Patent Application
20090123093
The present invention generally relates to the field of packaging and more specifically to the field of bags for containing, storing, and/or transporting material.
In the packaging industry, there are many different types of bags for containing material. Bag construction depends on a variety of factors, including the weight and type of material to be contained as well as the filling method. Bags may have one or more layers, flat bottoms, gussets, pasted valves and/or an open mouth.
Various types of prior art bags are the “Pasted Valve Stepped End” (PVSE), the “Pasted Open Mouth” (POM) and the “Pasted Open Mouth Pinch Bottom” (POMPB) bags. The PVSE, POM and POMPB bags present some difficulties in taking hold of the bags with one's hands to pick up and manipulate them, especially when the contents have an elevated weight such as about 25 to 40 Kg or a large volume. The traditional PVSE and POM bags are therefore often supported underneath when they are manipulated, which may decrease the efficiency of manual or automated manipulation.
Prior art PVSE bags may be provided with a space at the top of the bag, between the infold panel and the overlapping flaps to insert the valve. However, this space is not designated for inserting a hand to attempt to pick up the bag. This location is often weak and if pulled upon may result in small or large tears, which render the bag susceptible to subsequent tear propagation, or complete tearing of the overlapping flaps or bag walls. These tears often occur at the corner fold between the flap, the infold panel and the side wall and propagate inwardly due to shear forces.
In prior art PVSE bags, the valve is located between an overlapping flap and an infold panel. The valve of a PVSE bag enables material to be blown, conveyed or screwed into the bag, and is particularly useful when the material is susceptible to dust dispersion or scattering such as concrete or cement. For such materials, PVSE bags are often used, since the filling is performed by an endless screw or by blowing. For instance, the exit of the endless screw or the blowing tube is secured within the valve of the PVSE bag, and the material is screwed or blown within the bag, therefore limiting dispersion and excessive waste of the material.
In various filling methods and in other applications, it may be desirable to be able to lift and manipulate the filled bags by hand, for instance to unload the bags from a filling unit or stack the bags in a certain fashion.
The prior art also includes other types of bags, such as the “Pasted Bottom Open Mouth” (PBOM) and the “Sewn Open Mouth” (SOM) bags. These bags may also present difficulties in terms of lifting and manipulating. So-called “Open Mouth” bags are most often filled by gravity and this method of filling is not ideal for all products, for instance in the case of powdered cement. For such products, PVSE bags are often used, as was mentioned above. SOM bags may be provided with a valve that is glued on by hand, which is an inefficient process, to enable it to be filled by endless screw or blowing.
The prior art presents various deficiencies in terms of providing a bag that is cost-effective, has efficient manufacturability, and may be efficiently manipulated and lifted. There is indeed a need for a bag that overcomes at least one of the disadvantages of the prior art.
The present invention responds to the above-mentioned need by providing a bag for receiving contents and being manipulated by a lifting element, such as a users hands. The present invention also responds to this need by providing a process for manufacturing such a bag.
Accordingly, the present invention provides a bag for receiving contents and being manipulated by a lifting element. The bag includes a tube portion defined by at least two opposed side walls. The bag also includes two opposed end sections, the first end section closing the tube portion for defining a cavity for receiving the contents, the second end section having at least one flap extending from one of the side walls to be connected in relation to the other of the side walls. At least one slot is defined beneath and parallel to the flap in between the opposed side walls for receiving the lifting element. The flap and the slot thereby define a handle. The bag also includes at least one reinforcement member, each being applied to and extending between the at least one flap and the corresponding side wall.
