Patent Description:
A bag such as a plastic bag includes, for example, an engagement tool such as a zipper or a hook-and-loop fastener. The bag can be freely opened and closed with the engagement tool. Patent document <NUM> discloses a bag with an engagement tool.

The bag in Patent document <NUM> includes panel parts facing each other. Furthermore, adhesive is applied to the inner surfaces of both panel parts between an open edge of the bag and the engagement tool to peelably adhere the panel parts to each other. The bag is opened by the panel parts being peeled off from each other. After peeling, the bag can be opened and closed with the engagement tool. Such bags have been attracting attention because of their convenience.

The panel parts of the bag in Patent document <NUM> may snugly overlap with each other near the open edge. In this case, it is hard to expand the open edge by pulling apart the panel part, and thus, hard to open the bag.

<CIT> discloses an easy-open/reclosable bag including a first wall having an outer and inner surface; a second wall having an outer and inner surface; a bottom portion connecting the first and second walls; a first and second side seal; and a bag mouth; the first wall including a first folded edge portion including a first and second segment, a fold, and a PSA between the first and second segments; the outer surface of the first wall including an easy-open sealant; the outer surface of the second wall including an easy-open or regular sealant; and the inner surface of the first and second walls each including a regular sealant. <CIT> also discloses a method of making an easy-open/reclosable bag, and a package.

An object of the present application is to provide a bag making apparatus and a bag making method for making bags which are easy to open.

According to the invention, there is provided a bag making apparatus for making bags from a web and a continuous engagement tool. The web has a first surface, a second surface, a first side section and a second side section. The continuous engagement tool includes a first member and a second member which are configured to be detachably engaged with each other. The bag making apparatus includes: an applicator configured to apply adhesive to at least one of the first side section or the second side section on the first surface in a longitudinal direction of the web; a first folding device configured to fold the web along two first fold lines extending in the longitudinal direction of the web such that the first and second side sections face the second surface; a second folding device configured to, after application of the adhesive and folding of the web along the two first fold lines, fold the web along a second fold line extending in the longitudinal direction of the web between the two first fold lines such that the first and second side sections face each other with the adhesive interposed therebetween; a welding device configured to weld the first and second members to the second surface in the longitudinal direction of the web; and a cross cut device configured to, after welding of the first and second members and folding of the web along the second fold line, cross-cut the web, the continuous engagement tool and the adhesive in a width direction of the web so as to make bags each having an open edge formed from two folded edges which result from the folding of the web along the two first fold lines.

The bag making apparatus according to an alternative of the invention includes: an applicator configured to apply adhesive in a longitudinal direction of the web to the first side section on the first surface and/or to the second side section on the second surface; a first folding device configured to fold the web along a first fold line extending in the longitudinal direction of the web such that the first side section faces the second surface; a second folding device configured to, after application of the adhesive and folding of the web along the first fold line, fold the web along a second fold line extending in the longitudinal direction of the web such that the first and second side sections face each other with the adhesive interposed therebetween; a welding device configured to weld the first and second members to the second surface in the longitudinal direction of the web; and a cross cut device configured to, after welding of the first and second members and folding of the web along the second fold line, cross-cut the web, the continuous engagement tool and the adhesive in a width direction of the web so as to make bags each having an open edge including a folded edge which results from the folding of the web along the first fold line.

The adhesive may be heat-sensitive adhesive. The bag making apparatus may further include a heat device configured to heat the heat-sensitive adhesive so as to peelably adhere the first and second side sections to each other via the heat-sensitive adhesive.

The bag making apparatus may further include a slit device configured to slit the web along the second fold line after the folding of the web along the second fold line.

According to the invention, there is provided a bag making method for making bags from a web and a continuous engagement tool. The web has a first surface, a second surface, a first side section and a second side section. The continuous engagement tool includes a first member and a second member which are configured to be detachably engaged with each other. The bag making method includes: applying adhesive to at least one of the first side section or the second side section on the first surface in a longitudinal direction of the web; folding the web along two first fold lines extending in the longitudinal direction of the web such that the first and second side sections face the second surface; after application of the adhesive and folding of the web along the two first fold lines, folding the web along a second fold line extending in the longitudinal direction of the web between the two first fold lines such that the first and second side sections face each other with the adhesive interposed therebetween; welding the first and second members to the second surface in the longitudinal direction of the web; and after welding of the first and second members and folding of the web along the second fold line, cross-cutting the web, the continuous engagement tool and the adhesive in a width direction of the web to make bags each having an open edge formed from two folded edges which result from the folding of the web along the two first fold lines.

The bag making method according to an alternative of the invention includes: applying adhesive in a longitudinal direction of the web to the first side section on the first surface and/or to the second side section on the second surface; folding the web along a first fold line extending in the longitudinal direction of the web such that the first side section faces the second surface; after application of the adhesive and folding of the web along the first fold line, folding the web along a second fold line extending in the longitudinal direction of the web such that the first and second side sections face each other with the adhesive interposed therebetween; welding the first and second members to the second surface in the longitudinal direction of the web; and after welding of the first and second members and folding of the web along the second fold line, cross-cut the web, the continuous engagement tool and the adhesive in a width direction of the web to make bags each having an open edge including a folded edge which results from the folding of the web along the first fold line.

The adhesive may be heat-sensitive adhesive. The bag making method may further include heating the heat-sensitive adhesive to peelably adhere the first and second side sections to each other via the heat-sensitive adhesive.

The bag making method further include slitting the web along the second fold line after the folding of the web along the second fold line.

