Method of registering zipper for reclosable package

Abstract

An apparatus and method is disclosed for the manufacture of reclosable packages or bags. A drag sealer is upstream of the form fill and seal apparatus and is used to seal a continuous length of zipper to web or film. Upstream from the drag sealer, a zipper clamp is used to hold the zipper in place during slider insertion and end stomping, as regulated by a film encoder. A zipper accumulator configured as a dancer and a zipper de-accumulator are used to compensate for the intermittent motion of the continuous length of zipper.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method and apparatus for the manufacture of reclosable packages or bags, wherein a drag sealer is used to apply the processed zipper to the film web, then a form fill and seal (FFS) machine is used to finish the package or bag.

2. Description of the Prior Art

In the prior art of the manufacture of reclosable packages, particularly, form fill and seal processes, it is known to use an eye mark printed on the film in order to register the film, and to start the end stomp and slider insertion. However, such a configuration requires a separate step or previous manufacturing process to print the eye marks and the resulting printed film cannot easily be shifted to a manufacturing process wherein different dimensions are required.

Similar prior art manufacturing processes have typically included a drag sealer such as is disclosed in U.S. published patent application serial no. 2006/0207727, entitled “Apparatus for Repeatedly Advancing Fastener Tape a Predetermined Distance”, wherein the fastener tape is joined to the sides of a folded web of packaging material.

While these prior art manufacturing processes have been satisfactory for their intended purposes, further improvements are sought, such as eliminating the requirement for printed eye marks on the web.

OBJECTS AND SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a method and apparatus for the manufacture of reclosable packages or bags wherein the requirement for a printed eye mark is eliminated.

It is therefore a further object of the present invention to provide a method and apparatus for the manufacture of reclosable packages or bags wherein the drag sealer is used to fasten the zipper tape to the film prior to the form fill and seal manufacturing steps.

These and other objects are attained by a method and apparatus for the manufacture of reclosable packages or bags wherein the drag sealer is upstream of the form fill and seal apparatus. This method and apparatus further uses an encoder count on the film to start the end stomp and slider insertion. A zipper clamp is used to hold the zipper in place during slider insertion and end stomping. A zipper de-accumulator is used to feed the continuous motion drag sealer. When the insertion and stomp process is complete the zipper clamp is opened and the de-accumulator is forced to its extended position. The continuous motion of the drag sealer and the extension of the de-accumulator pulls the zipper through the slider inserter and end stomp units. The film encoder count then starts the process again. The bag machine then uses the slider or zipper end stomp for registration using a light or mechanical sensor.

A form fill and seal step is subsequently performed to complete the reclosable package or bag.

BRIEF DESCRIPTION OF THE DRAWINGS

Further objects and advantages of the invention will become apparent from the following description and from the accompanying drawings, wherein:

FIG. 1 is a schematic of the apparatus and method of the present invention.

FIG. 2 is a schematic of a drag sealer as used in the apparatus and method of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings in detail wherein like numerals indicate like elements throughout the several views, one sees that FIG. 1 is a schematic of the apparatus 10 and method of the present invention.

Apparatus 10 includes spool 12 from which a continuous length of zipper 14 is fed. Zipper accumulator 16 is comprised of rollers 18, 22 with stationary axes of rotation and roller 20 which has an axis of rotation which moves away from rollers 18, 22 to accumulate the continuous length of zipper 14 and which moves toward a position between rollers 18, 22 to de-accumulate the continuous length of zipper 14. Zipper accumulator 16 is thereby configured as an unwind dancer to accumulate zipper 14 from spool 12 while downstream portions of zipper 14 are intermittently clamped into stationary position. Zipper accumulator 16 can also isolate downstream apparatus components from irregularities in the rotation of spool 12. End stomper 26 uses ultrasonic apparatus to place end stomps on the zipper 14. Likewise, inserter 28 places the zipper sliders on the zipper 14. End stomper 26 and inserter 28 operate while zipper clamp 30 holds zipper 14 in stationary position. Likewise, zipper de-accumulator 32, is comprised of rollers 34, 38, with stationary axes of rotation and roller 36 which has an axis of rotation which moves away from rollers 34, 38 to accumulate the continuous length of zipper 14 and which moves toward a position between rollers 34, 38 to de-accumulate the continuous length of zipper 14. Zipper de-accumulator 32 thereby operates to provide a continuous feed of zipper 14 (including end stomps and sliders) to drag sealer 40 notwithstanding the intermittent motion of zipper 14 due to the upstream clamping of zipper 14 by clamp 30. More particularly, when clamp 30 is released or opened after the operation of end stomper 26 and inserter 28, zipper de-accumulator 32 is forced to its extended position thereby allowing accumulating zipper 14 to provide continuous feeding during the next clamping operation. Zipper 14 along with web 52 as fed from web spool 50 is fed to drag sealer 40. The continuous motion of the drag sealer 40 and the extension of the de-accumulator 32 pulls the zipper 14 through the end stomper 26 and the slider inserter 28. Moreover, the movement of web 52 from web spool is monitored by encoder 53.

