WO1997043114A1

WO1997043114A1 - Reclosable storage bag, method , and apparatus

Info

Publication number: WO1997043114A1
Application number: PCT/US1997/008056
Authority: WO
Inventors: Andrew Mcg. Martin; Dwight P. Fowler
Original assignee: Simple Packaging Solutions, Llc.
Priority date: 1996-05-13
Filing date: 1997-05-13
Publication date: 1997-11-20
Also published as: AU3065197A

Abstract

A preformed storage bag (200) and a method and apparatus for forming such a storage bag from a heat fusible, elastic, polymeric material. The storage bag contains a reclosure tie (202) formed as an integral marginal portion that includes overlying layers (203, 204) of bag material that form an elongated structure along an axis (213) with first and second ends (211, 212). A fused closure (214, 215) is formed in the marginal portion parallel to the axis and over a portion of the marginal portion spaced from one end thereof. This structure defines a tail (210). Other fused closures (216, 217) close the other end of the marginal portion to produce a fused structure that will not delaminate in ordinary use. The space between the tail portion and fused structure defines an open loop (220). The reclosure tie can be wrapped around an opened bag thereby closing the bag in a positive fashion by then cinching the tail portion through the loop portion.

Description

RECLOSABLESTORAGE BAG, METHOD. ANDAPPARATUS

This application is a continuation-in-part of copending application Serial No. 08/557,205 filed November 14, 1995 which is a continuation in part of Serial No. 08/420,446 filed April 10, 1995 (now abandoned) which is a continuation of copending application Serial No. 08/292,590 filed August 18, 1994 (now abandoned) which is a continuation of copending application 08/085,410 filed June 30, 1993 (now abandoned) which is a continuation of copending Serial No. 07/842,023 filed February 25, 1992 (now abandoned) for a Reclosable Storage Bag and Method For Making The Same which is assigned to the same assignee as this invention.

Description Technical Field

This invention generally relates to packaging and more specifically to a preformed storage bag that is easily reclosed and opened and to the methods and apparatus for making such a preformed storage bag. Background Art

There is a long-running effort to make storage bags of different types that are easily reopened and then reclosed after using some of the bag' s contents . This effort has led to criteria for judging the potential success of such storage bags, particularly bags that are fully sealed in order to protect perishable contents, such as frozen or fresh vegetables. Consumers require that such bags must be easily opened, reclosed, and reopened. The method of reclosure must be positive. From a manufacturer's standpoint, the method and apparatus required for forming the bag and reclosure structure must be easily added to a production line, operate without any appreciable reduction in production rates, add minimal production costs, have the capacity to be used with bags requiring a freshness seal and produce little or no waste material .

Generally this prior effort has produced bags that either incorporate a separate reclosable tie or an integral structure that forms a tie. The following patents are examples of bags with separate reclosure ties:

3,311,288 (1967) Lemelson 3,426,959 (1969) Lemelson 3,674,135 (1972) Simon 3,779,139 (1973) White Each Lemelson patent discloses a package with a tear strip of plastic or metallic foil. The tear strip may include a thread, string, wire or weld for added strength. The bag is reclosed by separating the tie from the bag and then wrapping and twisting the tie around the bag. The Simon patent discloses a roll of separable bags. A line of perforations along an edge or top of each bag enables a section of the material to be removed for use as a reclosure tie or tear strip. The tear strip may be reinforced by one or more heat seals or by the application of separate strengthening materials such as string, deformable metal or another ply of film.

The White patent discloses a bag with a transverse tear strip that can be removed from the end of the bag. This tear strip then can be tied in an overhand knot to reclose the bag.

Each of the foregoing reclosure tie structures achieve some of the previously discussed criteria. Most are relatively easy to use in reclosing a bag. Twisted tie wraps are also relatively easy to remove in order to reopen the bag. Those tied with overhand knots may or may not be easy to open depending upon the ease with which the overhand knot releases. However, these approaches have not found great acceptance because they all incorporate special structures or require very specialized apparatus that can reduce production rates or increase materials and manufacturing costs unacceptably. For example, the White patent discloses the formation of a bag with a series of steps that is not readily adapted to continuous form and fill processes as conventionally used in the food industry and other industries .

The following patents disclose packaging that uses integral tie strips that remain attached to a bag: 3,217,971 (1965) ShvetZ

1,150,037 (1969) Plusplan (GB) 3,480,198 (1969) Repko In accordance with the disclosure of the Shvetz patent a bag opens along a transverse tear line that terminates inwardly of the edges of the bag to form a tie. A longitudinal tear line allows a portion of a reclosable tie to be separated into two halves such that the reclosure tie or strip forms two individual tie strips attached to opposite edges of the bag. The two ties can be knotted together. In another version a side strip formed along an edge of the bag can be partially separated to form a single tie strip.

