AU2013201046A1 - Gusseted Bag - Google Patents

Abstract

Abstract A flexible intermediate bulk container for transport and storage of bulk granular 5 material, said container comprising a generally cuboid-shaped outer bag, a liner within the outer bag, and a baffle structure within the liner, wherein: - said outer bag comprises four bag side walls, a bag top and a bag bottom all formed of woven fabric and which define outside surfaces of the container, - the bag top includes a closable opening, 10 - the liner comprises four liner side walls, a liner top and a liner bottom all formed of plastics film, - each said liner side wall has a liner wall top edge which is welded to said liner top in a first weld region, - each said liner side wall has a liner wall bottom edge welded to said liner 15 bottom in a second weld region, - the baffle structure is approximately the same size as the bag, and comprises: - four baffle side walls made of woven fabric and defining therebetween four vertical baffle edge regions, each baffle side wall having a baffle wall top edge and a baffle wall bottom edge, and 20 - spanning each said vertical baffle edge region for at least most of the height of the bag side walls, a respective gusset panel made of woven fabric joining the two adjacent side walls of the baffle structure connected at that vertical baffle edge region, each said gusset panel sewn onto its respective baffle side walls and incorporating apertures whereby said 25 granular material can flow from the centre of the baffle structure to the respective vertical baffle edge region; and wherein: - each said baffle side wall top edge is sandwiched between the liner top and the respective liner wall top edge within the first weld region, and 30 - each said baffle side wall bottom edge is sandwiched between the liner bottom and the respective liner wall bottom edge within the second weld region. I/P-6 2't1

