MXPA99011131A - Resellable closure and method to make my - Google Patents

Abstract

The present invention relates to a resealable package for a product, characterized in that it comprises: a flexible container formed from a generally rectangular flexible sheet having internal and external surfaces, two opposite longitudinal edges and upper and lower transverse edges, the sheet being rolled to form a generally tubular structure having an inner surface portion adjacent a longitudinal edge sealed to a corresponding portion of the inner surface adjacent the other longitudinal edge to define a longitudinal seal, the tubular structure has adjacent internal surface portions to the lower edge sealed to other portions of the inner surface adjacent the lower edge to define a lower seal, and the container includes an upper end defining an opening for removal of the product from the tubular structure, the sheet defining a pair of side walls flexible opuest so that they have opposite inner surfaces, the side walls having edge portions that can be placed in overlapping relationship, the edge portions being separable from each other to create said opening in the container, and a seal that can be opened and resealed as desired. length of the opening, the seal being defined by the edge portions of the side walls placed in confronting relation together and adhesively sealed together, a layer of pressure sensitive adhesive being applied to the inner surface of at least one of the edge portions, and an adherent layer being applied to the inner surfaces of the edge portions and covering the pressure sensitive adhesive, the adhering layers of the edge portions being sealed together to form the resealable seal; the pressure having a greater affinity to adhere to the adherent than to the internal surface of the package, so the opening in The seal of the resealable seal causes the regions of the adherent layers in the two side walls to remain adhered together, such that the regions of pressure sensitive adhesive are separated from one side wall and remain in the other side wall, and thus that the upper seal can be resealed by pressing the edge portions of the two side walls to cause the separate regions of pressure sensitive adhesive to be reattached to the side wall, wherein the layer of adhesive sensitive to the The pressure is applied in a pattern that extends transversely along the upper edge of the sheet, and wherein a strip of adherent is applied to a portion of the inner surface that is not covered by the pressure-sensitive adhesive layer, and which extends transversely along substantially the total transverse width of the sheet, so that the resistance of the original upper seal is improved by the pull a adherent that adheres to itself in the initial seal of the super seal

Description

RESELLABLE CLOSURE AND METHOD TO DO THE SAME FIELD OF THE INVENTION The present invention relates to flexible product packages and, more particularly, to a flexible product package having a resealable closure.

BACKGROUND OF THE INVENTION Product packages that have reclosable mechanisms are often used to package products in situations where the consumer may wish to remove only a portion of the product and reseal the package. Particularly with the current popularity of "fat-free" baked goods, which are easily dried if left exposed to the atmosphere, there is great interest on the part of the product manufacturer for the easily and inexpensively produced gaskets that can be opened and repeatedly close. Flexible packaging produced from flexible sheet materials is generally favored for reasons of cost, functionality, and marketing interest. Several types of reclosable mechanisms have been developed to re-close a flexible package to preserve the unused portions of a fresh food product. Several such mechanisms are separately manufactured items that are added to the package either in a subsequent manufacturing step or by the consumer, such as resealable saws, tapes or tabs, sealing strips, clamps, and the like. However, said mechanisms are inconvenient because they require additional manufacturing materials and operations, thereby increasing the manufacturing cost. Consequently, efforts have been made to develop reclosable mechanisms based on adhesives for flexible packaging, although such packaging is easily produced in an automated flexible network control machinery, and the only required component is the flexible network which adhesive has been applied during the manufacturing process for the network. The manufacturing goal of the resealable mechanism is that based on the adhesive for resealing which is an adhesive that may be suitable to form the original packing seal, which must have sufficient strength and integrity to avoid the unexpected opening of the packaging and keeping the product fresh during handling and shipping, generally different from the type of adhesive that is desirable from the reseal point of view. Cold seals, hot fusions, and heat seals provide good seal strength and are thus suitable for the formation of original packing seals. Unfortunately, such materials generally do not provide sufficient closure capabilities. The pressure sensitive adhesives can be repeatedly removed and reattached to suitable substrates and thus provide closure capabilities. However, pressure sensitive adhesives do not provide sufficient seal strength to form reliable original packing seals in various applications. In addition, because pressure sensitive adhesives are inherently sticky and stick to any surface they come in contact with, automated control of the sheets or networks to which pressure sensitive adhesives have been applied is not easy. For example, the pressure sensitive adhesive can be adhered to the rollers of an apparatus, a problem known in the industry as "starting". Additionally, the network can adhere to itself when it is rolled on a roller and stored prior to its use, a problem known as "blocking". Accordingly, pressure sensitive adhesives are commonly used in conjunction with layers of reinforcing paper or other material to which the release coating has been applied as shown in US Pat. No. 3,827,625. When it is desired to operate a seal using said pressure sensitive adhesive mechanism, the reinforcing layer is removed to expose the pressure sensitive adhesive, and the pressure sensitive adhesive is pressed against a part that cooperates with the packing to effect a closure, either an original seal or a new sealing of a seal previously open Alternatively, the reinforcing layer is permanently attached to the cooperating part of the package to effect an original seal, and the substrate bearing the pressure-sensitive adhesive is separated from the urea reinforcement layer of the original seal, as shown in FIG. US Patent No. 3,272,422. In any case, the new closure is effected by pressing the pressure sensitive adhesive against the cooperating part of the reinforcing layer. The drawbacks of such closing mechanisms are that additional material and manufacturing operations are required to form the reinforcing layer, and the strength of the original seal is only as good as the resistance of the pressure sensitive adhesive, which, as previously observed, is insufficient in several cases.

