BAG FOR POURING
A bag made of plastic film suitable for pouring has first and second side panels and back and bottom gussets extending between the panels. Margins at front and top edges of the first side panel join margins at front and top edges of the second side panel at a first seam. A bottom margin of the back gusset joins a rear margin of the bottom gusset at a second seam with the back gusset terminating at a top, rear part of the first seam and the bottom gusset terminating at a bottom, front part of the first seam. A part of the bag film material integral with the back gusset and rear parts of the first and second side panels is formed as a handle at the rear of the bag. A closeable pouring device is integrated into a top front part of the first seam.
The present U.S. Utility patent application claims priority pursuant to 35 U.S.C. §120 as a continuation of U.S. Utility application Ser. No. 13/655,784 entitled “Bag with handle”, filed Oct. 19, 2012, which is hereby incorporated herein by reference in its entirety and made part of the present U.S. Utility patent application for all purposes.
FIELD OF THE INVENTIONThis invention relates to a bag made of flexible plastic film material, the bag suitable for pouring.
DESCRIPTION OF RELATED ARTPlastic bags are a ubiquitous and highly practical mode of carrying things and there is a whole panoply of shapes and structures of such bags depending on the particular function of the bag. Many bags have handles of some kind or other. These may be merely formations in the material of the bag itself or may include additional elements which are attached to the main carcass of the bag and which provide added strength and convenience.
Of particular interest from the viewpoint of reducing packaging materials are plastic bags that might replace in the marketplace freestanding, relatively thick-walled plastic jugs. Such a replacement is desirable for many reasons. Firstly, the volume of plastic material required in thick-walled plastic jugs is generally much higher in comparison with plastic bags configured to function as jugs. Secondly, placing of graphic materials is much easier on plastic bags where simple printing directly onto a paper-like plastic sheet can be implemented with the plastic sheet or a ply thereof being of a material such as polyester which readily accepts industry standard printing inks. This is in comparison with stiff-walled jugs which generally have some contour in the walls making it difficult for a print head to seat against anything but a very small wall area. This essentially mandates a relatively expensive process step of attaching labels to such jugs. Finally, prior to filling, thick-walled jugs being stored or shipped take considerable space in comparison with a compact stack of flat plastic bags.
The structure of a handled bag that is to function as a jug should have the strength to hold granular or fluid contents. It should also have a form enabling it to be gripped in one hand, moved from a standing into a pouring position and back again, and, ideally, for the pouring position to be retained as substantially all the contents of the bag are poured from a spout or functionally similar means. Throughout the use cycle, the bag should substantially retain a jug form and function until the contents have been emptied. Finally, such a structure must be easy to manufacture.
While bags with handles are known that can provide a substitute for jugs made of more rigid materials, further improvements are possible to improve the performance and manufacturability of such bags. Limitations and disadvantages of conventional and traditional approaches to bag-with-handle designs and manufacture thereof will become apparent to one of ordinary skill in the art through comparison of such bag and handle arrangements with the present invention.
For simplicity and clarity of illustration, elements illustrated in the following figures are not drawn to common scale. For example, the dimensions of some of the elements are exaggerated relative to other elements for clarity. Advantages, features and characteristics of the present invention, as well as methods, operation and functions of related elements of structure, and the combinations of parts and economies of manufacture, will become apparent upon consideration of the following description and claims with reference to the accompanying drawings, all of which form a part of the specification, wherein like reference numerals designate corresponding parts in the various figures, and wherein:
Referring to
Further details of the structure of the
To obtain a high production rate, processing operations are performed on a continuous web of plastic sheet material. During a production run, the web is fed continuously under tension from an input end where the web is unformed to an output end where, essentially, a complete bag has been produced and is cut from the web leading end. The web is led past a series of processing stations where processing operations are performed including, for example, positioning, stamping, cutting, folding and thermoplastic welding, depending on the stage of manufacture of the bag. As shown in
Before reaching the combining station, the handle web 88 is similarly processed as a continuous web drawn under tension (
As shown in
Referring in detail to
In the case of the
In the case of the
The web may be subjected to other welding steps to seal panels at their edges. However, one seam is left open to allow customers to fill the bag, this seam being welded by the customer after the bag is filled. In the case of the embodiment of
It will be understood that a handled bag using the principles of the invention can be made in many different ways. For example, as shown in the sequence of manufacturing steps illustrated in
Following tack welding of the double gusset web portion 112 to the web 110, the web 124 is brought down onto the web 110 with the web portion 112 sandwiched between the webs 110 and 124. The assembly is then advanced to a seam welder where a hot press tool produces thermoplastic welds at polyethylene contact regions. As in the prior embodiment, the juxtaposition of the webs 110, 112 and 124 is such as to bring polyethylene plies face-to-face in order to be able to effect thermal welds at desired regions. Thus, as illustrated in
The choice of attaching the gusset/handle in a side mount process or a cross mount process generally depends on the location of other gusset panels. It will be appreciated that, viewing the handle seams as being along one side of the bag, additional gusset panels can be incorporated along one or both of the top and bottom of the bag and along the opposite side of the bag, provided that a region of the bag perimeter is left open for filling.
