Patent Grant
12151878
Not applicable
Not applicable
The present invention relates to a bulk bag with heat sealed joints that includes a baffle insert that is also coupled within the body of the bulk bag using heat sealing. More particularly, the present invention relates to a stitchless bulk bag that includes a baffle insert that is coupled to the body of the bag with a hot melt coupler, e.g., preferably hot melt film, using a heat sealing process. The baffle insert includes tab portions that extend from longitudinal members of the baffle insert and in between lateral straps of the baffle insert.
Many industries exist in which large quantities of materials or products must be contained and transported. Such materials or products can be free-flowing, making it necessary to fully support the entire volume of the materials or products. Industries that deal with storing and transporting such dry, flowable products, e.g., sand, fertilizer, granules of plastic, powdered chemicals, carbon black, grains and food products use what are known as flexible intermediate bulk containers (FIBC), also known as bulk bags, industrial bags, or big bags. The bags are generally made from flexible fabric, typically woven polypropylene or polyethylene fabric. For example, the bags can be made from 5 oz per square yard woven polypropylene fabric. Traditionally in the prior art, the bags have been assembled from multiple pieces of flexible fabric and sewn together with stitched seams.
The present inventors, however, previously have developed a heat sealing process to create bulk bags without any stitched seams or stitch holes at least in a containment area of the bags, e.g., at joints/connections of a body portion to a top portion, body portion to a bottom portion, top portion to a top spout, and bottom portion to a discharge tube or discharge tube assembly. Stitchless bulk bags are advantageous to use because there are no stitch holes in a containment area of the bag so material contained in the bag does not sift out of any stitch holes and contaminates do not enter through stitch holes. These bags therefore also eliminate the need for including expensive liners in the bag to avoid material sifting out through the stitch holes. The following patent applications of the same inventors and/or Assignee discuss various preferred embodiments of a bulk bag including heat sealed joints, and methods of manufacture therefor, each of which is hereby incorporated herein by reference:
In the FIBC or bulk bag industry, it is generally preferred for bulk bags to be constructed in a square shape given that this shape allows for more efficiency and saved cost in manufacturing, and also given that these bags typically are transported on square pallets. When a square bulk bag, however, is filled with material, a rounding of the bag occurs and bulges form at the side walls. This prevents multiple bulk bags from being positioned as close together as they could be if they had straight side walls, which means storage space is not maximized. This also causes problems when the bags are stacked on top of one another as the bulges and imbalances in the bags can cause sagging, preventing a bag from having a level, or substantially level, top surface to stack another bag upon.
Bulk bags started to be constructed including longitudinal panels of fabric sewn across corners of the bag, from one sidewall to another, such that a triangular shape space is formed at the corners of the bag. In the industry, these longitudinal panels are sometimes called baffles, and the bags including this feature are referred to as baffle bags. Reference is made to U.S. Pat. No. 5,468,528, which is incorporated herein by reference, as an example of this type of baffle bag. The longitudinal baffle panels typically have cut-outs therein to allow the flow of material into the triangular shaped area at the bag corners. Including the longitudinal panels at the corners helped to reduce the rounding of the bag when it was filled with bulk material. The panels with the cut-out holes are sewn inside the bag, across each corner to prevent the bag from fully rounding out.
A sewn baffle bag currently on the market that is being sold by the Assignee, Ameriglobe, LLC, of the present application has baffles formed by lateral straps, with spaces in between the lateral straps, that simply cut across the four corners of the bag. The lateral straps can be spaced in between longitudinal panels. The straps pull across the corners to lessen the rounding effect of the bag when it is filled with product which essentially gives a corner rounded square shape to the bag. The spaces in between the straps allow the product to flow into the rounded corners. The longitudinal panels are sewn to the side walls.
Some other prior art bags include a net baffle which is formed in panels but only has small strings from side to side versus fabric with holes cut out.
U.S. Pat. Nos. 5,618,255 and 5,649,767 discuss use of heat sealing to join baffle strips of fabric to a bag liner, and the bag liner is then simply inserted into a bulk bag, or tape portions can be added to the liner and sewn into seams of a bag. The outer bag is made of woven polypropylene which is very strong. The inner baffled liner is made of film polyethylene which has a lot of stretch and is not nearly as strong. Sometimes during the stacking of these lined bags, the stretchiness of the liner will allow the bag to bulge out beyond the intended dimensions. It takes an amazing amount of labor to make the liner. This labor is in a completely separate construction area that is separate from the construction of the bag it will be attached to. Liners are often attached to the bag using a sewing method. The liner may have to be removed before the outer bag can be recycled. The liner is not considered to be re-useable where the costing of the bag is considered to be re-usable. To make the liner strong enough, the amount of polyethylene used is very thick, which is expensive. Next is the need to hand make each liner which leaves open the potential for mistakes. Another issue is the security of its attachment to the bag. As mentioned, the liner can be simply inserted into a bag without being coupled to the bag. Sometimes it can be attached in critical areas, but this is done by sewing small pieces of tape that have been adhered to the liner into the bag seams. These sewn connections can and have failed at times during use.
