| 摘要 |
1323592 Moulding embossed sheet material; laminating ANVER SA 8 July 1970 [22 July 1969] 33060/70 Headings B5A and B5N [Also in Division B6] Material comprising a support sheet upon which is located a layer of embossed thermoplastics material is made by forming a die having a configured surface from a low dielectric loss material, impregnating an absorbent sheet of thermoplastic material with a meltable plastics of the same chemical nature, bringing the impregnated sheet into overlapping relationship with a support sheet and pressing the die against the overlapped sheets whilst applying a high frequency electric field to melt the components of the absorbent sheet, to shape the sheet thus melted and to bend it to the support sheet. Preferably the die is of a silicone based material and is formed by a casting operation. The impregnating plastics may be in liquid, paste or powder form and both the absorbent sheet and its impregnant may be of P.V.C., in which case the supporting layer is preferably leather or a textile material. If desired, a layer of reinforcing material such as glass wool, felt or cotton or even rubber is included in the finished article. As shown in Fig. 1 a support sheet 6 and an impregnated absorbent sheet are compressed and dielectrically heated between a silicone rubber die 3 and a flat support 2. In a second embodiment (see Fig. 3, not shown), a composite comprising a support sheet, an absorbent layer and a flat configured die are passed on a conveyer belt between a pair of pressure rolls connected across a source of high frequency current. In a third embodiment (see Fig. 4, not shown) such a composite is passed between the platens of a dielectric heating press. In the embodiment illustrated in Fig.- 5, an impregnated absorbent layer 5a and a support layer 6a are passed upon a belt 7 between dielectric heating pressure rolls 22 and 23, the upper of which 23 is provided upon its surface with configured mould cavities 23a. The strip thus formed is finally passed to cutting press 25 where individual articles are blanked out. |
