GB2148245A - Semi-bulk transport bags - Google Patents

Abstract

Semi-bulk transport bags have lifting members 25, each formed from a plural layer folded strip of woven material of the same type as used for the bodies 11, 12 of the bags. These members 25 are anchored at or near the top corners of the bags to distribute lifting stresses across wide segments of the side panels of the bags. In one construction, Fig. 7, using a lifting loop member at each bag corner, the edges of the ends of each loop are overlapped and tacked into the bag corner by the corner seams joining the side panels of the bags. In another construction, Fig. 8, not shown, using only two lifting members, the ends of each lifting member are anchored into wide vertical hems on just two side panels of the bag, allowing use of a lighter weight material for the other two side panels. In yet another construction, using four lifting members, each lifting member is formed with a single twist to stiffen the lifting member and equalize load stress. <IMAGE>

Description

SPECIFICATION Semi-bulk transport bag Background of the invention The use of large bags of woven material for shipment of semi-bulk quantities of granular materials, powders, and other commodities has increased materially in recent years. These bags, referred to as semi-bulk transport bags, are each equipped with a harness so that the bag can be moved about by a fork-lift truck or other similar material handling equipment. In general, semi-bulk transport bags as used commercially have been of rectangular configuration; other shapes have been employed but afford no substantial advantages.

The weight capacity for a bag of this type is usually at least one ton; generally speaking, the upper limit is about four tons. The volumetric capacity of a bag of this kind ordinarily exceeds twenty cubic feet.

It is not particularly difficult to achieve adequate holding strength for the one to four ton capacity required of a semi-bulk transport bag; commercially available relatively inexpensive woven bag materials and conventional industry sewing techniques are quite adequate for this purpose. The critical part of virtually any semi-bulk transport bag, however, is the connection between the lifting loops or other lifting harness and the body of the bag itself. That is, the most common source of failure in a semi-bulk transport bag occurs at the connection between the lifting loops and the body of the bag, the point at which lifting stress is transferred to the bag body. This stress is often substantially in excess of the weight of the bag contents, particularly if the operator of a fork-lift truck is somewhat careless or abrupt in lifting the bag.

It is conventional wisdom that the lifting loops or other simlar harness for a semi-bulk transport bag should be formed from high density webbing of the kind commonly used for automobile seat belts.

Webbing of this kind is much stronger than the woven materials used in the bodies of the bags.

Furthermore, though more expensive than the bag material itself, the cost of webbing loops has been considered acceptable, partly because standard webbing of approximately two inches width is employed in great quantities in automobile seat belts and hence is less expensive than special purpose webbing. Examples of semi-bulk transport bags that use webbing for the lifting loops or other harness include Sandeman et al U.S. Patent No.

4,207,937, Manerba U.S. Patent No. 4,221,250, and others mentioned below.

To distribute the lifting stress from the webbing loops or other harness to the body of a semi-bulk transport bag, a variety of different attachment arrangements have been proposed. For the most part, these critical mounting arrangements for the lifting loops have entailed folding the bag material into multiple layers and anchor stitching the lifting harness webbing to the folded bag material, usually with the loop webbing captured within the folds of the bag material. Arrangements of this kind are disclosed in Nattrass et al U.S. Patent No.

4,010,784, Beaven et al U.S. Patent No. 4,301,848, Nattrass U.S. Patent No. 4,307,764, and Goodbody British Patent No. 1,591,866. Some of these arrangements have been quite effective and have seen widespread commercial use; perhaps the best are those in the two Nattrass patents. However, any of these techniques requiring multiple folding of the bag material at the point of attachment to a lifting loop or other webbing harness member add materially to the cost of bag manufacture.

Another technique that has been adopted in an attempt to meet the critical requirements for attachment of a webbing loop or other harness member to the body of a semi-bulk transport bag is to extend the webbing for most or all of the height of the bag and attaching the webbing to the bag throughout its height. Bags which employ this technique are shown in Williamson et al U.S. Patent No. 4,143,796 and in Nattrass published European Patent Application No. 1696. This expedient, however, is undesirable because of the substantial increase in cost entailed in the use of long lengths of relatively expensive webbing.