As illustrated in
An alternative implementation is illustrated in
Alternative embodiments of bag structure and method of manufacture are shown with reference to
The structure represented in
It will be appreciated that because the web portion 58, when fully welded, is in effect an endless loop, the particular positions of the folds 60 and the welds 24, 26, 37 and the sequence of folding and welding can be altered, but with the result that a structure is obtained that is visually and functionally comparable to the structure shown in
Bags made by the processes illustrated in
An alternative embodiment is illustrated in
As previously indicated, a bag using the design principles of the invention may find application as a jug for containing and storing granular materials and fluids. One such arrangement is shown in
Depending on the particular carrying and pouring characteristics that are desired and the expected weight distribution of contents in the filled bag, it may be convenient to site the carrying aperture 34 other than generally centrally. For example, the carrying aperture may be situated closer to the top or bottom of the bag. In another alternative, the slot-form aperture may be oriented so as to be inclined to the vertical. In a further alternative, the carrying aperture 34 may be configured as a plurality of apertures for insertion of individual fingers to enhance pouring control.
It will be appreciated that the handle may be held atop the bag for carrying but is normally held at the side for pouring. To assist in the carrying mode if the bag contents will be heavy, any or all of its seams can be strengthened as part of the manufacturing process. A strengthening rod, tube or leaf of thermoplastic material is located at the region of a weld prior to welding so that when the weld is completed it provides greater stiffness than is obtained from a weld made solely of the thermoplastic sheet materials. This is particularly valuable for a bag as illustrated in
If desired for aesthetic or other purposes, a handle 62 which is shorter than the full height of the bag is used by appropriately trimming the web portions as shown at 73 before folding and welding takes place or by punching out the unwanted parts of the bag handle once the welding is complete.
The embodiments of the invention previously described relate to pouch bags which are generally rectangular in plan. In such a pouch bag, for efficient use of plastic sheet material and ease of manufacturability, each of the several panels of the bag is generally rectangular, with seam welds along the boundaries of the panel where it joins other panels which may be gusset panels. It will be appreciated that any of the bag panels, including the extension pieces 28, 29 as illustrated in
A particular configuration of bag embodying the invention is shown in
In each of the embodiments of the invention described, the bag is formed from sheet plastic material that is at least partly a heat-sealable thermoplastic material and sealing/welding is effected by heat sealing. Such materials include, by way of example and not limitation, polyolefins such as polyethylene and polypropylene, vinyl polymers, and the like. The materials may be low-, medium- or high-density polymers and may be single or multi-layer composite material. Composite laminated materials may include adhesive layers. Sealing resins such as ethylene vinyl acetate may be used to improve sealing of certain polymer layers and the use of such sealing resins may obviate the use of adhesive tie layers. The invention contemplates the use of thermoplastics films which are made of, or which include, a barrier sheet material such as, for example, EVOH or a metal layer which provides a barrier generally preventing the transmission of gases. The thickness of the film material is selected mainly on the basis of the intended weight the bag must carry and generally ranges from about 2 to 20 mils.
The type of thermoplastic sheet material used will depend on the purposes to which the bag is to be put, whether it is easy to handle in manufacturing, whether it can be readily printed upon, whether it is waterproof, whether it is strong enough to resist tearing or bulging, etc.
A particular implementation uses a multi-ply plastic sheet material including a polyethylene layer which makes effective thermoplastic welds/bonds and has high strength, and a layer of polyester which accepts printed indicia very well. In the manipulation of the web portions, generally polyethylene surfaces are brought together where two parts of the sheet material have to be joined so that a bond/weld can be implemented by using thermoplastic heat sealing techniques rather than adhesive bonding. Similarly such manipulation is configured so as generally to present the polyester surfaces outwardly for application of print indicia. It will be understood however, that whereas thermoplastic welding of materials such as polyethylene is preferred, a bag according to this invention can be manufactured with any or all of the welded seams being substituted by adhesive seams.
In one example, the sheet plastic material of the bag has a polyethylene layer 1 to 7 mils thick, an adhesive polymer layer 0.1 to 0.5 mils thick, and a polyester layer 0.5 mils thick, the layers being coextruded or adhesively laminated. The layer thicknesses can be varied depending on desired sheet material characteristics. For example, the polyester layer which is better suited for accepting printed indicia than the polyethylene, can be made somewhat thicker to provided increased stiffness to the bag. This can be quite important where the bag is to function as a pouring bag and will be lodged or stored in an upright position similar to a jug. The multilayer plastic material can include additional layers of material depending on characteristics desired in the finished material. In another example, the plastic sheet material has outer layers of polyethylene so that both surfaces of the material are heat sealable. In yet another example, the plastic sheet material has a layer of nylon for added strength and/or a barrier layer such as metal foil, metallized polyester or EVOH. The selection of ply materials and the number of layers of each material is chosen for the particular properties desired in the bag. Thus, polyethylene has good heat sealing properties and relatively high strength. A copolymer polyethylene with high elastomeric content can be used where a softer material is required. The sheet film material or particular web portions used in the bag construction can be formed from thermoplastic film that has been oriented during manufacture to impart mechanical strength along a particular axis or at a critical stress site. Such oriented strength can be imparted by for example stretching at ambient temperatures, melt orienting during extrusion, etc. Heat sealing and bonding of layers of sheet material is effected by the application of temperature and pressure for a predetermined time at locations where the layers are to be heat sealed. The temperature, pressure and time are selected based on the particular nature of the sheet materials being bonded together. Bonding is typically effected at multiple bonding stations, with the bonded material subsequently being cooled.