The Plusplan patent discloses a similar structure in which a marginal section of a bag separates from the main portion of the bag along a tear line. However, the reclosure tie does not completely separate from the bag.

The Repko patent discloses a similar structure in which a marginal portion, with a weld or heat seal for strength, partly separates from a bag along a tear line defined by a series of apertures. The tear terminates at an end point, so the marginal portion remains physically attached to the bag.

Each of these structures either requires additional materials or prevents the bag from opening fully when the contents are to be dispensed. Moreover, the Repko patent requires a sophisticated structure for forming the plurality of apertures with seals intermediate and about each aperture to maintain any freshness seal.

The following patents disclose the bags in which a reclosure tie has an integral loop and tail section:

3,664,575 (1972) Lake 4,549,657 (1985) Martin 4,609,107 (1986) Martin et al 4,682,976 (1987) Martin et al 4,787,517 (1988) Martin In accordance with the Lake patent a portion of a bag adjacent the top is formed with an intermediate seal that extends partially across the bag to form a tail of a reclosure tie. Another transverse seal spaced from the first seal joins the layers of film to form a loop section. This reclosure tie can be separated from the bag and then cinches the bag when the tail is wrapped around the bag and thread through the loop. However this reclosure tie is disclosed in connection with storage bags without freshness seals. That adaptation of this structure to a bag with a freshness seal could increase material costs unacceptably. The Martin patents, U. S. Letters Patent Nos.

4,549,657 and 4,787,517, disclose a number of embodiments of easily opened and reclosable bags . Oppositely disposed sealing jaws form a closure seal with a reclosure tie and a freshness seal. The reclosure tie can be removed from the bag without disturbing the freshness seal. The bag is reclosed by wrapping the reclosure tie around the bag and extending one end through a loop formed at the intermediate section by the unsealed plies. In one embodiment it is suggested that the reclosure tie be formed as sealed plies of material except at an intermediate section offset to one end of the tie, thereby to form a tail.

In each of the Lake and Martin patents the loop section incorporates a seal. In the field that existed at the time of the Lake and Martin patents, polypropylene package was dominant. In fact the Martin patent was particularly directed to such packaging. The sealing mechanism in such packaging is a layer or ply of heat- sensitive material that acts much as an adhesive. More particularly, if a cinching force were applied by the tail portion, a large portion of that force would concentrate at an edge of the seal in the loop section. The seal would begin to fail due to delamination of the plies at the seal. With polypropylene such failure would manifest by random tearing. When this occurs, the integrity of the loop section is lost and the reclosure tie no longer is functional. The Martin et al patents, U. S. Letters Patent Nos. 4,609,107 and 4,682,976, disclose a reclosure tie formed as a tear strip across a top of a polypropylene bag in a margin portion beyond a freshness seal . The tear strip has a mold formed transversely in the bag for strength; it tears along a series of specially formed slots or perforations through the material in the margin portion beyond the freshness seal. In one embodiment a portion of the bag omits the mold proximate an edge thereby to provide a reclosure tie with a short mold channel and a loop spaced from one end. It is suggested that the other end of the reclosure tie pass through the loop as a tail to cinch the bag. Cinching, in this case, is also dependent upon an interaction of nubs formed on the edges of the reclosure tie. This approach is disclosed in connection with heat sealable, treated cellophane or other thin organic polymer materials. In fact, the bag has been used with polypropylene bags, but is not readily adapted for polyethylene-based bags. First, it is difficult to form a mold and channel in such material. Second and as previously indicated, the cinching forces will act against the seal that constitutes a potential failure point.

United States Letters Patent No. 5,284,002 issued February 8, 1994 is by the same inventors of and is assigned to the same assignee as this invention. This patent discloses an apparatus and method for making one type of reclosable storage bag that meets the foregoing criteria by producing a reclosable storage bag for production on vertical form and fill machines. The storage bag, that is formed of a heat fusible polymeric material, contains a removable reclosure tie formed as an integral marginal portion of the bag beyond one edge. The marginal portion includes overlying layers of bag material that form an elongated structure along an axis with first and second ends. A fused closure is formed in the marginal portion parallel to the axis and over a portion of the marginal portion spaced from one end thereof. This structure defines a tail and open loop that wrap around, an opened bag thereby to close the bag in a positive fashion when the tail portion is cinched through the loop portion. In this configuration the open loop extends from the tail as a continuous section of film that has sufficient strength to withstand the forces exerted on the loop as the tie is cinched around the bag during reclosure.