In an optional embodiment of the bag of the present invention the first and second end sections are respectively bottom and top sections. Optionally, the at least one flap includes two overlapping flaps, each extending from a respective one of the side walls and being secured together in an overlapping configuration. Also optionally, the slot includes two opposed slots located at opposite lateral sides of the two overlapping flaps. Also optionally, each reinforcement member includes two opposed reinforcement strips, each applied to a respective one of the two overlapping flaps and the corresponding side wall. Optionally, the two opposed reinforcement strips overlap at the two overlapping flaps and the two opposed reinforcement strips extend down the entire height of the corresponding side walls. It is also optional that the tube portion further includes lateral walls joining the opposed side walls, and each reinforcement member further includes a lateral portion applied to the lateral walls and joining the two opposed reinforcement strips. The at least one reinforcement member may include two pairs of reinforcement strips, each pair being arranged in spaced relation on a respective one of the overlapping flaps and the corresponding side wall. Also, each reinforcement strip may be located at a respective lateral edge of the corresponding flap. Optionally, each reinforcement strip of one pair is aligned with a respective reinforcement strip of the opposing pair and each reinforcement strip of one pair overlaps with a respective one of the opposing pair at the overlapping flaps.
Also optionally, the side walls, the bottom section and the top section are formed from a web. The web may be formed so as to comprise the tube portion with opposed ends, each of the opposed ends having opposed corners, each of the corners being scored with diagonal scores to provide inwardly folded infold panels and the overlapping flaps. The overlapping flaps at the bottom section may be folded and glued to close the bottom section. The infold panels at the corners of the top section may be spaced apart to provide an inlet opening in fluid communication with the cavity of the bag, and the overlapping flaps at the top section may be folded and glued so as to provide a valve opening between the overlapping flaps and at least one of the infold panels.
Optionally, a valve sleeve arranged and glued within the valve opening.
Also optionally, the web includes multiple superimposed offset plies and is formed into a pasted valve stepped end bag. The multiple superimposed plies may include an inner ply in contact with the contents and a neighbouring ply having inward and outward facing surfaces, the at least one reinforcement member being provided on the inward facing surface of the neighbouring ply. The multiple superimposed plies may also include an outer ply. Optionally, each flap of the outer and neighbouring ply is defined between two corner slits to form rectangular-shaped flaps and each flap of the inner ply is defined between inward corner folds to form trapezoid-shaped flaps. Also optionally, each of the at least one reinforcement member is strip-shaped and is glued or applied directly to the corresponding flap and side wall.
According to an optional aspect of the invention, the opposed side walls and the at least one flap are composed of a paper material, and each reinforcement member is composed of a reinforcing material enabling a greater tear resistance than the paper material. Optionally, the reinforcing material is a flexible polymer applied in sufficient thickness to avoid stretching thereof beyond a maximum elongation of the paper material and/or beyond a permanent deformation threshold of the flexible polymer, when the bag is loaded with the contents and lifted via the handle. In one embodiment, the reinforcement material is HDPE, which may have a thickness of about 0.005 inches.
The present invention also provides a process for making a bag including the steps of
In an optional embodiment of the process of the present invention, in step d) the at least one flap includes two overlapping flaps, each extending from a respective one of the side walls, and further including step e) of securing the flaps together in an overlapping configuration.
Optionally, in step d) the at least one slot includes two opposed slots located at opposite lateral sides of the two overlapping flaps.
Optionally, in step b) each reinforcement member is applied to the web so as to form in step d) two opposed reinforcement strips each extending between a respective one of the two overlapping flaps and the corresponding side wall.
Also optionally, in step d) the two opposed reinforcement strips overlap at the two overlapping flaps.
Optionally, in step c) the tube portion further includes lateral walls joining the opposed side walls, and in step b) each reinforcement member is applied so that in step d) each reinforcement member further includes a lateral portion located at the lateral walls and joining the two opposed reinforcement strips.
Optionally, in step b) the at least one reinforcement member includes two reinforcement members applied to the web in spaced relation so that in step d) each reinforcement strip is in spaced relation with one of the reinforcement strips of the other reinforcement member, to form a pair of reinforcement strips on each overlapping flap and corresponding side wall.
Optionally, in step d) each reinforcement strip is located at a respective lateral edge of the corresponding flap.