Description

GUSSETED BAG 5 Field of the Invention This invention concerns the use of containers for transport and storage of bulk materials. It particularly concerns the use of containers known to those skilled in the art as Intermediate Bulk Containers (IBCs) and containers known as bulk bags or 10 Flexible Intermediate Bulk Containers (FIBCs). FIBCs are flexible bags made from woven fabrics, to transport and store powdered, granular, particulate, pelletised or briquetted solid materials. The present invention has particular application to the use of FIBCs for the transport and storage of goods which may be exposed to rain or which tend to absorb moisture if exposed to humid conditions. It is particularly 15 applicable for granular or powdered goods which tend to cake in tropical conditions. Background to the Invention FIBCs are commonly made from heavy textile fabrics typically woven from 20 polyolefins such as polypropylene and polyethylene. FIBCs are commonly manufactured with a base of about 1100mm square and side walls about 1100mm high. They therefore fit neatly on a conventionally sized shipping pallet. However conventional FIBC's have a tendency to bulge or pillow out on their sides and thus do not pack as compactly as a perfect cuboid would. 25 The most common FIBCs have only a single skin of woven textile. It is usually fitted with a fill spout and often a discharge spout which are tied closed by cord or other means. Designs vary according to the rated capacity of the FIBC and whether it is for a single use only or is reusable. 30 2 It is known to use structured bags which incorporate baffles inside to hold them squarish so more bags can be fitted into an ISO shipping container. The baffles are sewn onto the bag walls and span corners. 5 FIBCs sometimes include an inner bag or liner made from polyethylene or polypropylene film to provide a barrier against moisture and/or gases. This inner bag may be closed by a tie or by heat sealing to provide a fully sealed package for the enclosed material. However such a liner bag cannot be used in a baffled bag because then the granular material could not flow to the corners of the FIBC. While attempts 10 have been made to put a liner between an outer bag and a baffle structure, it has always involved stitching the baffle structure to the liner with the consequent loss of sealing integrity. Liners including baffles and made entirely from plastic film are known but they are very expensive. 15 The present invention provides a cost-effective solution to providing an FIBC which maintains a relatively square or rectangular form in plan view while also preventing ingress of moisture from outside due to rainfall or high humidity. Summary of the Invention 20 In one aspect the invention provides a flexible intermediate bulk container for transport and storage of bulk granular material, said container comprising a generally cuboid-shaped outer bag, a liner within the outer bag, and a baffle structure within the liner, wherein: 25 - said outer bag comprises four bag side walls, a bag top and a bag bottom all formed of woven fabric and which define outside surfaces of the container, - the bag top includes a closable opening, - the liner comprises four liner side walls, a liner top and a liner bottom all formed of plastics film, 30 - each said liner side wall has a liner wall top edge which is welded to said liner top in a first weld region, 3 - each said liner side wall has a liner wall bottom edge welded to said liner bottom in a second weld region, - the baffle structure is approximately the same size as the bag, and comprises: - four baffle side walls made of woven fabric and defining therebetween 5 four vertical baffle edge regions, each baffle side wall having a baffle wall top edge and a baffle wall bottom edge, and - spanning each said vertical baffle edge region for at least most of the height of the bag side walls, a respective gusset panel made of woven fabric joining the two adjacent side walls of the baffle structure connected 10 at that vertical baffle edge region, each said gusset panel sewn onto its respective baffle side walls and incorporating apertures whereby said granular material can flow from the centre of the baffle structure to the respective vertical baffle edge region; and wherein: 15 - each said baffle side wall top edge is sandwiched between the liner top and the respective liner wall top edge within the first weld region, and - each said baffle side wall bottom edge is sandwiched between the liner bottom and the respective liner wall bottom edge within the second weld region. 20 Preferably the container comprises: - at each upper corner of the bag a respective lifting loop is sewn onto the bag, and - an opposite pair of said bag side wallsextend above said lifting loops to join above and clear of said bag top to form a self supporting 25 handle. In another aspect the invention provides a method of transporting a hygroscopic granular material in bulk to a destination, comprising: - loading the granular material through a closable opening in the top of 30 a container as defined above, - closing a closable opening in said liner, 4 - closing a closable opening in said outer bag, and - transporting the loaded container to said destination. In a further aspect the invention provides a method of manufacturing a flexible 5 intermediate bulk container comprising: - a generally cuboid-shaped outer bag made of woven fabric, - within the outer bag a waterproof liner made of plastics film, and - within the liner a baffle structure, wherein: 10 - said baffle structure comprises four side walls made of woven fabric, each said side wall having a top edge and a bottom edge, said four side walls defining therebetween four vertical edge regions of said baffle structure, and - said waterproof liner is generally cuboid, is of approximately the 15 same size as the bag and comprises four walls each having a top edge and a bottom edge, a top panel having edges and a bottom panel having edges, all formed of plastics film, said method comprising: - joining the top panel of the liner to the walls of the liner by welds 20 which incorporate the top edges of the walls of the baffle structure sandwiched between the corresponding edge of the top panel and the top edge of the walls of the liner, and - joining the bottom panel of the liner to the respective bottom edges of the walls of the liner by welds which incorporate the bottom edges of 25 the walls of the baffle structure sandwiched between the corresponding edge of the bottom panel and the bottom edge of the walls of the liner.

5 Brief Description of the Drawings In order that the invention may be more fully understood there will now be described, 5 by way of example only, preferred embodiments and other elements of the invention with reference to the accompanying drawings where: Figure 1 shows a container according to a first embodiment of the present invention; Figure 2 shows a waterproof liner incorporated into the container in Figure 1; 10 Figure 3 is a partially cut-away view of a baffle structure incorporated into the liner shown in Figure 2; Figure 4 is a partially cut-away view of the container shown in Figure 1; Figure 5 is an idealised illustrative representation of a horizontal thin slice section through the container shown as A-A in Figure 1: 15 Figure 6 is an idealized illustrative representation of a vertical thin slice section through the container shown as B-B in Figure 1, and Figure 7 is an external view of a container according to a second embodiment of the invention. 20 Description of the Preferred Embodiment and Other Examples of the Invention Figures 1 to 6 show aspects of a flexible intermediate bulk container (FIBC) 10 according to the first embodiment of the present invention and particularly adapted for carrying granular fertilizer in tropical environments. The FIBC 10 comprises a 25 baffle structure 90 inside a liner 62 inside an outer bag 12. The bag 12 has an approximately cubic shape with four side walls 14 to 17, a bottom 18 and a top 20. A typical external size for the bag 12 would be 109cm x 109cm x 125cm high. Pairs of adjacent side walls 14 and 15, 15 and 16, 16 and 17, and 17 and 18 respectively meet along vertically extending edges 22 which extend up to the bag top 20 where they 30 terminate at top corners 19 of the bag.