Other types of bags also have a need for reclosure. One such type is a preform bag that is manufactured and sold in bulk to be filled and sealed by other individuals. Apparatus that makes such preform bags typically folds sheet film taken from a roll and folds it into overlapping layers at the beginning of the preform bag manufacturing apparatus, typically along a film path or direction that is parallel to the fold. At one point, the film undergoes intermittent motion along the film path. When the film stops, a sealing/severing apparatus cuts the film transversely to the film path and simultaneously seals the film edges on each side of the cut. The film of the leading side of the cut then forms a bag with a bottom formed of the fold in the film and the sides sealed or fused at the edges. The end opposite the fold is open. When the bag is subsequently filled, a simple sealing bar closes the open end.

The process for manufacturing bags on vertical form and fill machines as specifically disclosed in United States Letters Patent No. 5,284,002 can not be directly applied to the production of preform bags primarily because the fold in a preformed bag can not be reoriented to appear in the end of the loop to provide the required film strength in the loop. Consequently the end of the loop would have to depend upon the normal seal at the edge of the bag. However, this seal does not provide sufficient strength and would fail during normal use of the reclosure tie. Disclosure of Invention

Therefore it is an object of this invention to provide a reclosable bag that is easy to open and contains a reclosure tie that facilitates the subsequent closure and reopening of a preformed bag.

It is another object of this invention to provide a reclosable preformed bag with an integral reclosure tie that does not require the addition of discrete elements or special components.

Another object of this invention is to provide a reclosable preformed bag with an integral reclosure tie that can be manufactured without the generation of waste materials . Still another object of this invention is to provide a reclosable preformed bag and reclosing tie structure with additional manufacturing costs limited primarily to the cost of additional bag material.

Still another object of this invention is to provide a reclosure tie for a preformed reclosable bag in the form of an integral reclosure tie with a strong integral loop portion and a tail portion.

In summary and in accordance with one aspect of this invention a preformed storage bag with an integral reclosure tie is characterized by overlying layers of a heat fusible elastic polymeric film with first and second parallel spaced fused edges defining a pouch extending along a pouch axis and having an opening at a first end thereof. The bag includes an end seal formed transversely to the pouch axis across said layers along a line spaced from a second end of the pouch thereby to define a contents portion of the storage bag between the end seal and the first end. First and second collinear, spaced reclosure seals are formed intermediate the end seal and the second end formed by fusing portions of the layers together whereby the layers form a loop therebetween intermediate the first and second reclosure seals. The first reclosure seal is longer than said second reclosure seal thereby to form the layers coextensive with the first reclosure seal into a tail for insertion through the loop. The bag additionally includes a separation structure intermediate the end seal and the first and second reclosure seals for enabling the removal of the layers between the separation structure and the second end as a reclosure tie including the loop and tail.

In accordance with another aspect of this invention, a method for forming a preformed storage bag with an integral reclosure tie includes moving an indeterminate length of elastic, fusible polymeric film as a continuous sheet along an axis. The film is folded into two overlapping layers. The fold is parallel to the axis and defines one of first and second parallel ends of the completed storage bag. After folding, the method continuously forms an end seal and reclosure seal in portions of the overlapped layers parallel to the fold. This structure is spaced from the first end by a distance determined by the size of a contents pouch. Portions of the film layers are fused together along separated line segments extending parallel to the end seal and intermediate the end seal and the second end to form a reclosure seal . Production is completed by severing and sealing an end portion of the film layers along a line parallel to the pouch axis that intersects each reclosure seal proximate one end thereof thereby to form a storage bag which includes unequal portions of two adjacent reclosure seals in the reclosure tie and by cutting the film along the fold whereby the storage bag has an opening at the first end and a reclosure tie at the second end with a tail portion formed by the longer of the two reclosure seals and a loop portion intermediate the two reclosure seals so that the reclosure tie is joined to the pouch by the separation structure. In accordance with still another aspect of this invention, apparatus for manufacturing reclosable storage bags includes a film transport for moving an indeterminate length of heat fusible elastic polymeric film as a continuous sheet along a transport axis. A folder folds the film into two overlapping layers with the fold being parallel to the transport axis and defining one of first and second parallel ends. Components at another station form a continuous end seal and separation structure in portions of the overlapped layers parallel to the fold and spaced from a first end by a distance determined by the size of a contents pouch. Components at a fusing station fuse portions of the film layers together along separated line segments intermediate the end seal and the second end to form a reclosure seal in a reclosure tie. At another station components sever and seal an end portion of the film layers along a line transverse to the transport axis that intersects each reclosure seal proximate one end thereof thereby to form a storage bag which includes unequal portions of two adjacent reclosure seals in the reclosure tie. A cutter cuts the film along the fold whereby the storage bag has an opening at the first end and a reclosure tie at the second end with a tail portion formed by the longer of the two reclosure seals and a loop portion intermediate the two reclosure seals, said reclosure tie being joined to the pouch by the separation structure . Brief Description of the Drawings Although the appended claims particularly point out and distinctly claim the subject matter of this invention, the various objects, advantages and novel features of this invention will be more fully apparent from a reading of the following detailed description in conjunction with the accompanying drawings in which like reference numerals refer to like parts, and in which:

