Plastic bag roll

Abstract

A roll of plastic bags having integral handles which can also be used to close each bag. The bags are formed as a continuous web of folded and flattened bags each joined to a longitudinally contiguous bag by a perforated severance line. The handles are defined by a cut-out region so that separation of the bags is effected by tearing the line of perforations only across a relatively short length.

Description

BACKGROUND OF THE INVENTION

This invention relates to plastic bags which are provided on a roll to be dispensed one at a time and, more particularly, to such a bag which is formed with unitary handles which are also usable for closing the bag.

Conventionally, plastic bags used for holding trash or the like are manufactured by extruding a tube of plastic material, expanding the tube with air before the plastic has set, flattening the tube, forming transverse heat seals and adjacent perforations at equally spaced intervals, and longitudinally folding and/or rolling up the flattened tube for storage and transport in a dispensing carton. The bags are removed one at a time from the dispensing carton by tearing them off the roll at the perforations.

When such a bag is filled, it is necessary to close it by utilizing a separate tie. The use of a separate tie is disadvantageous for a number of reasons. It is necessary to hold the bag closed with one hand while applying the tie with the other hand. The ties must be stored separately and can be misplaced. With overly full bags, the ties may be difficult to apply.

Various bag constructions have been proposed which incorporate integral tie strips. These constructions also possess numerous drawbacks. They require an additional act on the part of the user to tear away the integral tie strip from the remainder of the bag. They also reduce the useful capacity of the bag.

All of these constructions also require that the user separate the bags by tearing the line of perforations across the entire width of the bag. When pulling a bag from a dispenser carton, this can pose difficulty for a user.

It would therefore be desirable to have a bag construction which overcomes all of the drawbacks of these prior constructions.

SUMMARY OF THE INVENTION

According to the present invention there is provided a roll of plastic bags formed as a continuous web of folded and flattened bags each joined to a longitudinally contiguous bag by a perforated severance line. The web is formed from a tubular plastic strip having a central longitudinal axis and the sides of the strip are tucked in to form two equal inward folds, reducing the width of the strip by one half. The reduced width strip is folded in half along the central longitudinal axis so that there are eight layers of plastic material. The perforated severance lines are parallel one to the other, are equally spaced along the strip and are orthogonal to the central longitudinal axis of the strip. A pair of parallel heat seal lines flank each of the severance lines. A first of the heat seal lines extends through all eight layers of the plastic material and a second of the heat seal lines is formed of two heat seal lines each of which extends through a respective four contiguous layers of the plastic material. Finally, there is a cut-out region through the eight layers which extends from the central longitudinal axis along each severance line a first predetermined distance and then substantially parallel to the central longitudinal axis a second predetermined distance past the second heat seal line and then back to the central longitudinal axis. Accordingly, each first heat seal line is effective to seal the bottom of a respective bag, and each cut-out region and respective adjacent second heat seal line is effective to form a pair of handles of a respective bag.

In accordance with an aspect of this invention, the first predetermined distance is greater than one-half the width of the reduced width strip after it has been folded in half.

In accordance with another aspect of this invention, the second predetermined distance is greater than the first predetermined distance.

According to this invention, there is provided a plastic bag formed from a folded tubular plastic strip. The plastic bag comprises a closed bottom end including a heat seal line extending through eight layers of folded plastic strip, and an open top end having a pair of spaced handles. Each of the handles has a respective heat seal line extending through a respective four contiguous layers of folded plastic strip and the handles are separated by a cut-out region so that the handles extend past an opening in the top end of the bag.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing will be more readily apparent upon reading the following description in conjunction with the drawings in which like elements in different figures thereof are identified by the same reference numeral and wherein:

FIG. 1 is a perspective view showing a partially open bag constructed according to the present invention;

FIG. 2 is a plan view showing a portion of a roll of a continuous web of bags according to the present invention;

FIG. 3 is a sectional view taken along the line 3-3 in FIG. 2;

FIGS. 4, 6, 8 and 10 illustrate steps during the manufacture of the inventive bags; and

FIGS. 5, 7 and 9 are sectional views taken along the lines 5-5, 7-7 and 9-9 in FIGS. 4, 6 and 8, respectively.

DETAILED DESCRIPTION

As shown in FIG. 1, the inventive plastic bag 20 has a bottom end 22 and a transverse heat seal line 24 adjacent the bottom end 22. At the opposite end of the bag 20, there is an open top end 26 including a pair of handles 28,30, each with a respective transverse heat seal line 32,34. As will become clear from the following discussion, the heat seal line 24 extends through eight layers of the plastic material forming the bag 20 and each of the heat seal lines 32,34 extends through a respective four contiguous layers of the plastic material. The handles 28,30 can be tied together to close the open top end 26 of the bag 20, in addition to their use in assisting a user in holding the bag 20.

FIG. 2 shows a plurality of inventive bags 20 which have not yet been separated one from the other and which are wound into a roll 36. The bags 20 are joined by, and may be separated at, lines of perforations 38 between the heat seal lines 24 and 32,34. As is clear from FIG. 3, when the bag 20 is on the roll 36 and as it is unrolled from the roll 36, the bag 20 is folded to have eight layers of plastic material.