Optionally, in step d) each reinforcement strip of one pair is aligned with a respective reinforcement member of the opposing pair.
Optionally, in step d) each reinforcement strip of one pair overlaps with a respective one of the opposing pair at the overlapping flaps.
Optionally, in step d) the tube portion has opposed ends, each of the opposed ends have opposed corners, each of the corners are scored with diagonal scores to provide inwardly foldable infold panels and the overlapping flaps, the overlapping flaps at the bottom section are folded and glued to provide a closed bottom, the infold panels at the corners of the top section are spaced apart to provide an inlet opening in fluid communication with the cavity of the bag, the overlapping flaps at the top section are folded and glued so as to provide a valve opening between the overlapping flaps and at least one of the infold panels.
Optionally, the process also includes the step f) of arranging and gluing a valve sleeve within the valve opening.
Optionally, in step a) the web includes multiple superimposable offset plies and in step f) the bag is made into a pasted valve stepped end bag. The web may also include multiple superimposable plies. The multiple superimposable plies provided in step a) may include an inner ply and a neighbouring ply having an inner surface in contact with the inner ply, and wherein in step b) the at least one reinforcement member is provided on the inward facing surface of the neighbouring ply. The multiple superimposable plies may include an outer ply.
Also optionally, in step b) each of the at least one reinforcement member is strip-shaped and is glued or applied directly to the web.
According to one embodiment, the web is composed of a paper material and each reinforcement member is composed of a reinforcing material enabling a greater tear resistance than the paper material. The reinforcing material may be a flexible polymer applied in sufficient thickness to avoid stretching thereof beyond a maximum elongation of the paper material when the bag is loaded with contents and lifted via the handle.
According to one optional aspect of the invention, the reinforcement material is a polyethylene-based material. The polyethylene-based material may be HDPE and it may be applied in a thickness of about 0.005 inches.
The above process enables an efficient way of manufacturing a bag with a reinforced handle.
a and 1b are perspective top semi-transparent views of embodiments of the bag of the present invention.
a and 2b are perspective top semi-transparent views of the embodiment of the reinforcement member of the bag of
a and 3b are perspective top views of the embodiment of the reinforcement member of the bag of
a-6c are side plan views of the top of an embodiment of the bag of the present invention, showing folding and gluing steps.
The present invention includes a bag and a process of making the same. The bag includes a reinforcement member to prevent the tearing of the bag when it is lifted or manipulated by its handle.
It should be noted that the invention may be used in connection with a variety of different types of bags in order to reinforce the handles to facilitate lifting and manoeuvring.
a, 2a, 2b, 6a-6c and 9 illustrate a bag 10 or parts of the bag according to a first embodiment.
b, 3a, 3b, 4 and 5 illustrate a bag 10 or parts of the bag according to a second embodiment.
In a preferred aspect of the invention, the bag is formed from a web 11, examples of which are illustrated in
Referring now to
Referring now to
Alternatively, as illustrated in
Referring to
The bag 10 further includes two reinforcement members 30,40 each being applied to the flaps 24a,24b and side walls 14a,14b. It should be noted that there may be one reinforcement member applied to one of the flaps and extending down the corresponding side wall from which the flap extends. The reinforcement members 30,40 reinforce the intersection between the flaps 24a,24b and the side walls 14a,14b and in the region of the handles 28a,28b. Thus, when a user inserts their hands as lifting elements LE into the slots 26a,26b and lifts upward, the reinforcement members 30,40 resist inward tearing of the flaps 24a,24b and the side walls 14a,14b.
In a preferred aspect of the bag 10, as illustrated in
a and 2b illustrate the reinforcement members 30,40 in isolation. Referring to reinforcement member 30 in particular, the top ends of the opposed strips 32a,32b fold inward, since they are applied to the overlapping flaps of the bag (not illustrated here), when the flaps are overlapped and glued together.