There is a need in the art for a baffle bulk bag that includes baffles that can be coupled to a bulk bag without stitching.
There is also a need in the art for a baffle bulk bag that includes baffles that can be coupled to a bulk bag interior surface without including a heat seal coating on a bulk bag interior surface. Under the method as described in U.S. Pat. No. 10,112,739, a heat sealing coating can be VERSIFY™ 3000 (Trademark of The Dow Chemical Company), or other suitable propylene elastomer or plastomer coating with a melting point lower than the melting point of the polypropylene fabrics. A heat sealing coating can also be a standard polypropylene fabric coating, e.g., of the type typically applied as a laminate coating to an exterior of polypropylene fabric used to make a bulk bag that can have a majority percentage of polypropylene and a small percentage of polyethylene. Under the method as described in U.S. Pat. No. 10,112,739, a propylene elastomer or plastomer coating on one bag portion can be joined to another propylene elastomer or plastomer coating on another bag portion or to a standard polypropylene fabric coating on another bag portion.
There is also a need in the art for a baffle bulk bag that includes baffles that are heat sealed to a bag and without including a separate bag liner.
A preferred embodiment of the apparatus of the present invention is a bulk bag constructed with heat sealed joints that includes a baffle insert that is coupled to an interior surface of the bag with heat sealed joints. A heat sealed bulk bag of the present invention preferably includes a fill spout, top portion, body portion, bottom portion and discharge tube.
In one or more preferred embodiments, four individual baffle inserts can be inserted into a body portion of a bulk bag to make a baffle bulk bag. Each individual baffle insert can have a pair of longitudinal panels with a plurality of straps spaced in between the longitudinal panels. Preferably a tab portion extends from the longitudinal panels in the space in between the plurality of straps above and below the straps. Each baffle insert is preferably coupled to adjacent side walls of the bag body such that when the bag is in an expanded or filled configuration, the first longitudinal panel and set of tabs are coupled to one side wall, and the second longitudinal panel and set of tabs are attached to the adjacent side wall with the straps extending across a corner of the bag body along a diagonal, e.g., at or about at an angle of 30 to 45 degrees, forming a triangular shaped space behind the straps at the bag corner.
In other preferred embodiments a baffle insert can have an irregular tubular shape that preferably includes four longitudinal panels with a plurality of lateral straps spaced apart along a longitudinal length of the longitudinal panels and with spaces in between the straps. A plurality of tab portions extend from the longitudinal panel into the spaces in between the straps above and below the straps. The longitudinal panels can have a substantially rectangular shape with the lateral straps preferably extending in between two said longitudinal panels along a diagonal. For a tubular baffle insert, the baffle insert preferably is positioned within the body of a bulk bag so that when the bag is in an expanded configuration, or a filled configuration, each longitudinal panel is coupled to the body about centrally on a body side wall such that the lateral straps can cut across the corners of the body portion along a diagonal, e.g., at or about at an angle of 30 to 45 degrees, forming a triangular shaped space behind the straps at the bag corner.
With both the individual baffle insert portions and the tubular baffle insert portion, a portion of the longitudinal panel and the tabs of the baffle insert preferably include hot melt glue thereon, preferably in film form, which can be used to couple the baffle insert to the body interior surface using a heat sealing process where heat and pressure is applied to the body portion overlapped with the baffle insert, with the hot melt film in between body interior surfaces and baffle insert exterior surfaces to be joined.
A hot melt film used in the present invention preferably meets government “contact food grade” standards. A hot melt film of the present invention can be a Hot Melt Film Product no. HS 410 available from Cattie Adhesives out of Quakertown, PA, with the following product information/specification.
Cattie Adhesives PRODUCT: HS 410 transfer from 42 #Silicon liner
PRODUCT HS 410 transfer from 42 #Silicon liner is an EVA type heat seal adhesive self-wound on a 42 #silicon liner that is transferable from the silicon liner. Adhesive HS 410 has a wide range activation temperature with good adhesion to a variety of substrates including metals, coated films, papers and plastics.
Adhesive:
Although the Hot Melt Film Product no. HS 410 available from Cattie Adhesives was specifically formulated for use in metals, in experimentation it was found to work particularly well in heat sealing a baffle insert to a bag body under one or more preferred embodiments of the present invention.
