ZIPPER PROFILE WITH IMPROVED LEAK RESISTANCE

FIELD

[0001]The present disclosure generally pertains to plastic bags for containing items therein and more particularly to a plastic bag having a zipper-type closure capable of sealing items therein with improved leak resistance.

BACKGROUND

[0002]Plastic storage bags having zipper-type closures are known in the art and generally provide adequate closing function. However, in some instances when liquids are contained in the bag, leaking may occur when the bag is dropped or subject to a force that cause the liquid to bear against the closures.

BRIEF SUMMARY

[0003]Aspects of the present disclosure, provide a zipper profile with improved leak resistance.

[0004]In one aspect, a bag for containing at least one of liquid and solid items generally comprises a first sheet of flexible material having an exterior surface and an interior surface. A second sheet of flexible material has an exterior surface and an interior surface. The interior surfaces of the first and second sheets are generally opposed to each other in an interior of the bag, and the exterior surfaces of the first and second sheets face away from the interior of the bag. The first and second flexible sheets are connected to form an enclosed space, and are unconnected along an end of the bag to form an opening at a first edge of the bag. A male closure member is mounted on the interior surface of the first sheet proximate the opening and has a height extending away from the interior surface of the first sheet. A female closure member is mounted on the interior surface of the second sheet. The female closure member is arranged opposite the male closure member and the male and female closure members are constructed to repeatedly matingly engage each other to close the opening of the bag and to releasably disengage each other to open the opening of the bag. The female closure member comprises a first arm and a second arm extending along a length of the female closure member and defining a space for receiving the male closure member. A stabilizer is on the interior surface of the first sheet in a position closer to the first edge of the bag than the male closure member. The stabilizer has a height extending away from the interior surface that is less than the height of the male closure member. The stabilizer is arranged in closely spaced relationship to the first arm of the female closure member when the male and female closure members are engaged to close the opening and to engage the first arm of the female closure to limit deflection of the first and second closure members toward the first edge of the bag.

[0005]Other objects and features will be in part apparent and in part pointed out hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006]FIG. 1 is a schematic fragmentary elevation of a bag;

[0007]FIG. 2 is a schematic elevation of a male closure member of the bag;

[0008]FIG. 3 is a schematic elevation of a female closure member of the bag;

[0009]FIG. 4 is a schematic elevation showing the closure members pressed together;

[0010]Corresponding reference characters indicate corresponding parts throughout the drawings.

DETAILED DESCRIPTION

[0011]The present disclosure is directed to a bag (e.g., a plastic bag) for containing at least one of liquid and solid items therein. The bag includes two sheets each having interior and exterior surfaces. The interior surfaces of the first and second sheets are generally opposed to each other in an interior of the bag, and the exterior surfaces of the first and second sheets face away from the interior of the bag. The first and second sheets are connected such that an opening is defined at a first edge of the bag, and the interior of the bag is formed by sealing the first and second sheets together along other edges. In the illustrative embodiment of FIG. 1 these are shown as rectangular sheets 2, 4 sealed along three edges 6, 8, 10, but are unsealed along a fourth edge 12 for forming an opening of the bag. For purposes of illustration only, the lower left corner of the first sheet 2 is shown removed in phantom so that the second sheet 4 is visible. A zipper-type closure 14 is located proximate the opening for opening and closing the bag at the fourth edge 12.

[0012]The closure 14 comprises a male closure member, female closure member, and stabilizer designated 16, 18, and 20, respectively, in FIGS. 2-4. The male closure member 16 and stabilizer 20 are attached to the first sheet 2. The female closure member 18 is attached to the second sheet 4. As will be explained in greater detail below, the male and female closure members 16 and 18 are constructed to repeatedly matingly engage each other to close the opening of the bag and to releasably disengage each other to open the opening of the bag. The stabilizer 20 is shaped and arranged to engage the female closure member 18 and limit deflection of the male closure member 16 and female closure member toward the bottom edge 10 of the bag. A force applied transverse to the lengthwise extents of the male and female closure members 16, 18 (such as during sealing) tends to cause the first and second arms 44, 46 of the female closure member 18 to splay apart and release connection (or at least contact) with the male closure member 16. This results in leakage (when fluids are contained in the bag).

