Method of manufacturing tamper evident package

Abstract

A method of making a resealable package is provided. The method comprises providing an assembly that has a header section and a closure mechanism comprising first and second closure profiles constructed and arranged to selectively interlock. The method further includes providing a package comprising first and second panel sections joined together to define an enclosed region, first and second opposite side edges, a bottom and a mouth that provides access to the enclosed region. Finally, the method comprises attaching the assembly to the package such that the header section is attached to the closure mechanism at a point between the closure profiles and the bottom of the package.

Description

FIELD OF THE INVENTION

[0001] The present invention relates generally to a method of making polymer packages, for example, plastic bags. In particular, the present invention relates to a method of making a resealable bag having a tamper-evident structure.

DISCUSSION OF RELATED ART

[0002] Many packaging applications use resealable containers to store various types of articles and materials. These packages may be used to store and ship food products, non-food consumer goods, medical supplies, waste materials, and many other articles. Resealable packages are convenient in that they can be closed and resealed after the initial opening to preserve the enclosed contents. The need to locate a storage container for the unused portion of the products in the package is thus avoided. As such, providing products in resealable packages appreciably enhances the marketability of those products.

[0003] Resealable packages typically utilize a closure mechanism that is positioned along the mouth of the package. The closure mechanism often comprises profile elements or closure profiles that engage one another when pressed together. Resealable packages also often use a tamper-evident structure to allow consumers to determine if the package has previously been opened. Typically, these structures are attached above the closure mechanism, or are attached on the outside of the package. In those cases, it is necessary to fill the package prior to attaching or engaging the tamper-evident structure, or it is necessary to fill the package from the bottom. The former method is inconvenient, as the package must be moved to a station to attach the structure while the package is full of product. The packages that are made using this method are also susceptible to having product contaminate the closure mechanism as the package is filled through the top.

[0004] It is therefore desirable to attach the tamper-evident structure on the inside of the package, so the structure can be attached prior to filling the package and to protect the closure mechanism from contamination upon filling the package with product.

SUMMARY OF THE INVENTION

[0005] In an embodiment of the present invention, a method of making a resealable package is provided. The method comprises providing an assembly. The assembly comprises a header section, a closure mechanism comprising first and second closure profiles constructed and arranged to selectively interlock. The method further comprises providing a package comprising first and second panel sections joined together to define an enclosed region, first and second opposite side edges, a bottom and a mouth that provides access to the enclosed region. Finally, the method comprises attaching the assembly to the package such that the header section is attached to the closure mechanism at a point between the closure profiles and the bottom of the package.

[0006] In an alternate embodiment of the present invention, a header and closure mechanism assembly for use in a resealable package is provided. The assembly consists of a header section comprising two sides joined together defining first and second mouths, the first and second mouths being in fluid communication with each other; and a closure mechanism comprising first and second closure profiles, the first and second closure profiles constructed and arranged to selectively interlock.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The various features and benefits of the present invention are apparent in light of the following detailed description and the accompanying drawings, in which:

[0008] FIG. 1 is a perspective view of a flexible, resealable package in accordance with an embodiment of the present invention.

[0009] FIG. 2 is an elevated, side view of the resealable package of FIG. 1.

[0010] FIG. 3 is a cross-sectional view of the resealable package of FIG. 1, taken along line 3-3 of FIG. 2.

[0011] FIG. 4 is a perspective view of a flexible, resealable package in accordance with an embodiment of the present invention.

[0012] FIG. 5 is an elevated, side view of a consumer opening the resealable package of FIG. 4.

[0013] FIG. 6 is an elevated, side view of the resealable package of FIG. 4 after it has been opened.

[0014] FIG. 7 is an elevated, perspective view of a component used in constructing the header section and closure mechanism assembly in accordance with another embodiment of the present invention.

[0015] FIG. 8 is an elevated, perspective view of a component used in constructing the header section and closure mechanism assembly in accordance with another embodiment of the present invention.

[0016] FIG. 9a is an elevated, perspective view of a component used in constructing the header section and closure mechanism assembly in accordance with another embodiment of the present invention.

[0017] FIG. 9b is an elevated, perspective view of a component used in constructing the header section and closure mechanism assembly in accordance with another embodiment of the present invention.

