Patent Application
20240308731
Not applicable
Not applicable
The present invention relates to fabric bulk bags. More particularly, the present invention relates to a novel bulk bag configuration wherein the bottom of the bag has an octagonal or other multi-sided shape which, when filled with product, is fully supported by the pallet without the bag needing to shift and lean. As a result, the side walls stay naturally in position. This bag is more attractive and much safer to stack upon.
In the art of making bulk bags, the historical designs have all been created from the point of view of manufacturing efficiency. The goals have been to eliminate waste and reduce manpower.
Hence, almost all bulk bags have been made with square or rectangular bottoms with vertical walls rising up from the four sides. A good example of this would be the original designs of Peter Nattrass, one of the early inventors of the bulk bag concept.
This concept eliminates any lost fabric and makes production quite efficient with straight sewing lines in all major seams.
However, in usage, a bulk bag is simply a box shaped flexible fabric container. As loose product is poured into the bag, it applies equal pressure in all directions. Uncontained loose product when poured onto the ground forms a cone with a circular shaped bottom. When this natural action is applied to product entering into a fabric bag, the natural forces attempt to change the bag into a cylinder.
In the lower portions of the bag, this cannot occur as the fabric that is directly attached to the square bottom is held to that configuration. But the further up the vertical walls of the bag from the bottom, the less control the bottom square has over the side wall fabric. Within the first 10 inches (25 cm) of the vertical sidewalls above the bottom square panel, the shape of the bag becomes cylindrical. The constraints of the square bottom no longer applies. The flexible bag forms a nearly perfect cylinder in the central portions of the filled bulk bag.
The perimeter of the bag becomes the circumference of the cylinder. Bulk bags come in a variety of sizes. The most common are 34 inches (86 cm) square, 35 inches (89 cm) square, 36 inches (91 cm) square, 37 inches (94 cm) square and 38 inches (97 cm) square.
For purposes of discussion we will use the 37 inch (94 cm) square bag for all the following discussions but it is clear that this new design can be applied to all sizes of bags by using the same thought processes described below.
A bulk bag that is made 37 inches by 37 inches (94 cm by 94 cm) square has a perimeter of 37 inches (94 cm) times 4, or 148 inches (376 cm). A cylinder with a 148 inch (376 cm) perimeter has a diameter of 148/Pii (3.1416) or 47.1 inches (120 cm) in diameter.
Therefore a filled bulk bag that started out as a 37 inch (94 cm) square bag has a square bottom of 37×37 inches (94 cm×94 cm) and an area of 1369 square inches (8832 square cm). Approximately 7 to 8 inches (18 to 20 cm) above the floor the bag has rounded out to a cylinder with a diameter of 47.1 inches (120 cm) and a cross sectional area of 1742 square inches (11,238 square cm).
The resulting cylinder has an area that is greater than the base by 27.2%. This then leads to the conclusion that approximately 25% of the product within each standard bulk bag design is initially unsupported by the pallet or floor. This means that each side of the square bottom bag has unsupported columns of product that are greater than 6% of the total product.
Since the bag has no supporting structure, the loose product outside the support area of the floor or pallet will shift downward during the vibration of handling.
This movement will continue until the great majority of the product within the bag has reached a supported position.
Since the diameter in this case is 10 inches (25 cm) larger than the cross section of the base, the only way for the product to reach support is to convert a portion of the bag sidewall into a floor. In other words, 5 inches (13 cm) of sidewall will be laid flat to gain the support for the product in the 25% of unsupported cylinder that was described above.
If this happens evenly all around the bag, then the bag simply becomes approximately 5 inches (13 cm) shorter with a cylindrical shape from the floor or pallet to the top of the product area.
However, with any inertia such as happens with transport, the product settles to the floor more quickly in one direction versus the other directions. In this case, the product will lay more than 5 inches (13 cm) horizontally to that one side to reach support. This natural action then results in causing the bag to lean in that same direction. One side is longer than the opposite side so the bag is forced to lean toward the newly shortened side.
This is the basic cause of the instability that most bulk bags exhibit when being shipped or being stacked.
The only known exceptions to this are bulk bag designs called baffle bags and some bulk bags that are made with a fully circular bottom. In the case of baffled design bags, the main body of the bag has interior walls that prevent the bag from reshaping itself into a cylinder. While this is an option, it is a fairly expensive option that requires extra fabrics and extra sewing seams. Further, it separates the interior of the bag into 5 separate chambers. The baffle bag essentially tries to overcome the natural forces of gravity by force.
The proposed invention in this patent is attempting to work with the natural forces by providing a more natural rounding to the bag base.
The other known prior art are bags that have a circular bottom, for example, from Japan. While this bag is very stable, it is difficult to place on a square pallet. It has no straight sides to help the operator line up the edges. Further, the 47 inch (119 cm) diameter bag would have to be on a minimum 47 inch (119 cm) square pallet for full support. Since export containers are only 92 inches (234 cm) wide, 2 pallets of this side cannot fit into the containers side by side. Therefore, the bag will have areas of non-support that droop down over the edge of the necessarily smaller pallet and be vulnerable to damage. The invention proposed here eliminates this particular issue with the fully circular bottom bag.