6 The side walls 14 to 17 and the bottom 18 of the bag 12 are all made from panels of woven fabric. A suitable fabric is a woven polypropylene fabric having a weight of about 220gsm which then has a 30gsm polypropylene/polyethylene mix film laminated onto its inner-facing surface. 5 The top 20 of the bag is a panel 34 of the same fabric as the walls 14 to 17 and is fitted with a central circular loading spout 35 made of the same fabric and which can be tied closed by a draw cord 28. The spout 35 is 50cm diameter and 63cm long. 10 To construct the bag 12, appropriately cut pieces of fabric are sewn together at side edge seams 21 which form the join between adjacent side walls 14 and 15, 15 and 16, 16 and 17, and 17 and 14 respectively, at top edge seams 26 and at bottom edge seams 24. Extending out beyond each side edge seam 21, the fabric of the side walls loops out and back again to the edge seam so as to project outwardly as side edge flaps 23 15 for the full length of the vertical edges 22 of the bag. The prominently projecting flaps 23 provide substantial protection to the vertical edges 22 of the bag where it may otherwise be susceptible to damage during handling. It will be appreciated that the vertical edges 22 of a container constructed in this way 20 are extremely strong due to the overlapping of multiple layers of fabric. Four lifting loops 33 are attached at the top corners 19 of the bag 12. The loops 33 are formed by fabric straps sewn onto the vertical edges 22 as shown in Figure 1. Less desirably, each loop may alternatively straddle its respective top corner 19 and 25 be sewn instead to the respective top edge seams 26 and respective side walls a little distant from the respective top corner 19. The liner 62 has the general shape of a cuboid having approximately the same outside dimensions as the bag 12. However the liner 62 is made slightly oversize, being 30 higher and wider than the bag 12 in which it is used. This is so that, when the FIBC is in use, the load imparted by its granular contents is taken by the outer bag 12 instead of the liner 62.