A bag, not forming part of the invention but providing important background information for a better understanding of the invention, having an open edge and including: a first panel part and a first flap part which are formed by folding of a first sheet part; and a second panel part and a second flap part which are formed by folding of a second sheet part. The first and second panel parts face each other. The first and second flap parts are interposed between the first and second panel parts and face each other. The open edge is formed by a first folded edge of the first sheet part and a second folded edge of the second sheet part. The bag further includes an engagement tool interposed between the first and second panel parts and extending across widths of the first and second sheet parts. The engagement tool includes a first member and a second member which are configured to be detachably engaged with each other. The first member is disposed on the first panel part. The second member is disposed on the second panel part. The bag further includes adhesive located between the open edge and the engagement tool, interposed between the first and second flap parts and extending across the widths of the first and second sheet parts to peelably adhere the first and second flap parts to each other.

The first folded edge may be shifted from the second folded edge in a direction away from the engagement tool.

The bag may have a through hole located between the open edge and the adhesive and perpetrating through the first and second panel parts and the first and second flap parts. The bag may further include a handle formed by the first and second panel parts and the first and second flap parts between the through hole and the open edge.

Another bag, also not forming part of the invention but providing important background information for a better understanding of the invention, includes: a first panel part and a flap part which are formed by folding of a sheet part; and a second panel part, wherein the first and second panel parts face each other, wherein the flap part is interposed between the first and second parts, and wherein the open edge is formed by a folded edge of the sheet part and an end edge of the second panel part, the bag further including an engagement tool interposed between the first and second panel parts and extending across widths of the sheet part and the second panel part, the engagement tool including a first member and a second member which are configured to be detachably engaged with each other, the first member being disposed on the first panel part, the second member being disposed on the second panel part, the bag further including adhesive located between the open edge and the engagement tool, interposed between the flap part and the second panel part, and extending across the widths of the sheet part and the second panel part to peelably adhere the flap part and the second panel part to each other.

The end edge of the second panel part may be shifted from the folded edge in a direction away from the engagement tool.

The bag may have a through hole located between the open edge and the adhesive and perpetrating through the first and second panel parts and the flap part. The bag may further include a handle formed by the first and second panel parts and the flap part between the through hole and the open edge.

A bag, a bag making apparatus and a bag making method will now be described with reference to the accompanying drawings. Elements illustrated in the Figures are not drawn to scale, but only to illustrate function or operation thereof.

<FIG> illustrate an example bag <NUM>. <FIG> is a cross sectional view taken along the T-T line in <FIG>. The bag <NUM> has an open edge <NUM>. The bag <NUM> further includes a first panel part <NUM> and a second panel part <NUM> facing each other. The bag <NUM> further includes a first flap part <NUM> and a second flap part <NUM> which are interposed between the panel parts <NUM> and <NUM> and face each other.

The bag <NUM> includes a first sheet part <NUM> and a second sheet part <NUM>. The sheet part <NUM> is folded along a fold line extending across the width of the sheet part <NUM>. The panel part <NUM> and the flap part <NUM> are formed by this folding of the sheet part <NUM>. In other words, the panel part <NUM> and the flap part <NUM> are formed as one piece. The sheet part <NUM> is folded along a fold line extending across the width of the sheet part <NUM>. The panel part <NUM> and the flap part <NUM> are formed by this folding of the sheet part <NUM>. In other words, the panel part <NUM> and the flap part <NUM> are formed as one piece.

Each of the sheet parts <NUM> and <NUM> is a plastic film. The film may be a single-layer or multi-layer structure. The film of the multi-layer structure may include a base layer as one outer layer that functions as structural material, and a sealant layer as the other outer layer that functions as sealant. The film of the multi-layer structure may be used in such a manner that its base layer constitutes the outer surface of the panel part <NUM>, <NUM>, and its sealant layer constitutes the inner surface (facing surface) of the panel part <NUM>, <NUM>. Alternatively, each of the sheet parts <NUM> and <NUM> may include a base made of paper and a film or resin material laminated partially or fully to the base.

As illustrated in <FIG>, the open edge <NUM> is formed by a first folded edge <NUM> resulting from folding of the first sheet part <NUM> and a second folded edge <NUM> resulting from folding of the second sheet part <NUM>.

The bag <NUM> includes an engagement tool <NUM> interposed between the panel parts <NUM> and <NUM> and extending across the widths of the sheet parts <NUM> and <NUM>. The engagement tool <NUM> extends parallel to the open edge <NUM>. The engagement tool <NUM> is located apart from the tips of the flap parts <NUM> and <NUM> in the direction away from the open edge <NUM>. It is well-known that the bag <NUM> can be opened and closed freely with the engagement tool <NUM>.

As illustrated in <FIG>, the engagement tool <NUM> includes a first member <NUM> and a second member <NUM> which face each other and are configured to be detachably engaged with each other. The first member <NUM> is attached to the inner surface of the panel part <NUM> by means of welding, etc., and the second member <NUM> is attached to the inner surface of the panel part <NUM> by means of welding, etc. The engagement tool <NUM> is a zipper. The member <NUM> is a male member, and the member <NUM> is a female member. The engagement tool <NUM> may be, for example, a hook-and-loop fastener instead.