However, after 30 years of International recognition, this design has not moved successfully into the rest of the world. This has been primarily because of the expense and difficulty of producing this design.
In producing the same bag spoken about above, the perfect circle of 47.1 inch (120 cm) would have to be created from a minimum of a 51 inch (130 cm) square piece of fabric. The bottom panel on a bulk bag is a supporting panel and thus generally involves at least one fold of fabric to create two layers at all points of the seam. This means that the bottom requires a piece of fabric with an area of 2,601 square inches (16,781 square cm).
The bottom for the same bag in standard square design is made from 42×42 inches (107×107 cm) fabric with an area of 1764 square inches (11,381 square cm) of fabric. Therefore, the circular bottom requires 47% more fabric than the bottom of the square bag.
In a production situation, the sewing machines used in this industry are designed for straight line sewing. It is quite difficult for this type of machine to apply a seam in a circular manner. The operator must sew only an inch or two (3 to 5 cm) then stop and turn the fabric slightly. This happens approximately 74 times on this type of bag. This number of stops makes the cost of labor go up and the speed of production goes down.
Therefore, there is a need in the industry to provide a bag which will be stable when filled, yet which will be easy to construct without creating wasted fabric or slows down production, as does round bags. The present invention, which is a bag having an octagonal bottom, solves those problems. By going to an octagonal bottom, we speed up the sewing, reduce the waste, fit pallets and provide an appearance that is not square but also not round, which provides a larger footprint when the bag is filled to avoid the side walls of the bag from making contact with the surface upon which the bag rests and causing the filled bag to sag and being unable to support filled bags stacked on top of it.
The present invention solves the problems in the art in a simple and straightforward manner. What is provided is a fabric bulk bag and a method of constructing same, the bag including a continuous sidewall, which may or may not be constructed of panels of fabric sewn edge to edge to define the continuous sidewall, a top portion, and a bottom, all defining a bulk storage place therein; the bottom further comprising multiple sides, preferably eight sides, which define an octagonal shape, so that the bag wall is sewn to the bottom in less time than a round shape bag, and when filled the bag stands more upright to support other filled bags thereupon. In the method of producing the fabric bulk bag, the bag is constructed in less time than prior art round bags, uses less wall fabric than prior art square bags, and when constructed and filled, supports itself more stable on a floor or pallet; using the following steps of providing a continuous length of fabric sewn along a common edge to define a continuous wall portion of the bag; sewing a top to the upper edge of the continuous side wall portion of the bag; providing an octagonal shaped bottom of the bag; and sewing a straight seam between the lower edge of the side wall along each of the eight sides of the octagonal shaped bottom which results in quicker time to construct the bag and reduces or eliminates the bulging of the side walls when the bag is filled with bulk product.
Therefore, it is a principal object of the present invention to provide a new design for a bulk bag having multiple sides, greater than four in number, and would have a shape other than the current square or round shape of conventional bulk bags, which results in a bag having a larger footprint for supporting itself upright when filled with product.
It is a further principal object of the present invention to provide a new design for a bulk bag having an octagonal shape which results in a bag using less fabric than round bags for the bottom, less side wall fabric than square bags, and is faster to construct than a current round bottom bag.
It is a further object of the present invention to provide a bulk bag having an octagonal shaped bottom which is not necessarily unilateral in shape, and can be adjusted to match any particular pallet size that the consumer wishes to match.
It is a further object of the present invention to provide a bulk bag having an octagonal shaped bottom which rests securely on a pallet without leaning and maintains substantially straight sides when the bag is filled with bulk material.
It is a further object of this invention to provide a new base design that will improve stability for the filled bulk bags that is also economical to produce.
Further, in summary, the present invention provides a design for a bulk bag that eliminates the natural tendency for filled bags to lean while providing an efficient manner of production. This is accomplished by creating an octagonal shape for the bottom of the bag.
In the preferred embodiment, the shape of at least the bag bottom is eight-sided, or octagonal shape. The top of the bag may also be octagonal but is not necessary for the invention. However, the term multi-sided bag may be used to describe that embodiment and any other embodiment which may include sides which number greater than four.
For purposes of discussion, the continuous sidewall portion of the octagonal bag may be constructed of a one piece of fabric, or it may have a plurality of fabric panels sewn together at their edges to define the continuous sidewall as used herein.