Referring now to
Referring to
The two pairs of strips arranged in this way may enable a symmetrical reinforcement of the width of the bag and symmetrical reinforcement of the depth of the bag. In such embodiments, there is an improved reinforcement on various sides of the bag.
a and 3b illustrate the reinforcement members 30,40 of the second embodiment in isolation. Referring to reinforcement member 30 in particular, the top ends of the opposed strips 32a,32b fold inward, as they are secured to the overlapping flaps of the bag (not illustrated here). In addition, the lateral portion 38 includes top and bottom ends 39a,39b that fold inward and beneath the top ends of the opposed strips 32a,32b.
Referring now to
By locating the strips 32a,32b,42a,42b at least partly at the top corners of the bag 10—which in the case of PVSE type bags is where the flaps 24a,24b meet the infold panels 58 and the opposed side walls 14a,14b—the top corners of the bag are reinforced to resist vertical tensile forces as well as shear forces inwardly along the folded flaps 24a,24b, when the bag 10 is lifted or manipulated by a user. This strategic location may also enable an increased efficiency of the use of the strips' material and allow the strips to be efficiently applied.
Overlapping flaps may also be located at the bottom section 16, and are folded and glued to close the bottom section 16.
Referring back to
b and 6c also illustrate the inlet opening 60.
Referring still to
Referring briefly back to
In a preferred aspect of the bag 10, a valve sleeve 64 is arranged and glued within the valve opening. The valve may be glued to the infold panel to be beneath the corresponding slot and/or may be glued to the flap to be above the corresponding slot.
In another preferred aspect of the bag, the web to form the bag includes multiple superimposed offset plies and is formed into a pasted valve stepped end (PVSE) bag. The web may include two, three or more superimposed plies, more about which will be discussed hereinbelow.
Referring now to
Still referring to
Referring to
It should be indeed understood that a variety of alternative materials may be used. For instance, the strips 32a,32b,42a,42b may be thick or thin and composed of polymeric or other materials, preferably those that are flexible. The strips 32a,32b,42a,42b and the handles are composed of materials having properties and dimensions such that the strips 32a,32b,42a,42b may sufficiently reduce and preferably prevent the strain of the handle past a critical tearing threshold. Preferably, the strips 32a,32b,42a,42b prevent tearing of the flaps 24a,24b and side walls 14a,14b when the bag 10 is filled with about 25 Kg of product, and still preferably when it is filled with about 45 Kg of product, or more. It is also preferable that if the flaps 24a,24b or side wall 14a,14b undergo a small tear, the reinforcement strips 32a,32b,42a,42b are capable of preventing inward propagation of the tear.
The strips 32a,32b,42a,42b are thus arranged and chosen in such a manner as to increase the resistance to tearing when the bag 10 is lifted or manipulated by its handles 28a,28b. The strips 32a,32b,42a,42b preferably extend the entire height of the bag 10 and thus resist tension forces when the bag 10 is lifted. In addition, the strips 32a,32b,42a,42b resist shear forces where the flaps 24a,24b meet the side walls 14a,14b when the bag 10 is lifted. The strips 32a,32b,42a,42b may also allow for safer lifting of the bag and reduce the likelihood of paper cuts from the paper flap material, for instance when arranged at the lateral edges of the flaps. In addition, the strips 32a,32b,42a,42b are easily applied during one of the first steps of production of the bag 10 by an automated process, more of which will be discussed hereinbelow.
Also preferably, the HDPE strips 32a,32b,42a,42b are provided so as to not strain past their permanent deformation threshold when the bag 10 is lifted or manipulated, and thereby prevent tearing of the paper over an extended period of time. The dimensions and properties of the strips' materials may also be modified in accordance with the desired weight of the bag 10 and its contents.
Furthermore, the strips 32a,32b,42a,42b are preferably composed of thick HDPE because of its stiffness (relatively high Young's modulus). The HDPE preferably supports most of the tensile force exerted by lifting the bag 10 without stretching beyond the maximum elongation of the paper extended to rupture (stretch %). The stretch is often between about 2% and 8%.
