Patent Application
20080095581
One embodiment of a water flow control bag 12 of the present invention is depicted in
As depicted in the several Figures, the outer bag may be formed from a sheet of fabric which is folded back upon itself and stitched 30 together about its peripheral edges, thereby defining first and second side edges 20 and 22, respectively, and first and second end edges 24 and 26, respectively. Whereas stitching 30 may be applied along the folded edges of the outer bag, no such stitching is required, and preferably is to be avoided.
As may be seen from
In one embodiment the inner bag includes a loop 28 of cording or like strong material anchored in each of the four corners 32, 34, 36, and 38 of the outer bag, as by stitching 30 or other like means for anchoring the loop within its respective corner of the outer bag. Preferably, each loop projects laterally from its respective end of the outer bag in a direction generally parallel with the longitudinal centerline 40 of the inner bag and is exposed externally of the outer bag for purposes of aiding in the fixation of one or more bags into a gang of bags.
As depicted in phantom in
Desirably, the laid out dimensions of the inner bag do not appreciably exceed the laid out inner dimensions of the outer bag so that the inner bag will lie flat within the outer bag when the inner bag is disposed internally of the outer bag. Accordingly, the full interior of the inner bag is open for migration and ultimately expansion of the superabsorber contained therein when such superabsorber is exposed to water, for example. It is to be recognized that the particular superabsorber chosen may be specific to absorption of a given liquid, but in most instances, the liquid to be absorbed will be water, and, at times, a liquid petroleum-based product.
Assembly of the water flow control bag of the present invention may be of a variety of forms. In one embodiment, a sheet of the outer bag fabric is folded back upon itself and all non-folded margins of the folded sheet are closed as by stitching, adhesive, heat sealing or other suitable mode of closure of the fabric side margins. As desired, the folded side margins of the sheet also may be joined together but such is not desired. In similar manner, a sheet of inner bag fabric is folded back upon itself and all non-folded margins of the folded sheet are closed in similar manner as the closing of the margins of the outer bag fabric sheet. As a part of the assembly of the inner bag within the outer bag, each of the four corners of the outer bag is provided with a loop of a material such as cording or a like strong fabric which is anchored at respective corners of the outer bag and the underlying inner bag. This action further serves to anchor the inner bag in a fully laid out position within the outer bag. As desired, other loops may be tacked to the outer bag and inner bag at spaced apart locations along their overlying side and/or end margins. In any event, when assembled, desirably, the inner bag will lie flat and will be retained in its laid out flat attitude within the closed outer bag. In the assembled outer and inner bags, each of the loops includes a distal end which projects beyond its respective outer margin of the closed outer and inner bags and is not materially inhibited from flexing.
A quantity of powdered superabsorber is placed within the inner bag prior to closing of the inner bag, irrespective of how the inner bag is closed. This powder preferably merely lies loose within the inner bag such that the powder is free to uninhibitedly migrate of disperse to substantially any or substantially all locations internally of the inner bag.
An alternative method for assembly of the outer and inner bags with the superabsorber may include the steps of (a) forming an outer bag which is closed about its first and second opposite sides margins and at one of its opposite first and second ends, (b) in similar manner forming an inner bag which is closed about its first and second opposite side margins and at one of its opposite first and second opposite ends, (c) providing a quantity of a superabsorber in powder form, (d) placing the superabsorber powder into the inner bag, (e) disposing the inner bag inside the outer bag, (f) closing both the open end of the outer bag and the open end of the inner bag to effectively seal the powdered superabsorber within the inner bag, hence within the outer bag.
