WO2001094222A1

WO2001094222A1 - Plastic bag roll

Info

Publication number: WO2001094222A1
Application number: PCT/CA2000/000660
Authority: WO
Inventors: Bridget Lam; Richard Lam
Original assignee: Bridget Lam; Richard Lam
Priority date: 2000-06-05
Filing date: 2000-06-05
Publication date: 2001-12-13
Also published as: AU5378300A

Abstract

A continuous roll of plastic bags (1) is formed from a flattened elongate tube of suitable material such as a thermoplastic. The roll may be separated along a first straight perforated line (4) separator disposed between two seals (3) which close the tube to form the bottom of each bag. The roll may also be separated along a second separator which comprises first (5) and second (6) perforated lines which are substantially sinusoidal or wavy and intersect at least once. Preferably, the first line (5) is the inverse of the second line (6). The first and second separators are alternated along the roll.

Description

PLASTIC BAG ROLL

FIELD OF THE INVENTION

The present invention relates to packaging bags which are stored and dispensed in rolls.

BACKGROUND TO THE INVENTION

Rolls of packaging bags are generally formed from a flattened tube of thermoplastic material and are mounted on a dispenser and permits the user to tear off a bag, one at time, along a straight perforated line. The tube is sealed along a line parallel to and closely associated with the perforated line. Therefore, one end of the bag is closed, forming the bottom of the bag and one end is open, forming the mouth of the bag. By this method, the user is subjected to normal and frequent problems such as the following:

1. identifying which end of the bag is the opening;

2. once the opening is finally located, the user experiences the added problem of separating the two layers of this material at the opening;

3. once the bag is opened, the user then needs to close the opening after filling the bag with the desired items by using a fastener device such as a twist tie, strap or similar gadget. These fasteners are obtained from separate container which are often empty or not readily available in the areas where the bags are dispensed

In U.S. Patent No. 5,611 ,627 issued to Tenneco Packaging on March 18, 1997, easy open thermoplastic bags are disclosed which are dispensed from a roll. The bags are manufactured from a flattened tube of thermoplastic material which may be distinctively severed along independently phase shifted sinusoidal oscillating paths down the centre of the collapsed tube. However, in this patent, a single bag cannot be conveniently torn off the roll as each segment of the roll is composed of two bags. Therefore, after a single segment has been severed, it must then be severed again into two separate bags.

In U.S. Patent No. 5,246,110 issued to Greyvenstein on September 21 , 1993, there is shown thermoplastic bags having an open mouth side which defines projecting tie parts that can be readily tied by hand. Although this bag has an easily identifiable opening end, it does not permit easy separation of the two layers of material at the opening.

Therefore, there is a need in the art for a plastic bag roll which provides bags which are easy to open, the open end of which is easy to identify and which provides for projecting tie parts.

SUMMARY OF THE INVENTION

This invention will permit the user to tear off a bag, identify the opening, open and fill the bag and close the opening more easily than the traditional method. This invention relates to the method of dispensing packaging bags by permitting the user to tear off a bag, one at a time, from the dispenser. The unevenness of the opening will permit the user to easily identify the opening. The wave design of the opening produces two single-layer protruding edges. This allows for easy separation by pulling the protruding single-layer edges of the opening. In addition, the design of the opening of the bag with its two protruding edges, permits the user to tie the bag closed without resorting to the use of additional fastening devices.

It is the current practice for these bags to be dispensed in a roll with a straight line perforation and one parallel seam establishing the outside boundaries of each bag. The user has to pull the bag off, one at a time, identify the opening and separate the two layers of the material at the opening which are generally stuck together and, when the bag is filled, to search for a fastener to secure the opening.

We have found these disadvantages can be overcome by separating the bags with a wave-shaped perforation for the two connected and consecutive openings. The corresponding bottoms of the bags are separated by two parallel straight seams or heat seals with a perforated straight line which is preferably equidistant between these two seams.

The wave-shaped design of the opening permits the user to identify the opening of the bag once torn off the roll while the protruding edges of the opening allows the bag to be opened easily. The protruding edges can be used to tie the opening once the bag is filled, thus eliminating the need to provide other closing devices and the dispenser to contain these closing devices.

Therefore, in one aspect the invention, the invention comprises a continuous roll comprising an elongate flattened tube of a thermoplastic material, separatable into a plurality of thermoplastic bags; said roll comprising a first layer and a second layer; said roll having a plurality of first separators each comprising two seals where the first and second layers are fused together along a line substantially orthogonal to the longitudinal axis of the tube and the two seals are separated by a perforated line across both first and second layers; said roll further having a plurality of second separators comprising a first perforated line across the first layer and a second perforated line across the second layer wherein the first and second perforated lines do not overlap; wherein said first and second separators are spaced apart and alternate along the length of the roll.