In the sewn baffle bag that currently is being sold by Ameriglobe, LLC, the baffle straps, with spaces in between the baffle straps, cut across the four corners of the bag. The straps pull across the corners to lessen the rounding effect of the bag when it is filled with product which essentially gives a corner rounded square. The spaces in between the straps allow the product to flow into the rounded corners. In experimenting with how to make a similar baffle bag with heat sealed joints, the first challenge to overcome was that both tensile and peel forces are present at the intersection of the strap to the body. In heat sealed bulk bags produced according to one or more methods as described in U.S. Pat. No. 10,112,739B2, all the forces on bag joints in a containment area of a bag (e.g., joints joining the top to the body and the body to the bottom) are primarily in the tensile direction where a situation of needing to deal with both peel and tensile forces is not present. In developing the attachment of the lift loop assemblies as discussed in U.S. Pat. No. 10,479,599, which include a lift loop sewn to a patch, with the patch heat sealed to a bag body, the possibility that the lift loops would be mishandled by pulling the loop horizontally to the bag rather than vertically was a concern considered. Heat seals were included in areas of the patch beyond the attachment of the sewn lift loop to help overcome this concern. The peel concern with the lift loop was only if it was mishandled and there was not constant peel forces exerted on the connection. With the baffle straps, however, peel force is in existence at all times when a bag is full of bulk material.
A first attempt to counter the peel used adhesives for the tab. But adhesives stretch and deform when continual pull is present so this led to slow failures with the adhesives.
The second challenge was finding an attachment method to attach the baffle straps to the inside of the body portion tube. Preferred body portions for a bulk bag formed with heat sealed joints are spiral woven tubes with no seam. It is currently physically impossible to coat the inside of a body tube, e.g., with a propylene elastomer or plastomer coating or a standard polypropylene fabric coating, in any meaningful practical way. This meant that use of coatings in a heat sealing process as described in U.S. Pat. No. 10,112,739B2 was not practical if the body tube was used because an inside of the body tube would need to include a heat sealing coating.
Alternative means for forming a heat sealed joint were experimented with. It is noted that a heat-sealed joint can be formed by simply heating up plastic fabrics to at least their melting point and applying pressure to join them together. However, as discussed in more detail in U.S. Pat. No. 10,112,739, this is not preferred for bulk bags because it weakens the fabric, reduces needed flexibility and does not form a strong enough bond for what is desired and/or considered safe for use in a bulk bag that can carry 1 to 2 tons of bulk material, for example.
Hot melt glue that was dispensed in beads was experimented with, wherein the beads were applied to the baffle straps. The hot melt beads had to be heated and melted, and a way to dispense it evenly was experimented with. This type of hot melt glue was not preferred because there were variations in thickness which caused excess glue to extend out from under the fabric where it could become a contamination to the product area. These early bags failed with the straps peeling away under pressure of contents in the bags. It was thought that inconsistent dispensing of the beads possibly was a major contributor to the issue.
Hot melt glue that was available in film form was then experimented with and applied to baffle inserts. The tensile tests and peel tests were excellent and very consistent, but bags tested failed the 3-1 compression test as well as the 5-1 tests, with the baffle insert and/or straps peeling away.
It was then considered that peel forces on the strap may need to still be dealt with, and experiments were conducted where a novel tab was included in between the baffle straps. It was thought that a “tab” on both sides of the strap extending beyond the “pivot point” of the strap would counter the forces of peel. A pivot point referred to herein is the point where the straps make contact with the bag sidewalls. When a bag is flat and unfilled, the straps lie in the same direction as the side walls. As the bag is inflated or filled the straps then pivot towards the opposite corner. In a perfect square the straps and the side walls of the bag would essentially form a right triangle.
Experimentation established that including hot melt on tabs on both sides of a baffle strap increased the strength of the heat-sealed bond. For the first time a bag passed both a 3-1 compression test and 5-1 test.
In one or more preferred embodiments of the present invention, the various bag portions can be made from a flexible plastic fabric.
In one or more preferred embodiments of the present invention, the various bag portions can be made from a flexible polyester fabric.
In one or more preferred embodiments of the present invention, the various bag portions can be made from a flexible polypropylene fabric.
In one or more preferred embodiments of the present invention, the various bag portions can be made from a flexible polyethylene fabric.
In one or more preferred embodiments of the present invention, a heat sealing coating applied to a first bag portion fabric can be a typical laminate type coating for the type of fabric of the bag portion if a heat sealing coating applied to a second piece of fabric to which the first piece of fabric will be joined to is a propylene plastomer or elastomer coating.
In one or more preferred embodiments of the present invention, a heat sealing coating applied to a bag portion fabric can be a propylene plastomer or elastomer coating.
In one or more preferred embodiments of the present invention, a heat sealing coating applied to a baffle insert can be hot melt film.
In one or more preferred embodiments of the present invention, a heat sealing coating applied to a bag portion can be hot melt film.
A preferred embodiment of the apparatus of the present invention includes a bulk bag comprising:
In one or more preferred embodiments of the present invention, four baffle inserts can be included in the bulk bag at each of the first, second, third and fourth corners.
In one or more preferred embodiments of the present invention, the hot melt film extends along an entire exterior surface of each of the longitudinal members of the baffle insert.
In one or more preferred embodiments of the present invention, the baffle insert comprises four longitudinal members and comprises a tubular shape and each of the four longitudinal members are coupled to the body interior surface so that respective lateral members extend across each of the first, second, third or fourth corners of the bag along a diagonal.
In one or more preferred embodiments of the present invention, the hot melt film does not extend along an entire exterior surface of each of the longitudinal members of the baffle insert.
