Easy opening rear seam bags and packaging methods
A package bag may be made from a sheet of flexible packaging material that has been folded along a longitudinal direction with the edges of the sheet brought together and sealed to form a longitudinal rear seam. A starter cut has been formed only in the longitudinal seam to facilitate opening the package bag. The package bag may be opened by pulling in opposite directions on the longitudinal seam at points on either side of the starter cut. Such package bags may be made from a sheet of flexible roll stock having one or more notches formed at spaced apart locations along one or more edges of the sheet. When the sheet is folded such that the edges meet and are sealed to form a longitudinal rear seam of a package bag, the notches provide a starter cut for opening the package bag.
This invention relates to packaging and more particularly to easy open bags and methods of manufacturing such bags.
BACKGROUND OF THE INVENTIONModern packaging for food and other products often uses sealed bags having seams at one or more ends of the bag and an exposed seam that usually runs the entire length of the rear of the bag. Such bags have been conventionally made of a packaging material, such as a synthetic resin film or a laminated material formed by laminating the synthetic resin film and an aluminum foil or the like. The package bag is filled with a material to be packed, such as liquids, powders or viscous materials, before being hermetically sealed.
To open the package bag, therefore, it is common practice for a user of the products stored in the bag to cut a sealed portion of the package film as the packaging material with a knife or scissors or break it open with a fingertip. When the package bag is to be cut with a knife or scissors, the opening procedure is troublesome, as it requires a tool. When the package film is to be ruptured with a fingertip, the opening of the package film may not be accomplished easily. Unfortunately, the material from which these bags are made and the sealing of the seams can make the bag difficult to open.
There have been several attempts in the prior art to address the problem of opening sealed package bags. For example, U.S. Pat. No. 6,352,364 issued Mar. 5, 2002 to Mobs starts a tear on the side of the bag and then has the longitudinal seal cut to ease the tear through it. This requires that two cuts be aligned and also requires modification of the end seal.
Similarly, U.S. Pat. No. 6,343,876 issued Feb. 5, 2002 to Takahashi et al describes starting the tear on the side of a pouch that has seams running down each side and no rear seam.
U.S. Pat. No. 6,102,571 issued Aug. 15, 2000 to Moteki et al also initiates the tear from the side of the bag then has a second tear-able zone for tearing through the rear seam.
U.S. Pat. No. 5,371,997 issued Dec. 13, 1994 to Kopp et al describes a long and narrow bag with a longitudinal seam on one side of the bag with the tear being initiated from the side of the bag.
U.S. Pat. No. 5,067,306 issued Nov. 26, 1991 to Umezawa describes making micro cuts on the sides of the bag material as it is being packaged, but makes no mention of the problem tearing through the rear seam of the bag.
U.S. Pat. No. 4,725,329 issued Feb. 16, 1998 to Tani it uses a tear string to tear through the rear seam of a package bag. However, a tear string could be hard to manage on large bags like potato chips.
Thus, there is a need in the art, for an easy opening package bag and a method for manufacturing it.
SUMMARY OF THE INVENTIONAccording to an embodiment of the invention, a package bag may be made from a sheet of flexible packaging material that has been folded along a longitudinal direction with the edges of the sheet brought together and sealed to form a longitudinal rear seam. A starter cut is formed only in the rear seam to facilitate opening the package bag. The package bag may be opened by pulling in opposite directions on the longitudinal seam at points on either side of the starter cut.
According to another embodiment of the invention a composition of matter is provided for forming a package bag. This composition of matter includes a sheet of flexible roll stock having one or more notches formed at spaced apart locations along one or more edges of the sheet. When the sheet is folded such that the edges meet and are sealed to form a longitudinal rear seam, the notches provide a starter cut only in the rear seam for opening package bags formed from the sheet.
BRIEF DESCRIPTION OF THE DRAWINGSThe teachings of the present invention can be readily understood by considering the following detailed description in conjunction with the accompanying drawings, in which:
Although the following detailed description contains many specific details for the purposes of illustration, anyone of ordinary skill in the art will appreciate that many variations and alterations to the following details are within the scope of the invention. Accordingly, the exemplary embodiments of the invention described below are set forth without any loss of generality to, and without imposing limitations upon, the claimed invention.