BRIEF DESCRIPTION OF THE INVENTION The invention solves all the drawbacks of previous closures observed previously by providing a product package having a releasable closure employing an "adherent" seal such as heat sealing or cold sealing to give good strength of the original seal, and a Pressure sensitive adhesive for resealing capability, wherein the pressure sensitive adhesive does not interfere with the automated control of the packaging material, in which reinforcing layers are required for the pressure sensitive adhesive. For these purposes, the package of the invention comprises a generally flexible container having a flexible side wall and including an opening that is limited in confronting the edge portions of the side wall. The package has an openable seal that can be released along the opening. The seal is formed by placing the first and second portions of the inner surface of the side wall adjacent to the opening in confronting relation to each other and sealing them by a seal composed of pressure sensitive adhesive and adhesive layers. A layer of pressure-sensitive adhesive is applied to at least the first portion of the inner surface, and a layer of the adherent is applied to the first and second portions of the surface, so that the adherent covers the layer of the sensitive adhesive to the pressure. The tackifier has good control properties so that it does not easily adhere to the machinery controlling the packing, and because the tackifier covers the pressure sensitive adhesive, the inherent stickiness of the pressure sensitive adhesive does not interfere with the control of the packaging during manufacture. The pressure sensitive adhesive has a higher affinity for adhering to the adherent than to the internal surface of the package. Thus, in the initial opening of the upper seal, the adhering layers in the first and second portions of the inner surface tend to remain adhered, and the pressure-sensitive adhesive layer that lies below the adherent in the first portion tends to remain attached. to remain adhered to the translative adherent layer. Accordingly, the regions of the pressure sensitive adhesive are peeled off from the first portion and remain with the adherent layer on the second portion of the inner surface. Reseal of the seal is achieved by placing the first and second portions of the inner surface approximately in their positions in their original sealed positions and pressing them to cause the detached regions of the pressure-sensitive adhesive to re-attach to the first portion. of the internal surface. The package is preferably formed of a generally rectangular flexible sheet having an internal surface facing the product, two opposite longitudinal edges, and upper and lower transverse edges. The sheet is folded around the longitudinally extending fold lines to form the generally tubular packing having a portion of the inner surface adjacent a longitudinal sealing edge for a corresponding portion of the inner surface adjacent to the other longitudinal edge to define a longitudinal seal. Similarly, the upper and lower seals are produced by sealing the sheet itself along the upper and lower edges. One of the three stamps is formed as a seal that can be closed. In a preferred embodiment of the invention, the pressure sensitive adhesive is applied in a pattern that extends transversely along the upper edge of the rectangular sheet, and the adhesive is then applied along the top edge to cover the adhesive sensitive to pressure. In this way, when the original top seal is formed by the crease of the upper edge portions (and also the application of heat if the adherent is a hot seal), a bond of adherent to adherent is formed between the layers of the adherent in the opposite portions of the upper edge. In an alternative preferred embodiment of the invention, the reclosable seal is formed along the longitudinal seal, in the same manner as described above for the upper seal. Because the original strength of the resealable seal is only as good as the strength of the pressure sensitive adhesive, the resealable seal preferably is increased by a strip of adherent applied to a portion of the seal. the inner surface which is not covered by the pressure sensitive adhesive and which extends substantially along the entire edge of the sheet. The adherent strip improves the strength of the original top seal by adhering likewise without the interposition of any pressure-sensitive adhesive between the adherent and the sheet. The adherent strip is advantageously located between the upper edge of the sheet and the pressure-sensitive adhesive layer, so that the adherent strip forms to the outermost part of the upper seal and prevents the pressure-sensitive adhesive layer from forming. Separate from the inner surface until the upper seal has fully opened. To reduce the tendency of the adherent to form long chains of adhesive upon opening the seal, which can contaminate the pressure sensitive adhesive and reduce the tackiness and thus the performance of the upper seal to reclose, the adhesive strip is It can be applied in a discontinuous pattern, such as a series of circular points spaced across the top edge of the sheet. Alternatively or additionally, the adherent strip can be stamped into a screen pattern having substantially less than 100% coverage of the internal surface by the adherent, and preferably around 50% coverage. The substrate or network forming the package is preferably laminated from several layers of different materials each imparting a desired property to the laminar unit. For example, in accordance with a preferred embodiment of the invention, the sheet comprises an outer layer of polyethylene terephthalate (PET), a middle layer of high density polyethylene (HDPE), and a 60 gauge inner layer of a cold metallized seal of oriented release of polypropylene. The PET layer is easily printed with the inks commonly used to place graphics and signs on the packaging. The cold sealing of the release layer facilitates the decoupling of the pressure sensitive adhesive from the substrate, so that the top tack adhesives can be used, and the metallization of the release layer provides a moisture barrier function. The HDPE layer provides the laminar unit with additional resistance to detachment. In an alternative preferred embodiment of the invention, the laminar unit comprises an outer PET layer and a 75 gauge inner layer of metallized cold seal release. By adding thickness to the release layer, the HDPE layer can be removed.

