| 摘要 |
790,228. Laminated materials; seaming. IMPERIAL CHEMICAL INDUSTRIES, Ltd. Jan. 6, 1956 [Jan. 28, 1955], No. 2606/55. Classes 42 (1) and 140. Fluted upholstery material is made by assembling a cover sheet, 7, Fig. 1, over a backing sheet 2 laid on a flat plate 1 and welding the two sheets along localized lines, the flutes being formed and located in the cover-sheet by formers, 3, which are withdrawn after welding. The cover sheet may be a sheet of thermoplastic resin or a fabric coated on one or both sides with a thermoplastic resin, while the backing sheet may be thermoplastic coated canvas or hessian. Suitable coating compositions are polyvinyl chloride compositions. Welding may be done by high-frequency electric heating using horizontal upper electrodes 6, and plate 1 as lower electrode. Alternatively the electrodes may be plain and grooved rollers 1, 6, Fig. 3. The formers may be D-shaped or comprise the major segment of a circle; in the latter case the upper electrode consists of pairs of spring-loaded, finger-type electrodes. Padding such as foamed rubber may be inserted in the flutes after welding or may be inserted in hollow formers which may have bell-shaped ends or may be made in two parts. The padding may be clamped in position while the formers are withdrawn from the flutes. The foamed rubber may be of larger diameter than the fomer so that it expands to fill the whole flute. |