In one or more preferred embodiments of the present invention, during heat sealing to form the joint, the body can be in a folded gusseted configuration including a pair of body gussets and the baffle insert can be folded and overlapped with at least one of the body gussets when the heat and pressure is applied.
In one or more preferred embodiments of the present invention, during heat sealing, the body can be in a folded gusseted configuration including a pair of body gussets and two of the baffle inserts can be folded and overlapped with one of the body gussets and the other two of the baffle inserts can be folded and overlapped with the other body gusset.
In one or more preferred embodiments of the present invention, during heat sealing, the body can be in a folded gusseted configuration including a pair of body gussets and the baffle insert can be gusseted in a folded gusseted configuration including two baffle gussets and the baffle gussets can be overlapped with the body gussets.
In one or more preferred embodiments of the present invention, the tabs counter peel forces exerted on the joint when the bulk bag is filled with bulk material and/or lifted.
In one or more preferred embodiments of the present invention, the baffle insert counters both peel and tensile forces exerted on the joint when the bulk bag is filled with bulk material and/or lifted.
In one or more preferred embodiments of the present invention, said tabs that are on both sides of one said lateral member extend beyond a pivot point of said lateral member at a junction of said lateral member and the longitudinal member and counters the forces of peel encountered by the lateral member and the longitudinal member.
In one or more preferred embodiments of the present invention, each tab extends at least 2 inches laterally away from the longitudinal member and into the space above or below a said lateral member.
In one or more preferred embodiments of the present invention, said lateral members can be free and are not connected to the body portion.
In one or more preferred embodiments of the present invention, the plurality of tabs protect the joint at a pivot point located where one said lateral member that is free extends away from one said longitudinal member that is coupled to the body portion at the joint.
In one or more preferred embodiments of the present invention, the body portion is connected to the top portion and to the bottom portion with heat sealed joints.
In one or more preferred embodiments of the present invention, the body portion is connected to the top portion and to the bottom portion with stitched seams.
A preferred embodiment of the method of the present invention includes a method of forming a heat-sealed baffle body portion that is stitchless, comprising the following steps:
In one or more preferred embodiments of the present invention, during heat sealing in step (f) an upper heat seal bar of a heat seal machine rocks in an end to end or lengthwise direction and a mating lower seal bar rocks in a side to side or widthwise direction to facilitate even heating through overlapped layers, even in areas where fabric thicknesses differ.
A preferred embodiment of the apparatus of the present invention includes a stitchless baffle body portion comprising:
A preferred embodiment of the apparatus of the present invention includes a heat sealing method of manufacturing a baffle bulk bag comprising the following steps:
In one or more preferred embodiments of the present invention, the top portion, body portion, baffle insert and bottom portion are made from flexible plastic fabric or polyester fabric.
In one or more preferred embodiments of the present invention, the top portion, body portion, baffle insert and bottom portion are made from flexible polypropylene fabric.
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;
A second preferred embodiment of the apparatus of the present invention, designated generally herein by the numeral 50, is shown in
Referring to
A fill spout 1 can have opening 55. A top portion 2 can have opening 11. A baffle insert 4 can having opening 12. A body 3 can have opening 13. A bottom insert or reinforcer 5 can have opening 14. A bottom 6 can having opening 15. A discharge tube 7 can have opening 16.
Preferably a baffle bulk bag 10, 50 is manufactured so that joints between fill spout 1 and top 2, between top 2 and body 3, between body 3 and bottom 6 and between bottom 6 and discharge tube 7 are formed via a heat sealing method. If a bottom insert 5 is included, preferably the joint coupling an insert 5 to bottom 6 and discharge tube 7 is also formed via a heat sealing method. Preferably the said joints are all formed via heat sealing so that a containment area of the baffle bulk bag 10, 50 does not include any stitch or sewing holes. A baffle bulk bag 10, 50 can also include one or more lift loop assemblies, wherein preferably a patch 52 of a lift loop assembly is joined to an exterior of a bag body 3 with a heat sealed joint. A lift loop assembly can include a patch 52 with a lift loop 51 stitched to patch 52 or heat sealed to patch 52 (see, e.g.,
A baffle insert 4 of either the first or second preferred embodiments of a baffle insert of the present invention as shown in
A preferred width ratio of tab 17 to strap 9 width is 1.3 inch. For example, under a current most preferred embodiment, there is a 1.5 inch tab 17 width at base of a tab 17 to 2 inch strap 9 width at a base of strap 9, and this is the currently most preferred strap 9 width and ratio of tab 17 (and space 29) width to strap 9 width. This ratio can change due to increased adhesion ability of a hot melt film 21. If the adhesion ability of hot melt film 21 increases, then tab 17 width can decrease in relationship to strap 9 width. On the other hand, if the adhesion ability of hot melt film 21 decreases, then tab 17 width would need to increase. With the current preferred formulation of hot melt film 21 using a hot melt film from Cattie Adhesives, this ratio can vary up to 10%. As long as this ratio is maintained, the number of straps 9 can increase or decrease per linear foot without materially affecting the overall strength of a bag 10, 50. For example, if straps 9 are spaced too far apart a bag 10, 50 will try to round out more between the straps 9 than if straps 9 are closer together.