In some prior art bags there are no separate lifting loops as such. Instead, opposed side walls are extended upwardly above the bag top. In Derby et al British patent application No. 2,050,298 these side wall extensions are folded over with their edges sewn to the top edges of those side walls to afford two tunnel-like lifting loops each extending the full width of the bag. In LoLift British patent No. 1,581,437 the side wall extensions are joined together at the center of the bag to form a single tunnel-like lifting member. These arrangements are awkward to mount on the tines of a fork-lift truck and the tunnel-like loops are rather easily damaged in use.

In many ways the use of high-density webbing in the lifting loops or other harness of a semi-bulk transport bag is essentially self-defeating. The webbing is excellent in providing the harness strength necessary to permit lifting of the loaded bag by a fork-lift truck or other similar material handling equipment, but accentuates the problems at the critical point of connection to the body of the bag, due to the limited surface area of the webbing. One possible solution to this difficulty would be the use of webbing having widths substantially in excess of the standard two inch width, because the wider webbing allow for direct distribution of the lifting stress over a greater width of the woven material constituting the body of the bag.But webbing in widths substantially exceeding two inches is difficult to obtain and non-standard webbing is excessively expensive for this application.

Summary of the Invention It is a principal object of the present invention, therefore, to provide a new and improved construction for a semi-bulk transport bag that uses the same woven material that constitutes the body of the bag in the lifting members for the bag, elim inating all webbing in the lifting harness, in a construction that is effective to provide better distribution of lifting stresses from the lifting harness to the body of the bag than has been possible using conventional webbing.

Another object of the invention is to provide a new and improved construction for a semi-bulk transport bag, using a lifting harness formed of the same kind of woven material as the body of the bag, that affords improved distribution of lifting stress from the lifting members to the body of the bag without requiring any folds in the bag material at the points of attachment to the lifting members, and that facilitates assembly of the lifting harness to the body of the bag.

Another object of the invention is to provide a new and improved construction for a semi-bulk transport bag, using lifting members formed of the same type of woven material as the body of the bag, which makes it possible to employ a lighter weight material for a major portion of the bag body, with a stronger and heavier woven material used only for two side panels of the bag and with the transfer of lifting stress from the lifting members to the bag body confined to those two side panels.

Another object of the invention is to provide a new and improved construction for a semi-bulk transport bag having a lifting harness that remains upstanding and provides relatively wide openings that can be readily engaged for lifting by the tines of a fork lift truck.

A specific object of the invention is to provide a new and improved semi-bulk transport bag construction, utilizing lifting members made of the same type of woven material as the body of the bag, that is simple and inexpensive in construction yet affords adequate safety factors in high capacity bags.

Another specific object of this invention is to provide a new and improved semi-bulk transport bag construction, utilizing lifting members made of the same type of woven material as the body of the bag, which members are designed to equalize load stress, when used to lift the bag, across the full width of each lifting member at its juncture with each of the two adjacent side panels to which the lifting member is secured.

.Accordingly, in one aspect the invention relates to a semi-bulk transport bag having a volumetric capacity of the order of at least twenty cubic feet and a weight capacity of the order of at least about two thousand pounds, comprising a bottom panel and four side panels with the side panels stitched at their edges to the bottom panel and to each other, the bag having a plurality of lifting members anchored to the top of the bag, the side panels and bottom panel all being formed of a woven panel material of high tensile strength. Each lifting loop comprises an elongated strip of at least three superimposed layers of the same type of woven material as the panel material, stitched longitudinally to form a loop member having a width W of at least about three inches.Furthermore, each lifting member has two end portions, each end portion having a height H of at least about six inches and each secured to a top portion of a different side panel of the bag by anchor stitching extending throughout the surface area of the lifting member end portion to distribute the transfer of lifting stress from the lifting member to an area of the side panels having a total width of approximately 2W and height H.