FIGS. 1 through 4 are perspective views of different embodiments of prior art storage bags;

FIG. 5 is a perspective view of a preform bag constructed in accordance with this invention;

FIG. 6 is a cross section through FIG. 5 along lines 6-6;

FIG. 7 is a view, in schematic form, of one embodiment of assembly equipment for producing the bag disclosed in FIG. 6;

FIGS. 8 and 9 depict the basic operation of one subassembly in the equipment shown in FIG. 7; and FIG. 10 is a view, in schematic form, of another embodiment of assembly equipment for producing the bag disclosed in FIG. 6.

Best Mode For Carrying Out the Invention Prior Art Reclosable Storage Bags FIGS. 1 through 4 depict prior art storage bags including a storage bag 100 in FIGS. 1 through 3 that is produced on a vertical form and fill machine. Typically the bag 100 will be formed of an elastic coextruded polymer such as low density polyethylene and ethyl vinyl acetate or a copolymer including polyethylene. When heat is applied to adjacent film layers of these materials, the material seals by fusing adjacent layers. These films are also characterized by reasonably high resistance to puncture and to the initiation of a tear. Such materials may also be co-extruded with other films for particular applications and still use the foregoing characteristics. It is intended that the phrase "heat fusible elastic polymeric material" include all such polyethylene-based materials as well as other materials that exhibit similar characteristics.

FIG. 1 also depicts an adjacent, or lower, bag 101 after as being severed from the bag 100 as occurs in a normal production of successive storage bags. Each bag has the same basic construction. Using the storage bag 100 in FIGS. 1 through 3 as an example, the film forms a generally cylindrical open-ended pouch 102 comprising a sheet of heat fusible elastic polymeric film wrapped around a cylinder. The edges overlap and produce a longitudinally extending back seam 103. A "bottom" seal 104 and a "top" seal 105 close the ends of the pouch 102 so the bag can store food or other articles. A perforation line 106 defines a boundary between the storage bag 100 and an attached, integral reclosure tie -li¬ no.

Specifically the reclosure tie 110 constitutes a margin portion and includes film layers forming extensions 111 and 112 beyond the seal 105. The extensions 111 and 112 terminate at margin end portions 113 and 114 and the reclosure tie 110 lies along an axis 115 that parallels the top seal 105. Two fused seals 116 and 117 parallel the axis 115 and extend from the margin end 113 to a position intermediate the back seam 103 and the margin end 114 and spaced from the margin end 114. A top edge 118 of the extensions 111 and 112 constitutes a parting line for adjacent bag. Reference numeral 118 also designates the parting line for the bags 100 and 101.

The portion of the extensions 111 and 112 that are coextensive with the fused lines 116 and 117 along the axis 115 produce a tail portion 120 in which the layers

111 and 112 are fused together along spaced fuse lines 116 and 117. The remaining portions of the extensions 111 and

112 including the end 114 form a loop portion 121. As shown in FIG. 1, therefore, each of a series of storage bags such as storage bags 100 and 101 has an integral extension of the film forming two layers beyond a top seal line. The extensions form a tail and loop structure that can be readily torn from the bag along the perforation line 106.

To open the bag, a consumer tears the reclosure tie 110 from the bag 100 along the perforation 106 as shown in FIG. 2. Then the consumer separates the film layers along the top freshness seal 105 to open the bag fully. After some of the contents are removed, the individual gathers the bag 100 above the remaining contents to form a closed neck 122 as shown in FIG. 3, wraps the reclosure tie 110 around the neck 122 and passes the tail portion 120 through the loop portion 121. When the consumer pulls the tail portion 120, the reclosure tie 110 slides longitudinally such that the loop 121 adjacent the margin end 114 slides along and tightens the noose formed around the gathered neck 122. All pressure on loop 121 is applied against the end 114 that is free of any material that might otherwise delaminate, such as the back seam 103. When the loop 121 is firmly cinched in place and the tail portion 120 is released, the material, that stretched in tension, relaxes. The end margin 114 of the loop 121 cinches against the tail portion 120 thereby preventing its inadvertent loosening. However, as is characteristic in such loops, intentional release of the reclosure tie 110 is readily accomplished by sliding the end of the loop 121 toward the margin end 113 of the tail portion 120 thereby releasing the cinching action and enabling a consumer to readily remove the closure tie.