A plurality of tabs 17 extend from each longitudinal panel 8 in a lateral direction into a space 29 that is in between two straps 9. Preferably a tab 17 is located above and below each strap 9 at both ends of each strap 9. Thus, as shown in the figures, some tabs 17 are also located above the topmost straps 9 and some tabs 17 are also located below the bottommost straps 9. A topmost tab 17 can extend to top 27 of a longitudinal panel 8. A bottommost tab 17 can extend to bottom 28 of a longitudinal panel 8. Referring to
Referring now to a second preferred embodiment of a baffle bulk bag, designated by the numeral 50, a plurality of baffle inserts designated by the numeral 40 (instead of a single tubular baffle insert 4) are included in a baffle bulk bag 50. A third preferred embodiment of a baffle insert, designated by the numeral 40 is shown in
A fourth preferred embodiment of a baffle insert is designated generally by the numeral 40 in
A baffle insert 4 or 40 can be made of the same flexible plastic fabric as body 3, e.g., preferably uncoated (e.g., without a laminate type coating or other heat sealing coating, e.g., a propylene plastomer or elastomer coating, thereon), woven polypropylene fabric. Preferably, instead of using a heat sealing coating as described in the applications incorporated herein by reference, hot melt 21 film is applied to desired portions of an insert 4, 40.
The shape of straps 9 can be changed if desired, e.g., straps 9 can have a shape of the first or second preferred embodiments of baffle insert 4, or of the third or fourth preferred embodiment of a baffle insert 40, or another desired shape. A shape of a strap 9 included in a baffle insert 40 can also be included in a baffle insert 4 and vice versa. But, in all embodiments of a baffle insert 4 or 40, preferably at least some space 29 is left in between straps 9 to enable bulk material contained in a baffle bulk bag 10 or 50 to flow through the spaces 29 and fill corners 20 of a baffle bulk bag 10 or 40.
Portions of exterior surface 25 of a longitudinal panel 8 or 80 and exterior surfaces 31 of tabs 17 of baffle insert 4 or 40 are preferably coupled to an interior surface 26 of body 3 via a heat sealing method as shown in
In
When baffle insert 4 is coupled to body 3, preferably each longitudinal panel 8 is positioned about centrally on a body 3 sidewall 33, 34, 35, or 36 and the straps 9 extend across corners 20 at a diagonal, e.g., preferably at an angle of, or between, about 30 to 45 degrees from one side wall, e.g., side wall 36, to another side wall, e.g., side wall 33 (see
Along right and left sides of longitudinal panel 8, hot melt 21 film can be applied longitudinally, e.g., preferably at about a two-inch width (designated by arrows 24 in
Preferably, hot melt 21 in film form is applied continuously to an entire exterior surface 31 of a tab 17 along a length of tab 17 (designated by arrows 23 in
Preferred heat sealing methods of heat sealing the first, second, third and fourth preferred embodiments of a baffle insert 4, 40 to bag body 3 will now be discussed.
In
Baffle insert 4, in a folded/gusseted heat sealing configuration as shown in
Body 3 in gusseted configuration as seen in
When heat sealing baffle insert 4 to body 3, the baffle insert 4 is inserted into body 3 with gusset 41 of baffle insert 4 overlapped with gusset 69 of body 3, and with gusset 42 of baffle insert 4 overlapped with gusset 70 of body 3. Preferably the overlapping occurs so that hot melt 21 film on tabs 17 and longitudinal panel 8 is in contact with interior surface 26 of body 3 and aligned about centrally on a side wall of body 3 whether the sidewall is on a top layer of fabric, bottom layer of fabric, or part of a gusset in the folded configuration.
The overlapped baffle insert 4 and body 3 can be moved into a heat sealing machine 110 wherein heat seal bars, e.g., upper and lower heat seal bars, can move into contact with top and bottom surfaces of the gusseted and overlapped body 3 and apply heat and pressure to melt the hot melt 21 film that will then join body 3 to tabs 17 and longitudinal panel 8. Preferably a temperature of about 275 degrees Fahrenheit and about 90 second dwell time is used during heat sealing. Since the body 3 is fully gusseted, a single pair of seal bar assemblies 101, 102 can be used to heat seal a baffle insert 4 to body 3 at all four corners. After heat sealing to form joints 32 coupling body 3 to baffle insert 4 a baffle body 140 is formed and baffle body 140 can open up or expand to a configuration as shown in
Four baffle inserts 40, either of the third preferred embodiment as shown in
When using baffle inserts 40 to form a baffle bulk bag 50, four baffle inserts 40 can be coupled to body 3 across corners 20 of body 3. Hot melt 21 in film form is preferably applied onto exterior surface 31 of tabs 17 and an exterior surface 25 of longitudinal panels 80 for four baffle inserts (one to extend across each corner 20 of body 3) in the shaded area as shown in
A baffle insert 40 as shown in
A carrier plate 150, described further below herein, can be adapted to also receive the overlapped body 3 and baffle insert 4, 40 if desired and to be moved into heat seal machine 110 during heat sealing. Stops and/or guides can be added to heat seal machine 110 to receive a carrier plate 110 and facilitate proper alignment of an overlapped body 3 and baffle insert 4 or 40 in a machine 110.