BRIEF DESCRIPTION OF THE DRAWINGS Additional objects, features, and advantages of the invention will become apparent from the following detailed description of the particular embodiments thereof, taken in conjunction with the accompanying drawings in which: Figure 1 is a perspective view of a package that includes a package of the product according to the present invention, with the package in a closed condition as initially sealed during a packaging operation; Figure 2 is a fragmentary view similar to Figure 1, showing one end of the package open to form an opening for removal of the product from the package; Figure 3 is a top elevation view of a sheet to form a package according to the invention; Figure 3A is an enlarged view of a portion of the adhesive not sensitive to screen printing pressure; Figure 3B is a fragmentary elevation view of the external surface of the sheet of Figure 3, showing the indicia together with the tongue; Figure 4 is a cross-sectional view taken on line 4-4 of Figure 3; Figure 5 is a cross-sectional view taken on line 5-5 of Figure 1, showing the cooperating portions of the sealed package to define an initial seal along the end of the openable package, with the adhering layers sealed each; and Figure 6 is a cross-sectional view taken on the line 6-6 of Figure 2, showing the cooperating portions of the package after being separated to open the initial seal at the openable end of the package, with the adherent layers still adhered and the pressure sensitive adhesive below one of the adherent layers having separated from the packing sheet to which it was originally applied; Figure 7 is a view schematically showing an apparatus and method for manufacturing a laminated network and applying a pressure sensitive adhesive adhering to the network; Figure 8 is a view similar to Figure 3, showing a sheet for forming another preferred embodiment of a package according to the invention; and Figures 9A-F show yet another preferred embodiment of a package according to the invention, in which the resealable seal extends along the package.

