The present invention relates to water absorbing and retention bags which can be utilized with, or in place of, sand bags for such uses as flood control, amongst others.
U.S. Pat. No. such as 6,715,960 and probably others in Class 405/114 describe super absorbent polymers (SAPs) utilized in a bag for flood control. However, the applicant has found that when testing products available on the market, the SAPs in the bags normally have a molecular weight less than one (i.e., they float), and they have a tendency to have extremely poor desorption characteristics.
Floodbloc is a company selling a product with a bag available on the market which has an SAP with a molecular weight greater than one, and improved desorption characteristics over many other alternatives. However, the bag as being provided today is believed to have room for at least significant improvement.
An improved water absorbing and retention bag is believed to be advantageous for many applications.
It is an object of the present invention to provide improved bag constructions over prior art constructions.
It is another object of the present invention to provide bag materials for at least some embodiments which at least assists in providing improved desorption characteristics.
It is another object of at least some embodiments of the present invention to provide a bag which receives a pellitized SAP of known characteristics.
It is another object of at least some embodiments of the present invention to provide a bag which has serged stitches which resist unraveling and/or separating.
It is another object of at least some embodiments of the present invention to provide a bag having loops extending from sides of an exterior bag formed with bands stitched about the bag, possibly in the narrower dimension.
It is yet another object of at least some embodiments of the present invention to provide a bag having a “firm pillow” inflation upon taking on water which facilitates stacking like sand bags preferably at about 40 pounds of weight while minimizing leakage around bags. See graph of
It is still another object of at least some embodiments of the present invention to invert at least the inner bag, if not both an inner and an outer bag after serging at least one of a side and an end to assist in potentially preserving the stitched portions.
Accordingly, in a preferred embodiment of the present invention, a bag is preferably created with a first or inner bag configured to retain a preferred SAP therein. The SAP utilized preferably provides an absorption ratio of SAP to water of about 1/500. The SAP may be pelletized as one or more pellets and provided in a known amount to achieve a desired inflation of the inner bag with a desired weight. 31.5 grams of SAP as provided either as a single pellet or as a powder have been found to provide a “firm pillow” upon taking one water which sufficiently plugs leaks and provides stackability similar to sand bags.
With a sheet of material such as 24×28 inches folded in half so that it is 24×14 inches. The side opposite the fold may be sewn (such as with serge stitching) as well as one of the two open ends. The SAP may then be inserted. An outer or second bag may then be constructed similarly, if not bought premade, but is preferably constructed out of different material. The outer bag may be 14×26 inches or other appropriate dimension when laid out flat.
The inner bag may be a China twill such as 108×56 (weft and warf) with a 32 mesh weave and 100% cotton twill. The outer bag is 9 ounce woven jute material. Air permeability is preferably 28 or greater. The outer bag is preferably provided with an open end. Twill bands or tape encircles the front and back of the outer bag and is sewn to provide two loops (i.e., one on either side of the bag, one at the fold side, the other at the stitched side opposite the fold) near the sewn end of the outer bag. The inner bag with the SAP is inserted in the outer bag and the open end of the inner bag may be somewhat closely aligned with the open end of the outer bag and folded down over itself together with the open end of the outer bag. Another band of twill may be run over the fold and the folded end with tape is preferably surged to provide loop handles while sealing the inner bag inside of the outer bag with the palletized SAP contained and sealed within the inner bag. The loops may then be cut to provide strands for assisting in connecting bags or other structure to the bags.
The particular features and advantages of the invention as well as other objects will become apparent from the following description taken in connection with the accompanying drawings in which:
In accordance with a presently preferred embodiment of the present invention, an improved bag 10 can be provided as shown in
Serge stitches 22,26 have been found to be particularly effective over other stitching methods for many embodiments. In some embodiments other stitches have had a tendency to spread apart, and then separate allowing expanding or expanded SAP to escape the inner bag 12. Of course, either embodiments may use other stitching options.
A premade outer bag 30 such as a 9 ounce woven jute material may be employed, or otherwise fabricated as shown in
Loops 40,42 are formed with tape or band, such as twill band 44 which may be sewn to the outer bag 30 toward closed end 36. The band 44 preferably encircles the front and back of the outer bag 30 and may be top stitched to the outer bag 30. Loops 40,42 may have a length of six inches or other dimension and may be cut into straps after forming the loops to facilitate tying the outer bag 30 to other bags 30 or structures. Twill tape 44 may have a length of about 53 inches prior to encircling the outer bag 30 as shown, and then being sewn as shown. It is preferable not to entrap the inner bag 12 to the outer bag 30 when stitching the twill tape 44 to the outer bag 30 at the closed end 36 but could be done in some embodiments.
Twill tape 52 may be sewn to the outer bag 30 such as with topstitch as shown. Loop handles 54 may preferably be formed in somewhat of a similar manner as loops 40,42 were formed at the other end with tape 44.
The material selection for the inner bag 12 and outer bag 30 has been performed with trial and error based on desorption characteristics of the SAP employed. Specifically with the SAP utilized, a 10-14 day desorption rate is achieved as long as the humidity remains at or under 60%. At least some other materials tested maintained the SAP moist longer thereby creating desorption issues. The SAP utilized has a molecular weight greater than one, such as 1.6.
31.5 grams of SAP water as particulate 46 or pellet(s) 48 with an absorption ratio of 1/500 has been found to satisfactorily fill up the volume of bag 10 to provide a “firm pillow” feel which also has a weight of about 40 pounds (that normally specified for sand bags). The firm pillow feel allows the bag 10 to fill and plug leaks in a preferable manner. Too inflated causes leakage issues against adjacent bags. A lack of inflation can also cause the bags to leak at adjacency areas.
Another advantageous embodiment provides for the inversion of at least one of the inner or outer bags 12,30 after stitching the side and end 18,24 and/or 34,36. By turning at least one of the bags 12,30 inside out, there is less of a chance of stitching coming unraveled or disengaged from the appropriate bag 12,30. Furthermore, serging the stitches has been found to assist in many embodiments.
After using the bags 10, the bags 10 can be desorbed and stored for future use. The cycle life of bags 10 is not normally intended to be indefinite, but may more likely be 2-5 cycles in some embodiments. The SAP may also be rendered inert with the application of a high pH bath which can break down bonds prior to disposal in a landfill.
Bags 10 can be utilized for many applications. If pre-wetted bags 10 may not absorb much, if any, contaminants in the environment. Furthermore, rinsing off the bags 10 after use, may prevent any contaminants from entering the SAP.
Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to the preferred embodiment of the invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims.
Having thus set forth the nature of the invention, what is claimed herein is:
This application claims the benefit of U.S. Provisional Patent Application Nos. 61/174,523 filed May 1, 2009 as well as 61/174,232 filed Apr. 30, 2009. Furthermore, this application is a continuation in part of U.S. patent application Ser. No. 11/549,333 filed Oct. 13, 2006.
Number | Date | Country | |
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61174523 | May 2009 | US | |
61174232 | Apr 2009 | US |
Number | Date | Country | |
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Parent | 11549333 | Oct 2006 | US |
Child | 12770198 | US |