Patent Application
20100296754
The invention relates in general to heavy duty plastic bags used for the transport of, for example, particulate material, and more specifically to an auxiliary grip or handle for such bags to facilitate the pouring or emptying of the contents from the bag.
Heavy duty plastic bags are widely used to package products such as fertilizers, water conditioning salts, pet food, lawn and garden soils, potting soil, limestone, cedar mulch, marble chips and other similar products. These bags, when filled, can be very heavy and bulky. They can easily weigh 20 kg or more. To empty the bags, past practice has been to cut the bag open at one end, either transversely across the bag end or diagonally across a corner, with a utility knife or scissors, and to lift the bag via the handle, if one was provided, with one hand while placing the other hand at the bottom of the bag. While lifting the bag using both hands the user would then tilt the bag to pour the contents therefrom. In the past, one Improvement has been to provide a tear-away corner section by way of a perforated tear line diagonally across the corner thus eliminating the necessity of using a cutting tool to gain access to the bag interior. Typical easy-opening tear-away or cut-away features are shown in U.S. Pat. No. 5,593,229 (Warr); U.S. Pat. No. 5,482,376 (Mosely et al) ; U.S. Pat. No. 5,636,925 (Smiley); and U.S. Pat. No. 6,402,379 (Albright). None of these patents addresses the problems in actually lifting a heavy, flexible plastic bag filled with pourable material and lifting and tilting the bag for emptying the contents. However, it is known to do this with rigid cans such as shown in U.S. Pat. Nos. 4,911,562, 4,928,860 and D504616, wherein the containers are injection molded.
The plastic bag is manufactured by extruding polyolefin through a circular die, typically used for blown film, or a flat die, typically used for a cast film, into a sheet or tubular plastic film. It can be a single layer or a multiple layer film.
The plastic bag can be constructed using a single type or a combination of polyolefins such as low density polyethylene, linear low density polyethylene, high density polyethylene, polypropylene, rubber modified high density polyethylene, ethyl vinyl alcohol, nylon or other appropriate polyolefin. The typical thickness of the film material ranges from 3 mils to 10 mils.
The tubular film typically has a front wall, a back wall, and two edges. If the extrusion process is in a sheeting style then the Rim must be folded over and heat sealed into a tubular stock. The tubular film is then cut into the desired bag lengths. One end of a bag length is then transversely heat sealed, leaving one open end for filling purposes. The transverse heat seat is typically about ⅜″ away from the end of the film, leaving a skirt area for the attachment of an external rigid or main handle.
Another embodiment of the bag will have two transverse heat seals, one about ⅜″ away and the other about 3″ away from the same end of the film. The area between the heat seals forms a handle area where a pre-cut patch of film up to 12 mil thick is applied. Thereafter the film and patch are die cut, forming a patch handle for the bag.
The easy-open tear-away corner feature is documented in the prior art patents previously mentioned. That feature is a combination of a slit at the top of the bag, extending to just above the transverse seal, and a perforated line, forming the tear line, through both the front and the back wail, extending to the adjacent edge of the bag. The perforated line is usually at a top corner of the bag. Once it has been torn away there is an open corner which forms the pouring spout for the bag. The perforated line can be in various shapes: an arcuate shape (U.S. Pat. No. 5,482,376); an arcuate transition shape (U.S. Pat. No. 6,402,379); or simply a diagonal line forming a triangle at the corner of the bag. In all cases, the material at the corner is meant to be tom completely away along the perforated line, leaving the open corner as the pouring spout.
The difficulty with the easy open feature bag is in tilting the filled bag easily and pouring out the contents. The filled bag is lifted up via the main handle with one hand; the free hand then struggles to find a portion of the bag to grab onto to tilt the bag empty the contents therefrom from the corner spout opening.
It is a feature of the present invention to provide a plastic bag of the type adapted to pour its content from a corner spout with the ability to be easily gripped and tilted to pour the bag contents from the bag.