In another aspect, the invention relates to a semi-bulk transport bag of the kind having a volumetric capacity of the order of at least twenty cubic feet and a weight capacity of the order of at least about two thousand pounds, comprising a bottom panel and four side panels stitched together at their edges to form a bag body of generally rectangular cross sectional configuration, the bag having a plurality of lifting members anchored to the bag body adjacent its top corners, the side panels and bottom panel all being formed of a woven panel material of high tensile strength. Each lifting member comprises an elongated strip of stiff highstrength material having its opposite ends secured to the top portions of two adjacent side panels of the bag body but spaced from the corner formed by such side panels by a distance ofe at least six inches.Furthermore, each lifting member has a single twist therein to equalize load stress, member when used to lift the bag, across the full width of the lifting member at the juncture between the Ifiting member and each of the two side panels to which it is secured.

Brief description of the drawings Figure 1 is a perspective view of a semi-bulk transport bag constructed in accordance with one embodiment of the invention; Figure 2 is a plan view of the bag of Fig. 1 with a portion of a top cover cut away to reveal the bottom of the bag; Figure 3 is a perspective detail view illustrating how the top cover is incorporated in the bag of Figs. 1 and 2; Figure 4 is a detail view illustrating the kind of woven material used in the bag of Figs. 1-3; Figure 5 is a detail view illustrating a strip of woven material employed in fabrication of one of the lifting members for the bag of Figs. 1 and 2; Figure 6 is a detail view illustrating a lifting member made from the strip shown in Fig. 5; Figure 7 is a detail view, on an enlarged scale, of one corner of the bag of Figs. 1 and 2; ; Figure 8 is a perspective view illustrating another embodiment of the invention; Figure 9 is a perspective view of the top portion of a semi-bulk transport bag constructed in accordance with another embodiment of the invention; Figure 10 is a plan view, on an enlarged scale, of one corner of the bag of Fig. 9; Figure 11 is a side elevation view of the corner of the bag shown in Fig. 10; and Figure 12 is a cross-section view, on a enlarged scale, taken along line 12-12 of Fig. 11.

Description of the preferred embodiments Figs. 1 and 2 illustrate a semi-bulk transport bag 10 constructed in accordance with one embodiment of the invention; in Fig. 1, the top cover that is usually provided on bag 10 has been omitted in order that the internal construction of the bag can be better shown.

The semi-bulk transport bag 10 of Figs. 1 and 2 comprises a main body member formed of a continuous wide sheet of heavy duty woven material that is folded twice into a U-shaped configuration to form two side panels 11 and a bottom 13 (Fig. 2) for the bag. To complete the body of bag 10, two side panel members 12 and 14 are joined to the side panels 11 and the bottom panel 13 afforded by the main body member. Attachment of the side panel members 12 and 14 to the main body member is most economically and effectively accomplished, in each instance, by a continuous Ushaped stitched seam 16 joining the edges of the side panel to of the main body member as shown in Fig. 1. Seam 16, typically, may comprise sixtyfive pound test or stronger polyester twine.

Bag 10 includes a lifting harness comprising four lifting members or loops 15, one mounted at each corner of the body of the bag. Bag 10 may also include a top cover 17. In the illustrated construction, the dimensions of cover 17 are made slightly larger than the opening at the top of the walls 11, 12 and 14 of the bag so that cover 17 can be folded and stitched into the top of the bag by a single continuous seam 18 as shown in the detail view, Fig. 3. There is a central opening in cover 17 with an attached fill tube 19. Fill tube 19 may be provided with an attached tie 20 as shown in Fig.

2. Cover 17 may be a substantially lighter material than body panels 11-14. Alternatively, cover 17 may be equipped with a reusable fill/discharge opening having the construction described in Nattrass U.S. Patent No. 4,364,424.