For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:
Prior to turning to the bulk bag of the present invention, reference is made to
In
However, as illustrated in
In the example given of a 37 inch (94 cm) square prior art bag, the floor portion 16 is 37 inches (94 cm) square but the cylindrical portion 18 is 47.1 inches (120 cm) in diameter. Or a little over 10 inches (25 cm) wider than the square base 16 of the bag 10. The results that occur because of this difference is illustrated in
As illustrated in
An additional problem with the Prior Art Bags is illustrated in
In
Having to start with a larger square of fabric requires, in this case, nearly 300 square inches (1935 square cm) of extra fabric cost. Additionally, as shown in
Turning to the present invention, reference is made first to
As illustrated by
Although the octagonal shape is the preferred embodiment of the bag, reference is made to
Returning to the preferred embodiment of the bulk bag illustrated in
In order to end up with 44.6 inch (113 cm) centerline dimensions in both directions, a 48 inch (122 cm) piece of fabric is the preferred starting material. This piece of fabric has 2304 square inches (14,864 square cm) of area. This is 15% less materials than is required by the round bottom bag and 30% more than the bottom for the square bag.
When this 44.6 inch (113 cm) Octagonal bottom 72 is sewn to the side walls 12 of a 37 inch (94 cm) square bag, it would have eight (8) 18.5 inch (47 cm) sides which add up to 148 inches (376 cm) of perimeter. This is identically equal to the perimeter of a 37 inch (94 cm) square bulk bag or a 47 inch (119 cm) diameter cylinder.
The resulting bottom will then have 1646 square inches (10,619 square cm) of area to support the 1742 square inches (11,239 square cm) of cylinder above it. This works out to 94.5% of the total area of the cylinder above, which defines the larger footprint of the bag.
In practical terms, the bag will have a slight bulge at the centerline of each side 12 of the original square based bag. This bulge is now only 1.25 inches (3.18 cm) beyond the base of the bag or 1.3% of the total product is bulging out beyond the base on each side.
The average bulk bag carries 2200 lbs (998 kg). In the original square bag, the amount of unsupported product is 25% of the 2200 lbs (998 kg) or a total weight of 550 lbs (249 kg). As experienced in the industry, this is more than enough unsupported weight to influence the reshaping of the bulk bag.
In the present invention, only 5.5% or 121 lbs (54.9 kg) of product is unsupported and that is divided up into 8 parts by the octagon instead of 4 parts for the prior art. Therefore, the imbalances in the octagonal shaped bag 80 have an average of only 15.1 lbs (6.85 kg) in any direction. This represents a less than 1% influence on the stability of the present invention.
As to the cost of this bag, since the prior art uses 5 inches (13 cm) of sidewall to allow the bag to get to full support position, then the present invention can be made 5 inches (13 cm) shorter and hold the same amount of product. In the example explained above, there is a saving 5 inches (13 cm) of fabric on each of 4 sides of the original square bag for a total savings of 740 Square inches (4774 square cm) of side wall fabric.
As was discussed earlier, the octagonal bottom 72 required a piece of fabric with an area of 2304 square inches (14,864 square cm) as opposed to the square bag bottom which required only 1764. However, since the octagonal bottom 72 allows the drop in side wall height of 5 inches (13 cm), we can see that the present invention uses an almost identical amount of fabric. The present invention uses 2304 sq. inches (14,864 sq. cm) for the bottom but saves 740 square inches (4774 sq. cm) on the side walls. This presents a net usage of 1564 square inches (10,090 sq. cm) for the present invention versus 1764 square inches (11,380 sq. cm) for the prior art.
On the labor side, the sewing machine operator is still sewing the same 148 inches (376 cm) of perimeter bottom but is making 8 stops and turns instead of 4 stops and turns. The effect of this is minimal and probably equal in value to the 200 square inches (1290 square cm) of fabric that the octagonal bag saves over the prior art.
As can now be seen, the octagonal bag 80 has a cost roughly equal to the prior art but has a greatly improved stability.
The shape of the octagonal bottom 72 can be altered to accomplish different objectives without substantially affecting the stability. In one design, as seen in
Now one can see that the wider base improves stability through providing a greater support surface, or a greater footprint, as it could be defined. We can also see that in the stacking of these bags, a similar top would also be beneficial as it will provide a greater surface for the upper bag to rest securely upon as well. However, it is not necessary to apply this design to the top to get the benefits of a bag that will stand stably by itself.
It is also noted that providing a larger base, or footprint, through the use of the octagonal shaped bottom is beneficial for stacking. Therefore, using this technology to provide a larger panel on the top of the bag will provide a wider stacking surface for any bags being stacked on bags with octagonally shaped tops. This will further improve the stacking safety and stability of such bulk bags.
The following is a list of parts and materials suitable for use in the present invention:
All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. All materials used or intended to be used in a human being are biocompatible, unless indicated otherwise.
The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.
This application claims priority from U.S. Provisional Patent Application, Ser. No. 61/234,449, filed 17 Aug. 2009, incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| 61234449 | Aug 2009 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 18366485 | Aug 2023 | US |
| Child | 18610109 | US | |
| Parent | 17543531 | Dec 2021 | US |
| Child | 18366485 | US | |
| Parent | 16805236 | Feb 2020 | US |
| Child | 17543531 | US | |
| Parent | 15876981 | Jan 2018 | US |
| Child | 16805236 | US | |
| Parent | 14156180 | Jan 2014 | US |
| Child | 15876981 | US | |
| Parent | 12842601 | Jul 2010 | US |
| Child | 14156180 | US |