In one embodiment, the method may take the form of laying out a sheet of fabric suitable for the outer bag, providing a sheet of fabric suitable for the inner bag and which includes one or more loops projecting from one or more of the corners of the inner layer of fabric, overlaying the inner sheet fabric in register with the sheet of outer bag fabric, overlaying a quantity of superabsorber onto the sheet of inner bag fabric, simultaneously overfolding the outer bag and inner bag fabrics back upon theirselves, capturing the superabsorber therebetween, and thereafter, closing all of those side and end margins of the overlying sheets of outer and inner bag fabrics which are do not involve folds. As desired, the folded side or end margins of the outer bag and inner bag fabrics may also be included in the margin sealing process. Sealing of these fabric margins may be by stitching, for example employing a chain stitch, lock stitch or a serging stitch, the latter being capable of cutting away dangling cut ends of either the outer bag or the inner bag fabrics as the closures are made. In any event, preferably, the closing operation is carried out in a manner which does not leave or create internally of the inner bag a substantial stricture or barrier to the ready migration of the powdered superabsorber within the inner bag. The thread employed for stitching of the outer and inner bags during their closure preferably is biodegradable, such as cotton. Other threads may be chosen as the in-use environment of the bag dictates. Preferably, the corner loops of the bag of the present invention are placed and anchored at the corners of the outer and inner bags in the course of closure of the outer and inner bags.
In one embodiment, the outer bag of the present invention is formed from a 12 oz coarsely-woven jute, flax or hemp burlap fabric. To form one outer bag, a rectangular sheet of burlap measuring about 24 inches long and about 36 inches wide is provided. In this embodiment, the inner bag is formed from a 2×2 twill weave of 100% cotton yarn and 118 warp yarns/inch and 60 weft yarns/inch. This woven material is exceptionally strong and exhibits a very smooth surface which permits ready migration and/or dispersion of the powdered superabsorber within the inner bag when the superabsorber is dry so that as the bag is deployed in use, a relatively small amount of handling of the dry bag will result is good distribution of the superabsorber over the internal volume of the inner bag. Such distribution of the superabsorber has been found to enhance the rate of expansion of the superabsorber when water enters the inner bag. The strength factor of the inner bag is selected to provide maximum containment of the superabsorber when it expands upon entry of water into the inner bag. The close weave of the inner bag fabric is important as respects its contribution to the strength of the inner bag as the inner bag expands upon hydration. Moreover, this inner bag construction provides for maximum containment of the powdered superabsorber both in an initial use and then, again, when reused multiple times. Additionally, it has been found that this inner bag does not puncture when, for example, a length of rebar is driven through the assembled bag as a anchor for aiding in the retention of the water flow control bag in use.
The dimensions of the inner bag preferably are at least substantially the same as, but not materially greater than, the dimensions of the outer bag, so that when the respective sheets of the outer bag and of the inner bag are laid out atop one another, their peripheral margins are substantially in register. It will be recognized, however, that the dimensions of the inner bag must not be so much larger than the dimensions of the outer bag that upon expansion of the hydrating superabsorber, the inner bag develops folds, wrinkles or the like which would tend in inhibit substantially evenly distributed expansion of the superabsorber. As noted above, alternative methods of disposing the inner bag within the outer bag may require selection of alternative relative dimensions of either the inner bag and/or the outer bag.
In one embodiment, the superabsorber material may be identified by the formula:
where n is a number approaching or exceeding as much as one million and R is an absorbancy enhancer such as sodium.
The superabsorber employed in the present invention is in a powder form comprising individual particulates 42 ranging from about 100 to 500 μm diameter. The particulates preferably are generally spherical either individually or in small generally spherical clusters 44. By reason of this geometry of the particulates, the superabsorber powder readily migrates within the inner bag, merely as a function of gravity and/or physical movement of the assembled bag. Such migration may be enhanced with relatively little manipulation of the inner bag, such as by routine handling of the outer bag/inner bag/superabsorber assembly. Such ready migration within the inner bag by the superabsorber aids in ensuring minimization of “build ups” of powder at one or more locations within the inner bag. Such build-ups are further inhibited by reason of the side and end stitching mode for closing of the inner bag. Further, the superabsorber of the present invention has a melting point in excess of 500 degrees F., is biodegradable, not subject to known Hazmat handling requirements, and is not objectionable under known environmental control regulations.