[0013]Broadly, the male closure member 16 comprises a base 22, a stem 24 extending up from the base, and a head 26 that is wider than the stem. The male closure member 16 is mounted on the interior surface of the first sheet 2 at the base 22. The stem 24 and head 26 are configured to matingly engage with the female closure member 18 to close the opening of the bag. As shown in FIG. 2, the male closure member has a height H1 that extends from the interior surface of the first sheet 2 to a distal end of the head 26. Moreover, the male closure member 16 comprises a first side and a second side with the second side being positioned proximate the stabilizer 20, and the first side being spaced apart from the second side toward the top edge 12 of the bag.

[0014]The male closure member 16 includes a first intersection 28 between the stem 24 and head 26 on the first side and a second intersection 30 between stem and head on the second side. In a preferred embodiment, the first intersection 28 is shaped differently from the second intersection 30. For example, in one embodiment, at the first intersection 28 the stem 24 and head 26 make an angle that is less than 90 degrees. The stem 24 and head 26 make an angle that is greater than 90°at the second intersection 30.

[0015]In the illustrated embodiment, the head 26 has a roughly arrow head shape including a first outwardly projecting shoulder 34 and second outwardly projecting shoulder 36. Furthermore, the first outwardly projecting shoulder is 34 is nearer the first side of the male closure member 16, and the second outwardly projecting shoulder 36 is nearer the second side of the male closure member. In an exemplary embodiment, a height of the first outwardly projecting shoulder 34 is greater than a height of the second inwardly projecting shoulder 36. The head 26 comprises a first arcuate section 38, a second arcuate section 40, and peak arcuate section 42. The first arcuate section 38 extends from the first outwardly projecting shoulder 34 to the peak arcuate section 42. The second arcuate section 40 extends from the second outwardly projecting shoulder 36 to the peak arcuate section 42. In an exemplary embodiment, the first outwardly projecting shoulder 34 has a radius of curvature that is less than a radius of curvature of the second outwardly projecting shoulder 36. Furthermore, the radius of the peak arcuate section 42 is less than the radius of the first arcuate section 38 and the radius of the second arcuate section 40.

[0016]The female closure member 18 broadly comprises a first arm 44 and a second arm 46. The first and second arms 44, 46 extend along a length of the female closure member from edge 6 to edge 8 of the bag. The first arm 44 is located closer to the bottom edge 12 of the bag and the second arm 46 is located closer to the top edge 10 than the first arm. The first and second arms 44, 46 define a space 48 between them for receiving and releasably capturing the male closure member 16. Each of the first and second arms 44 and 46 comprise an end portion and a base portion extending from the corresponding end portion of the respective first or second arm. Each end portion intersects its corresponding base portion to form an elbow on a side of the respective first or second arm 44, 46 that is located on an interior of the female closure member 18. The base portions of the first and second arms 44, 46 of the female closure member 18 are connected together at ends of the base portions opposite the end portions of the first and second arms. The female closure member 18 mounts to the interior surface of the second sheet 4 at the ends of the base portions opposite the end portions of the first and second arms 44, 46.

[0017]In an exemplary embodiment, the free end portion of the first arm 44 is shaped and arranged differently from the free end portion of the second arm 46. In one example, a first catch 49 at the free end portion of the first arm 44 and the base portion of the first arm 44 of the female closure member 18 form a first elbow. The first elbow has an angle of 90°or less. A second catch 50 at the free end portion of the second arm 46 and a base portion of the second arm form a second elbow. The second elbow has an angle of more than 90°. In another example, the first arm 44 comprises a height extending from the interior surface of the second sheet 4 to the end portion of the first arm, and the second arm 46 comprises a height extending form the interior surface of the second sheet to the end portion of the second arm. Accordingly, the height of the second arm 46 is greater than the height of the first arm 44. In one embodiment, the first catch 49 of the first arm 44 is constructed to latch under the first outwardly projecting shoulder 34 of the head 26, and the second catch 50 of the second arm 46 is formed to latch under the second outwardly projecting shoulder 36.