In
In
Heat and pressure applied to exterior surface 98 of body 3 from heat seal bar assemblies 101, 102 will travel below exterior surface of body 3 through all the layers of fabric of body 3 and baffle insert 40 and holt melt 21 while in folded/gusseted configuration and overlapped together as shown in
A baffle insert 4, 40 preferably is sealed within a body 3 without overlapping with other bag portions. A baffle body 140 having a body 3 with a baffle insert 4, 40 coupled thereto can then be put into a heat seal assembly line production method as described further below to complete a baffle bulk bag 50.
A baffle heat seal machine 110 as shown in the figures includes a table 111 having legs 112. A top 105 of table 111 is adapted to accommodate the pair of lengthwise heat seal bar assemblies 101, 102, each having upper and lower seal bars 95 and includes openings 120. A pair of frames or bridge assemblies 113 can support pneumatic cylinders 114 adapted to raise and lower upper heat seal bars 95. Air tubing or lines 115 can connect a pneumatic cylinder 114 to a heat seal bar 95. Water lines or tubing 116 can be included as part of a heat seal bar 95 to enable cooling of heat seal bars 95 during a cool down time of the process, after applying heat and pressure to a body 3.
A bar code reader 117 can be included if desired. Guide edges 106 and end stop 107 can also be included on the machine to help position and assure proper alignment of a gusseted body 3 with baffle insert 4, 40 overlapped therewith in the machine, e.g., to ensure a body 3 with a baffle insert 4 or 40 overlapped therewith is in proper position in a baffle heat seal machine 110 wherein heat seal bar assemblies 101, 102 are properly aligned above and under the area to be heat sealed. As described, a body 3 and overlapped insert 4, 40 can be manually placed in a machine 110 and guide edges 106 and end stop 107 can be used to ensure proper alignment of the overlapped body 3 and insert 4, 40 with the seal bar assemblies 101, 102. The heat seal bar assemblies 101, 102 can be positioned at about sixteen (16) inches from center to center in a heat sealing machine 110. If desired, a baffle carrier plate that is similar to a carrier plate 150 can also be used to properly place a body 3 and overlapped insert 4, 40 in a machine 110 and guide edges 106 and end stop 107 can be adapted and moved if necessary to ensure proper alignment of a baffle carrier plate with the body 3 and overlapped insert 4, 40 thereon with heat seal bar assemblies 101, 102. To make a baffle carrier plate or carrier, openings 151 can be adjusted and changed to accommodate baffle heat seal bar assemblies 101, 102, for example.
Referring to
In the heat sealing machines of U.S. Pat. No. 11,338,527, for example, it was preferred, and only necessary to have an upper heat seal bar have a rocking motion when using heat seal bars that were two inches wide to facilitate even heat sealing over different thickness areas of a piece of fabric. During experimentation when using a wider heat seal bar 95 that is four inches wide for example, it was found that the increased width increased a chance of mis-alignment of upper and lower heat seal bars 95 due to fabric thickness variations. In general, an impact of the fabric thickness variations is a direct function of width. For heat sealing baffle inserts 4 or 40 to a body 3, it is preferred to have a lower seal bar 95 rock in a widthwise or side to side direction while an upper seal bar 95 is rocking in a lengthwise or end to end direction into alignment with the lower seal bar 95 using a slotted yoke bracket and pivot yoke bracket as described in U.S. Pat. No. 11,338,527, for example. Upper seal bars 95 also preferably can be raised to an open position, e.g., when not performing a heat sealing function, e.g., in a manner as described in U.S. Pat. No. 11,338,527. The view as shown in
A heat seal bar 95 can be the same or similar to a seal bar as disclosed in U.S. Pat. No. 11,338,527 (e.g., see in particular
Preferably a width of a heating element on a heat seal bar body 97 can be about 4 inches to enable heat sealing about a 2-inch width portion of a longitudinal panel 8 or 80 to a body 3 as well as tabs 17 to body 3 having about a 2-inch length. The width of a heating element can also be about 1 to 6 inches, for example if desired, depending on the width of the area of a baffle insert 4 or 40 to be heat sealed. A length of a heating element can preferably be about 76.6 inches long, or 50 to 100 inches long for example, depending on the length of a baffle insert 4 or 40. A height of a seal bar 97 can be about 2 to 3 inches.