As illustrated in <FIG>, the bag <NUM> further includes side sealed sections <NUM> extending across the length of the bag <NUM> along the opposite side edges of the sheet parts <NUM> and <NUM>. The side sealed sections <NUM> include: the portions in which the panel parts <NUM> and <NUM> are sealed to each other along the opposite side edges thereof except for the area where the flap parts <NUM> and <NUM> extend; the portions in which the panel part <NUM> and the flap part <NUM> are sealed to each other along the opposite side edges of the flap part <NUM>; and the portions in which the panel part <NUM> and the flap part <NUM> are sealed to each other along the opposite side edges of the flap part <NUM>. Here, the flap parts <NUM> and <NUM> are not sealed to each other along the opposite side edges thereof. In other words, the side sealed sections <NUM> are not formed along the opposite side edges of the flap parts <NUM> and <NUM> between the flap parts <NUM> and <NUM>. Alternatively, the side sealed sections <NUM> may further include portions in which the flap parts <NUM> and <NUM> are sealed to each other along the opposite side edges thereof.

The bag <NUM> further includes a bottom sealed section <NUM> extending across the width of the bag <NUM> along the end edges of the sheet parts <NUM> and <NUM> (the panel parts <NUM> and <NUM>) located opposite to the open edge <NUM>. The bottom sealed section <NUM> consists of the portion in which the panel parts <NUM> and <NUM> are sealed to each other along the end edges thereof.

<FIG> is an enlarged view of the region S in <FIG>. As illustrated in <FIG>, the bag <NUM> includes adhesive <NUM> interposed between the flap parts <NUM> and <NUM>, located between the open edge <NUM> and the engagement tool <NUM>, and extending across the widths of the sheet parts <NUM> and <NUM> to peelably adhere the flap parts <NUM> and <NUM> to each other. The adhesive <NUM> is part-coating.

A user can expand the open edge <NUM> and peel off the flap parts <NUM> and <NUM> from each other against the adhesive strength of the adhesive <NUM>, thereby opening the bag <NUM>. After peeling off, a user can freely open and close the bag <NUM> using the engagement tool <NUM>.

<FIG> illustrates a partial cross section of the bag <NUM> according to the prior art disclosed in Patent document <NUM>. The bag <NUM> includes panel parts <NUM> and <NUM>, and an open edge <NUM> is formed by the end edges of the panel parts <NUM> and <NUM>. The bag <NUM> also includes an engagement tool (not shown) and adhesive (not shown).

In <FIG>, if the panel parts <NUM> and <NUM> snugly overlap with each other near the open edge <NUM>, it is hard to expand the open edge <NUM> and thus hard to open the bag <NUM>. In contrast, in <FIG>, a gap is formed by the folded edges <NUM> and <NUM> between these <NUM> and <NUM>, which makes it easy to expand the open edge <NUM> and thus easy to open the bag <NUM>.

In <FIG>, the open edge <NUM> may easily cause injury, such as cutting a finger by the open edge <NUM>. In contrast, in <FIG>, since the open edge <NUM> is constituted by the folded edges <NUM> and <NUM>, it is less likely to cause injury by the open edge <NUM>.

The bag <NUM> has a thickness corresponding to four sheets (the total thickness of the parts <NUM>, <NUM>, <NUM> and <NUM>) near the open edge <NUM>. This facilitates holding the bag <NUM>. In addition, the fact that the flap parts <NUM> and <NUM> are peelably adhered to each other via the adhesive <NUM> at this easy-to-hold location also improves easiness to open the bag <NUM>.

<FIG> illustrates another example bag <NUM>. As illustrated in <FIG>, the first sheet part <NUM> and the second sheet part <NUM> may be formed as one piece. In other words, a single sheet is folded along a fold line extending across the width of the sheet, and the sheet parts <NUM> and <NUM> are formed by this folding. The end edge located opposite to the open edge <NUM> is formed by an additional folded edge <NUM> which results from this folding of the single sheet. Thus, the bag <NUM> of <FIG> does not include the bottom sealed section <NUM> (<FIG>).

<FIG> illustrates another example bag <NUM>. As illustrated in <FIG>, one folded edge <NUM> may be shifted from the other folded edge <NUM> in the direction away from the engagement tool <NUM>. The shift amount is, for example, <NUM> to <NUM>.

<FIG> illustrates a partial cross section of a bag <NUM> according to the related art. This bag <NUM> is a variation of the bag <NUM> in <FIG>, in which the end edge of one panel part <NUM> is shifted with respect to the end edge of the other panel part <NUM> by, for example, <NUM> to <NUM>. In comparison with the bag <NUM> in <FIG>, the bag <NUM> in <FIG> makes it easier to pull apart the panel part <NUM>, <NUM> at the open edge <NUM>. It is clear from a comparison of <FIG> with <FIG> that the sheet parts <NUM> and <NUM> in <FIG> are much easier to be pulled apart near the open edge <NUM> than the bag <NUM> in <FIG>.

<FIG> illustrate another example bag <NUM>. <FIG> is a cross section taken along the P-P line in <FIG> is a cross section taken along the Q-Q line in <FIG>. In this bag <NUM>, a through hole <NUM> is formed to penetrate through the panel parts <NUM> and <NUM> and the flap parts <NUM> and <NUM> between the open edge <NUM> and the engagement tool <NUM>. Thereby, a handle <NUM> is formed between the through hole <NUM> and the open edge <NUM> by the panel parts <NUM> and <NUM> as well as the flap parts <NUM> and <NUM>. The handle <NUM> has a thickness corresponding to four sheets, and therefore, is sturdy and easy to hold.