[0018]The stabilizer 20 is mounted on the interior surface of the first sheet 2 closer to the bottom edge 10 of the bag than the male closure member 16. In general, the stabilizer 20 is arranged in closely spaced relationship to the first arm 44 of the female closure member 18 when the male and female closure members are engaged to close the opening, as shown in FIG. 4. The stabilizer 20 is shaped and arranged to engage the first arm 44 of the female closure 18 to limit deflection of the first and second closure members toward the bottom edge 10 of the bag. The stabilizer 20 resists the tendency of the female closure member 18 to twist and cause the first and second arms 44, 46 to splay apart. The stabilizer 20 is spaced apart from the male closure member 16 at a distance that is sufficient to permit the end portion of the first arm 44 of the female closure member 18 to pass between the male closure member and stabilizer. In the illustrated embodiment, a stabilizer 20 is provided on only one side of the male closure member and is a single strip of material. However, additional stabilizers (not shown) could be provided, and be located at spaced apart positions. A stabilizer could be mounted on the second sheet 4.

[0019]In the illustrated embodiment, the stabilizer 20 includes a base 52 proximate the interior surface of the first sheet 2 and an upper portion 54 extending away from the base and the interior surface. As shown, the base 52 of the stabilizer and the base 22 of the male closure member 16 are formed as one piece of material. However, the male closure member 16 and the stabilizer 20 could be formed separately and applied to the interior surface of the first sheet 2. The upper portion 54 of the stabilizer 20 tapers from the base 52 toward a distal end 56 of the stabilizer. In the illustrated embodiment, the stabilizer 20 is mound-shaped in cross-section and the upper portion 54 includes a peak section having a flat plateau. The male closure member 16 and the stabilizer 20 are separated from each other by a channel 58. The channel 58 is shaped and arranged to permit the end portion of the first arm 44 of the female closure member 18 to pass between the male closure member 16 and stabilizer 20. Furthermore, the stabilizer 20 has a height H3 extending away from the interior surface of the first sheet 2 that is less than the height H1 of the male closure member 16. In one embodiment, the height of the stabilizer H3 is less than one half the height H1 of the male closure member 16.

[0020]In general, the male closure member 16, female closure member 18, and stabilizer 20 are elongate and configured to extend a long a width of the bag.

[0021]The zipper closure material 14 is manufactured from, for example, LDPE, LLDPE, HDPE or PP. In such embodiments, the Shore D hardness of the zipper material is greater than about 45, such as between about 45 and about 85. The bag sheets 2, 4 can be made from any suitable material including typically LDPE and LLDPE, or optionally another polyolefin such as HDPE, PP, etc.

EXAMPLE 1

[0022]Male and female closure members are coextruded and mating films were aligned, sealed, and cut to form bags. All components were made from a suitable material such as LDPE. The male and female closure members had the following dimensions, with reference to FIGS. 2 and 3: the height H1 of the male closure member 16 was about 0.032 inch; the width of stabilizer 20 at its base 52 was about 0.017 inch; the distance between stabilizer 20 and male closure member at their bases 22, 52 on the first sheet 2 was about 0.015 inch; the height H3 of the stabilizer 20 was about 0.012 inch; the width of the head 26 at its widest point was about 0.025 inch; and the height H2 of the female closure member 18 was about 0.041 inch. More specifically, the first arm 44 of the has a height of about 0.041 inch and the second arm 46 has a height of about 0.039 inch (i.e., the first arm is taller than the second arm).

[0023]Having described the invention in detail, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims.

[0024]When introducing elements of the present invention or the preferred embodiments(s) thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0025]In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

[0026]As various changes could be made in the above products without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

[0027]The Abstract and Summary are provided to help the reader quickly ascertain the nature of the technical disclosure. They are submitted with the understanding that they will not be used to interpret or limit the scope or meaning of the claims. The Summary is provided to introduce a selection of concepts in simplified form that are further described in the Detailed Description. The Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the claimed subject matter.