摘要 |
PCT No. PCT/SE96/01300 Sec. 371 Date Apr. 8, 1998 Sec. 102(e) Date Apr. 8, 1998 PCT Filed Oct. 11, 1996 PCT Pub. No. WO97/13695 PCT Pub. Date Apr. 17, 1997A method of producing a rectangular cross-section cardboard tubing by passing a plurality of cardboard strips having a thermoplastic coating thereon through a heating unit so as to hear the plurality of strips and melt the thermoplastic coating. Thereafter, the plurality of heated strips are passed through a guiding unit so as to align the strips in an overlapped configuration. The aligned plurality of strips are wound around an elongated, rectangular cross-section, rotating core so as to place the plurality of strips in an overlapped, spiral configuration along the core and form a tubing. The tubing is fed along the core, and a cutting unit cuts the tubing into lengths.
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