FIG. 4 discloses another prior art bag 130 that includes a pouch 132 formed of two layers of film.

Parallel, spaced side seals 134 and 135 form the pouch 132. The seal 135, however, is disposed inwardly of an edge 137 and perforation line 136 parallel to and proximate the seal 135 of the bag to define a reclosure tie 140 formed by the film layers 141 and 142 between the seal 135 and the edge 137. The reclosure tie 140 has a structure that is similar to that shown in FIG. 1, namely ends 143 and 144 lie transverse to an axis 145 parallel to the seal 135. Seals 146 and 147 formed intermediate the perforation line 136 on the edge 137 form a tail portion 150 and leave loop portion 151. In this bag the top opening 152 is formed merely by the edges of the overlapped portion and a bottom closed portion of the bag is formed by a fold 153 produced when the two layers of film are folded over one another.

This storage bag 130 has some of the features of a preformed storage bag because it is formed by folding the film about the fold 153 that becomes the bottom of the bag and is completed by side seals 134 and 135. It also meets the criteria of having a loop portion 151 that is a continuous film remote from the tail portion 150. However, the use of sealing jaws of the type required to form the necessary seals the width of the reclosure tie 140 would require inordinate dwell times for the film as it moves along a film path. That is very difficult to accomplish without introducing expensive take-up mechanisms that would utilize additional floor space and could require a major modification of existing apparatus for making preformed bags .

FIGS. 5 and 6 depict a storage bag 200 that is readily made on conventional preformed bag manufacturing apparatus with minimal modifications and that is composed of polyethylene or other elastic, heat fusible polymeric material. As shown particularly in FIG. 5, the storage bag 200 comprises a main or pouch portion 201 and a integrally formed, detachable elongated reclosure tie 202. Two film layers 203 and 204 form the pouch portion 201 when the layers are sealed along edges 205 and 206 and along a transverse line to form an end seal 207. Each of these seals is formed by heating causing the materials in the layers 203 and 204 to fuse along fusion lines at the positions of the seals 205 through 207. The reclosure tie 202 comprises extensions of the layers 203 and 204 beyond the end seal 207 that form a tail portion 210. The tail portion 210 extends from one edge 211, that is an extension of the seal 205, toward an opposite edge 212, that is an extension of the seal 206. In this particular embodiment the tail portion 210 extends along an axis 213 that parallels the seal 207 and contains two parallel, spaced, thin fused portions or lines 214 and 215 formed by fusing the contiguous materials in the layers 203 and 204 through localized heating. Two similar fused portions or lines 216 and 217 are in line with and spaced from fused portions 214 and 215 respectively. The fused portions 216 and 217 form an area 218 at the second edge 206; and the area between the tail portion and the end portion 218, by virtue of not having any fused portions therein, forms an open loop portion 220.

Looking particularly at FIG. 6, that is a section through the fused portions 214 and 216, the tail portion 210 and end portion 218, with its fused, essentially homogenous cross section, have the strength of the material itself. The walls 203 and 204 in the open loop portion 220, by virtue of having no fused portions, form an open loop 221. Applying separating forces on the portions 203 and 204 in the loop portion 220 will not, under the types of forces normally encountered in utilization of this reclosure tie, cause the film to delaminate by virtue of the fused nature of the portions 214 through 217. Therefore the open loop area 220 is free of any structure that is subject to failure by film delamination even though in this particular embodiment the open loop area 220 terminates in the fused end area 218, whereas in the other disclosed embodiments the loop is formed as a fold in the film without any fused portions so the loop is continuous in areas corresponding to the fused end portion 218. Thus the bag includes at least one axially extending fused portion of overlapping layers that form the tail portion 210 and overlapping layers of film 203 and 204 in a open loop area 220 that forms an open loop 514 free of any structure that is subject to failure by film delamination.

The reclosure tie 202 is detachable by tearing along a perforation line 222 in FIG. 5 that is formed of individual spaced perforations through the two-layers 203 and 204. The perforation line 222 lies intermediate the end seal 207 and a line through the fused portions 214 and 216. This enables easy removable of the reclosure tie 202 from the pouch portion 201.