DETAILED DESCRIPTION OF THE DRAWINGS With reference to Figure 1, a package is broadly designated with the reference number 10. The package 10 includes a product 12 covered by a flexible package 14. The package 14 is formed of a flexible film material. For the packaging of food products that are adversely affected by changes in moisture content caused by evaporation of moisture from the product or by contact of the product with external moisture, the package 14 is preferably made of a film that acts as a moisture barrier. Suitable materials include polyethylene, low density polyethylene (LDPE), high density polyethylene (HDPE), polyethylene terephthalate (PET), oriented polypropylene (OPP), metallized OPP, PVP coated with PVDC, polyamide, and others. The package 14 is generally in the form of a tubular container formed of a generally rectangular sheet having its opposite longitudinal edges 16 and 18 sealed to form a seal 20 extending longitudinally along the package 10. Alternatively, the package is can form the film that has been extruded into a tubular shape, so that the longitudinal seal 20 is not found. Preferably, however, the package is formed of film material in the form of a flat sheet, to facilitate the stamping the designs and / or signs on the external surface of the package prior to wrapping the product and sealing the edges of the sheet. The transverse edges 22 and 24 are sealed in the same manner in the transverse seals 26 and 28, respectively, to close the two opposite ends of the tubular cover, thereby wrapping and sealing the product 12 in the package 14. Either of the end seals 26 or 28, or alternatively the longitudinal seal 20, can be formed as a seal that is It can open and it can be resealed. In the embodiment of the invention shown in Figures 1-6, the upper seal 26 defines the seal that can be resealed. Figure 2 shows the seal 26 in an open condition with the opposite portions or side walls of the package 14 having been separated to define an opening 30 through which the product 12 can be removed or inserted. Figure 3 shows a top elevation view of a flexible sheet 40 to form the package 14. The sheet 40 has opposite longitudinal edges 16, 18 and opposite transverse edges 22, 24. The sheet 40 can be cut from an elongated network 42 of film material, either before or after the adhesives are applied to the sheet 40 to make the seals of the package 14, in which case the sheet 40 is formed by cutting the network 42 together with two cross-cut lines for create the edges 22 and 24. The sheet 40 has a surface 44 facing the product 12 in the formation of the sheet 40 in the package 14. The product facing the surface 44 is advantageously made of a soft material, substantially not porous to which the adhesives easily adhere without being significantly absorbed.

As further described below, the product facing the surface 44 is preferably a metallized OPP or OPP coated with PVDC which acts as a release material for the pressure sensitive adhesive. The longitudinal adhesive strips 46 and 48 are applied to the product facing the surface 44 adjacent the longitudinal edges 16 and 18, respectively, and a transverse adhesive strip 50 is applied adjacent the transverse edge 24. The adhesive strips 46, 48 and 50 Preferably they are formed of an adherent which adheres easily to the product facing the surface 44 and to the latter, which is easily sealed together with the overlapping portions of the packaging film to which the adherent has been applied in the application of pressure with or without heat to the overlapping portions by a tight seal or the like, as is well known in the packaging industry. Preferably, the adhesive comprises a cold-sealed adhesive which seals itself only by applying pressure. In this way, as described below, the longitudinal adhesive strips 46 and 48 are brought into contact with each other and sealed to create the longitudinal seal 20, the sheet 40 thus forming a generally tubular configuration. The opposite portions of the sheet 40 adjacent the transverse edge 24 are joined to place the transverse adhesive strip 50 on one of the opposite portions in contact with the strip 50 on the other portion and the portions are sealed to create the transverse seal 28. seal 28 is not intended to be opened, and if it is opened, the adherent does not provide the resealing capabilities. The opposite transverse seal 26 differs from the transverse seal 28 in that the seal 26 can be resealed after the initial opening thereof. To this end, the seal 26 is formed by the unique application of the adhesive and the pressure sensitive adhesive to the product facing the surface 44 adjacent the transverse edge 22. Thus, with reference to FIGS. 3 and 4, the strips and pressure sensitive adhesive 52 are first applied to the product facing the surface 44 of the sheet 40 together and adjacent the transverse edge 22, and then an adherent strip 54 is applied to the pressure sensitive adhesive strip 52. adherent preferably extends closer to the transverse edge 22 than the pressure-sensitive adhesive strips 52, so that an adherent strip 56 is applied to the surface 44 of the sheet 40 without the interposition of the pressure-sensitive adhesive therebetween. . In the formation of the transverse seal 26 together with the edge 22, the adherent strip 56 forms an outer portion of the seal 26 that has a strength greater than that of the seal portion 26 formed by the adherent strip 54 and the adhesive strips sensitive to the seal. pressure 52, and also prevents the operation of the resealable property of seal 26 until seal 26 has been fully opened. "Adherent" refers to an adhesive that when dried is substantially non-tacky, so that it is not susceptible to start-up or substantial blockages, and that it readily adheres to itself in the application of pressure (such as cold-sealed) or in the application of pressure and heat (such as heat sealing). The resealable feature of the seal 26 is provided by the layering of the adherent 54 in the pressure sensitive adhesive 52. As shown in Figure 5, when the seal 26 is sealed and intact, the adhering layers 54 and 56 in the portions opposite of the sheet 40 contact and adhere to each other. The pressure sensitive adhesive layers 52 adhere to the overlapping adhesive layers 54 and also to the sheet 40. However, the pressure sensitive adhesive and the inner surface 44 of the sheet 40 are selected in such a way that the sensitive adhesive at the pressure it has a greater affinity to the sheet 40 to adhere to the adherent 54. In this way, as shown in figure 6when the seal 26 is opened, the adhesive bond between the adherent layers 54 and the pressure sensitive adhesive 52 is stronger than that between the pressure sensitive adhesive layers 52 and the sheet 40 and, consequently, the pressure sensitive adhesive 52 is separated from each other from the opposite portions of the sheet 40. In practice, separation of the pressure sensitive adhesive does not necessarily occur uniformly, but may occur in regions of a portion of the sheet 40 and other regions of the opposite portion of the sheet 40. However, as a result of the opening of the seal 26, there is a pressure sensitive adhesive 52 exposed on one or both of the opposite portions 40.

