| 摘要 |
676,709. Seaming non-metallic sheet material. ANDREWS, A. M., and PHILLIPS SCREW CO. Dec. 22, 1949, No. 32871/49. Class 42 (i). Two pieces of non-metallic flexible sheet material are seam-bonded together by soaking a thread in a bond-effecting liquid, laying the thread with its absorbed liquid between the sheets of material where the bond is desired while substantially protecting the liquidcontaining thread from the atmosphere, and immediately applying pressure to the sheets of material and the thread therebetween. As shown, plastic sheets 3, 4 (e.g. of vinyl resin) are fed between driven pressure rollers 14, 15. Thread is drawn from a spool 5 through a reservoir 1 containing solvent 2 for the plastic material ; surplus liquid is stripped from the thread by a felt 9 against which it is spring- pressed. The thread then passes through a tube 12, which protects it from the atmosphere, to a point 13 at which it is fed between the sheets 3, 4 as they pass between rollers 14, 15. Roller 15 is grooved to accommodate the thread and allow the sheets to be pressed together at each side of the thread. The solvent squeezed from the thread by the rollers effects two parallel bonds spaced apart by the width of the thread. The thread, which is not bonded to either sheet, may be subsequently withdrawn from the seam, or may be broken by stretching the material along the seam ; or the thread may be made of a material related to that of the sheets so that it bonds to the sheets, the groove in roller 15 being in this case omitted. A small amount of the material of the sheets may be dissolved in the solvent. |
