Manufacture of Spinnerets for Synthetic Micro-fibers by LIGA and Micro-injection Molding Technique

摘要

In the past, the capillaries of fiber-spinneret were made by micro drilling or by micro electro-discharge-machining (M-EDM). However, the productivity and uniformity of M-EDM are restricted. Hence, a new approach related to LIGA technique was developed. The micro mold of the capillaries was made by LIGA. Micro plastic cores were then duplicated by micro injection molding. With consequent treatments and electro-forming, the spinneret die can be mass produced. Better process conditions for micro molding will be determined by Taguchi's experiment design method. Through a single injection molding cycle, a 48-capillary structure was formed at once. The diameters of each capillary were inspected at three locations along the longitudinal direction carefully. The results show that the accuracy of the diameters of capillaries can be controlled within 200 ± 1 μm. Capillaries die to spin * and w-shaped micro-fibers were also developed in this work. Thanks to LIGA process, spinnerets with higher aspect ratios (even up to 30) can be achieved more easily. By applying micro injection molding, consequent treatments and electro-forming processes, the spinnerets can be produced in a batch and mass production way. The technology developed here can also be used in the fabrication of Micro-Electro-Mechanical (MEMS) components.