As illustrated in <FIG>, notches <NUM> may be formed on the opposite sides of the flap parts <NUM> and <NUM>. Sealant <NUM> (<FIG>) may be filled into each notch <NUM>, so that the panel parts <NUM> and <NUM> are sealed to each other via the filled sealant <NUM>. Where the sealant layer of the multi-layer film constitutes the inner surface of each panel part <NUM>, <NUM> as described above, the sealant layers of the panel parts <NUM> and <NUM> are sealed to each other at the notches <NUM> as they face each other directly at the notches <NUM>. Where the flap parts <NUM> and <NUM> are not sealed to each other along the opposite side edges thereof, each of the sheet parts <NUM> and <NUM> may flap towards the outside of the bag <NUM> in the area L where the flap parts <NUM> and <NUM> extend. The sealant <NUM> reduces this flapping. The above configuration is useful when the flap parts <NUM> and <NUM> are long in order to form the handle <NUM>. Instead of the notches <NUM>, holes may be formed in the flap parts <NUM> and <NUM>. The notches <NUM> or the holes may be formed, for example, by means of punching the sheet parts <NUM> and <NUM> (the flap parts <NUM> and <NUM>) in advance.

The bag <NUM> may further include a restraining sealed section <NUM> extending across the widths of the sheet parts <NUM> and <NUM>. The restraining sealed section <NUM> includes the portion in which the panel part <NUM> and the flap part <NUM> are sealed to each other in the tip of the flap part <NUM>, and the portion in which the panel part <NUM> and the flap part <NUM> are heat-sealed to each other in the tip of the flap part <NUM>. If the restraining sealed section <NUM> is not formed so that the tips of the flap parts <NUM> and <NUM> are not restrained as illustrated by the regions R in <FIG>, there is a possibility that, in taking out contents, the contents will enter between the panel part <NUM> and the flap part <NUM> and/or between the panel part <NUM> and the flap part <NUM> through the region(s) R. The restraining sealed section <NUM> prevents this.

The configuration(s) of each example bag <NUM> may be incorporated into another example bag <NUM>. For example, the notches <NUM> or holes in <FIG> used for sealing the panel parts <NUM> and <NUM> to each other or the aforementioned restraining sealed section <NUM> may be included in the bag <NUM> with no handle in <FIG>.

The example of the bag making apparatus and the bag making method will be described. <FIG> illustrates the upstream section of the bag making apparatus <NUM>. The bag making apparatus <NUM> include a feed device (not shown) that continuously unrolls a web <NUM> from a roll <NUM>' and feeds the web <NUM> in the longitudinal direction of the web <NUM>. The feed device includes, for example, at least one pair of feed rollers. The reference sign X<NUM> designates the feed direction.

The web <NUM> has a first surface <NUM> and a second surface <NUM>. In <FIG>, the web <NUM> is fed with the first surface <NUM> facing upward and the second surface <NUM> facing downward. The web <NUM> further has a first side section <NUM>, a second side section <NUM>, a first side edge <NUM>, and a second side edge <NUM>.

The web <NUM> in the implementation is a plastic film. The film has a laminated structure, the surface <NUM> of which is formed by a base layer and the surface <NUM> of which is formed by a sealant layer having a lower melting point than that of the base layer. The base layer is OPP (biaxially oriented polypropylene), ONY (biaxially oriented nylon) or PET (biaxially oriented polypropylene), etc. The sealant layer is CPP (non-oriented polypropylene) or LDPE (low density polyethylene), etc. Different from the implementations, the web <NUM> may have a single-layer structure made of such material as polyethylene. For example, the web <NUM> may include a base made of paper and a film or plastic material laminated partially or fully to the base.

The bag making apparatus <NUM> may include a printer <NUM> that prints on the web <NUM>. The printer <NUM> is disposed facing the surface <NUM> such that characters, figures, patterns, etc. are printed on the surface <NUM> of the web <NUM> using ink by the printer <NUM> while the web <NUM> is fed through the printer <NUM>. An accumulator (not shown) may be disposed to ensure a feed distance enough to dry the ink.

The bag making apparatus <NUM> includes an applicator <NUM> configured to apply adhesive <NUM> to the side sections <NUM> and <NUM> on the surface <NUM> along the longitudinal direction of the web <NUM>. The applicator <NUM> in the implementation includes a first application unit <NUM> disposed facing the surface <NUM> to apply the adhesive <NUM> to the side section <NUM>, and a second application unit <NUM> disposed facing the surface <NUM> to apply the adhesive <NUM> to the side section <NUM>. While the web <NUM> is fed through the applicator <NUM>, the adhesive <NUM> is applied to the side sections <NUM> and <NUM> by the application units <NUM> and <NUM>, respectively. Thereby, the adhesive <NUM> is applied in the longitudinal direction of the web <NUM> as illustrated in <FIG>, which are enlarged views of the areas G and G' in <FIG>.

Adhesive that develops its adhesive property upon being heated and is cured upon heat removal, i.e., heat-sensitive adhesive is used as the adhesive in the implementation. The heat-sensitive adhesive in the implementation is part-coating. Part-coating may be, for example, solvent-based or water-based adhesive that is commonly available on the market. Alternatively, the heat-sensitive adhesive may be, for example, adhesive such as EVA (ethylene vinyl acetate)-based, olefinic-based, or polyamide (nylon)-based hot melt.

