Kazuo Matsunaga

Relationlship between Springback and Stacking Characteristics of Paper

Paper handling technology related to sorting, feeding and stacking, has recently become of importance as a result of the development of high-speed, high-resolution printers. Consequently, the clarification of paper processing characteristics is of vital concern. Although there have been numerous reports on metal processing characteristics, very few studies have been carried out on paper processing characteristics such as springback.In the previous paper, a mechanical model for paper behavior was proposed. The present study deals with paper processing characteristics related to stacking.Using the previously proposal mechanical model, an analysis was made of springback in the bending phenomenon for paper and the results were compared with those for metal plates. The results were successfully applied to make clear the correlation between springback and stacking stability in a printer. The main conclusions are as follows:(1) When the strain rate dependency was taken into consideration, close agreement was found between the observed and calculated values of paper in this springback analysis.(2) The stacking stability increased as springback decreased. It was seen that greater paper thickness and the absence of a fixing process results in better stacking characteristics.

Weldability of copper alloy with YAG laser.

This paper describes how the lapped spot welding of copper alloy material for structural components is performed with a YAG laser. Welding conditions and their relation to mechanical characteristics and metal structures is examined. The main results of this paper are summarized as follows: (1) Laser power, amount of defocus and welding strength are determined by using newly introduced equations. (2) Laser power is 10-12.5 J, amount of defocus is ±1 mm, and the pulse duration is 1-3 ms. With these conditions, a welding strength of over 150 N is obtained. (3) The welded part of the metal structures is, dendrite. This clarifies the validity of the metal structures and hardness characteristics under YAG laser operating conditions.