[0018] FIG. 10a is an elevated, perspective view of a component used in constructing the header section and closure mechanism assembly in accordance with another embodiment of the present invention.

[0019] FIG. 10b is an bottom view of the component used in constructing the header section and closure mechanism illustrated in FIG. 10a.

[0020] FIG. 11 is an elevated, perspective view of a partially constructed header section and closure mechanism assembly in accordance with another embodiment of the present invention.

[0021] FIG. 12 is an elevated, perspective view of a partially constructed header section and closure mechanism assembly in accordance with another embodiment of the present invention.

[0022] FIG. 13 is an elevated, perspective view of a partially constructed header section and closure mechanism assembly in accordance with another embodiment of the present invention.

[0023] FIG. 14 is an elevated, perspective view of a partially constructed header section and closure mechanism assembly in accordance with another embodiment of the present invention.

[0024] FIG. 15 is an elevated, perspective view of a header section and closure mechanism assembly in accordance with another embodiment of the present invention.

[0025] FIG. 16 is an elevated, perspective view of a partially constructed, resealable package in accordance with another embodiment of the present invention.

[0026] FIG. 17 is an elevated, perspective view of a flexible, resealable package in accordance with another embodiment of the present invention.

[0027] FIG. 18a is a largely schematic view of a portion of a process for constructing a flexible, resealable package in accordance with another embodiment of the present invention.

[0028] FIG. 18b is a largely schematic view of the remainder of the process for constructing a flexible, resealable package partially illustrated in FIG. 18a.

DETAILED DESCRIPTION OF THE INVENTION

[0029] FIGS. 1-3 illustrate an example of a resealable, flexible package 10 having a closure mechanism 20 with first and second closure profiles 33, 35 and a slider device 30 to open and close the profiles 33, 35.

[0030] The flexible package 10 includes first and second opposed panel sections 12, 14 made from a flexible, polymeric film. For some manufacturing applications, the first and second panel sections 12, 14 are heat-sealed together along two edges 13, 17 and meet at a fold line in order to form a three-edged containment section for a product within the interior of the package 10. The fold line comprises the bottom edge 15. Alternatively, two separate panel sections 12, 14 of polymeric film may be used and heat-sealed together along the two edges 13, 17 and at the bottom 15.

[0031] As illustrated in FIGS. 1-3, the flexible package 10 also includes a closure mechanism 20 made in accordance with an embodiment of the present invention. The closure mechanism 20 includes first and second closure profiles 33, 35. The first and second closure profiles 33, 35 may be of any appropriate design known in the art. Example closure profiles are disclosed in U.S. Pat. Nos. 5,983,466, 5,947,603, and 6,217,215.

[0032] A slider device 30 is mounted on the closure mechanism 20 to facilitate the opening and closing of the closure mechanism 20. Slider devices and how the function to open and close such mechanisms, in general, are taught, for example, in U.S. Pat. Nos. 5,063,644, 5,301,394, 5,442,837 and 5,664,229, each of which is incorporated by reference herein. A preferred slider device is taught in U.S. Pat. Nos. 6,293,701 and D434,345 which are incorporated herein by reference, in their entirety.

[0033] Two portions of the closure mechanism 20, one close to the first side edge 13 and another close to the second side edge 17, act as slider stop areas. These slider stop areas are preferably crushed, such as by ultrasonic crushing, shown as crush areas 23, 27 in FIG. 2. The slider stop areas or crush areas 23, 27 securely seal the first and second closure profiles 33, 35 together to minimize the chance of the slider device 30 sliding off the side edges 13, 17 of the package 10. The slider stop areas or crush areas 23, 27 further minimize the tendency for slider device 30 to abut against either of the first side edge 13 or the second side edge 17, and may in fact entirely preclude contact between the slider device 30 and either side edge 13, 17.

[0034] A notch 21 (shown in FIG. 1) is preferably disposed within the closure mechanism 20. The notch 21 is designed to provide a “park place” into which the slider 30 settles when the closure mechanism 20 is sealed. The notch 21 decreases the chances an incomplete interlock between the first and second closure profiles 33, 35. Examples of notches are disclosed, for example, in U.S. Pat. Nos. 5,067,208 and 5,301,395, each of which is incorporated herein by reference.