7 The liner 62 is formed of a 70 micron low density polyethylene (LDPE) film and has four side walls 64-67, a top 70 having a central tubular loading spout 72, and a bottom 74. The liner 62 is constructed from four pieces of the polymer film. The 5 first piece is a tubular length of polymer film 68 which forms the side walls 64-67. Another piece is a square base panel 76 which forms the bottom 74 of the liner. The third piece is a square panel 69 which forms the top 70 of the liner 62. Finally a tubular length of film forms the spout 72. 10 The bottom edge of the spout 72 is ultrasonically or thermically welded at seam 71 to the top panel 69. The bottom edges 51 of the liner walls 64-67 are ultrasonically or thermically welded to the base panel 76 at bottom edge seams 80 to each produce an outwardly extending bottom edge flap 88 which extends the full length of each respective bottom edge seam 80. The top edges 52 of the liner walls are similarly 15 welded to the top panel 69 at the top edge seams 81 to each produce an outwardly extending top edge flap 86 which extends the full length of each respective top edge seam 81. Those ultrasonic welded seams are about 10mm in width. The edges of panels 69 and 76 and of the tube 68 extend approximately 40mm beyond the respective adjacent weld to form the flaps 86 and 88. 20 The baffle structure 90 is formed of a woven fabric laminated with a polymer film. It has four baffle side walls 91 which correspond in size to the bag side walls 14-17. The baffle side walls are preferably formed from a single tubular length of fabric, so there are no seams along the baffle structure's vertical edge regions 92 which in use 25 are formed as the baffle structure 90 and liner 62 are pressed by the granular material into the vertical edges 22 of the outer bag. Spanning each vertical edge region 92 is a respective gusset panel 93. Each gusset panel 93 is made of the same type of fabric as the baffle side walls 91 and is a little 30 shorter than the vertical edges 22 of the bag. Each gusset panel is positioned centrally across its respective vertical edge 22 and has a width such that the seams 95 divide the baffle side walls 91 into three portions of approximately equal width. The vertical 8 edges 94 of the gusset panels are sewn by seams 95 to the side walls 91. The gusset panels incorporate large apertures 96 which allow the granular material to flow from the centre 97 of the baffle structure 90 through the panels 93 to the respective vertical baffle edge region 92. The shape of the apertures 96 shown in the drawings is 5 elliptical, but they can be any shape desired. The use of gusset panels of the general type described is known to those skilled in the art from baffled bulk bags. However in the present invention involves a novel way by which the gusset panels are attached through the baffle structure 90 to the top and 10 bottom edges of the liner 62. The baffle structure constrains the bulging of the FIBC's side walls, but it creates a vertical ribbing effect on the walls of the bag. At the top edge of the fabric forming the baffle side walls, the fabric is slit for a short distance in the centres of the vertical edge regions 92. This creates a long, narrow top 15 flap 98, at the top of each baffle side wall. Similarly, bottom flaps 99 are formed at the bottom edge of the fabric forming the baffle side walls. As described below, those top flaps 98 and bottom flaps 99 are the sole means by which the baffle structure 90 is fastened to the liner 62. 20 The gusset panels 93 are not joined directly to the liner. They are only sewn onto the baffle side walls 91. The baffle side walls are attached to the liner 62 only at the bottom edge seams 80 and the top edge seams 81. As shown in Figure 6, each top edge flap 98 and bottom edge flap 99 of the baffle 25 structure is captured within the corresponding flaps 86 and 88. This is achieved by inserting each flap 98 between the respective liner wall top edge 52 and the edge of the liner top 70 when welding them to form the top edge flap 86. The flaps 98 are thus incorporated into the welds which form the top edge seam 81. Similarly each flap 99 is inserted between the respective liner wall bottom edge 51 and the edge of 30 the liner bottom 74 when welding them to form the bottom edge flap 88. The flaps 99 are thus incorporated into the welds which form the bottom edge seam 80.