The bag making apparatus <NUM> includes a first folding device <NUM> configured to fold the web <NUM> along two first fold lines 4a and 4b (<FIG>) extending in the longitudinal direction of the web <NUM>, such that its side sections <NUM> and <NUM> face the surface <NUM>. The first folding device <NUM> in the implementation is a well-known configuration including first, second, and third guide rollers <NUM>, <NUM> and <NUM>, as illustrated in <FIG>. As the web <NUM> is fed, it is guided by the guide rollers <NUM>, <NUM> and <NUM> to be folded along the first fold lines 4a and 4b such that the side sections <NUM> and <NUM> face the surface <NUM>. The reference numerals <NUM> and <NUM> in <FIG> designate the folded edges resulting from folding of the web <NUM> along the fold lines 4a and 4b, respectively.

<FIG> illustrate the midstream section of the bag making apparatus <NUM>. The bag making apparatus <NUM> further includes a second folding device <NUM> configured to, after the above-mentioned application of the adhesive <NUM> and the folding of the web <NUM> along the fold lines 4a and 4b, fold the web <NUM> along a second fold line 4c (<FIG>) which extends in the longitudinal direction of the web <NUM> between the fold lines 4a and 4b.

The second folding device <NUM> is a well-known guide device including a guide roller <NUM>, a triangular plate <NUM>, and suction rollers <NUM>. As the web <NUM> is fed, it is guided by the guide roller <NUM>, the triangular plate <NUM> and the suction rollers <NUM> to be folded along the fold line 4c and to cause the feed direction X<NUM> to be diverted by <NUM>°. The fold line 4c in the implementation coincides with the longitudinal centerline of the web <NUM>.

In this way, the web <NUM> is folded in half by the second folding device <NUM> such that the side sections <NUM> and <NUM> face each other with the adhesive <NUM> interposed therebetween. The outer surface of the web <NUM> which has been folded in half is the surface <NUM> which is the base layer, and the inner surface of this web <NUM> is the surface <NUM> which is the sealant layer. The reference numeral <NUM> designates the folded edge resulting from folding of the web <NUM> along the fold line 4c.

The folded edges <NUM>, <NUM>, and <NUM> may be heated for creasing.

The adhesive <NUM> in the implementation has not yet adhered the side sections <NUM> and <NUM> to each other because it has not yet developed the adhesive property up to this step.

After this step, the feed of the web <NUM> is appropriately converted from continuous feed to intermittent feed by a dancer device (not shown). Therefore, the web <NUM> is repeatedly paused and fed.

<FIG> illustrates the downstream section of the bag making apparatus <NUM>. The bag making apparatus <NUM> includes a heat device <NUM> configured to heat the adhesive <NUM> after folding of the web <NUM> along the fold line 4c (<NUM>) so as to peelably adhere the side sections <NUM> and <NUM> to each other via the adhesive <NUM> (not shown in <FIG>).

While the web <NUM> is fed through the heat device <NUM>, the heat device <NUM> heats the adhesive <NUM> sandwiched between the side sections <NUM> and <NUM> using a heater or heat seal bars, etc., thereby developing the adhesive property of the adhesive <NUM>. This causes the adhesive <NUM> to peelably adhere the side sections <NUM> and <NUM> to each other.

The heat device <NUM> in the implementation heats the adhesive at a temperature lower than the melting point of the sealant layer that constitutes the surface <NUM>, to prevent melting of the sealant layer. Thus, the adhesive <NUM> has been selected in advance, which is capable of developing its adhesive property at a temperature lower than the melting point of the sealant layer. Where the web <NUM> is a single-layer film, the heat device <NUM> heats the adhesive <NUM> at a temperature lower than the melting point of the single-layer film to prevent melting of the single-layer film.

The bag making apparatus <NUM> further includes a welding device <NUM> configured to supply a continuous engagement tool <NUM> to the web <NUM> in the longitudinal direction of the web <NUM> and to then weld the engagement tool <NUM> to the surface <NUM> of the web <NUM> in the longitudinal direction of the web <NUM>.

<FIG> illustrates a cross section of the continuous engagement tool <NUM>. The engagement tool <NUM> includes a first member <NUM> and a second member <NUM> which are configured to be detachably engaged with each other. The engagement tool <NUM> in the implementation is a zipper made of plastic. The member <NUM> is a male member, and the member <NUM> is a female member.

The welding device <NUM> in the implementation supplies the engagement tool <NUM> with the members <NUM> and <NUM> engaged with each other, and introduces it between the two layers of the folded web <NUM>. For this purpose, the welding device <NUM> includes a guide unit (not shown) (such as extension rollers) that expands the two layers of the web <NUM> at the folded edges <NUM> and <NUM>, and a guide roller <NUM> for guiding the engagement tool <NUM> and introducing the engagement tool <NUM> between the two layers of the web <NUM> through the area expanded by the guide unit.

The welding device <NUM> further includes a welding unit <NUM> configured to weld the members <NUM> and <NUM> to the surface <NUM> of the web <NUM> in the longitudinal direction of the web <NUM> after the engagement tool <NUM> is introduced between the two layers of the web <NUM>. The welding unit <NUM> welds the members <NUM> and <NUM> to the surface <NUM> by means of, for example, heat-sealing using a pair of heat seal bars or laser irradiation using a laser device. Specifically, the member <NUM> is welded to one layer of the web <NUM>, and the member <NUM> is welded to the other layer of web <NUM>.

The bag making apparatus <NUM> further includes a slitter <NUM> for slitting the web <NUM> along the fold line 4c (<FIG>), i.e., along the folded edge <NUM>. As the web <NUM> is fed, it is slit in its longitudinal direction by the slitter <NUM>. Thereby, an open edge <NUM> is formed. The waste <NUM> generated during this is wound up and collected.