Web or film 52 is sealed to zipper 14 by drag sealer 40. Optical sensor 54 senses either the slider or the end stomp placed on the zipper 14 so as to provide the form fill and seal apparatus 60 with information regarding the registration of the zipper 14 as the web 52 with zipper 14 sealed thereto is fed to form fill and seal apparatus 60 for the formation of a reclosable package or bag.

Drag sealer 40 is shown in further detail in FIG. 2. Web 52 and zipper 14 are pulled through the nip formed between first and second endless barrier strips 60, 62 and are sealed to each other by first pair of reciprocating sealing bars 64, 66 and second pair of reciprocating sealing bars 68, 70. The sealing is accomplished by electrically heating the sealing bars 64, 66, 68, 70, the heat being conducted through the first and second endless barrier strips 60, 62 made of polytetrafluoroethylene (Teflon) or a similar material, which circulate on respective first set of rollers 72, 73, 74, 75 and second set of rollers 76, 77, 78, 79. Additionally, the endless barrier strips 60, 62 and the web 52 with zipper 14 pass between first pair of guide rollers 80, 81 prior to first set of sealing bars 64, 66; second pair of guide rollers 82, 83 between first set of sealing bars 64, 66 and second set of sealing bars 68, 70; and third pair of guide rollers 84, 85 after second set of sealing bars 68, 70. Optional guide roller 86 may be used to redirect web 52 with zipper 14 sealed thereto if necessary.

Pinch rollers 88, 90 pull the web 52 with the zipper 14 sealed thereto through drag sealer 40 and are typically part of form fill and seal apparatus 60. As stated previously, form fill and seal apparatus 60, which may be any of the numerous such devices known in the prior art, completes the reclosable package.

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.

Claims

1. An apparatus for providing zipper to a reclosable package making apparatus comprising:

a supply of continuous length of zipper;

a device for intermittently maintaining a portion of the continuous length of zipper in a stationary position;

a device for inserting a slider onto the portion of continuous length of zipper in a stationary position;

a device for placing an end stomp onto the portion of continuous length of zipper in a stationary position;

a supply of web;

an encoder for regulating the feeding of web from the supply of web;

a sensor for sensing the end stomps or the sliders on the continuous length of zipper; and

a drag sealer for sealing the zipper to a web from the supply of web.

2. The apparatus of claim 1 wherein the device for intermittently maintaining a portion of the continuous length of zipper is a clamp.

3. The apparatus of claim 2 wherein the device for placing an end stomp onto the portion of continuous length of zipper uses ultrasonic apparatus.

4. The apparatus of claim 3 further including an accumulator device to allow feeding the continuous length of zipper from the supply while a portion of the continuous length of zipper is in a stationary position.

5. The apparatus of claim 4 wherein the accumulator device includes first and second rollers with stationary axes of rotation, and a third roller with an axis of rotation which moves away from the first and second rollers to accumulate the continuous length of zipper and which moves toward a position between the first and second rollers to de-accumulate the continuous length of zipper.

6. The apparatus of claim 4 further including a de-accumulator device to allow feeding the continuous length of zipper to the drag sealer while a portion of the continuous length of zipper is in a stationary position.

7. The apparatus of claim 6 wherein the de-accumulator device includes first and second rollers with stationary axes of rotation, and a third roller with an axis of rotation which moves away from the first and second rollers to accumulate the continuous length of zipper and which moves toward a position between the first and second rollers to de-accumulate the continuous length of zipper.

8. The apparatus of claim 6 further including a package making apparatus receiving the web with zipper sealed thereto from the drag sealer.

9. The apparatus of claim 8 wherein the package making apparatus is a form fill and seal apparatus.

10. The apparatus of claim 9 wherein the form fill and seal apparatus includes rollers to pull the web with zipper sealed thereto from the drag sealer to the form fill seal apparatus.

11. (canceled)

12. The apparatus of claim 1 wherein the sensor is optical.

13-14. (canceled)

15. The apparatus of claim 1 wherein the drag sealer includes at least one pair of opposed sealing bars.

16. The apparatus of claim 1 wherein the drag sealer includes at least two pairs of opposed sealing bars.

17. The apparatus of claim 15 where the drag sealer includes two loops of material which travel between the sealing bars and the zipper being sealed to the web.

18. The apparatus of claim 17 wherein the two loops of material are comprised of polytetrafluoroethylene.

19. The apparatus of claim 1 wherein the supply of continuous length of zipper includes a first spool.

20. The apparatus of claim 19 wherein the supply of web includes a second spool.