry import, change from license system to report system for business foundation, and liberalization of overseas travel globalized eye of consumers. Such social environment change largely vitalized domestic jewelry market and domestic jewelry market expanded to include not only jewelry but also accessories. As boundary of accessories and jewelry was unclear, jewelry market broke away from handmade measures which is limited to small amount of type and production and entered casting generation which allows various kinds and mass production. However, although many years have passed since the introduction of such casting system, there is no clear data or standard for optimal casting methods. Also, there has been no research on supplementing method for various defects during casting and supplementing method is only passed by oral tradition or experience of technicians.
Methods This study aims to organize various defects frequently occurred during casting, discover causes of such defects, and suggest supplementing methods for such defects. Furthermore, this study organized general example and form for casting and analyzed easily accessible environment for high-quality casting result. The study also conducted research on type of defect and supplement method for such defects through field experience. For alloy jewelry casting defect, the study took a picture of defect when casting failed. Then, the study attached the picture and solved the cause of defect since product failed on casting has unique pattern. After solving the cause, the study compared the pictures of defect picture and result picture and organized corresponding casual relationship. The study also created data on optimized casting method based on survey conducted on people involved in jewelry industry at field. Through the survey on the most frequent answer and averaged content, the study covered stable casting method with low failure rate. The study also referred to the fact that different casting data is used based on thickness of the product group.
Result Following is the defect type, supplement method for major defect, and recommendation obtained from this study. First, among the causes of major defect on casting, defects occurred during wax injection process were identified. Defect during wax injection, defect due to was pressure and inadequate rubber mold bonding, defect due to insufficient review, supplement measures after wax injection, defect due to careless wax tree glueing, and defect due to unskilled wax stream bonding were found through test. The study researched on supplement method and suggested recommendation for solving such defects. Second, defects occurred during investment mold process were identified. The defect due to mixing ratio difference between gypsum and water, defect due to unskilled vacuum dewaxing during investment mold, and defect due to gypsum setting time control were identified through test. The study researched on supplement method and suggested recommendation for solving such defects. Third, defects occurring due to casting temperature control failure were identified. The defect due to unskilled temperature control for dewaxing(burning) at electric furnace, squeeze casting(melting pot) temperature defect due to unskilled control of oxygen/gas torch, differentiation based on thickness and width of cast(object) were identified through test. The study researched on supplement method and suggested recommendation for solving such defects.
Conclusion The research shows that the development of a more systematic optimized casting technique and production of successful products will contribute to the virtuous cycle of the precious metal related industry by taking advantage of the loss rate and time saving effect considering the high precious metal characteristics. |
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| Key Words |
| 귀금속, 주조공법, 주조결함, Precious, Casting Method, Casting defect |
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