| 摘要 |
A method of forming articles such as ring binders comprising laying down sheets (8, 9, 10) of a stiffening material sandwiched between a pair of facing sheets (6, 12) of a plastics material, securing the edges of the facing sheets (6, 12) to one another by high frequency welding around the peripheries of the sheets (8, 9, 10) and securing a further member (13) of a plastics material to the facing sheet (12) at a position overlying the sheet (10) of stiffening material thereby to form a pocket, the method including the step of providing, between the sheet of stiffening material (10) and the facing sheet (12), a piece of electrically conductive material (11) at the position at which the further member (13) is to be secured, welding of the further member (13) to the facing sheet (12) at a position overlying the stiffening member (10) being effected simultaneously with welding together of the two facing sheets (6, 12) around the peripheries of the sheets (8, 9, 10) of stiffening material. <IMAGE> |