Manufacturing Methods and Apparatus FIG. 7 depicts, in schematic form, apparatus for producing a preform bag such as the preform bag 200 shown in FIG. 5 and as exiting the apparatus in FIG. 7. Film 240 from a roll 241 passes through a folding apparatus 242 to form, in this embodiment, the folded sheets having a fold 243 at the top in FIG. 7, a lower layer 244 and an upper layer 245. The film moves along a transport path or axis designated by a film path arrow 246 under other film transport apparatus as known in the art . Typically the film moves in this folded position at a substantially constant velocity into a take-up roller station 247 before passing through a sealer/cutter 248. The sealer/cutter 248 stops the film intermittently while it severs the bags and seals the layers adjacent the severing line. The roller section 247 allows this intermittent advancing of the film through the sealer/cutter section 248 while still allowing the film 245 to the rollers 247 in a continuous fashion. Consequently when this operation terminates in prior art systems, the fold forms the bottom of the bag and the sides, extending perpendicularly to the fold, are also sealed leaving the opposite end, at the top of FIG. 7, open. Each of the foregoing components and their operation are well known in the art, so no further discussion is included or necessary for an understanding of the structure and operation of these devices .

Still referring to FIG. 7, apparatus for producing the bag 200 is added to the system intermediate the folding station 242 and the take-up roller section 247. Consequently it operates on the film 240 while it moves at a substantially constant speed in the direction of the arrow 246. In this embodiment a knife 250 slits the film along the fold 243. As shown in FIG. 7 at a next station 251 a heated wheel 252 presses against a shaft 253 to form a continuous fused line 254 that becomes the seal 207 in the bag 200. A next station 255 comprises a lower unheated roller 256 and a pair of heated rollers 257 and 258 mounted on a common shaft 259. In FIG. 8 a positioning mechanism 260 elevates the shaft 259 so the film layers 244 and 245 pass under the heated rollers 257 and 258 without contact, but against the unheated roller 256. In this position therefore the film passes the station 255 without the formation of any seal or fused portions. In FIG. 9 the positioner 260 has lowered the shaft 259 in the wheel 257 so that heated rollers 257 and 258 contact the film 244 to begin the production of a fused seal portion. Consequently as shown in FIG. 7, the wheels 257 and 258 produce a set of parallel fused portions 261 and 262 that are spaced from an adjacent set of fused portions 263.

A station 264 includes an unheated roller 265 below the film and a perforating wheel 266 above the film. As the film passes this station, the wheel 266 turns and in conjunction with pressure exerted with the roller 265, produces a series of perforations along a line 267. This becomes the perforation line 222 in the bag 200.

As is also known, film moving along a path 246 generally includes a registration mark for controlling the operation of various parts of the apparatus . The heat sealer/cutter is controlled in this manner to time its operation such that the cutting line, shown as space 270 in FIG. 7, divides the set of parallel seals or fusion lines from the wheels 257 and 258 proximate one end of the seals. In this particular embodiment, the continuation of the seals to the right of the space 270 extends from the edge 205 to a point beyond the portable center 271 of the bag 200. The portion 272 to the left of the space 270 is short and can be in the order of a quarter of an inch.

Consequently when the cutter/sealer/severer 248 operates, the bag 200 is produced with the sides 205 and 206, a bottom seal 207 and the seals 214 and 215 that define the tail portion and the seals 216 and 217 that form an end and a portion of the loop that is free of any structure that will delaminate in use. After a portion of the contents of the bag are used, the bottom portion of the bag that forms the reclosure tie 202 can be readily removed by tearing along the perforation line 222. FIG. 10 discloses the same apparatus components organized differently. As in FIG. 7, however, the film 240, dispensed from a roller 241, passes through a folding station 242 to produce overlapping layers 243 and 244. In this particular embodiment, however, the fold 243 is formed at the bottom of the apparatus as shown in FIG. 10, as opposed to the top as shown in FIG. 7. The perforating station 264 is next in line. After the line of perforations 267 is formed, the station 251 produces the continuous seal 254 that will become the sealed end of the bag. An intermittent fusing station 255 has the same structure of that shown in FIGS. 7 through 9 and forms the intermittent seals 261 and 262. As film comprising the layers 244 and 245 moves along the axis 246 in a continuous fashion to the take-up station 247 a knife station 250 slits the fold 243. As will be apparent it is necessary to slit the fold 243 in order that there be access through the loop 221 in the bag 200. As before, the bag 200 leaving the apparatus has an open section formed by the layers 203 and 204, sealed side portions 201 and 206, the bottom seal 207, the line of perforations 222, the fused lines 214 and 215 that form the tail section and the fused lines or segments 216 and 217 that assure that the material of the loop 221 does not delaminate in use.

