Machine for processing of web stock particularly of thermoplastic synthetic plastic material

Abstract

Abstract A machine in which a plastic film web continually unwound from a supply roll passes through a film motion equalizing take-up mechanism from which it is draw generally horizontally stepwise by advance rolls intermittently actuated to permit seam welding, severing, punching, and other film working operations-as used, for example, in manufacture of bags, sacks or other packaging-to be performed on the web while stationary, at a "tool" station subsequently to the take-up. The take-up mechanism, as a separate assembly including continuous draw rolls and swinging equalizer rolls, is mounted above and shiftably horizontally along the general web path, so that the spacing from the take-up to the tool station may be kept short for better and safer feed as permitted by the tooling used. With spaced pairs of draw rolls commonly driven by a continuous flexible chain or belt drive and establishing a reach of intermittently moved web along which one or more process step tools or stations are locatable, the first draw pair is also mounted on the shiftable take-up, and the flexible element is at one end supported by a rotating idler shiftable to change belt tension as required by or for the draw roll shift. By dividing the advance rolls and idler each at mid-length into aligned halves connectable to rotate unitarily and disconnectable for independent rotation and providing separate belt drives on each side, single wide webs or two distinct webs (with likewise divided tooling where appropriate) may be processed through a single two-section shiftable take-up, and with respective separately shiftable take-ups plastic film products of different lengths may be fabricated. Two spaced take-ups are disclosed along one web so that continuous-intermittent- continuous motion sequence of a web is available; also a single take-up, shiftable away from the supply roll, so that tooling may be used carrying out operations on the web while moved continuously such as slitting or cylinder printing in a machine carrying out also intermittent type operations. Also disclosed is modular construction for the take-up and for other operating sections of a film working machine.

Inventors

• 👤 Michael Lehmacher
• 👤 Hans Lehmacher

Bibliographic Details