FIGS. 4-10 illustrate steps in the formation of the bag 20. As shown in FIGS. 4 and 5, the bag starts as a continuous endless tubular plastic strip 40 traveling in the direction of the arrow 42. The strip 40 may be considered to have a central longitudinal axis 44 which is parallel to the direction arrow 42. The first step in the formation of the bag 20 is to tuck in the two side edges 46,48 of the strip 40 to form two equal inward folds and reduce the width of the strip 40 by one half, as shown in FIGS. 6 and 7.

The strip 40 then passes through a first sealing and cutting mechanism (not shown) which forms the heat seal lines 32 and 34 and the cut-out region 50. The heat seal lines 32 and 34 are co-linear (they are preferably formed in a single step) and transverse (preferably orthogonal) to the central longitudinal axis 44. Each of the heat seal lines 32 and 34 extends through a respective four contiguous layers of the plastic material of the strip 40, as is clear from FIGS. 8 and 9. The cut-out region 50 is substantially rectangular and extends in two directions away from the central longitudinal axis 44 substantially orthogonally thereto a first predetermined distance “a” along the line 22, and then substantially parallel to the axis 44 a second predetermined distance “b” past the heat seal lines 32 and 34, and then back to the axis 44 along the line 26 orthogonally to the axis 44. Preferably, the first predetermined distance from the axis 44 along the line 22 is greater than one-half the width of the strip 40 after the side edges 46,48 have been tucked in. Also preferably, the second predetermined distance (i.e., the distance between the lines 22,26) is greater than the first predetermined distance.

The final step in the formation of the bag 20 is illustrated in FIG. 10. As shown therein, the strip 40 is folded in half along the central longitudinal axis 44 so that it comprises eight layers of plastic material. The strip 40 then passes through a second sealing and cutting mechanism (not shown) which forms the heat seal line 24 and the line of perforations 38, both of which extend through all eight layers of the strip 40. The heat seal line 24 and the line of perforations 38 are both transverse to the axis 44 and preferably are orthogonal thereto. The line of perforations 38 is between the heat seal lines 24 and 32,34 and is aligned with the line 22 of the cut-out region 50. After this final formation step, the finished strip 40 is rolled up to form the roll 36, which may comprise a desired number of bags 20. On the roll 36, the bags are so configured that the bottom end 22 of each bag is further into the roll 36 than the top end 26. The roll 36 may then be placed into an appropriate carton for storage, shipment and dispensing.

In use, a bag 20 is pulled from the roll 36 by the handles 28,30 until the line of perforations 38 at its bottom end 22 is exposed. The bag which was pulled from the roll is then separated from the next bag in the roll by tearing along the line of perforations 38. An advantage of the disclosed construction is that only a relatively short line of perforations needs to be severed, due to the cut-out region 50, which is also effective to provide separate handles 28,30.

Accordingly, there has been disclosed an improved roll of plastic bags. While a preferred embodiment of the inventive plastic bag has been disclosed, it will be appreciated by those of skill in the art that various adaptations and modifications to the disclosed bag are possible. It is therefore intended that this invention be limited only by the scope of the appended claims.

Claims

1. A roll of plastic bags formed as a continuous web of folded and flattened bags each joined to a longitudinally contiguous bag by a perforated severance line, wherein:

the web is formed from a tubular plastic strip having a central longitudinal axis;

the sides of the strip are tucked in to form two equal inward folds reducing the width of the strip by one half;

the reduced width strip is folded in half along the central longitudinal axis so that there are eight layers of plastic material;

the severance lines are parallel one to the other and are equally spaced along the strip;

the severance lines are orthogonal to the central longitudinal axis of the strip;

a pair of parallel heat seal lines flank each of the severance lines, wherein a first of the heat seal lines extends through all eight layers of the plastic material and a second of the heat seal lines is formed of two heat seal lines each of which extends through a respective four contiguous layers of the plastic material; and

there is a cut-out region through the eight layers which extends from the central longitudinal axis along each severance line a first predetermined distance and then substantially parallel to the central longitudinal axis a second predetermined distance past the second heat seal line and then back to the central longitudinal axis;

whereby each first heat seal line is effective to seal the bottom of a respective bag, and each cut-out region and respective adjacent second heat seal line is effective to form a pair of handles of a respective bag.

2. The roll according to claim 1 wherein the first predetermined distance is greater than one-half the width of the reduced width strip after it has been folded in half.

3. The roll according to claim 2 wherein the second predetermined distance is greater than the first predetermined distance.

4. The roll according to claim 1 wherein the two heat seal lines of the second heat seal line are co-linear.

5. A plastic bag formed from a folded tubular plastic strip, comprising:

a closed bottom end including a heat seal line extending through eight layers of folded plastic strip; and

an open top end having a pair of spaced handles each having a respective heat seal line extending through a respective four contiguous layers of folded plastic strip, the handles being separated by a cut-out region so that the handles extend past an opening in the top end of the bag.

6. The plastic bag according to claim 5 wherein the cut-out region is substantially rectangular.