9 After the granular material is put into the FIBC, the liner spout 72 is heat sealed before the bag 12 has its spout 35 tied with the draw cord 28. In the embodiment described above neither the baffle structure 90 nor the liner 62 is 5 sewn or welded to the side walls, bottom or top of the outer bag 12. However the liner may be lightly glued to the inside of the bag to facilitate easier filling and prevent misalignment. Alternatively, or in addition, the loading spout 72 of the liner may be attached to the loading spout 35 of the bag by a ring of stitching (shown as 73 on Figure 4) which is located above where the liner spout 72 would be sealed. 10 The container 10 is intended as a single use FIBC. To unload the container, it is raised by its loops 33 and a sharp knife is used to cut through the bottoms 18 and 74 of the bag and the liner so the granular material flows out. The entire FIBC is then discarded. 15 The embodiment of the invention shown in Figure 7 is a container 110 which has a liner and baffle structure the same as that of container 10 described above. However its outer bag 111 has a different form. The bag 111 has four side walls 112-115, a square bottom 116 and a top 120 within which the liner and baffle structure are fitted. 20 The top 120 is sewn to the walls 112-115 at respective top edges seams 124-127. Each adjacent pair of side walls 112-115 meets at a respective vertical edge 118 which extends from the bottom 116 up to the top edges 124-127. Each vertical edge 118 carries a reinforcing structure comprising two layers of 50mm wide webbing 131 25 between which the previously overlocked seams in the fabric at respective edges of the side wall fabric are sewn at sewn seams 122. Where each vertical edge 118 meets the upper face 120, an upper corner 136 is formed and a lifting loop 130 is sewn to the bag. 30 A fabric panel 121 sewn into the top edges 124-127 forms the main portion of the top 120 of the bag 110. At the centre of the panel 121 is sewn a circular inlet spout 134 10 the same as the spout 35 in Figure 1. The liner is closed at its top by bunching it in with the inlet spout 134 which is then tied off with the tape 142. The fabric forming a first pair of opposite walls 112 and 114 continues upwards, as 5 fabric portions 144 and 146 respectively, beyond the top edges 124 and 126 respectively, and these portions are sewn to each other above the top 20 of the bag so as to form a handle 150. The fabric forming the other pair of opposed walls 113 and 115 terminates at the top edges 125 and 127 respectively. 10 A sleeve 151 of fabric is wrapped around the central (uppermost) portion of the handle 150. This provides substantial stiffening and protection of the handle from abrasion during moving and lifting operations. The bag 111 has a horizontal cross-section which is square, and a vertical cross 15 section which is rectangular and elongated vertically. The bag 111 has a 950mm square cross-section horizontally. The vertical edges extend for 1450mm between the bottom 116 and the top edges 124-127. This is the fill height of the container. The bottom 116 of the bag 111 has a centrally located circular opening 158 of 450mm 20 diameter which includes a cylindrical spout 170 about 500mm long of textile fabric sewn around the perimeter of the opening 158. Surrounding the spout 170 is a fabric spout cover 176 which has a tie tape 172 threaded pyjama style into the periphery of the cover 176. The spout 170 may therefore be rolled or folded up to close the opening 158, and then pushed into the bag 111 before tightening the tape 172 to 25 prevent the spout 170 from re-opening. The circular opening 132 and top spout 134 are each 500mm diameter and the top spout is 500mm long. The centre of the opening 132 is at approximately the centre of the bag top 120. 30 11 A clear pocket 152 is sewn onto the side wall 113 adjacent an edge 118. This pocket is used to insert an identification card or some other indication of the product in the container. 5 The side walls 112-115 and bottom 116 of the bag are sewn from 290gsm woven polypropylene fabric which has a waterproof 35 micron polyethylene film laminated onto its inner surface. The inlet spout 134 and discharge spout 170 are made of 100gsm woven polyethylene which has a waterproof polyethylene film laminated onto its inner surface. The spout cover 176 is made of uncoated woven polyethylene. The 10 sleeve 151 on the handle is made of 31 Ogsm weight woven polypropylene fabric. The lifting loops 130 are 300mm long and made from polypropylene monofilament webbing 50mm wide. The webbing of the loops 130 is sewn over the top of the webbing 131 and continues down the respective edges 118 for a short distance 15 sufficient to provide a strong enough stitched attachment. Alternatively (and not shown in Figure 7) the webbing of the loops 130 may be a continuation of the same webbing 131 which is sewn along the full height of the vertical edges 118 onto the outside of previously formed overlocked seams. 20 A webbing/fabric collar 148 is sewn around the bottom of each lifting loop 130 for additional reinforcement. The edges 138 of the fabric in the handle 150 are bound with a webbing 40 to serve as reinforcement. The webbing 140 is a 50mm wide polypropylene monofilament 25 webbing which is wrapped around the edges 138 and sewn there along stitching line 141. It is this webbing which takes a substantial portion of all the weight of the loaded bag when lifted by the handle 150. The webbing 140 is sewn onto the edge of the fabric of the handle before the webbing 131 is sewn onto the vertical edges 118. The webbing 140 may alternatively be woven from PET multifilament fibre to 30 provide a stiffer edge if desired.