The rear seam 102 usually lies flat against the package bag 100 but can easily be lifted to provide finger grab points on both sides of the starter cut 104. Embodiments of the present invention work with any bag that has a seam that can be lifted from the bag. During manufacturing of the bag the rear seam 102 may be formed perpendicular to the rear surface of the bag and then folded over to lay flat against the bag. This makes it very handy to pull the seam up and use it to provide finger grab points for tearing the bag open.
In some embodiments, one or more guide strips 105, 107 are placed laterally across the package bag near the starter cut 104 to guide the tear that results when the rear seam 102 is pulled. The guide strips are made of tear-resistant material, such as plastic that are formed onto or into the material of the bag 100. A single guide strip may be used or, as shown in
Embodiments of the present invention may be used with other types of bags having a longitudinal rear seam. Examples of such bags include a gusseted bag 110 and a flat bottom bag 120, respectively depicted in
Package bags of the type described herein may be used to store any type of products commonly stored in sealed bags. Such products include, but are not limited to snacks, such as potato chips and pretzels, coffee, cheese, produce, candy, frozen foods, sealed medical products such as bandages, tape medicine, detergent, chemical powders, cosmetics among many others.
Package bags of the type described herein can be fabricated by a number of different techniques. Products are often packaged in bags using vertical form-fill machines or horizontal form-fill machines. Such machines form the bags from a continuous sheet of roll stock and fill them as the bags are fabricated.
The sheet 202 is drawn from a roll 204 over a series of rollers to a vertical form-fill tube 206. The sheet 202 wraps around the form-fill tube 206 and the edges of the sheet 202 are brought together to form the sheet 202 into a tube. A longitudinal sealer device 207 seals the edges of the sheet 202 together to form the rear seam 208 of a bag 210. An end sealer 211 then seals one end of the bag 210. Typically the edges and ends are sealed by some combination of heat and pressure. After the end is sealed the bag 210 is filled through the form-fill tube 206. Then the second end is sealed to close the bag 210. A shearing device 212 cuts the sheet 202 along the end seal to separate the bag from subsequent bag that is formed from the same sheet material 202. The shearing device 212 may leave part of the end seal on the bag 210 and part on the subsequent bag.
The starter cut described above can be made in the rear seam at any point in this procedure. For example a notch-cutting device 214, e.g., a sliding knife can cut a notch 215 in the rear seam 208 to form the starter cut. In
In an alternative embodiment, the starter cut may be made as part of the production of the roll stock used to form the bags. This is particularly advantageous in that such a roll stock can be used in an existing form-fill machine without having to modify the machine to make the starter cut in the rear seam.
One or more notches 306 are formed at spaced apart locations along one or more edges 308 of the sheet 302. When the sheet 302 is folded such that the edges 308 meet and are sealed to form a longitudinal rear seam, the notches 306 provide a starter cut for opening package bags formed from the sheet 302. In some embodiments a single notch is formed along one edge. In other embodiments, aligned notches 306 are formed in both edges 308 of the sheet 302. The aligned notches 306 overlap at least partially to form a starter cut all the way through the rear seam.
Embodiments of the present invention provide for easy opening bags with only minor modifications to existing packaging equipment and processes. Such easy open bags are more desirable for consumers and relatively inexpensive to manufacture compared to other types of easy open bags. Although the above discussion mentions vertical form-fill-seal systems, embodiments of the invention are not limited to such systems for making and filling bags. Other bag filling and sealing systems, such as horizontal fill machines and those that use pre-made bags, may be adapted to implement embodiments of the present invention.
While the above is a complete description of the preferred embodiment of the present invention, it is possible to use various alternatives, modifications and equivalents. Therefore, the scope of the present invention should be determined not with reference to the above description but should, instead, be determined with reference to the appended claims, along with their full scope of equivalents. In the claims that follow, the indefinite article “A”, or “An” refers to a quantity of one or more of the item following the article, except where expressly stated otherwise. The appended claims are not to be interpreted as including means-plus-function limitations, unless such a limitation is explicitly recited in a given claim using the phrase “means for.”
