Design and Fabrication of Injection Mold Using Gypsum

• Main Authors: Guo-Hao Li, 李國豪
• Other Authors: Chung-Chih Lin
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/j2kabw

碩士 === 國立虎尾科技大學 === 機械與電腦輔助工程系碩士班 === 104 === This study addresses the potential of gypsum as a candidate for the mold insert for injection mold. The design and fabrication process of the mold insert is implemented, starting with the gypsum powder, mixing the powder with binder, forming and machining the powder block into the mold insert, assembly and validation by injection test. This work provides an alternative mold-making process that can create tools quickly and with minimum labor cost for pilot run during product development. Traditionally the mold made of gypsum only can be applied in low pressure molding process such as casting, vacuum forming, etc. as result of its porosity. However the weak strength of gypsum makes it too brittle to be used in injection mold directly. In an attempt to develop a rapid and feasible method for making the mold insert with better Compressive strength, some processing parameters for gypsum preparation were investigated in this study. The mold insert made of gypsum were mechanically characterized and the influences of binder with different ratios, mechanical compression for the mold insert preparation, and thickness of the mold insert were assessed. The results showed the potential of the mold insert made of gypsum to compete with conventional techniques for improving venting, especially for the injection molding of small quantity of parts; also, it was showed that this technique allows the injection molded parts with adequate mechanical performance in welding line and, therefore, does not need to be restricted to the production of mockups and prototypes.