The bag making apparatus <NUM> further includes a cross seal device <NUM> configured to seal the web <NUM> in the width direction of the web <NUM> after folding of the web <NUM> along the fold line 4c. The cross seal device <NUM> in the implementation heat-seals the web <NUM>, for example using a pair of heat seal bars, during every pause phase of the intermittent feed cycle. Since the surface <NUM>, which is the sealant layer, constitutes the inner surface of the folded web <NUM>, sealant layer of the surface <NUM> is melted by the cross seal device <NUM>. Thus, the two layers of the web <NUM> are heat-sealed to each other. One layer of the web <NUM> and the side section <NUM> are heat-sealed to each other, and the other layer of the web <NUM> and the side section <NUM> are heat-sealed to each other. Thereby, a cross sealed section (not shown) is formed. In contrast, the side sections <NUM> and <NUM> are not heat-sealed to each other because their facing surfaces are formed by the surface <NUM>, which is the base layer.

The bag making apparatus <NUM> further includes a cross cut device <NUM> configured to cross-cut the web <NUM>, the adhesive <NUM> and the engagement tool <NUM> in the width direction of the web <NUM> after welding of the members <NUM> and <NUM>, folding of the web <NUM> along the fold line 4c, slitting of the web <NUM>, and formation of the cross sealed section. The cross cut device <NUM> in the implementation cross-cuts the web <NUM>, the adhesive <NUM> and the engagement tool <NUM> , for example using a cutter, in the width direction of the web <NUM> during every pause phase of the intermittent feed cycle. The position of cross-cutting is the position of the cross sealed section. A bag <NUM> is made every cross-cutting.

Referring to <FIG> and <FIG>, the sheet parts <NUM> and <NUM> of the bag <NUM> are formed from two layers of the web <NUM>. The flap parts <NUM> and <NUM> are formed from the side sections <NUM> and <NUM>. The open edge <NUM> is (the folded edges <NUM> and <NUM> are) formed from the folded edges <NUM> and <NUM>. The adhesive <NUM> is formed from the adhesive <NUM>. The engagement tool <NUM> is formed from the engagement tool <NUM>. Each of the side sealed sections <NUM> is formed from the cross sealed section. The open edge <NUM> (<FIG>) opposite to the open edge <NUM> is formed from the open edge <NUM>. The contents may be filled through this open edge <NUM>. After the filling, the bag <NUM> may be sealed along the open edge <NUM> such that the bottom sealed section <NUM> is formed.

In this way, the aforementioned bags <NUM>, which are easy to hold and open, are successively made. The adhesive <NUM> is applied to the first surface <NUM> which will form the outer surfaces of the bags <NUM>. Thus, the step for applying the adhesive <NUM> and the step for printing on the web <NUM> can be carried out simultaneously at the same stage.

The step for slitting the web <NUM> using the slitter <NUM> may be eliminated so that the bag <NUM> illustrated in <FIG> is made. The folded edge <NUM> (<FIG>) of the bag <NUM> is formed from the folded edge <NUM>. The adhesive <NUM> may not be heated by the heat device <NUM>. After the bag <NUM> is shaped, the contents may be filled into the bag <NUM> through the open edge <NUM>, and then the adhesive <NUM> (formed from the adhesive <NUM>) may be heated by another heat device to develop its adhesive property, thereby peelably adhering the flap parts <NUM> and <NUM> to each other.

In the case of making the bags <NUM> in <FIG>, the application position of the applicator <NUM> and the positions of the fold lines 4a, 4b and 4c may be adjusted such that the folded edge <NUM> is shifted with respect to the folded edge <NUM> when the web <NUM> is folded along the fold line 4c.

In the case of making the bags <NUM> each with the handle <NUM> as illustrated in <FIG>, the application position of the applicator <NUM> and the fold lines 4a, 4b and 4c are properly adjusted to obtain sufficient lengths of the side sections <NUM> and <NUM>. Then, the punching machine (not shown) of the bag making apparatus <NUM> punches a through hole, which corresponds to the through hole <NUM>, in the web <NUM> before cross-cutting, or punches a hole <NUM> in the bag <NUM> after cross-cutting.

As illustrated in <FIG>, the bag making apparatus may include a punching machine <NUM> configured to punch holes <NUM> and <NUM> (<FIG>) in the side sections <NUM> and <NUM>. The punching machine <NUM> may include a first punching unit <NUM> configured to punch a first hole <NUM> in the side section <NUM> between the fold line 4a and the side edge <NUM>, at a position not interfere with the adhesive <NUM>, for example using a punching blade, and a second punching unit <NUM> configured to punch a second hole <NUM> in the side section <NUM> between the fold line 4b and the side edge <NUM> at a position not to interfere with the adhesive <NUM>, for example using a punching blade.

When the web <NUM> is then folded along the fold line 4c by the folding device <NUM>, these holes <NUM> and <NUM> are aligned with each other. As described above, when the web <NUM> including the base layer and the sealant layer is then heat-sealed by the cross seal device <NUM>, the side sections <NUM> and <NUM> are not heat-sealed to each other. Therefore, the flap parts <NUM> and <NUM> of the bag <NUM> are not sealed to each other along the opposite side edges thereof. During this heat-sealing, the sealant layer of the surface <NUM> (inner surface) of the web <NUM> melts so that the sealant flows into the holes <NUM> and <NUM>. Thereby, the two layers of the folded web <NUM> are sealed to each other via the sealant which has flowed into the holes <NUM> and <NUM>.