Claims
1. A package bag, comprising a sheet of flexible packaging material that has been folded along a longitudinal direction, wherein first and second edges of the sheet have been brought together and sealed to form a longitudinal rear seam along the longitudinal direction, wherein a starter cut has been formed only in the rear seam to facilitate opening the package bag, whereby the package bag may be opened by pulling in opposite directions on the longitudinal seam at points on either side of the starter cut.
2. The package bag of claim 1 wherein a first end of the folded sheet has been sealed to close a first end of the bag.
3. The package bag of claim 2 wherein a second end of the folded sheet has been sealed to close a second end of the bag.
4. The package bag of claim 1 wherein the longitudinal seam is substantially free to be pulled up and used to provide one or more finger grab points for opening the package bag.
5. The package bag of claim 1 further comprising one or more guide strips running laterally across the bag proximate the starter cut.
6. The package bag of claim 5 wherein the one or more guide strips include two guide strips disposed such that the starter cut lies between the two guide strips.
7. The package bag of claim 1 wherein the sheet of flexible packaging material has been folded to form a pillow bag, gusseted bag or flat bottom bag.
8. A composition of matter for forming a package bag, comprising:
- a sheet of flexible roll stock having one or more notches formed at spaced apart locations along one or more edges of the sheet, wherein, when the sheet is folded such that the edges meet and are sealed to form a longitudinal rear seam, the notches provide a starter cut only in the rear seam for opening package bags formed from the sheet of flexible roll stock.
9. The composition of matter of claim 8 wherein the one or more notches include one or more pairs of aligned notches that overlap at least partially when the sheet is folded such that the edges meet.
10. The composition of matter of claim 8, further comprising one or more guide strips formed onto the sheet of roll stock, wherein the guide strips run laterally across the sheet proximate the one or more notches.
11. The composition of claim 8 wherein the one or more guide strips include pairs of two closely-spaced guide strips disposed such that the starter cut lies between the two guide strips.
12. A packaging method, comprising the steps of:
- folding a sheet of flexible packaging material along a longitudinal direction first to bring first and second edges of the sheet together;
- sealing the first and second edges to form a longitudinal rear seam along the longitudinal direction; and
- forming a starting cut only in the longitudinal seam to facilitate opening the package bag
13. The method of claim 12 wherein forming the starter cut includes, before folding the sheet of flexible packaging material, forming one or more notches in the sheet of flexible packaging material at spaced apart locations along one or more edges of the sheet, wherein, when the sheet is folded to bring the first and second edges together and are sealed to form the longitudinal seam, the notches provide the starter cut.
14. The method of claim 12, further comprising the step of forming one or more guide strips onto the sheet of flexible packaging material, wherein the guide strips run laterally across the sheet proximate the starter cut.
15. The method of claim 14, wherein the one or more guide strips include two closely spaced guide strips disposed such that the starter cut lies between the two guide strips.
16. The method of claim 12, further comprising the step of, after folding the sheet of flexible packaging material, sealing a first end of the folded sheet to close a first end of a bag.
17. The method of claim 16 wherein the starter cut is formed before sealing the first end of the folded sheet.
18. The method of claim 16, further comprising the step of, after sealing the first end of the folded sheet to close the first end of the bag, filling the bag with one or more products.
19. The method of claim 18 further comprising, the step of, after filling the bag with one or more products, sealing a second end of the folded sheet to close a second end of the bag.
20. The method of claim 18 wherein forming the starter cut takes place before sealing the second end of the sheet or before filling the bag.
21. A package bag, comprising:
- a sheet of flexible packaging material that has been folded along a longitudinal direction,
- wherein first and second edges of the sheet have been brought together and sealed to form
- a longitudinal rear seam along the longitudinal direction, wherein a starter cut has been formed in the rear seam to facilitate opening the package bag;
- and one or more guide strips running laterally across the bag proximate the starter cut,
- whereby the package bag may be opened by pulling in opposite directions on the longitudinal seam at points on either side of the starter cut.
Type: Application
Filed: Dec 10, 2004
Publication Date: Jun 15, 2006
Inventor: Randy McKellar (Hayward, CA)
Application Number: 11/009,183
International Classification: B65D 33/00 (20060101); B65D 30/20 (20060101);