Furthermore, it was found that a three-ply bag was sufficiently reinforced in the handle region by using strips 32a,32b,42a,42b of HDPE of 0.005 inches thick to avoid tearing under heavy loads in the order of 45 Kg.
Referring now to
Referring now to
Referring to
In operation, the bag 10 as illustrated in
In some applications, the bag may be filled or lifted by the bottom section and thus the flaps and reinforcement members may be also be arranged at the bottom section of the bag to form the handle at that location. In such cases, the lifting element could be inserted into the bottom slots and manipulated sideways or lifted. The bottom handles may be reinforced to improve resistance to inward tearing of the flaps and side walls. Optionally, there are reinforced handles at the top and bottom of the bag.
It should also be noted that the preferred embodiment of the bag is a PVSE type bag, but it may alternatively be a POM type bag or another type of bag having a flap extending between two side walls to be reinforced by a reinforcement member in the manner of the invention.
Referring to
Step a) includes providing the web 11, which may have a variety of forms but preferably is flat and provided with pre-cut flaps. Preferably, the web 11 is made of paper. At this point, the web is preferably substantially flat to facilitate application of the strips thereon. It should be understood that the preferred embodiment has three superimposed plies (not illustrated in
Step b) includes applying at least one reinforcement member 30,40, which may comprise various reinforcement strips 32a,32b,42a,42b, on the web 11. This is preferably done by gluing the strips 32a,32b,42a,42b, especially when they are composed of HDPE or an equivalent material, onto the paper layer. This is preferably an automated process performed by a gluing unit. Each HDPE strip is preferably applied in sufficient thickness and width to provide good resistance to tearing of the web material, which is preferably paper. In the preferred embodiment having three superimposed plies, this step b) is preferably performed on the second ply 68 only, particularly on its surface which will be inward facing. Being on the middle layer may enable preventing any contact between the contents of the bag and the strips. Alternatively, in some cases, the strips may be applied on one of the other layers on the inward or outward facing surface thereof. The strips may alternatively be directly applied to the web, for instance by laminating and/or thermal application.
The strip-shaped nature of the reinforcement member facilitates the application thereof during one of the early steps of the bag's production, preferably by an automated process, and enables an efficient use of material.
Step c) includes assuring that the web 11 has a tube portion 12 with at least two opposed side walls 14a,14b. On the one hand, if the strips 32a,32b,42a,42b were applied to the web while it was still flat, then the web should be subsequently formed into a tubular shape. On the other hand, if the web was already in tubular form when the strips 32a,32b,42a,42b were applied, then step d) may be performed straight away. In the preferred embodiment, the “tubular” shape does not have gussets, since a PVSE bag is to be made.
Step d) includes providing the closed bottom section 16 and the top section 22 at opposite ends of the tube portion 12, so that the top section 22 comprises at least one flap 24a,24b extending from one of the side walls 14a to be connected in relation to the other of the side walls 14b. Step d) also includes providing a slot 26a that is defined beneath and parallel to the flap 24a and in between the opposed side walls 14a,14b so that the flap 24a and the slot 26a define the handle 28a. Step d) also includes providing the reinforcement member 30 so that it extends between the at least one flap 24a and the corresponding side wall 14a.
Preferably, the process of making the bag has various additional steps—such as folding, scoring, gluing, cutting, etc.—to form one of the preferred embodiments of the bag as shown in the Figs.
However, it should be understood that different types of bags may be manufactured and thus additional or modified steps may be included to provide certain features, such as gussets, valves, additional folds, etc.
It should be understood that the embodiments of the present invention are put forth here as examples only and do not limit what has actually being invented. Many modifications can be made to these embodiments without departing from what has actually been invented.
| Number | Date | Country | |
|---|---|---|---|
| 60996347 | Nov 2007 | US |