As thus far described, the semi-bulk transport bag 10 of Figs. 1 and 2 is generally similar to a number of prior art bags, particularly that shown in the aforementioned Nattrass U.S. Patent No.

4,307,764. The woven material used to form the main body member comprising side panels 11 and bottom panel 13 is preferably a burlap-weave material 22 having the construction shown on an enlarged scale in Fig. 4.

The weight and strength of material employed is dependent upon the size and capacity required for bag 10. Typically, the material 22 used for the main body member and for side panels 12 and 14 is woven from resin fibers such as polypropylene and has a tensile strength of at least three hundred pounds per inch in both warp and woof directions.

Cut, non-selvage edges are preferably heat-sealed to preclude ravelling. The dimensions D1, D2, and D3 for the body of bag 10 depend to a substantial extent on the required volumetric capacity for the bag; typically, each of these dimensions is of the order of three feet and the volume of bag 10, accordingly, is usually twenty-seven cubic feet or more, though some bags made have a smaller capacity down to about twenty cubic feet. The height D4 for each of the lifting harness members 15 is subject to variation but is usually at least ten inches.

The critical difference between bag 10 and the semi-bulk transport bags of the prior art is found in the construction of the lifting members 15 and the manner in which those lifting loops distribute lifting stress to the body of the bag. Unlike the lifting loops or other lifting harness employed in a great majority of previously known bags, each lifting loop 15 is formed from an elongated strip 15A, Fig.

5, of the same woven material as is used for the panels 11-14 in the bag body. The strip 15A used in fabrication of a lifting member for bag 10 has a length L at least one foot longer than twice the height D4 (Fig. 1) of finished lifting loop 15. The width WS of strip 15A, on the other hand, is at least about nine inches and preferably is ten inches or more.

To form a lifting loop 15 as shown in Fig. 6, the woven material strip 15A of Fig. 5 is folded longitudinally east twice. In the specific construction shown in Fig. 5, strip 15A is folded along two longitudinal fold lines 23 and 24. The folded strip is then sewn longitudinally, as indicated by the stitching 25 in Fig. 6, and this completes the basic construction of the lifting member 15. Heavy duty polyester twine, like seam 16, is preferably used for stitching 25. The lifting loop member should have a width W of at least three inches. The plurallayer lifting loop member 15 is much stiffer than a conventional webbing loop, a substantial advantage when the loop is to be engaged by the fork of a fork-lift truck.

The attachment of the lifting member 15 to the body of the semi-bulk transport bag 10 is shown in Fig. 7. At the time when one of the side panels 12 is being sewn to an adjacent side panel 11 of the main body member for the bag, the edges of the ends of a lifting loop 15 are overlapped with each other, as shown in Fig. 7, and aligned with the top corner portions of side panels 11 and 12. The seam 16 that is used to join panels 11 and 12 also extends through the overlapped edges of the lifting loop member 15, so that the end portions of the lifting loop member are tacked into the corner of the bag body by stitching 16. Subsequently, continuous zig-zag anchor stitching 27 is applied throughout essentially all of the height H of each end portion of lifting loop 15 as that extends below the top edge of the bag. Height H is at least about six inches.Loop member 15 could be made longer, and could extend below anchor stitching 27, but any such extension would merely be a waste of material if not engaged by the anchor stitching. For anchor stitching 27, thirty-five pound test nylon thread is suitable.

It should be noted that neither of the side panels 11 and 12 is folded over the legs of lifting member 15. There is no need to fold the panel material over the lifting loop legs because the relatively large width W of the lifting member (three inches or more) distributes lifting stress to a sufficient width of each side panel so that the junction between the lifting loop and the body of the bag is strong enough to withstand the high stresses created when the loaded bag is lifted by a fork-lift truck or other like equipment. Furthermore, the initial tacking of loop 15 into the corner of the bag body, accomplished by positioning the loop at the top juncture of panels 11 and 12 before application of seam 16, holds the loop in place for subsequent application of anchor stitching 27.

