EP-4737111-A1 - WEB FORMING DEVICE AND FORMING METHOD, AND BAG MAKING MACHINE FOR DOUBLE BAG

EP4737111A1EP 4737111 A1EP4737111 A1EP 4737111A1EP-4737111-A1

Abstract

A web former forms a double-layer web folded in half and including a first web and a second web. The web former includes a first tension adjuster configured to control tension of the first web being fed in a longitudinal direction of the first web, and a second tension adjuster configured to control tension of the second web being fed in a longitudinal direction of the second web independently of the first tension adjuster. The web former includes a guide disposed downstream of the first and second tension adjusters to guide the first web and the second web downstream while superposing the first web and the second web on each other, and a single triangular plate disposed downstream of the guide to fold the first and second webs superposed by the guide, in half along a fold line extending in the longitudinal direction of the first and second webs.

Inventors

OHNISHI YUJI

Assignees

Totani Corporation

Dates

Publication Date: 20260506
Application Date: 20240611

Claims (12)

A web former for use in making double-layer bags and for forming a double-layer web folded in half and comprising a first web and a second web, the web former comprising: a first tension adjuster configured to control tension of the first web being fed in a longitudinal direction of the first web; a second tension adjuster configured to control tension of the second web being fed in a longitudinal direction of the second web independently of the first tension adjuster; a guide disposed downstream of the first and second tension adjusters to guide the first web and the second web downstream while superposing the first web and the second web on each other; and a single triangular plate disposed downstream of the guide to fold the first and second webs superposed by the guide, in half along a fold line extending in the longitudinal direction of the first and second webs.
The web former according to claim 1, wherein the web former is a gusset former for forming a double-layer gusset web as the double-layer web, the double-layer gusset web comprising an outer gusset web as the first web and an inner gusset web as the second web.
The web former according to claim 1, wherein the first tension adjuster is further configured to switch the first web from continuous feed to intermittent feed, and the second tension adjuster is further configured to switch the second web from continuous feed to intermittent feed.
The web former according to claim 1, wherein the first tension adjuster is a first dancer mechanism, wherein the second tension adjuster is a second dancer mechanism, wherein the first dancer mechanism comprises a first dancer roller for engaging with the first web to apply tension to the first web, and wherein the second dancer mechanism comprises a second dancer roller for engaging with the second web to apply tension to the second web.
The web former according to claim 1, further comprising a temporary fixer disposed downstream of the triangular plate and configured to temporarily fix the first web and the second web to each other.
The web former according to claim 1, wherein the guide is a guide roller.
A bag making apparatus for successively making double-layer bags each comprising a first double-layer panel, a second double-layer panel, and a double-layer gusset, the bag making apparatus comprising: an intermittent feeder configured to intermittently feed a first outer panel web, a first inner panel web, a second outer panel web, and a second inner panel web in a longitudinal direction thereof; a pair of superposing rollers for superposing the first outer panel web, the first inner panel web, the second inner panel web, and the second outer panel web on each other in this order; the web former according to claim 2, the web former being configured to supply the double-layer gusset web to interpose the double-layer gusset web between the first inner panel web and the second inner panel web in the longitudinal direction when the first outer panel web, the first inner panel web, the second inner panel web, and the second outer panel web are superposed on each other at the pair of superposing rollers; at least one heat sealer disposed downstream of the pair of superposing rollers and configured to heat-seal the first and second outer panel webs, the first and second inner panel webs, and the double-layer gusset web during every intermittent feed cycle; and a cross cutter disposed downstream of the at least one heat sealer and configured to cross-cut the first and second outer panel webs, the first and second inner panel webs, and the double-layer gusset web in a width direction thereof during every intermittent feed cycle to shape a double-layer bag wherein the first double-layer panel is formed from the first outer panel web and the first inner panel web, the second double-layer panel is formed from the second outer panel web and the second inner panel web, and the double-layer gusset is formed from the double-layer gusset web.
The bag making apparatus according to claim 7, further comprising a spout attacher disposed downstream of the pair of superposing rollers and upstream of the at least one heat sealer, and configured to attach a spout to the first outer panel web and the first inner panel web superposed on each other during every intermittent feed cycle, the spout attacher comprising: a plurality of guide rollers for temporarily separating the second outer panel web, the second inner panel web, and the double-layer gusset web from the first outer panel web and the first inner panel web to create a temporary separation zone; a temporary fixing unit disposed in the temporary separation zone and configured to temporarily fix the first outer panel web and the first inner panel web to each other; a punching unit disposed downstream of the temporary fixing unit in the temporary separation zone and configured to punch a hole for the spout in the first outer panel web and the first inner panel web; and an attaching unit disposed downstream of the punching unit in the temporary separation zone and configured to insert the spout into the hole and attach the inserted spout to the first outer panel web and the first inner panel web by heat-sealing.
The bag making apparatus according to claim 7, wherein the web former further comprises a puncher configured to punch a hole for heat-sealing in the double-layer gusset web, wherein the at least one heat sealer is configured to heat-seal the first and second inner panel webs to each other through the hole for heat-sealing.
A web forming method for forming a double-layer web folded in half and comprising a first web and a second web for making double-layer bags, the method comprising: feeding the first web in a longitudinal direction of the first web; feeding the second web in a longitudinal direction of the second web; controlling tension of the first web using a first tension adjuster; controlling tension of the second web using a second tension adjuster independently of the controlling the tension of the first web using the first tension adjuster; guiding the first web and the second web downstream while superposing the first and second webs on each other using a guide located downstream of the first and second tension adjusters, and folding the superposed first and second webs in half along a fold line extending in the longitudinal direction of the first and second webs using a single triangular plate located downstream of the guide, to interpose the folded first web between the folded second web.
The web forming method according to claim 10, wherein the first web comprises a first surface layer and a second surface layer having a lower melting point than a melting point of the first surface layer, and the second web has a lower melting point than the melting point of the first surface layer, and wherein the first web and the second web are folded in half along the fold line by the triangular plate to contact the second surface layer with the second web.
The web forming method according to claim 10, wherein the first web is unwound from a first roll and continuously fed in the longitudinal direction thereof, wherein the second web is unwound from a second roll and continuously fed in the longitudinal direction thereof, wherein the first web is switched from continuous feed to intermittent feed by the first tension adjuster, and wherein the second web is switched from continuous feed to intermittent feed by the second tension adjuster.