[0035] The flexible package 10 also preferably includes a tamper-evident header section 40 that is attached to the closure mechanism 20 at the seal 41. The header section 40 comprises two sides 45, 47 (shown most clearly in FIG. 3) sealed together along the two edges 46, 48. The two sides 45, 47 define first and second mouths 42, 44 (shown in FIG. 3). Access to the interior 11 of the flexible package 10 can be gained through the first and second mouths 42, 44.

[0036] The header section 40 includes a preferential area of weakness 38 that extends along a portion of the header section 40. The preferential area of weakness 38 is included to facilitate removal of the header section 40 from the package 10. To that end, the header section 40 may also include a notch 39 (shown in FIG. 2) at one or both of the intersections of the preferential area of weakness 38 and the sides 45, 47. The notch 39 acts as a “starter” for removing the header section 40 from the package 10 by tearing the header 40 at the preferential area of weakness 38.

[0037] As can be seen best in FIGS. 1 and 3, the header section 40 is preferably attached to the closure mechanism 20 at a point 41 where, when the closure mechanism 20 is attached to the side panels 12, 14, the point 41 is between the closure profiles 33, 35 and the bottom 15 of the package 10. The header section 40 extends from the attachment point 41 and between the first and second closure profiles 33, 35. Preferably, the header section 40 extends well past the first and second closure profiles 33, 35. In this way, when package 10 is filled with a product through the mouth 42 of the header section 40 the first and second closure profiles 33, 35 are protected from contamination by the product.

[0038] After a product has been placed in the interior 11 of the package 10, the mouth 42 of the header section 40 is sealed, as illustrated in FIG. 4. This creates a tamper-evident seal 44 along the length of the header section 40. In order to gain access to the product once the package 10 has been filled and sealed, the consumer simply removes the header section 40, as illustrated in FIG. 5. For example, the header section 40 may be removed by tearing, starting at the notch 39, along the preferential area of weakness 38. Once the header section 40 is removed, the closure mechanism 20 may be sealed (or re-sealed) by sliding the slider 30 along the length of the package 10, as shown in FIG. 6.

[0039] FIGS. 7-17 illustrate a method of manufacturing the package 10 in accordance with an embodiment of the present invention. FIG. 7 shows the first and second header sides 45, 47 joined together at the header bottom, 43. The first and second header sides 45, 47 may be provided as separate sheets that are sealed together at the bottom 43. Preferably, however, the first and second header sides 45, 47 are formed by providing a single sheet of material that is then folded in half at the bottom 43.

[0040] Once the two header sides 45, 47 are formed, the preferential area of weakness, 38 is formed on the header sides 45, 47, as shown in FIG. 8. The preferential area of weakness 38 is provided by scoring the header sides 45, 47, in a manner that is known in the art. The header sides 45, 47 may be scored individually, but are preferably scored simultaneously. Alternatively, a single sheet of material may be provided that is pre-scored prior to folding the sheet.

[0041] As shown in FIG. 9, the header sides 45, 47 are sealed together at the seals 48a, 46a. The seals 48a, 46a are preferably formed by heat sealing or by other means such as compression, ultrasonic welding, vibration welding or adhesives. The seals 48a, 46a eventually comprise the header edges 48, 46, as shown in FIG. 1. In the preferred embodiment shown in FIG. 9, the seals 48a, 46a are L-shaped, with the bottom edge of the seal aligned with the preferential area of weakness 38. This allows for the starter notch 39 to be formed in later steps at the corner of the L (as shown in FIG. 10). While the seals 48a, 46a in this embodiment are L-shaped, the seals may also be C-shaped, or any other appropriate shape known in the art. It is noted that sealing the header sides 45, 47 together defines the header mouth 42. Mouth 44 is created by eliminating a portion of the bottom 43, as illustrated in FIG. 9a. The portion that is eliminated creates the mouth 44, that is in fluid communication with the mouth 42, as illustrated in FIG. 10b. The portion eliminated to create the mouth 44 may be removed by any appropriate means known in the art, for example, by punching out or cutting out the desired portion. The formation of the seals 48a, 46a results in the formation of a header section 40 having a mouth 44 that is smaller relative to the mouth 42.

