Hiroshi Koresawa

Injection mould with permeability utilised Metal Laser Sintering Combined with High Speed Milling

This paper describes the fundamental experimental results done on producing injection mould with permeability utilised Metal Laser Sintering Combined with High Speed Milling. The process is one of the layered fabrication processes that uses surface finish milling with every certain thickness interval of a mold. It is therefore suitable for producing molds having deep rib shape. However, mould of this shape have difficulty of venting air in the mould during the injection moulding process. This is due to residue air in the mould is compressed and generates heat thus giving negative effect on the product. By using permeable materials, influence of residue air on the product can be reduced. We confirmed that injection mould with permeability is effective for influence of residue air on the product and discussed in this paper.

Investigation on Fabricating 3D Structures Using Inkjet Printing Technology

Recently a rapid prototyping method for building parts layer-by- layer has led to interest in fabrication of electrical circuits and optical devices by inkjet printing. In this study a Java program was developed to control a commercial piezoelectric inkjet printer whose nozzles are about 30 μm with experiments focusing on the drop positioning and arrangement required to fabricate three-dimensional structure layer by layer. A single nozzle inkjet device whose nozzles are about 100 μm was also fabricated to study the basic operating parameters affecting the fluid drop formation such as cavity length, viscosity and amplitude voltage.

Development of a High Efficiency Rough Cutting for Metal Molds and Dies Machining.

This paper deals with a development of CAM system for rough cutting of metal dies and molds. A number of rough cutting methods have been proposed and developed to improve machining efficiency, however, there are remained functions to be considered. To solve remained functions, in this study, a new rough cutting system is developed. Developed system consists of two operational processes. In the first process, blank material is divided into several layers having thickness corresponding to available maximum cut of depth. Each layer is subdivided into domains possible to machine by tool path with linear motion. In the second process, contour line tool path is generated for machining unremovable parts in the first process. In this time, to reduce a sudden change of cutting force due to affect tool life, offset surface is generated as constantly keeping volume to be machined. Tool path simulations and practical machining tests by using developed system show : (1) total amount of NC data can be reduced for conventional rough cutting, and (2) both high efficiency machining and extension of tool life can be realized by applying linear motion and reducing change of cutting force.