Therefore in accordance with this invention, there has been described a structure for a preform bag that has a reclosure tie that is manufactured without significant additional cost. The addition of the apparatus shown in FIGS. 7 and 10 should not reduce the time necessary to manufacture a bag. For a given size bag the only additional material costs are those associated with the additional material that is formed below the seal 207 It is important, however, that in this structure with the side seals 205 and 206 that an additional reinforcement, such as provided by the sealed segments 216 and 217, be provided in order that the loop 221 does not contain any structure that would delaminate during use. The seal 206 by itself does not constitute such a structure. As previously indicated, the addition of the seals 216 and 217 formed by fusing the material layers 203 and 204 provides a structure that does not delaminate. It is more likely that under such stress that the film itself would fail before the fused portions would fail given the effective increased thickness m the fused areas . In summary there have been disclosed diverse embodiments of preformed storage bags with integral reclosure ties and apparatus for effecting methods of manufacturing certain of these embodiments. Each embodiment provides a bag that is easy to open. Each bag contains a reclosure tie that facilitates subsequent closure and reopening of the bag. The bag, with its integral reclosure tie, does not require the addition of any discrete elements or special components. Manufacturing does not produce waste materials and any additional manufacturing costs are limited primarily to the cost of additional material in a small margin portion. In each bag the reclosure tie is readily detached and used and, with its strong integral loop portion and tail portion, provides a secure and an easy to use reclosure structure. FIGS. 7 and 10 depict two particular modifications for implementing the method and apparatus of this invention. It will be apparent, however, that a number of variations are possible. This application, for example, depicts two parallel intermittent seal portions such as the seal portions 214 and 215. Some applications might use a single seal, others might use three or more parallel seal segments. Each of the embodiments discloses seal segments 214 and 215 forming the tail portion that extend over 50% of the width of the bag. Other ratios could also be used. Therefore it is the intent of the appended claims to cover all such variations and modifications as come within the true spirit and scope of this invention.

Claims

1. A preformed storage bag with an integral reclosure tie comprising:

A. overlying layers of a heat fusible elastic polymeric film with first and second parallel spaced fused edges defining a pouch extending along a pouch axis and having an opening at a first end thereof,

B. an end seal formed transversely to the pouch axis across said layers along a line spaced from a second end of said pouch thereby to define a contents portion of the storage bag between said end seal and said first end,

C. first and second collinear, spaced reclosure seal means intermediate said end seal and said second end formed by fusing portions of said layers together whereby said layers form a loop therebetween intermediate said first and second reclosure seal means, said first reclosure seal means being longer than said second reclosure seal means thereby to form said layers coextensive with said first reclosure seal means into a tail for insertion through said loop, and

D. separation means intermediate said end seal and said first and second reclosure seal means for enabling the removal of said layers between said separation means and said second end as a reclosure tie including the loop and tail.

2. A reclosable storage bag as recited in claim 1 wherein each of said first and second reclosure seal means includes a plurality of spaced parallel linear fused portions.

3. A reclosable storage bag as recited in claim 1 wherein each of said first and second reclosure seal means includes a pair of spaced parallel linear fused portions.

4. A reclosable storage bag as recited in any of claims 1 through 3 wherein said separation means includes a line of spaced perforations formed through said overlying layers of film.

5. A reclosable storage bag as recited in claim any of claims 1 through 4 wherein said first reclosure seal means intersects one of said first and second parallel spaced fused edges and said second reclosure seal means intersects the other of said first and second parallel spaced fused edges.

6. A method for forming a preformed storage bag with an integral reclosure tie comprising the steps of:

A. moving an indeterminate length of elastic, fusible polymeric film as a continuous sheet along an axis,

B. folding the film into two overlapping layers with the fold being parallel to the axis and defining one of first and second parallel ends,

C. continuously forming in portions of the overlapped layers parallel to the fold and spaced from a first end by a distance determined by the size of a contents pouch an end seal and separation structure,

D. fusing portions of the film layers together along separated line segments extending parallel to the end seal and intermediate the end seal and the second end to form a reclosure seal,

E. severing and sealing an end portion of the film layers along a line parallel to the pouch axis that intersects each reclosure seal proximate one end thereof thereby to form a storage bag which includes unequal portions of two adjacent reclosure seals in the reclosure tie, and

F. cutting the film along the fold whereby the storage bag has an opening at the first end and a reclosure tie at the second end with a tail portion formed by the longer of the two reclosure seals and a loop portion intermediate the two reclosure seals, said reclosure tie being joined to the pouch by the separation structure .