Then, when the web <NUM> is cross-cut by the cross cut device <NUM>, the holes <NUM> and <NUM> are divided into two, resulting in the notches <NUM> (<FIG>). Therefore, the sealant <NUM> (<FIG>) is formed from the sealant which has flowed into the holes <NUM> and <NUM>.

The bag making apparatus <NUM> may further include a longitudinal seal device (not shown) configured to heat-seal one layer of the web <NUM> and the side section <NUM> to each other, and the other layer of web <NUM> and the side section <NUM> to each other in the width direction of web <NUM> after folding of it along the fold line 4c. The longitudinal seal device performs heat-sealing, for example using a pair of heat seal bars, to form a longitudinal sealed section during every pause phase of the intermittent feed cycle. As described above, the side sections <NUM> and <NUM> are not sealed to each other at this time. Thus, when the bag <NUM> is shaped, the restraining sealed section <NUM> (<FIG>) is formed from the longitudinal sealed section.

The bag <NUM> illustrated in <FIG> is made by the combination of the above respective steps.

The applicator <NUM> may apply the adhesive <NUM> to only one of the side sections <NUM> and <NUM>. Unlike the implementation, the adhesive <NUM> may be applied to at least one of the side sections <NUM> or <NUM> by the applicator <NUM> after the web <NUM> is folded by the first folding device <NUM>. Adhesive, e.g., viscous adhesive, other than heat-sensitive adhesive, may be used as adhesive <NUM>, <NUM>. In this case, when the web <NUM> is folded by the second folding device <NUM>, the side sections <NUM> and <NUM> are peelably adhered to each other via the adhesive <NUM>, without the step for heating the adhesive <NUM> using the heat device <NUM>.

<FIG> illustrate yet another example bag <NUM> in partial cross section. One of the differences from the aforementioned bag <NUM> is that one sheet part <NUM>/<NUM>, e.g., the sheet part <NUM> is not folded. Thus, in this example, the sheet part <NUM> only consists of the panel part <NUM> and is not provided with any flap part. Only one flap part <NUM> is interposed between the panel parts <NUM> and <NUM>. The open edge <NUM> is formed by the folded edge <NUM> of the sheet part <NUM> and the end edge <NUM> of the panel part <NUM>. The engagement tool <NUM> extends across the widths of the sheet part <NUM> (panel part <NUM>) and the panel part <NUM>. The adhesive <NUM> is interposed between the flap part <NUM> and the panel part <NUM> and extends across the widths of the sheet part <NUM> (the panel part <NUM>) and the panel part <NUM> to peelably adhere the flap part <NUM> and the panel part <NUM> to each other. In <FIG>, for the sake of convenience, the flap part <NUM> and the panel part <NUM> are separated from each other.

The end edge <NUM> of the panel part <NUM> is shifted from the folded edge <NUM> in a direction away from the engagement tool <NUM>. This further facilitates opening the bag.

The bag <NUM> may have a through hole (not shown) located between the open edge <NUM> and the adhesive <NUM> and pretreating the panel parts <NUM> and <NUM> and the flap part <NUM>, and may further include a handle (not shown) formed by the panel parts <NUM> and <NUM> and the flap part <NUM> between the through hole and the open edge <NUM>. Also, the bag <NUM> in <FIG> may include the same additional features as those included in the aforementioned bags.

Where the bag making apparatus makes the bags <NUM> illustrated in <FIG>, it is configured as follows. The folding device <NUM> is configured to fold only one side section <NUM>/<NUM> of both side sections <NUM> and <NUM> of the web <NUM> along the fold line 4a/4b. For example, the folding device <NUM> folds the side section <NUM> along the first fold line 4a, but does not fold the side section <NUM>. In this example, the applicator <NUM> is configured to apply the adhesive <NUM> in the longitudinal direction of the web <NUM> to the side section <NUM> on the surface <NUM> using the application unit <NUM> and to the side section <NUM> (which is not folded) on the surface <NUM> using the application unit <NUM>. In addition, the second folding device <NUM> is configured to fold it along the second fold line 4c such that the side sections <NUM> and <NUM> face each other with the adhesive <NUM> interposed therebetween. The subsequent configurations and steps are substantially the same as those in the aforementioned examples. In this example, the end edge <NUM> of the panel part <NUM> is formed from the side edge <NUM> of the web <NUM>.

Either one of the application units <NUM> and <NUM> may be dispensed with, and this case results in the bag <NUM> in <FIG>.

Also, as an example, viscose adhesive /a seal having an adhesive surface of viscose adhesive may be interposed between the first and second flap parts <NUM> and <NUM> by means of applying/affixing to peelably adhere the flap parts <NUM> and <NUM> to each other and to enable resealing the bag <NUM> after opening it. This extends the effectiveness of the desiccant or oxygen absorbing material packed, and contributes to restraining deterioration of the contents, such as food products.

In making the bags <NUM>, it is possible to appropriately select the distance and arrangement from the peelable adhesive part with the adhesive <NUM> to the through hole <NUM>, the distance from the engagement tool <NUM> to the open edge, the length (area L) of the flap parts <NUM> and <NUM>, and the presence or absence of sealing at the notches <NUM>, etc., taking into consideration the balance of the entire bag and the easiness of opening the bag, etc. For example, sealing at the notches <NUM> may be performed to prioritize the stability of the bag (to prevent the handle <NUM> from flapping) if the bag <NUM> in <FIG> is longitudinal in shape and the contents therein are also longitudinal in shape. On the other hand, if the contents are individually packaged confectioneries, sealing at the notches <NUM> may not be performed and the dimension of the area L may be set shorter so that the bag can be opened at the section which is right upper to the engagement tool <NUM>, in order to prioritize easiness of taking out the contents.