The reseal of the seal 26 is achieved by placing the opposite portions of the sheet 40 approximately in their original sealed positions and pressing the opposite portions to cause the pressure sensitive adhesive 52 to adhere to the opposite portion of the sheet 40, so that the seal 26 again assumes a condition similar to that shown in figure 5. It is not important that the pressure-sensitive adhesive 52 be placed in the exact register with the region of the sheet 40 from which it separated, although the pressure sensitive adhesive 52 will readily adhere to the sheet 40, the adherent 54, or another region of the exposed pressure sensitive adhesive 52. The inner surface 44 of the sheet 40 preferably comprises a release material for the adhesive sensitive to pressure. Suitable release materials include OPP, metallized OPP, and OPP coated with PVDC. The use of a release material allows the use of pressure sensitive adhesives having a relatively superior tack, which is advantageous for good resealing strength, although it still allows the pressure sensitive adhesive to easily separate the substrate during the opening. Examples of suitable tackifiers include the cold sealing adhesives Nip-Weld C7089, C1099, 210, and 1293 available from ATO Findley Inc. of Wauwatosa, Wisconsin. Examples of suitable pressure sensitive adhesives include the C7088 pressure sensitive adhesives available from ATO Findley.

Cold-sealed adhesives have a tendency to "string", that is, to form strands when separated. When the cold-sealed adhesive is used to be the resealable seal 26, the tendency to form cords represents a problem since the strands of cold-seal adhesive can contaminate the exposed surfaces of the pressure-sensitive adhesive and thus a uneven reseal performance. In order to reduce said contamination problem, the cold-sealing adhesive strip 56 is advantageously applied in a stencil pattern, so that substantially less than 100% of the surface 44 in the region of the strip 56 is covers by the cold seal adhesive. Preferably, about 50% of the surface is covered by the cold-seal adhesive, as shown in Figure 3A. The application of the cold-sealed adhesive substantially reduces in this way the amount of lacing in the cold-sealed adhesive. To facilitate the opening of the seal 26, the package 14 preferably includes a tab 60. The tab 60 comprises a portion of the adherent strip 56 that is interrupted and an adjacent portion of the adherent strip 54 that is intended to be separated from the edge 22 of the web. sheet 40, so that the adherence of the opposite portions of the sheet 40 in the region defined by the interrupted and indented portions is not carried out. As shown in Figure 3B, the outer surface 62 of the sheet 40 is advantageously provided with indicia 64 for instructing a consumer in the use of the tab 60. Figure 8 is a view similar to Figure 3, showing an embodiment alternative preferred sheet 40"to make a package according to the invention The sheet 40 'differs from the sheet 40 in the application of the pressure sensitive adhesive and the adhesive together with the upper edge 22" of the sheet. Specifically, the pressure sensitive adhesive is applied to two discrete and spaced strips 52"each of which has a curved shape, the curved strips 52 'being located on opposite sides and a longitudinal center line of the sheet 40 'A strip 54' of the adherent covers the strip 52"and extends the total width of the sheet. A tab notch 60"is defined on an adhesive strip 54 'A continuous strip 56' of the adhesive extends in the total width of the sheet between the upper edge 22 'and the strip 54'. a sieve pattern that has substantially less than 100% coverage, preferably around 50% coverage. The curved configuration of the strips 52 'facilitates the separation of the pressure sensitive adhesive from the sheet 40' by the initial promotion of the separation of the vertices closest to the upper edge 22", the separation then proceeds from the edges of the inclination The curve Advantageously, but not necessarily, the pressure sensitive adhesive strips 52 'are printed in a screen pattern having substantially less than 100 percent coverage.

