Numerous types of plastic shopping bags have been developed and marketed particularly since the 1980's. The most common of such shopping bags which are in use today are fabricated by extruding tubing of a material such as high density polyethylene which may be flattened, gusseted, cut to desired lengths, sealed at the ends of such lengths and then subjected to die-cutting near one end of the rectangular sealed tubing lengths to produce bags each having a mouth defined by a pair of side handles. Because they somewhat resemble T-shirts, they have been and are currently referred to as "T-shirt bags." Customarily, they are delivered in packs of from 50 to 150 bags packed flat, one upon another. The walls of the bags are usually quite thin, but they have sufficient strength to hold articles weighing at least ten pounds.
Customarily, such T-shirt bags, when dispensed, are mounted on racks having a pair of arms spaced from each other which may be extended through some type of orifice in each of the registering arms of the T-shirt bags in the pack.
Because of the fact that when the bags are suspended on forward protruding rods extending through their respective bag arms, the bags tend to sag in the middle. Consequently, bag dispensing racks are often provided with a central mounting tab which is orificed to permit such element to be looped over some type of forwardly and upwardly projecting member.
It has also been a feature of such prior art bags to be made self-opening in the sense that as the first bag is pulled off the rack, the rear wall of the first bag is sufficiently adhered to the front wall of the next ensuing bag so that, as such rear wall is brought forward on the rack, it will pull the front wall of the next ensuing bag to open it, until sufficient force detaches the rear wall of the leading bag from the front wall of the next ensuing bag. Such adherence may be accomplished by glue, cold staking, and/or corona treatment of the outside walls of the bag, together with pressure points extending transversely through stacks of the bags.
In addition, provision has been made on occasion for fabricating bags by co-extrusion of different types of polyethylene, e.g. high density polyethylene for an inner bag layer and low density polyethylene for the outer layer. As a consequence, such bags may be provided with a degree of stiffness as well as of stickiness for the outer bag walls.
In use, after T-shirt bags are removed from their mounting rods and the intermediate hooking element, the user must insert his or her hand through each of the bag handles in order to carry the bag with whatever articles may have been placed in it. Because the bags are normally very thin, the handles tend to become rope like from the downward force occasioned by the weight of articles placed in the bag, with a tendency to place stress on the carrying hand.
While in some instances this has been sought to be remedied by providing a central handle hole through bag walls--not, however, in T-shirt type bags, but in bags which may be mounted at their corners such as is shown in U.S. Pat. Nos. 5,487,884, 4,7597,639, 5,248,040 and 4,903,839. In these patents, the bags are mounted on projecting arms of a rack at the corners of the bags which are detachable upon removing the bags on the rack arms.