SMCのロール成形―非均質に基づく界面効果を考慮した成形性―
Roll Forming of SMC Considering the Boundary Effects Caused by Heterogeneous Properties
平井恒夫
Hirai, Tsuneo
SMC Compression Moulding is used extensively today in manufacturing the outer panels and structural parts of transportation vehicles. In an effort to further decrease the power requirement caused by spherical stress tensor while maintaining cycle time, fabrication by rolling has been developed. A continuous uniform cross section by longitudinal rolling in progressive steps and by carrier type rolling using more complicated shaped dies driven by a coupling-roll unit. Actual moulded examples in T-shaped and channel shaped profiles indicate good surface quality and especially suitable fibre orientation.
The basic deformation behavior depends on the given conditions for the rolling process. The physical properties of the SMC due to the following characteristics of the SMC, that is, the heterogeneous nature and the laminate component.
As the SMC is a laminate, the initial rolling behavior of the macroscopic interface between plies with resin-rich surfaces should be considered. As the interface could be assumed discontinuous compared with the prepreg material, the deformation on the admissible stress field and stress field discontinuity in the cross section was analyzed to obtain the eigen modes.
The first problem is to control the flow and filling behavior during the fabrication process which is influenced by the rigid rotation due to different stiffnesses of fibre and resin at the microscopic interface covering each ply range.
The effects of feed rate on the flow pattern is a very important problem for the fabrication of different shape products. The selection of a lower value of feed rate generally gives better filling behavior for heterogeneous materials compared to homogeneous materials.
Key words: Roll forming / Feed rate / Longitudinal continuous rolling / Carrier type rolling / Macro-and micro-scopic interface