| 摘要 |
601,256. Compound sheet materials. HAIM, G., and ZADE, H. P. June 5, 1945, No. 14172. [Class 140] [Also in Group XVII] Sheets or films of polythene or like thermoplastic material of low loss angle and dielectric factor are welded together over certain areas only by high frequency electric field welding by applying to the outer surfaces of the polythene a film of polyvinyl chloride or other material of high loss angle covering only those areas to be welded. The polyvinyl chloride may be cut from film or sheet in the form desired, or may be applied by coating, stencilling, or printing. The pressure may be applied by metal plates or rollers constituting the electrodes. Specification 592,960 is referred to. |