As previously noted, the invention is not limited to packages that have the seal that can be opened and resealed at the end of the package. Figures 9A-F show a package 110 according to an embodiment of the invention in which the resealable and resealable seal 112 is a longitudinal seal extending along the package. The seal 112 is constructed similarly to the resealable seals of the 10 and 10 'packages described above. The seal 112 can be formed by joining two opposing edge potions of the sheet 114, each having the adhesive pressure sensitive / adhesive system, similar to the 10 and 10"packages described above, alternatively, and as illustrated in FIG. 9A-F, the seal 112 can be formed by folding a sheet 114 along the fold line 116, so that two opposite portions of the sheet are joined, each of the portions having the system sensitive to the pressure / adherent In such case, the packing coverage on the seal 112 is initiated at the first moment by cutting the fold line as shown in Figure 9A, so that the opposite portions of the sheet can be separated Fig. 9B shows a cross section in the seal 112 after the fold line 116 has been cut off. Each of the opposite portions of the sheet 114 includes a pressure sensitive adhesive layer 120 adhered to its inner surface. and a layer adherent 122 covering the pressure sensitive adhesive layer 120. The seal 112 is formed by sealing the adherent layers 122 as shown above.

Figure 9C and 9D show the opening of the seal 112 when separating the opposite portions of the sheet 114 from each other. Because the pressure sensitive adhesive 120 has a greater affinity with the adhesion of the adhesive 122 than with the sheet 114, the pressure sensitive adhesive 120 is separated from the sheet 144. Figures 9E and 9F show the new closure of the adhesive. seal 112 by pressing the opposite portions of the sheet 114, so that the separate pressure sensitive adhesive 120 is reattached to the sheet 114. The seal 112 can be opened and closed several times. According to a preferred embodiment of the invention, the network from which the sheet is taken to form a package comprises a laminar unit. As schematically illustrated in Figure 7, the network is advantageously manufactured in a rotary press having a plurality of stations for carrying out various stamping, laminating and adhesive application functions. A first layer 70 that forms the outer layer of a resulting package passes through a plurality of stamping stations 72, where identification graphics and / or indicia are printed on the layer. The layer 70 then passes through a laminating station 74 where it is laminated to a prelaminar unit 76 comprising two layers 78 and 80. The adhesive is applied to the outer layer 70 in an adhesive applicator 82 and an outer layer 70 then it is laminated in a prelaminar unit 76. The prelaminar unit 76 may be a preformed network that simply takes a supply roll; alternatively, and as illustrated in Figure 7, the prelaminar unit 76 can be formed just upstream of the rolling station 74 by applying the adhesive to the layer 78 (or the layer 80) in the adhesive applicator 84 and after the lamination of the two layers 78 and 80. After leaving the laminating station 74, the three-layer laminate 86 passes through a pressure-sensitive adhesive applicator 88 where the pressure sensitive adhesive is applied in the inner surface (facing the product) by a cylinder 90. The cylinder 90 has a surface engraved or machined configured to apply the pressure sensitive adhesive in a desired pattern, such as the pattern shown in Figure 3. The laminar unit 86 then passes through an oven 92 where the pressure sensitive adhesive dries. Immediately after, the adhesive is applied to an applicator 94 having an engraved or machined cylinder 96. Finally, the laminar unit passes through a second oven 98 to dry the adherent, and the finished network is wound onto a coil 99 for later use . The resulting roll 100 of the network material can be subsequently processed by any suitable machinery and packaging to form packages according to the invention. According to a preferred embodiment of the invention, the layer 70 (also called embossing network) comprises 48 gauge PET. The laminar unit 76 comprises a layer 78 of 1.0 mil HDPE laminated in a 60 gauge layer 80 of metallized OPP which forms a release layer for the pressure sensitive adhesive. The HDPE layer 78 provides additional release resistance for the laminar unit. The metallization of the OPP release layer 80 provides a moisture barrier function. In an alternative embodiment, layer 78 of HDPE is removed, and release layer 80 comprises a 75 gauge layer of metallized OPP. The thicker release layer 80 helps to compensate for the peel strength that is lost by the omission of the HDPE layer. From the foregoing description in the specific embodiments of the invention, it will be appreciated that the invention provides a unique seal for the package that combines good resistance to the original seal with reclosing capabilities. Although the invention has been explained with reference to the particular embodiments thereof, the invention is not limited to the details of said particular embodiments. The modifications can be made to the illustrative embodiments without departing from the scope of the invention. Accordingly, the scope of the invention will be determined with reference to the appended claims.

