Apparatus for processing continuously fed elongate material

Abstract

Apparatus for processing continuously fed elongate material, such as forming sealed bags from continuously fed film tubes, uses at least one pair of orbital tools that are cantilevered from tool drives (e.g., crank arms) at one edge of the material, extending transversely across the direction of material travel to engage opposite faces of the material. During material engagement the tools run synchronously with the moving material, but may be returned upstream rapidly to reengage the material for the next processing cycle. In order to achieve a higher throughput an additional pair of tools can be used, cantilevered and driven from the opposite edge of the material, maintaining the same processing (e.g., sealing) time. Through this arrangement the tools on opposing sides can alternate contact with the material and be run independently of each other.

Description

TECHNICAL FIELD [0001] The invention relates to apparatus for the processing of continuously fed material with tools which act on the material intermittently. Such apparatus is used, for example, in the production of filled bags made from an elongate film tube which is welded or glued at discrete locations to form the ends of the bags and seal in their contents. The film material typically is made of a thermoplastic foil which can be sealed by the application of pressure and heat or adhesive. BACKGROUND ART [0002] Depending on bag length, tools (e.g., sealing jaws) typically used in such apparatus extend perpendicularly of the film feed direction and intermittently flatten and glue or weld the film tube, using heat and pressure to form the ends of the bags. To allow adequate time for the heated sealing jaws to act on the packaging material so that the film tube is sealed to form the bag ends, the sealing jaws must travel at the same speed as the film tube, and must return to the adv...

AI Technical Summary

Benefits of technology

"The invention provides an improved apparatus for processing elongated material, such as film tubes, by using cyclically driven tools that can increase the throughput of processed material while maintaining the required synchronous movement of the tools with the material. The tools are cantilevered transversely of the processing path, which allows for independent control of the tool drives and flexibility in adjusting tool motion. The apparatus can be used in a bag forming and filling apparatus to produce bags with sealed edges. The invention also provides a swivel connection between the tool carrier and the crank arm, simplifying pneumatic and electrical connections to the tool."

Problems solved by technology

The paddle wheel-type sealing mechanism significantly limits throughput speed because of the required contact (sealing) time of the sealing jaws, and because return of the sealing jaws upstream to the start position requires more time than the filling of a bag, thus requiring the film feed to be slowed or stopped.

Similar problems exist with other types of known sealing mechanisms.

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