摘要:
945,854. Seaming non-metallic sheet material. FR. HESSER MASCHINENFABRIK A.G. Sept. 4, 1962 [Dec. 11, 1961], No. 33802/62. Heading B5K. [Also in Division B8] Seams in fibrous packaging material, such as paper or cardboard, are formed by applying high frequency pressure impulses in the region to be seamed. Blanks or a web of the fibrous material may be passed between a sonotrode of an ultrasonic generator and a fixed anvil. The sonotrode is pressed under a predetermined pressure against the parts to be seamed whilst the generator transmits pressure impulses, preferably in the supersonic range, to the sonotrode. The pressure vibrations are preferably applied parallel to the plane of the layers of material to be seamed. Seaming may be continuous or intermittent. The method is applicable to seaming tea infusion bags made of coarse fibrous, permeable filter paper.