7. A method as recited in claim 6 wherein said step of fusing the separated line segments includes fusing a plurality of spaced parallel portions to form multiple parallel spaced line segments.

8. A method as recited in claim 7 wherein said step of fusing the separated line segments includes fusing first and second parallel, spaced portions to form a pair of parallel spaced line segments.

9. A method as recited in any of claims 6 through 8 wherein said step of severing and sealing includes continuously forming the end seal and continuously forming a separation structure in the layers along a line intermediate the end and the reclosure seals.

10. A method as recited in claim 9 wherein said film folding produces a fold at the first end, said method ordering the steps remaining steps in the sequence of cutting the film, continuously forming the end seal, forming the reclosure seals, continuously forming the separation structure and severing and sealing the film layers.

11. A method as recited in claim 9 wherein said film folding produces a fold at the second end, said method ordering the steps remaining steps in the sequence of continuously forming the separation structure, continuously forming the end seal, forming the reclosure seals and severing and sealing the film layers .

12. Apparatus for forming a preformed storage bag with an integral reclosure tie comprising:

A. transport means for moving an indeterminate length of heat fusible elastic polymeric film as a continuous sheet along a transport axis,

B. means for folding the film into two overlapping layers with the fold being parallel to the transport axis and defining one of first and second parallel ends,

C. means for continuously forming an end seal and separation structure in portions of the overlapped layers parallel to the fold and spaced from a first end by a distance determined by the size of a contents pouch, D. means for fusing portions of the film layers together along separated line segments intermediate the end seal and the second end to form a reclosure seal in a reclosure tie,

E. means for severing and sealing an end portion of the film layers along a line transverse to the transport axis that intersects each reclosure seal proximate one end thereof thereby to form a storage bag which includes unequal portions of two adjacent reclosure seals in the reclosure tie, and

F. means for cutting the film along the fold whereby the storage bag has an opening at the first end and a reclosure tie at the second end with a tail portion formed by the longer of the two reclosure seals and a loop portion intermediate the two reclosure seals, said reclosure tie being joined to the pouch by the separation structure.

13. Apparatus as recited in claim 12 wherein said means for fusing the separated line segments includes a plurality of spaced means for forming multiple parallel spaced line segments simultaneously.

14. Apparatus as recited in claim 13 wherein said plurality of spaced means comprises a roller mounted on a first shaft and a plurality of heated wheels mounted on a second shaft, said first and second shafts being transverse to the transport axis, the film passing between said roller and said heated wheels and means for displacing said second shaft between retracted and contacting positions, said heated wheels, in the contacting position, raising the temperature of portions of the overlapped layers in contact therewith to a level at which fusing occurs .

15. A method as recited in claim 12 wherein means for fusing the separated line segments includes first and second spaced fusing means thereby to form a pair of parallel spaced line segments.

16. Apparatus as recited in claim 15 wherein said fusing means includes a roller mounted on a first shaft and said first and second spaced fusing means include first and second heated wheels mounted on a second shaft, said first and second shafts being transverse to the transport axis, the film passing between said roller and said heated wheels and means for displacing said second shaft between retracted and contacting positions, said heated wheels, in the contacting position, raising the temperature of portions of the overlapped layers in contact therewith to a level at which fusing occurs.

17. Apparatus as recited in any of claims 12 through 16 wherein said severing and sealing means includes means for continuously forming the end seal and means for continuously forming a separation structure in the layers along a line intermediate the end and the reclosure seals and parallel to the transport axis.

18. A method as recited in claim 17 wherein said film folding means produces a fold at the first end, said apparatus positioning said means to receive the folded film in sequence through said means for continuously forming the end seal, said means for forming the reclosure seals, said means for continuously forming the separation structure and said means for severing and sealing the film layers .

19. A method as recited in claim 17 wherein said film folding means produces a fold at the second end, said apparatus position said means to receive the folded film in sequence through said means for continuously forming the separation structure, said means for continuously forming the end seal, said means for forming the reclosure seals and said means for severing and sealing the film layers.

20. Apparatus as recited in claim any of claims 12 through 19 wherein said means for continuously forming the end seal comprises a rotatable roller and a rotatable heated wheel for receiving the overlapped layers therebetween thereby to elevate the temperature of the overlapped layers to a level at which fusing occurs.