Referring back to
There have been described herein various embodiments of a bag structure. Also described in brief detail are particular production process steps involved in manufacturing such bag structures. Such embodiments and processes have features that distinguish the present invention from the prior art. It will be apparent to those skilled in the art that the bags and the manufacture thereof may be modified in numerous ways and may assume many embodiments other than the preferred forms specifically set out and described above. Accordingly, it is intended by the appended claims to cover all modifications of the invention which fall within the scope of the invention.
Claims
1. A bag formed of plastic film material, the bag having a first side panel, a second side panel, a back gusset extending between the first and second side panels, and a bottom gusset extending between the first and second side panels, margins at front and top edges of the first side panel joining margins at front and top edges of the second side panel at a first seam, a bottom margin of the back gusset joining a rear margin of the bottom gusset at a second seam, the back gusset terminating at a top, rear part of the first seam, the bottom gusset terminating at a bottom, front part of the first seam.
2. A bag as claimed in claim 1, a part of the bag film material integral with the back gusset and rear parts of the first and second side panels formed as a handle at the rear of the bag.
3. A bag as claimed in claim 2, the bag having a generally wedge shaped horizontal sectional form over a major intermediate part of its height when the bag is full of product material and is seated on the bottom gusset.
4. A bag as claimed in 3, the bottom gusset and a front part of the first seam extending generally vertically when the bag is full of product material and is seated on the bottom gusset.
5. A bag as claimed in claim 4, the handle strengthened by a stiffener element of thermoplastic material extending generally vertically when the bag is full of product material and is seated on the bottom gusset, the stiffener element thermally welded to the plastic film material forming the handle.
6. A bag as claimed in claim 4, the handle strengthened by a stiffener element extending generally vertically when the bag is full of product material and is seated on the bottom gusset, the stiffener mechanically attached to the plastic film material forming the handle.
7. A bag as claimed in claim 1, at least a front part of the bottom gusset terminating as a generally triangular part, an apex of the triangular part terminating at the first seam.
8. A bag as claimed in claim 1, the back gusset being generally rectangular.
9. A bag as claimed in claim 1, in which at a front bottom corner of the bag, a first margin portion of the first side panel is thermally welded to a second margin portion of the second side panel, a third margin portion of the first side panel is thermally welded to a fourth margin portion of the bottom gusset, and a fifth margin portion of the second side panel is thermally welded to a sixth margin portion of the bottom gusset.
10. A bag as claimed in claim 1, in which at a rear bottom corner of the bag, a first margin portion of one of the first and second side panels is thermally welded to a second margin portion of the back gusset, a third margin portion of said one of the first and second side panels is thermally welded to a fourth margin portion of the bottom gusset, and a fifth margin portion of the back gusset is thermally welded to a sixth margin portion of the bottom gusset.
11. A bag structure for the bag of claim 1, at least a part of at least one seam being open to allow filling of the bag.
12. A bag as claimed in claim 1, the bag having a closeable pouring device partially inserted between the first and second side panels, edges of the first and second side panels adjacent the closeable pouring device being seam welded to each other and sealed around the outer surface of the closeable pouring device.
13. A bag as claimed in claim 12, the closeable pouring device being one of a slide fastener or zip, a Velcro® type fastener, and an opening cut at the time the bag is first used for pouring.
14. A bag as claimed in claim 12, the first seam having a middle part extending diagonally between a top part of the first seam and a front part of the first seam, the closable pouring device sealed in the diagonally extending middle part.
15. A bag as claimed in claim 1, at least part of the bag made of a multi-ply material with at least one of the plies being one of a surface thermoplastic material, a surface layer amenable to accepting printing thereon, a barrier layer and a strength layer.
16. A bag as claimed in claim 1, the first and second side panels being generally rectangular in shape.
17. A bag as claimed in claim 1, the seams being thermoplastic welds.
18. A bag as claimed in claim 1, the seams being effected using adhesive.
Type: Application
Filed: Jan 7, 2015
Publication Date: May 7, 2015
Inventors: Michael Reid Martin (Toronto), Brian George Hutchison (Brampton), Arjang Tajbakhsh (Richmond Hill)
Application Number: 14/591,139
International Classification: B65D 30/08 (20060101); B65D 33/02 (20060101); B65D 33/25 (20060101); B65D 30/20 (20060101); B65D 33/06 (20060101);