[0042] In order to transform the seals 48a, 46a to the sides 48, 46, respectively, the sections 48b, 46b inside of the L-shaped seals 48a, 46a are removed, as illustrated in FIG. 10a. The sections 48b, 46b may be removed by any suitable means known in the art. Preferably, sections 48b, 46b are removed by use of a punch-out apparatus. After sections 48b, 46b are removed, the header section is notched at the corners of the L-shaped seals 48a, 46a. The notches 39a, 39b are aligned with the preferential area of weakness 38. The notches 39a, 39b may preferably act as starters for removing the header section 40 at the preferential area of weakness 38 when it is desirable to open the package 10 for the first time. The header section may contain no notches, one of the notches 39a, 39b or both of the notches 39a, 39b.

[0043] After the header section 40 is completed, it is placed between the first and second closure profiles 33, 35 as illustrated if FIG. 11. If the first and second closure profiles 33, 35 are provided in an engaged state, they must first be separated. Once they are separated, the header section 40 is placed between the first and second closure profiles 33, 35. The header section 40 is positioned such that the preferential area of weakness 38 is disposed beneath the interlocking closure members (as shown in FIG. 3). By “beneath” it is meant that the preferential area of weakness is placed in a position that will be between the interlocking closure members and the bottom 15 of the package 10, once the closure mechanism 20 is attached to the side panels 12, 14 of the package 10. When the header section 40 is properly positioned between the first and second closure profiles 33, 35, it is attached to the first and second closure profiles 33, 35, as illustrated in FIG. 12. Preferably, the header section 40 is attached to the first and second closure profiles 33, 35 by heat sealing.

[0044] As is shown in FIGS. 13-15, the slider 30 is placed on the closure mechanism 20. The slider 30 may be placed on the closure mechanism 20 by several means, examples of which are discussed below. Preferably closure mechanism 20 is also notched, to provide the notch 21 as a “resting place” for the slider 30 when the slider 30 is moved into the fully closed positioned. Spot seals 23, 27 may also be provided on the ends of the closure mechanism 20. The spot seals 23, 27 are provided to help prevent the slider 30 from sliding off of the closure mechanism 20 and to halt the travel of the slider 30. This completes the construction of assembly 70.

[0045] FIGS. 16-17 illustrate the steps of positioning the assembly between the side panels 12, 14 of the package 10, and attaching the side panels 12, 14 of the package 10 to the assembly 70. Once the assembly 70 is attached to the side panels 12, 14 of the package 10, the side panels 12, 14 are sealed together at edges 13, 17 to complete construction of the package 10.

[0046] With reference to FIGS. 16-17, as well as FIG. 3, in order to fill the package 10, the mouth 42 is opened and product is dispensed through mouth 42, through the mouth 44, and into the interior 11 of the package 10. The header section, because it is joined to the closure mechanism 20 beneath the interlocking closure members and passes between those interlocking closure members, protects the interlocking closure members from the possibility of contamination by product as the package 10 is being filled. The mouth 42 of the header section 40 is then sealed to form a tamper-evident structure.

[0047] FIGS. 18a and 18b illustrate one embodiment of a continuous process for producing the resealable package 10 of the present invention. The process starts with a spool 100 of pre-folded header material. The material is unrolled from spool 100 and fed past score line applicator 102 which applies the preferential area of weakness 38. Alternatively, the spool 100 of pre-folded header material my have been pre-scored. The header material continues in-line to sealing station 104, where the L-shaped seals 48a, 46a are formed, for example, by heat sealing.

[0048] After the L-shaped seals 48a, 46a are formed, the material inside the L is punched out at punching station 106. The header material then passes over the spool 108 of closure profiles 33, 35. The header material is inserted between the closure profiles 33, 35, as described above. Once the header material is between the closure profiles 33, 35, the header material and closure profiles 33, 35 pass through the slider application station 110. The slider application station 110 applies the slider 30 to the closure mechanism 20 through the use of a vibratory feeder, applies the stop seals 23, 27, and punches the notch 21 in the closure profiles 33, 35 as described in U.S. patent application Ser. No. 09/649,557, filed Aug. 28, 2000, the entire contents of which are hereby incorporated by reference.

