| 摘要 |
PURPOSE:To enhance the productivity of a sheet for lowering the price of the product by continuously molding a bottom plate portion, a sheet surface portion, and panel portions between said portions by using an injection molding machine capable of concurrently molding different kinds of material. CONSTITUTION:A bottom plate 1 is molded into a side arched from of a rigid synthetic resin material, e.g., polypropylene copolymer, etc., in such a way that the lower edge portion of widthwise side wall is gradually raised from almost intermediate portion to the rear end 1b of number plate side. A resin spring 2 is molded into a side C-shaped form on the bottom plate 1 by injection molding method using an inorganic fiber-reinforced rigid synthetic resin material, e.g., glass fiber-reinforced nylon, etc. Also, a sheet surface skin 3 is concurrently molded of a soft synthetic resin material, e.g., polyvinyl chloride, etc., in such a way that it is hot-bonded with all circumferences of the bottom plate 1 and the upper end 2a of the resin spring 2. |