In another aspect of the invention, the invention comprises a plurality of thermoplastic bags joined together into an elongate continuous flattened tube having a first layer and a second layer wherein:

(a) each bag has a closed end and a mouth;

(b) each closed end abuts the closed end of an adjacent bag;

(c) each mouth abuts the mouth of an adjacent bag;

(d) each pair of closed ends is separatable along a perforated line that is orthogonal to the longitudinal axis of the tube and positioned between the closed ends; and

(e) each pair of mouths is separatable along a first perforated line in the first layer and a second perforated line in the second layer where the first perforated line does not overlap the second perforated line. BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the present invention will now be described with reference to the enclosed drawings in which:

Figure 1 shows a plastic bag roll showing a single bag which may be separated from the roll.

Figure 2 shows a view of the plastic bag roll showing closed end seam (first separator) and the open end seam (second separator) of the roll.

Figure 3 is a view of a single plastic bag severed from the roll.

Figure 4 is a view of a full single plastic bag with the open end tied off.

DESCRIPTION OF THE INVENTION

The plastic bag roll (1) of the present invention may be comprised of a flattened tube of thermoplastic material which is divided into a plurality of plastic bags by a series of first and second separators. The bags are joined in a "bottom to bottom" and "top to top" manner. The first separator (2) is a straight perforated line (4) which has a seam (3) on either side of it. The first separator separates the bottom ends of two adjacent bags. The seam (3) is created by bonding the top and bottom layers of the tube together to seal the tube. The seam (3) becomes the closed bottom end of the bag once separated from the roll. The second separator (10) comprises two perforated lines (5, 6); one through each of the top and bottom layers of the tube. In one embodiment, the two perforated lines do not overlap. The second separator separates the top (or open) ends of two adjacent bags. Preferably, the two perforated lines are sinusoidal, or substantially sinusoidal, and intersect at least once. Alternatively, the two perforated lines may be described as being wave-shaped. More preferably, the first perforated line (5) is the sinusoidal inverse of the second perforated line (6), as is shown in the Figures, creating an uneven opening having protruding lobes (7) of material. These lobes (7) may be used to tie the bag closed once it is filled as is shown in Figure 4. This design encompasses variations in sizes of the bag, types of pliable soft material, color of the material, shapes of the bag. etc. In addition, the uneven opening of the bag can have a variation of different shapes providing the protruding edges are uneven enough to allow for the separation of the opening of the bag easily. Consequently, the shape of the lobes may differ without compromising its design purpose. Tearing off a bag from a roll suspended on a dispenser adds to the efficiency but is not entirely necessary.

The plastic bag roll is preferably comprised of conventional low-density polyethylene, although any suitable material may be used, including metallized plastics or any other conventional packaging material.

As will be apparent to those skilled in the art, various modifications, adaptations and variations of the foregoing specific disclosure can be made without departing from the teachings of the present invention.

Claims

Claims:

1. A continuous roll comprising an elongate flattened tube of a thermoplastic material, separatable into a plurality of thermoplastic bags; said roll comprising a first layer and a second layer; said roll having a plurality of first separators each comprising two seals where the first and second layers are fused together along a line substantially orthogonal to the longitudinal axis of the tube and the two seals are separated by a perforated line across both first and second layers; said roll further having a plurality of second separators comprising a first perforated line across the first layer and a second perforated line across the second layer wherein the first and second perforated Ifnes do not overlap; wherein said first and second separators are spaced apart and alternate along the length of the roll.

2. The roll of claim 1 wherein the first and second perforated lines are substantially sinusoidal lines that intersect at least once.

3. The roll of claim 2 wherein the first perforated line is the inverse of the second perforated line.

4. A plurality of thermoplastic bags joined together into an elongate continuous flattened tube having a first layer and a second layer wherein:

(a) each bag has a closed end and a mouth; (b) each closed end abuts the closed end of an adjacent bag;

(c) each mouth abuts the mouth of an adjacent bag;

(d) each pair of closed ends is separatable along a perforated line that is orthogonal to the longitudinal axis of the tube and positioned between the closed ends; and (e) each pair of mouths is separatable along a first perforated line in the first layer and a second perforated line in the second layer where the first perforated line does not overlap the second perforated line.

5. The plurality of thermoplastic bags of claim 4 wherein the first and second perforated lines separating the mouths of adjacent bags are substantially sinusoidal lines that intersect at least once.

6. The plurality of thermoplastic bags of claim 5 wherein the first perforated line is the inverse of the second perforated line.