Description

TECHNICAL FIELD The present application relates to a web former and a method for forming a double-layer web folded in half, such as a double-layer gusset web, for use in making double-layer bags. The present application also relates to a bag making apparatus for successively making double-layer bags. BACKGROUND Double-layer bags are well-known, for example, as disclosed in Patent Documents 1 and 2. A double-layer bag at least includes two double-layer panels facing each other. A storage space is formed by and between these two double-layer panels. Each of the double-layer panels consists of an inner panel part and an outer panel part which are superposed on each other. The double-layer bags disclosed in Patent Documents 1 and 2 each further include a pair of double-layer gussets. Each of the double-layer gussets also has a double-layer structure and thus consists of an outer gusset part and an inner gusset part which have been folded in half with themselves superposed on each other. Patent Document 1 discloses a bag making apparatus for successively making such double-layer bags. The bag making apparatus includes a gusset former that forms a double-layer gusset web from which the double-layer gussets will be formed. The gusset former unwinds an outer gusset web (for the outer gusset parts) and an inner gusset web (for the inner gusset parts) from their respective rolls, and superposes them on each other. The gusset former then folds the superposed outer gusset web and inner gusset web in half along a fold line extending in their longitudinal direction, thereby forming the double-layer gusset web. Patent Document 1 discloses folding the superposed outer gusset web and inner gusset web in half with only one triangular plate. This configuration, which folds two webs with a single triangular plate, typically may cause one of the two webs to sag or meander. It is therefore difficult to fold the outer gusset web and the inner gusset web with a neat alignment. If the double-layer gusset web is poorly finished, the finished bag, of course, will have poor quality. CITATION LIST PATENT DOCUMENT Patent Document 1: JPA 2016-141427 Patent Document 2: JPA 2022-7011 SUMMARY The present application provides a web former and a web forming method for forming a well-finished double-layer web folded in half, and a bag making apparatus including said web former. According to the present application, there is provided a web former for use in making double-layer bags and for forming a double-layer web folded in half and including a first web and a second web, the web former including: a first tension adjuster configured to control tension of the first web being fed in a longitudinal direction of the first web; a second tension adjuster configured to control tension of the second web being fed in a longitudinal direction of the second web independently of the first tension adjuster; a guide disposed downstream of the first and second tension adjusters to guide the first web and the second web downstream while superposing the first web and the second web on each other; and a single triangular plate disposed downstream of the guide to fold the first and second webs superposed by the guide, in half along a fold line extending in the longitudinal direction of the first and second webs. For example, the web former may be a gusset former for forming a double-layer gusset web as the double-layer web, the double-layer gusset web comprising an outer gusset web as the first web and an inner gusset web as the second web. The first tension adjuster may further be configured to switch the first web from continuous feed to intermittent feed. The second tension adjuster may further be configured to switch the second web from continuous feed to intermittent feed. The first tension adjuster may be a first dancer mechanism. The second tension adjuster may be a second dancer mechanism. The first dancer mechanism may include a first dancer roller for engaging with the first web to apply tension to the first web. The second dancer mechanism may include a second dancer roller for engaging with the second web to apply tension to the second web. For example, the guide may be a guide roller. The web former may further include a temporary fixer disposed downstream of the triangular plate and configured to temporarily fix the first web and the second web to each other. According to the present application, there is also provided a bag making apparatus for successively making double-layer bags each comprising a first double-layer panel, a second double-layer panel, and a double-layer gusset, the bag making apparatus comprising: an intermittent feeder configured to intermittently feed a first outer panel web, a first inner panel web, a second outer panel web, and a second inner panel web in a longitudinal direction thereof; a pair of superposing rollers for superposing the first outer panel web, the first inner panel web, the second inner panel web, and the s