| 摘要 |
PURPOSE: To facilitate perforating workability by a method wherein a specific number of sheets of a prepreg obtained by impregnating napped woven glass base material with a resin and drying, are piled up, and an amount of glass fiber in the laminate is reduced by thermally pressurizing. CONSTITUTION: Napped woven glass base material becomes a prepreg of a large space and a much resin content. When such prepreg of the much resin content is piled up and thermally heated, a flow of a resin at an initial period of heating is large, and a specific thickness can not be secured. Then, as resin varnish to be impregnated with, the resin varnish wherein 100-150 pts.wt. filler is mixed in 100 pts.wt. resin solids content to raise melt viscosity, is used. As the filler, talc, calcium, carbonate, etc., are used. That of at most 3 Mohs hardness is preferable among them. Since an amount of glass fiber in a laminate is decreased relatively, resistance to a perforating tool is little. Therefore, clean perforation can be carried out, and since the base material is a woven fabric and the fiber is continuously woven, strength can be secured. |