In one embodiment of a water flow control bag of the present invention having laid out flat rectangular dimensions of 24 inches by 36 inches (developing a completed outer bag having rectangular dimensions of 24 inches by 18 inches, there is deposited about ⅓ cup of powdered superabsorber of the present invention. The superabsorber of the present invention exhibits a water takeup value of at least 500 grams of water per gram of superabsorber. Such water takeup is rapid, consuming about 2. 49 minutes for about ⅓ cup of powdered superabsorber to expand to the extent that the water flow control bag of the present invention will block the flow of water through the bag and will divert flowing water around the bag.
In accordance with one aspect of the present invention, at least one, and more commonly, a plurality of the water flow control bags of the present invention are positioned in the path of flowing water to effect a blocking or directional diversion of such water flow. To this end, in one embodiment, each bag includes an anchoring loop anchored in each of the four corners of the assembled outer and inner bags. In one embodiment, these loops are anchored to the corners of the inner bag and project outwardly from the outer bag at its corners, thereby providing for ready access to the loops. As desired, the loops may be anchored to the corners of the assembled outer and inner bags, but in any event, the loops are exposed externally of the assembled bag so that they are available for use in assembling of a multiplicity of bags in a gang, stack or other array as dictated by the type of water flow control environment encountered. For example, several bags may be tied together in end to end relationship to provide an elongated barrier to water flow. Multiple layers of such interconnected bags may be employed when greater height of the barrier is required.
In another aspect of the present water flow control bag, the bag may be anchored to a selected location on the ground or other surface employing a rebar rod driven through the bag and into the underlying surface to thereby anchor the bag in place. By reason of the construction of the woven cotton fabric of the inner bag, the inner bag readily permits the passage of the rebar through the inner bag without rupture of the inner bag or development of a permanent opening through the inner bag through which powdered superabsorber may escape from within the inner bag. Upon removal of the rebar anchor, the fabric of the inner gab merely closes in as the rebar is withdrawn, sealing the opening created by the entry of the rebar into and/or through the inner bag.
As noted, when in their dry state, each of the bags of the present invention may be folded and stored compactly for future use. Thus, relatively large quantities of the dry folded bags may be stored in a relatively small area. When initially deploying a bag in position to block water flow, individual ones of the bags may be either anchored in place while dry or as desired, each bag may be exposed to the water flow, thereby commencing the expansion of the superabsorber prior to placement of the bag in the path of the water flow. In this latter situation, the added weight of the water absorbed by the superabsorber aids in anchoring the bag in place, thereby providing for retention of the positioned bag until the worker can prepare and deposit a further bag on an underlying bag or alongside a previously positioned bag, for example.
Irrespective of the manner in which one or more of the bags of the present invention may be positioned or anchored to block a flow of water, the rapid takeup of water by the superabsorber of the present invention causes the superabsorber to rapidly expand to substantially fill the inner bag, thereby expanding the inner and outer bags and concomitant compaction of the expanding superabsorber. This action renders the bag essentially impervious to flow of water through the bag, resulting in the bag defining a barrier against the flow of water sought to be retained or diverted. As further expansion of the superabsorber takes place, the resistance of the bag to the flow of water therethrough is enhanced.
Upon recovery of a bag of the present invention following its use as a barrier against water flow, the bag may be dried, such as by exposing the bag and its expanded contents to sunlight. This drying process returns the superabsorber of the present invention to its initial powdered state within the inner bag. Thereafter, the bag may be folded, stacked or otherwise stored for future use. The bags of the present invention have been determined to be reusable in this manner for up to five times without material loss of effectiveness of the bags as a barrier to water flow.
In those instances where the bags of the present invention are not readily or even possible to be recovered, the present bags, being biodegradable, may be left in their barrier positions until they eventually harmlessly disintegrate. In similar manner, after a bag of the present invention has served out its useful life, it may be disposed of in a conventional garbage dump.
Whereas the present invention has been described herein employing examples and specific data, as the context makes clear, one skilled in the art will recognize various acceptable modifications or substitutions which do not deviate from the scope of the present invention. It is therefore intended that the invention be limited only as set forth in the claims appended hereto.
