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1. Field of the Invention
The apparatus of the present invention relates to fabric bulk bags and more particularly to an improved bulk bag having at least the upper portion of the side walls extending inward from the vertical to allow the material in the bag to stabilize the filled bag.
2. General Background and Description of the Invention
Over the history of the use of bulk bags, one of the greatest issues has been the stabilization of bulk bags being carried on pallets and stacked in warehouses. Historically, bulk bags, when “filled” with product, are never actually full, and would show loose fabric on the top, due to settling of the product. The problem of stabilization was never an issue for bags being carried by the loops because in the suspended condition, there is tension on the side walls to keep the product in a stable position.
However, once the bag is placed on a platform, such as the floor or a wood pallet, there no longer is the side wall tension, and the bag is able to slump and bulge in response to any product movement. This is why one of the most common instructions for filling these fabric bags is start with the bag's bottom corners 2 to 3 inches above the platform. This position automatically applies tension to the side walls and encourages the product into good vertical columns. Once the bag is released, there is no longer anything holding the vertical tension in the side walls and product shaping within the bag is left to the fabric. As long as the fabric stays tightly stretched around the product, the bag's appearance and performance when being handled is good.
However, in all the current designs that this inventor is aware of, the side walls of the bag are dimensionally equal from top to bottom. Therefore, any space at the top of the bag, allows the fabric to slip down the sides of the product columns. This produces extra fabric, which is no longer filled, to be adjacent to the product. This provides product with inertia from movement or transportation to have chance to move and destabilize the bag.
Therefore, there is a need in the industry to provide a bulk bag which when filled, and moved, or lifted, the product in the bag is undisturbed, and when returned to its position, maintains the sidewalls firm, with no sagging or slipping, to allow stability to the bag, and allow other bags to be stacked thereupon.
The improved bag of the present invention addresses this problem in a very simple and straight forward manner. What is provided is an improved bulk bag which includes the design of shrinking the outer dimensions of the bag so that the top of the bag is significantly smaller than the bottom of the bag, by forming one or more darts, as defined herein, either on one or more corners of the bag or along one or more sidewalls. By forming at least a portion of the bag sidewalls to face inwardly from the vertical, there is created a situation whereby the fabric remains in tension at all times. That is, the fabric cannot slip down around the product as the product downwardly adjacent to any portion of fabric is bigger in diameter than the fabric. The product would have to ‘squeeze’ upward to fit into the smaller fabric space.
Therefore, it is a principal object of the present invention to provide a new bag design whereby the bag cannot slip down and create space for movement;
It is a further object of the present invention to provide a bag design whose stability producing tension can be achieved even if the bag is only partially full;
It is a further object of the present invention to provide a bag that will remain stable although a range of product heights is used in a single bag;
It is a further object of the present invention to provide a bag that will remain stable even though product within the bag shifts due to density changes or when a user uses a single bag for multiple products;
It is a further object of the invention to provide a bag whereby although product can shrink and reduce in height, the bag will still provide support as long as the product is maintained inside the bags design that is enlarging as the product shrinks;
It is a further object of the present invention to provide an improved bulk bag that prevents the slumping of sidewalls and product by providing an upper portion of the sidewalls that slopes inward from vertical, with the use of one or more darts, so that the product maintains the fabric in its full vertical position;
It is a further object of the present invention to provide an improved bulk bag with an upper portion of the sidewalls that is sloped inward from vertical so that when the fabric is stretched upward in the lifting process, thereby creating tension in the vertical fabrics, the tension will be maintained after the bag is no longer in a lift position, as the fabric cannot slide back down around the product due to the restricted size of the fabric and such tension provides stronger restrictions to product movement to provide increased stability.
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 a discussion of the present invention, reference is made to
Almost every product moves after being poured into the bag. It densifies (settles) with time or during handling and shipping. The particles are irregularly shaped and the movement allows these particles to lodge closer and closer together, thus reducing the product height. By lifting the bag by the loops after filling, a great percentage of this settling is achieved immediately. At the same time, during the lift, the fabric is stretched and the widest part of the fabric is raised above the maximum amount of product and the maximum amount of the restricted portion of the bag is raised above the product to hold as much tension as possible.
With all of this in mind, there created a need for a bag to be designed to match the product characteristics in a manner that the intended amount of product initially fits into the bag and the settled or densified product is still above a certain point along the sidewalls of the bag, after the required lifting and stretching of the fabric to improve stability. The present invention addresses this need.
The bag of the present invention, as illustrated by the numeral 100 in
Unlike any previous bulk bag known to the inventor, bag 100 includes an improvement which eliminates sagging of the side walls 102, at any time while filled with bulk material. This improvement is illustrated clearly in isolated view in
As an alternative, as illustrated in
For purposes of definition, a “dart” is defined herein as a line of stitching extending from a point along the sidewall upwards to the top of the bag at an angle so that two or more layers of fabric form the dart, but preferably two layers. The dart may be formed at one or more corners of the bag sidewalls or anywhere along one or more sidewalls between the corners. An example of a dart formed on the corner as defined herein is shown in
In
As was explained earlier in reference to the prior art bag shown in
The experiments show, as illustrated in
As seen in
Likewise, this new design can probably be used to modify any existing design such as circular woven, u-panel, one piece bags, baffle bags, Portabulk, etc.
All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, 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 provisional patent application, entitled “Improved Design for Stabilizing Fabric Bulk Bags,” filed on Nov. 9, 2005, bearing Ser. No. 60/735,642, incorporated herein by reference thereto.
Number | Date | Country | |
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60735642 | Nov 2005 | US |