A heat seal bar 95 can have a heat seal bar body 97 having seal bar ends 121, 122. A plurality of openings 123 can be included on each side of a heat seal bar body 97 for receiving a plurality of water lines or tubes 116. A plurality of openings 124, 126 can be included on ends 121, 122 of heat seal bar 97 for receiving a desired fastener 127, 128, 181, e.g., springs, nuts, pins, and washers, screws bolts for coupling end caps 125 to each heat seal bar end 121, 122. An end cap 125 can have a plurality of openings 180 for also receiving a fastener 127, 128, 184. A heating element (not shown) is also included in a heat seal bar 95 with an insulator (not shown) in between the heating element and heat seal bar body 97. Reference is made to U.S. Pat. No. 11,338,527 and U.S. patent application Ser. No. 17/330,668 for more information on heat seal bar components.
If using a heat seal bar apparatus as disclosed in U.S. patent application Ser. No. 17/330,668, then heat seal bar 95 can include a body portion 97 that is shaped according to a desired bag joint shape. An insulating pad (not shown) and a protective sheet 139 can be in between a body portion 97 and heating element. A cover can be on top of heating element. A heating element is also preferably shaped according to a desired bag joint shape. End plates or end caps 125 can be included. End plates or end caps 125 and a heating element can be coupled to the heat seal bar body 97 with a desired fastener assembly, e.g., springs, nuts, pins, and washers. A cover can be coupled to a heat seal bar body 97 with screws, or other desired fasteners. Bumpers and clips can also be coupled to a heat seal bar body with screws. Bumpers are preferably in position to provide a bumper, e.g., for a carrier plate 150 or a baffle carrier plate if used. Cooling lines 116 can also be included on a heat seal bar body 97, which can be coupled to a heat seal bar body 97 with a desired fastener, e.g., with an elbow, screws, and tie holder, or with another desired fastener. A calibration sensor, electrical lines and power wires for connecting transformers, etc. as part of a sensorless heat sealing process can be used with such a heat seal bar 95 if desired in the manner as described U.S. patent application Ser. No. 17/330,668. For example, electrical line/voltage measuring wire from voltage transducer 187, and electrical line/power wires from transformers 188 can be coupled to a heat seal bar 95.
Referring to
The carrier plate 150 as shown in the figures, is designed to accommodate heat seal bars for sealing top spout 1 to top 2, top 2 to body 3, body 3 to bottom 6 and bottom 6 to discharge tube 7 with laterally spaced openings and guides to help alignment of these parts. This particular carrier plate is not designed to also accommodate the longitudinal baffle heat seal bar assemblies 101, 102. A carrier plate is not needed to heat seal a baffle insert 4 or 40 to a body 3, but a baffle carrier plate can be used that is similar to a carrier plate 150 and adapted to accommodate the longitudinal heat seal bar assemblies 101, 102 and act as quality check for parts alignment of the overlapped baffle insert 4, 40 and body 3 if desired.
A pre-heat sealed bulk bag 142 can be assembled on a carrier plate 150 as shown in
A pre-heated sealed bulk bag 142 can be put together, for example, by overlapping respective bag portions together to form desired joint locations for a bag 10, 50 on a carrier plate 150 (see
A heat seal machine 141 can include a table 153, a fill spout/top heat seal bar assembly 147, a top/body heat seal bar assembly 154, a bottom/body heat seal bar assembly 160, a discharge tube/bottom heat seal bar assembly 149 and a document pouch/body heat seal bar assembly 155.
Carrier plate 150 with pre-heat sealed bag 142 can be passed through one or more heat sealing machines, e.g., heat seal machine 141, including machine heat seal bar assemblies that have heat seal bars with heating elements. The heat seal bar assemblies can be calibrated at control panels 220, if using a sensorless temperature sensing and control method as disclosed in described U.S. patent application Ser. No. 17/330,668, prior to passing a pre-heat sealed bulk bag 142 through a heat seal machine to undergo a heat sealing process to form a bag 10, 50 with heat sealed joints. Resistance and temperature readings during heat sealing of heat seal bar assemblies can also be gathered at control panels 220.
In a preferred embodiment as shown in
Following heat sealing in machine 146, a completed bag 50 is shown on table 144. A return table 145 for after a pre-heat sealed bulk bag 142 and partially heat sealed bag 171 is finished undergoing a heat sealing process to form a completed bag 10, 50 is also shown in the figures.
In other embodiments, any desired number of joints for a bag can be formed in a desired heat seal machine. For example, some bags may have less than four lift loop assemblies 158, may not have a document pouch 156 and/or may not have a bottom/discharge tube cover 54. Other styles of bulk bags than what are shown in the figures can also be made with a desired number of heat sealed joints.
Lift loop assembles 158 are also folded on a carrier 143 that includes bottom/discharge tube cover 54 near heat seal machine 146 and are ready to be assembled on a partially completed bag 171 before entering heat seal machine 146. If a bottom insert 5 is to be included in a bulk bag 10, 50, a bottom insert 5, discharge tube 7 and bottom 6 are preferably overlapped together and bottom 6 can be heat sealed to both insert 5 and discharge tube 7 in a heat sealing machine 146.