12 The webbing 140 bound onto the edges 138 of the handle extends fully to the upper corners 136 where it is sewn onto the webbing 131. By this means the load borne by the handle webbing 140 when lifting a filled bag is effectively transferred to the vertical edge webbing 131. 5 To discharge the product, the FIBC 110 is lifted by using either the loops 130 or the handle 150. The spout cover 176 is then untied and the spout 170 allowed to drop. The bottom of the liner is then cut so that the contents of the container can discharge through the discharge spout 170. The discharge may be slowed or ceased at any time 10 by rolling or folding up the spout 170 and re-tightening the tape 172. The liner and baffle structure is conveniently discarded after emptying, but the bag 111 may be reused after fitting a fresh liner and baffle structure within it. 15 Whilst the above description includes the preferred embodiments of the invention, it is to be understood that many variations, alterations, modifications and/or additions may be introduced into the constructions and arrangements of parts previously described without departing from the essential features or the spirit or ambit of the invention. 20 It will be understood that the word granular when used in this specification to describe materials is intended to include materials that may have some substantially large hard lumps and/or fine powder included. 25 When the term "edge" is used in this specification in relation to a portion of fabric or film, it is intended to refer to a narrow band of fabric forming the edge. It will be also understood that where the word "comprise" and variations such as "comprises" and "comprising" are used in this specification, unless the context 30 requires otherwise such use is intended to imply the inclusion of a stated feature or features but is not to be taken as excluding the presence of any other feature or features.

13 The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that such prior art forms part of the common general knowledge in Australia. 5|

Claims (4)

1. A flexible intermediate bulk container for transport and storage of bulk granular 5 material, said container comprising a generally cuboid-shaped outer bag, a liner within the outer bag, and a baffle structure within the liner, wherein: - said outer bag comprises four bag side walls, a bag top and a bag bottom all formed of woven fabric and which define outside surfaces of the container, - the bag top includes a closable opening, 10 - the liner comprises four liner side walls, a liner top and a liner bottom all formed of plastics film, - each said liner side wall has a liner wall top edge which is welded to said liner top in a first weld region, - each said liner side wall has a liner wall bottom edge welded to said liner 15 bottom in a second weld region, - the baffle structure is approximately the same size as the bag, and comprises: - four baffle side walls made of woven fabric and defining therebetween four vertical baffle edge regions, each baffle side wall having a baffle wall top edge and a baffle wall bottom edge, and 20 - spanning each said vertical baffle edge region for at least most of the height of the bag side walls, a respective gusset panel made of woven fabric joining the two adjacent side walls of the baffle structure connected at that vertical baffle edge region, each said gusset panel sewn onto its respective baffle side walls and incorporating apertures whereby said 25 granular material can flow from the centre of the baffle structure to the respective vertical baffle edge region; and wherein: - each said baffle side wall top edge is sandwiched between the liner top and the respective liner wall top edge within the first weld region, and 30 - each said baffle side wall bottom edge is sandwiched between the liner bottom and the respective liner wall bottom edge within the second weld region. 15

2. A container according to claim 1 wherein: - at each upper corner of the bag a respective lifting loop is sewn onto the bag, and 5 - an opposite pair of said bag side wallsextend above said lifting loops to join above and clear of said bag top to form a self supporting handle.

3. A method of transporting a hygroscopic granular material in bulk to a destination, 10 comprising: - loading the granular material through a closable opening in the top of a container according to any one of the previous claims, - closing a closable opening in said liner, - closing a closable opening in said outer bag, and 15 - transporting the loaded container to said destination.

4. A method of manufacturing a flexible intermediate bulk container comprising: - a generally cuboid-shaped outer bag made of woven fabric, - within the outer bag a waterproof liner made of plastics film, and 20 - within the liner a baffle structure, wherein: - said baffle structure comprises four side walls made of woven fabric, each said side wall having a top edge and a bottom edge, said four side walls defining therebetween four vertical edge regions of said 25 baffle structure, and - said waterproof liner is generally cuboid, is of approximately the same size as the bag and comprises four walls each having a top edge and a bottom edge, a top panel having edges and a bottom panel having edges, all formed of plastics film, 30 said method comprising: 16 - joining the top panel of the liner to the walls of the liner by welds which incorporate the top edges of the walls of the baffle structure sandwiched between the corresponding edge of the top panel and the top edge of the walls of the liner, and 5 - joining the bottom panel of the liner to the respective bottom edges of the walls of the liner by welds which incorporate the bottom edges of the walls of the baffle structure sandwiched between the corresponding edge of the bottom panel and the bottom edge of the walls of the liner. 10