<Reference Examples> Reference examples will be described below. <FIG> illustrates a reference example bag <NUM>. The bag <NUM> in <FIG> is an improvement of the bag <NUM> according to the prior art in <FIG>. The method for making the bags <NUM> includes, before the step for forming the cross sealed section <NUM>, locally toasting the edges <NUM> and <NUM> of the panel parts <NUM> and <NUM> (which constitute the open edge <NUM> of bag <NUM>) in the predetermined range (<NUM>×r1) that is centered on the position of cross-cutting, to make these edges rounded as illustrated in <FIG> and each have a maximum thickness t2 that is greater than the thickness t1 of the panel part <NUM>, <NUM>. This causes the portions each with thickness t2 to be located protruding from the cross sealed section <NUM> by a length ( r1 - r2) inward of the bag <NUM> at the opposite ends of the shaped bag <NUM>. Here, the reference sign r1 designates the area actually toasted, and the reference sign r2 designates the width of the cross sealed section <NUM>. The method for toasting an edge is disclosed in <CIT>.

The reference numeral <NUM> designates an engagement tool having the same configuration as the engagement tool <NUM> in the above examples. The reference numeral <NUM> designates a bottom sealed section having the same configuration as the bottom sealed section <NUM> in the above examples. The reference numeral <NUM> designates a peelable adhesive having the same configuration as the adhesive <NUM> in the above examples.

<FIG> is an H line arrow view of <FIG>, and <FIG> is a J-J line cross section of <FIG> is a K-K line cross section of <FIG>. In forming the cross sealed section <NUM> using the seal bars after the step for toasting, the portions each with the thickness t2 of the edges <NUM> and <NUM> in the sealed area (see the reference sign r2) are pressed against each other by the seal bars into a portion with a thickness t3 (< <NUM> × t2). As a result, the portions each with the thickness t2 of the edges <NUM> and <NUM> have the remaining length (r1 - r2) and are located protruding from the cross sealed section <NUM> inward of the bag <NUM>. The remaining portions each with the thickness t2 form a gap <NUM> between the panel parts <NUM> and <NUM> at the open edge <NUM> of the bag <NUM>. This gap <NUM> facilitates peeling off the adhesive <NUM> by pinching the panel part <NUM>, <NUM>, and thus opening the bag <NUM>.

Instead of the cross sealed section <NUM>, it is possible to seal the opposite sides of the bag <NUM> by cross-cutting the panel parts <NUM> and <NUM> by means of fusion cutting in the way as disclosed in <CIT> and <CIT>. As illustrated in <FIG>, a gap <NUM> that facilitates opening the bag <NUM> is formed by the fuse-cut edge <NUM>' resulting from fusion cutting.

For reference information, the advantages of a bag with a zipper and part-coating/hot melt over a bag with a zipper and a notch are as follows.

Bag with a notch: In the manufacturing step, after creating a notch serving as a trigger for tearing, it requires a scoring process using a laser or a process for cutting the film by approximately half of its thickness in advance in order the tear line to be parallel to the zipper. Furthermore, in order to make the strength of the film have orientations, it is sometimes strengthened or weaken in advance in the direction in which it can extend. Thus, the burden on manufacturing is unexpectedly large.

Claim 1:
A bag making apparatus (<NUM>) for making bags (<NUM>) from a web (<NUM>) and a continuous engagement tool (<NUM>), the web (<NUM>) having a first surface (<NUM>), a second surface (<NUM>), a first side section (<NUM>) and a second side section (<NUM>), the continuous engagement tool (<NUM>) comprising a first member (<NUM>) and a second member (<NUM>) which are configured to be detachably engaged with each other,
the bag making apparatus (<NUM>) comprising:
an applicator (<NUM>) configured to apply adhesive (<NUM>) to at least one of the first side section (<NUM>) or the second side section (<NUM>) on the first surface (<NUM>) in a longitudinal direction of the web (<NUM>);
a first folding device (<NUM>) configured to fold the web (<NUM>) along two first fold lines (4a, 4b) extending in the longitudinal direction of the web (<NUM>) such that the first side section (<NUM>) and the second side section (<NUM>) face the second surface (<NUM>);
a second folding device (<NUM>) configured to, after application of the adhesive (<NUM>) and folding of the web (<NUM>) along the two first fold lines (4a, 4b), fold the web (<NUM>) along a second fold line (4c) extending in the longitudinal direction of the web (<NUM>) between the two first fold lines (4a, 4b) such that the first side section (<NUM>) and the second side section (<NUM>) face each other with the adhesive (<NUM>) interposed therebetween;
a welding device (<NUM>) configured to weld the first member (<NUM>) and the second member (<NUM>) to the second surface (<NUM>) in the longitudinal direction of the web (<NUM>); and
a cross cut device (<NUM>) configured to, after welding of the first member (<NUM>) and the second member (<NUM>) and folding of the web (<NUM>) along the second fold line (4c), cross-cut the web (<NUM>), the continuous engagement tool (<NUM>) and the adhesive (<NUM>, <NUM>) in a width direction of the web (<NUM>) so as to make bags (<NUM>) each having an open edge (<NUM>) formed from two folded edges (<NUM>, <NUM>) which result from the folding of the web (<NUM>) along the two first fold lines (4a, 4b).