Referring to
A coating 81 on a bag body 3 can be a heat sealing coating 81 that is either a propylene plastomer or elastomer coating or a standard polypropylene laminate type coating. A coating 81 on a bag top 2 can also be a heat sealing coating 81 that is either a propylene plastomer or elastomer coating or a standard polypropylene laminate type coating, depending on what type of coating is on body 3. A propylene plastomer or elastomer coating can be bonded to another propylene plastomer or elastomer coating or to a standard polypropylene laminate type coating. A body 3 to bottom 6, fill spout 1 to top 2, and/or discharge tube 7 to bottom 6 joint can be formed in the same manner when respective bag portions are overlapped together. Reference is made to U.S. Pat. Nos. 10,112,739; 10,618,225 and 11,338,527 for more details on this process.
Other heat-sealed joints of a heat-sealed bag 10, 50 can be formed in a similar or same manner. Preferably bag portions are folded/gusseted so that inner folds or gussets do not touch. This helps prevent an unwanted joint being formed between inner folded portions. This is illustrated in
Other adhesives besides a hot melt film potentially can also be used, such as cold adhesives which would require roller pressure or flat bar pressure to form the seal. Hot melt is currently preferred though because cold adhesives bond at ambient. Under pressure, over time, the bonds tend to gradually stretch and lose strength.
The hot melt beads originally experimented with potentially can be used in the method of the present invention to form a heat sealed joint between a baffle insert and bag body, for example, if the glue can be placed uniformly in the desired locations on the baffle insert.
Including a heat seal coating on a baffle insert and the body interior also potentially can be used to make a heat sealed connection between a baffle insert and body interior surface. For example, a heat seal method that is the same or similar to that disclosed in U.S. Pat. No. 10,112,739 can be used if a plastomer and elastomer coating is included on one piece of flexible plastic fabric, e.g., polypropylene fabric of the baffle insert portion, that would be joined to another plastomer or elastomer coating on another piece of flexible plastic fabric, e.g., polypropylene fabric of a body portion interior. Or, a stitchless baffle bulk bag can be made using a heat seal method that is the same or similar to that disclosed in U.S. Pat. No. 10,112,739 wherein a plastomer and elastomer coating on one piece of flexible plastic fabric, e.g., polypropylene fabric of a baffle portion or body portion, would be joined to a standard fabric coating, e.g., a standard polypropylene fabric coating, on polypropylene fabric of an interior body portion surface or baffle insert exterior surface. Currently, however, as discussed the interior of tubular flexible plastic fabrics are not coated in the industry and it is difficult to coat the interior of a tubular flexible plastic fabric, which is the preferred type of fabric for a body portion of a bulk bag made using the heat sealing process of U.S. Pat. No. 10,112,739, for example, so use of a hot melt film as described herein is currently preferred. A tubular body can also be formed from a flat piece of material. A desired heat seal coating can potentially be applied to both sides of the flat piece of material and then it can be formed into a tube with a single vertical seal. Such a body with a desired coating on an interior surface could be coupled to a baffle insert with a desired coating on an exterior surface when folded, and with heat and pressure applied to join the coatings and form a bond therebetween.
In another preferred embodiment, another to way to make a baffle bag of the present invention is to let the circular bag form an octagonal shape with the cut outs for the product flow on the four diagonals across the ‘corner’ of the bag. Then add four corner panels to attach on the circular bag just outside the cut outs.
In preferred embodiments as described herein, a baffle insert is heat sealed, and not sewn, to an interior of a bag body. A body having a baffle insert heat sealed therein preferably is used as a body portion in constructing a heat sealed bulk bag with no stitches or sewn seams in a containment area of bag. However, if desired, any of the embodiments of a baffle body portion formed as described herein using heat sealing can also be used as a body portion in other types of bags or bulk bags that have sewn seams.
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 claims.
Priority to and/or the benefit of U.S. Provisional Patent Application Ser. No. 63/281,670, filed on 20 Nov. 2021, and U.S. Provisional Patent Application Ser. No. 63/281,694, filed on 21 Nov. 2021, which are each hereby incorporated herein by reference, is hereby claimed.
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| 102083771 | Mar 2020 | KR |
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| Entry |
|---|
| PE Lining Bulk Polyethylene Liner PE Liner Waterproof 1000kg/Customized-China Gusseted Liner and Gambo Liner (https://yunduplastic.en.made-in-china.com/product/IFcTeMCPbaYt/China-PE-Lining-Bulk-Polyethylene-Liner-PE-Liner-Waterproof-1000kg-Customized.html) (Visited Oct. 7, 2022). |
| Cesar Gambo Liner web page (available at https://www.cesur.com/en/product/gambo-liner-bigbag) (Visited Oct. 7, 2022). |
| Cesar PE Films web page (available at https://www.cesur.com/en/product/pe-films-bigbag) (Visited Oct. 7, 2022). |
| Number | Date | Country | |
|---|---|---|---|
| 63281694 | Nov 2021 | US | |
| 63281670 | Nov 2021 | US |
