1. Field of the Invention
This invention relates to the manufacture of reclosable packaging and pertains to a method for improving registration when inserting a zipper with slider clips into packaging film, by use of an eye-mark and an encoder.
2. Description of the Prior Art
The prior art of zipper registration in the manufacture of reclosable packages and bags is well-developed for its intended purposes. For example, commonly-assigned U.S. Pat. No. 7,172,545 entitled “Registration of Intermittently Moved Fastener Tape With Continuously Moving Web” issued on Feb. 6, 2007 to Howell and Wallace discloses an apparatus and method using continuous film motion through the zipper-sealing machine and only the zipper has intermittent motion (stop-starts) with the aid of an accumulation assembly. Related art is disclosed in US 2006/0207727 entitled “Apparatus for Repeatedly Advancing Fastener Tape a Predetermined Distance” filed on Mar. 16, 2005 by Cortigiano and US 2008/0134632 entitled “Method of Registering Zipper for Reclosable Package”, filed on Dec. 6, 2006 by Howell.
Other prior art devices utilize a similar method to accumulate film. The machine jogs the film and attached zipper using a servo to eye-mark and stop it. Upstream of the stop, an ultrasonic unit stomps the zipper but no clip is inserted. Downstream of the stop, the film with the zipper attached is fed out of an accumulator to the bagger.
However, further improvements are sought in the registration of the zipper, particularly when inserting zipper with clips into packaging film.
It is therefore an object of the present invention to provide improvements in the registration of a zipper in the manufacture of reclosable packages, particularly when inserting zipper with clips into packaging film.
It is therefore a further object of the present invention to allow a continuous motion bagger/wrapper to be coupled with an intermittent motion zipper-sealing machine.
These and other objects are attained by a method and apparatus which uses a servo motor and an accumulator dancer arm to buffer a stop-start motion of film, with the zipper and clips (or sliders) already attached, in the zipper-sealing machine. The servo drives the film to an eye-mark and then stops the film. Downstream of the servo motor, film,runs out of an accumulator to the vertical or horizontal bagger. Upstream of the servo motor, the film and zipper stops so that the zipper can be processed, typically by an ultrasonic crush application and a clip application.
Further objects and advantages of the invention will become apparent from the following description and from the accompanying drawings, wherein:
Referring now to the drawings wherein like numerals refer to like elements throughout the several views, one sees from
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As film 200 passes in front of eye-mark sensor 34 and an eye-mark 202 is detected, the eye-mark sensor 34 signals servo motor 36 to momentarily stop film 200 upstream of servo motor 36. Zipper 100 is likewise stopped upstream as it passes through first and second ultrasonic crush stations 22, 24 and first and second clip insertion stations 26, 28 thereby permitting the crush and clip insertion operations to be performed on a momentarily stationary zipper. Meanwhile, the operation of the second accumulator 40 allows the film 200 (with zipper 100 attached) to continuously feed the bagger/wrapper apparatus at a substantially constant speed. After the operations on stationary zipper 100 at stations 22, 24, 26, 28 are completed, the servo motor 36 drives zipper 100 and film 200 at a rate fast enough to replenish the second accumulator 40. The process then repeats itself, thereby allowing for intermittent motion of the zipper 100 and film 200 while providing a continuous feed at a substantially constant speed from second accumulator 40 to the bagger/wrapper apparatus.
Thus the several aforementioned objects and advantages are most effectively attained. Although preferred embodiments of the invention have been disclosed and described in detail herein, it should be understood that this invention is in no sense limited thereby and its scope is to be determined by that of the appended claims.
This application claims priority under 35 U.S.C. §119(e) of provisional application Ser. No. 61/044,563 filed on Apr. 14, 2008, entitled “Zipper Registration Using Eye-Mark Encoder”.
Number | Date | Country | |
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61044563 | Apr 2008 | US |