According to the above feature, from a broad aspect, the present invention provides a heavy duty plastic bag for pourable material. The bag comprises a front wall and a rear wall with the walls defining sealed opposed side edges. A seal provided at one end of the bag and extends transversely from the opposed side edges. A main carrying handle is provided at this one end of the bag adjacent the transverse seal and located generally centrally of the bag. A corner section adjacent the main carrying handle is adapted to form a pouring spout between the one end of the bag and one of the side edges. An auxiliary grip section adjacent is provided adjacent the other of the side edges diametrically opposite the corner section below about mid-length of the bag. The auxiliary grip section is sealed from the interior of the bag and facilitates the lifting, tilting and emptying of the bag.
According to a further broad aspect of the present invention there is provided a method of forming a heavy-duty plastic bag for pourable material. The method comprises the steps of providing a plastic bag having sealed opposed side edges, a sealed top edge with a main carrying handle secured thereto. The bag has a corner section adjacent the main carrying handle which is adapted to form a pouring spout between the one of the opposed side edges and the top edge. An auxiliary grip is formed adjacent the other of the side edges below about mid-length of the bag and diametrically opposed to the corner section, by heat sealing the front and rear walls together to define a grasping area.
The auxiliary grip or handle is an area that is sealed off from the Interior of the bag such that the contents of the bag are restricted therefrom. The auxiliary grip area is preferably formed by a heat seal, starting from the edge of the bag below mid-length thereof and projecting downwardly spaced from the side edge to terminate back at the side edge or downwardly at the bottom edge to define an auxiliary grip area along the opposed side edge. The auxiliary grip area can be die cut to provide a gripping portion, as for example by two half-moon shaped die cuts to be used as finger grips or handle hole to insert the hand. The invention will now be described in greater detail with reference to the drawings.
The plastic bag 10 is formed using a combination of polyolefin such as polyethylene or polypropylene having a thickness range from 3 mils to 10 mils. It can be of monolayer or multilayer construction. The bag 10 will have overlaying walls 11 and 12 defining side edges 13 and 14. The top end edge 15 is closed by way of a transverse heat seal 16 which extends from edge 13 to edge 14, approximately ⅜″ from the top edge 15, leaving a skirt area. An external rigid handle 24 can be attached in the center of the bag at the skirt area either by heat sealing or by ultrasonic sealing as is well known in the art.
In one example of such plastic bag a tear-away spout section may be formed in a corner of the bag. In accordance with this known practice a slit 17 is provided above the transverse seal 16 and a line 18 of perforations extends diagonally (or arcuately) from the slit 17 at the transverse seal 16 downwardly toward the edge 14. In use, one will pull the skirt material adjacent the slit 17 in the direction of the line 18 of perforations. The perforations will give or separate, allowing the user to tear the corner section away from the bag along the line 18, so that the bag contents can be poured from the bag as shown in
The auxiliary grip or handle section 25 of the present invention is found at the lower or bottom corner of the bag, diagonally opposite the line 18 of perforations. There it will be seen that an arcuate heat seal 19, of about a 2″ radius, extends inwards of the bag from the edge 13, starting about 6″ from the open end of the bag. A generally straight heat seal 20 extends from the lower end of the arcuate heat seal to the open end of the bag, generally parallel to the edge 13. The heat seal can be about ⅛″ to ¼″ wide. Preferably, two half-moon punch holes 21 and 22 will be die cut in the grip area to be used as finger grips.
The drawings have illustrated a preferred form of the auxiliary grip or handle 25. As alternative embodiments a different shape of die cut hole could be provided in place of the half-moon shaped holes, or it would be possible to completely eliminate any die cut holes, leaving the user to grasp or squeeze the gripping area 26 itself. The gripping area 26 could also be reinforced with a patch film for additional strength. The patch film could be inserted into the tubular film prior to application of the heat seals 19, 20 or it could be applied externally using an adhesive. While the auxiliary grip or handle section of the present invention is intended primarily to aid the user when pouring contents from the bag it could also be used along with the main handle when carrying the bag from one location to another.
