Original paper(Vol.45 No.8 pp.871)

Development of SMC roll forming - influences of reduction and driving speed -

Katayama Tutao; Yamanouchi Toshiyuki; Hayakawa Yuuzuo; Hakotani Masahiro

Abstract:SMC (Sheet Molding Compound), which has such excellent characteristics as surface brilliance, formability and mechanical property, is usually formed by compression molding. This method has short cycle time of processing, but needs huge energy for forming because of formation of hydrostatic stress domain in the mold. So, roll forming is proposed for SMC so as to decrease the forming energy by losing a formation of hydrostatic stress and to keep short cycle time.
At first, the fundamental experiment is carried out to see the behavior of deformed material using a constant reduction on each forming condition. It is necessary to decrease the number of roll stand for making a compact roll forming system. But the condition for large reduction results in that the deformed material shows an instability behavior between roll stands. And, the condition for low reduction can improve the formability of the flange of channel shaped products.
The tension brought in by the difference in driving speed makes material stable from the exit of one roll to the entrance of the next roll, and this tensile load affects the deformation of the materials. The result of this research is useful to decide the driving speed during reduction.

Key Words:SMC, roll forming, reduction, driving speed