Claims (10)

NOVELTY OF THE INVENTION CLAIMS

1. - A resealable package for a product, which comprises: a flexible container that includes a pair of opposed flexible side walls that have opposite internal surfaces, the side walls having edge portions that are placed in overlapping relationship, the edge portions being separable each other to create an opening in the container; and a seal that can be opened and resealed in the opening, the seal being defined by the edge portions of the side walls placed in opposite relation to each other and adhesively sealed, a layer of pressure sensitive adhesive being applied to the internal surface of at least one of the edge portions, and an adherent layer being applied to the inner surfaces of the edge portions and covering the pressure sensitive adhesive, the adhering layers of the edge portions being sealed to form the seal; the pressure-sensitive adhesive having an affinity for adhering to the greater adherent to that of the inner surface of the package, wherein the initial opening of the seal causes the regions of the adherent layers on the two side walls to remain adhered, so that regions of the pressure-sensitive adhesive are separated from one side wall and remain in the other side wall, and wherein the top seal can be resealed by pressing the edge portions of the two side walls to cause the regions separated from the pressure sensitive adhesive are reattached to a side wall.

2. The package according to claim 1, further characterized in that the container comprises a generally tubular structure including a sealed lower end and an upper end defining the opening for the removal of the product from the tubular structure, the seal that it can be resealed by extending along the upper end.

3. The package according to claim 2, further characterized in that the generally tubular structure is formed of a generally rectangular flexible sheet having internal and external surfaces, two opposite longitudinal edges, and upper and lower transverse edges, the sheet being wrapped for forming the generally tubular structure, having a portion of the adjacent inner surface of a longitudinal edge sealed to a corresponding portion of the inner surface adjacent to the other longitudinal edge to define a longitudinal seal, the tubular structure having portions of the adjacent inner surface of the edge bottom sealed to other portions of the adjacent inner surface of the lower edge to define the lower seal.

4. The package according to claim 3, further characterized in that the layer of the pressure-sensitive adhesive is applied in a pattern that extends transversely at the upper edge of the sheet, and wherein an adherent strip is applied to a portion of the internal surface that is not covered by the pressure-sensitive adhesive layer that extends transverse substantially in the total cross-sectional width of the sheet, wherein the strength of the original top seal is improved by the adhesive strip that is Adheres to itself in the initial seal of the upper seal.

5. The package according to claim 4, further characterized in that the transverse strip of the adherent is disposed between the upper edge of the sheet and the layer of the pressure-sensitive adhesive, so that in the initial sealing of the upper seal, the adhesive strip prevents separation of the pressure sensitive adhesive until the upper seal is fully open.

6. The package according to claim 5, further characterized in that the adherent strip is applied in a discontinuous pattern between the upper edge of the sheet and the pressure-sensitive adhesive.

7. The package according to claim 5, further characterized in that the strip of the adherent of the upper edge of the sheet and the pressure-sensitive adhesive are stamped in a screen pattern having a coverage substantially less than 100% to reduce the formation of adhesion cords upon opening of the upper seal .

8. The package according to claim 7, further characterized in that the coverage of the stencil pattern of the adherent is about 50 percent.

9. - The package according to claim 4, further characterized in that a portion of the adherent strip adjacent the upper edge of the sheet is indented away from the upper edge to define a tongue to assist the consumer to initially open the upper seal.

10. The package according to claim 1, further characterized in that the container comprises a generally tubular structure having a sealed lower end and a sealed upper end, the opening extending in a longitudinal direction along the packing between the upper ends and lower.