[0049] Once the header assembly 70 is complete, it passes to a typical horizontal form fill and seal machine, as shown in FIG. 18b. The material comprising the side panels 12, 14 of resealable package 10 is provided on roll 150. The material is unwound and passes over folding board 145 to form the two side panels 12, 14. In this embodiment, there is a slot 146 in the folding board 145 through which the header assembly 70 passes. This positions the header assembly 70 between the side panels 12, 14. The side panels 12, 14 are then heat sealed to the closure profiles 33, 35. Alternatively, the header assembly 70 travels over the upper edge of the film after it travels over the folding board 145 instead of passing through the slot 146 in the folding board 145, thus being positioned between the side panels 12, 14. Other embodiments may include utilizing a tube or guide mechanism to position the header assembly 70 between the side panels 12, 14.

[0050] The continuous line of packages continues to sealing bars 112 that seal the sides 13, 17 of the package 10. The packages then pass under hopper 114 that contains the product to be placed in package 10. As the packages pass under the hopper 114, product passes through the mouth 42 and the mouth 44 of the header section 40 and into the interior 11 of the package 10. The mouth 42 is then sealed by sealing bars 116 to form the tamper-evident structure. Finally, the continuous line of packages is separated into individual packages by cutting knife 118.

[0051] It should be understood that other methods of attaching the header assembly 70 to the side panels 12, 14 may be used. The header assembly 70 may be incorporated into other package manufacturing processes known in the art, such as a horizontal-form vertical-fill-seal method, a pre-made pouch method, and a fill seal method.

[0052] While specific embodiments and methods for practicing this invention have been described in detail, those skilled in the art will recognize various manifestations and details that could be developed in light of the overall teachings herein. Accordingly, the particular mechanisms disclosed are meant to be illustrative only and not to limit the scope of the invention which is to be given the full breadth of the following claims and any and all embodiments thereof.

Claims

1. A method of making a resealable package comprising:

(a) providing an assembly comprising:

(i) a header section;

(ii) a closure mechanism comprising first and second closure profiles;

(1) the first and second closure profiles constructed and arranged to selectively interlock;

(b) providing a package comprising:

(i) first and second panel sections joined together to define an enclosed region, first and second opposite side edges, a bottom and a mouth that provides access to the enclosed region; and

(ii) attaching the assembly to the package such that the header section is attached to the closure mechanism at a point between the closure profiles and the bottom of the package.

2. The method of claim 1, wherein the header section comprises two sides joined together to define first and second mouths, the first and second mouths being in fluid communication with each other.

3. The method of claim 2, wherein the step of providing the assembly comprises sealing a portion of the two sides together.

4. The method of claim 3, wherein the seals are formed in a pair of mirror-image L-shapes.

5. The method of claim 4, wherein the step of providing the assembly further comprises removing the portions of the header inside of the L-shaped seals.

6. The method of claim 2, wherein the header section includes a preferential area of weakness.

7. The method of claim 6, wherein the area of weakness is produced by scoring the header section.

8. The method of claim 6, wherein the preferential area of weakness includes at least one notch cut into the header section.

9. The method of claim 2, wherein the two sides are formed by folding a single sheet of header material in half, and the second mouth is formed by eliminating a portion of the header material around the fold.

10. The method of claim 1, wherein step of providing the assembly comprises sealing the header section to the flanges of the closure mechanism.

11. The method of claim 10, wherein the step of sealing the header section comprises

(a) separating the first and second closure profiles;

(b) placing a portion of the header section between the first and second closure profiles;

(c) attaching the slider to the closure mechanism;

(d) notching the closure profile at one end, the notch to be used as a park position for the slider; and

(e) applying a stop seal to at least one end of the closure mechanism.

12. The method of claim 1, wherein the step of attaching the assembly to the package comprises heat sealing the closure profiles to the two opposing panels.

13. The method of claim 12, wherein the step of attaching the assembly to the package further comprises sealing the sides and bottom of the two opposing panels together.

14. The method of claim 1, further comprising filling the package with a product through the first mouth of the header section.

15. The method of claim 1, further comprising sealing the first mouth of the header section.

16. A header and closure mechanism assembly for use in a resealable package consisting essentially of:

(a) a closure mechanism comprising first and second closure profiles, the first and second closure profiles constructed and arranged to selectively interlock; and

(b) a header section comprising two sides joined together defining first and second mouths, the first and second mouths being in fluid communication with each other, the header section being attached to the closure mechanism.

17. The assembly of claim 16, further consisting essentially of a slider attached to the closure mechanism.

18. The assembly of claim 17, wherein the closure mechanism defines a notch near one end of the closure mechanism.