Lifting loop member 15 could also be formed, for instance, from three or more separate strips of bag material, rather than using the folded construction of Figs. 5-7. In a construction of that kind two longitudinal seams should be used at the edges of the loop strips. The folded construction shown in the drawings is preferable, however; it is inherently stronger and sturdier.

Figure 8 illustrates a semi-bulk transport bag 110 constructed in accordance with another embodiment of the invention. Bag 110 includes a main body member affording two side panels 111 that are part of a continuous strip with a bottom panel for the bag (not shown). The main body member is joined to two side panel members 112 and 114 by two continuous U-shaped seams 116, as in the previously described embodiment. The top of bag 110 is shown as being open, but the bag can be provided with a top cover as previously described.

In bag 110, each of the side panel members 112, 114 is provided with two vertical hems 131, each hem located immediately adjacent an edge of the side panel member joined to one of the side panels 111 of the main body member. Seams 132 are used to secure the edges of hems 131.

Bag 110 includes just two lifting members 115.

Like the lifting loops 15 of the previously described embodiment, each lifting member 115 is formed from an elongated strip of the same type of woven material as used in the panels of the bag body, folded longitudinally at least twice and stitched longitudinally as indicated at 125 to form the lifting member. In bag 110, each strip used to form a lifting member 115 should have a width WS (Fig. 5) of at least about fifteen inches so that the effective width W of each lifting member 115 is at least five inches. As in bag 10, the lifting members 115 are much stiffer than conventional webbing loops, adding materially to the ease of use.

In bag 110, the lifting members 115 are not sewn into the bag corners in the same manner as in bag 10, Figs. 1, 2 and 7. Instead, the end portion of each lifting member 115 is inserted into one of the side panel hems 131 to a height H of about six inches or more and is then anchor stitched into the hem of the side panel member by zig-zag anchor stitching 127. It is thus seen that the lifting members 115 are not directly attached to the main body member that affords side panels 111. Instead, the lifting loop members are mounted only on the two side panel members 112 and 114. Each outer edge of the lifting members may be further protected and reinforced by a piece of webbing 141 folded over and sewn to the edge of the lifting member; see Fig. 8.

Bag 110, Fig. 8, particularly due to the relatively great width of lifting members 115, affords adequate strength and stress distribution for those occasions on which the filled bag is lifted by means of lifting members 115. Furthermore, because the lifting members are attached only to the side panel members 112 and 114 and not to the main body member affording side panels 111, it is possible to use a lighter weight material for the main body member than for the side panel members without sacrificing weight capacity and strength characteristics for the bag. Typically, if side panel members 112 require an eight ounce woven material, the material used for the main body may be six and a quarter ounce or even five ounce material. Thus, bag 110 affords a substantial cost saving with no sacrifice in bag strength or capacity.Of course, this construction can be varied by attaching lifting members 115 to side panels 11 rather than panels 12 and 14, in which case the lighter material is used for side panels 12 and 14 and the heavier material for the main body member, panels 11 and 13.

In bag 110, seams 116 and stitching 125 preferably use the heavy duty polyester twine referred to above for stitching 16 and 25 in bag 10; stitching 127 and 132 can use lighter nylon thread.

In both bag 10 and bag 110 the lifting members are substantially stiffer than conventional webbing loops, and hence more convenient to use in mounting on the tines of a fork lift. The plural-layer lifting members are tough and strong, yet quite inexpensive as compared with webbing loops. Furthermore, the wide lifting members distribute lifting stresses effectively without requiring folding into the body panels or other such expedients.

Figs. 9 through 12 illustrate a semi-bulk transport bag 210 constructed in accordance with another embodiment of the invention. Bag 210 includes a main body member affording two side panels 211 that are part of continuous strip with a bottom panel for the bag (not shown). The main body member is joined to the two side panels 212 and 214 by two continuous U-shaped seams 216, as in the previously described embodiments. The top of bag 210 is shown as being open, but the bag can be provided with a top cover as previously described.

The top edges of the side panels 211,212 and 214 are folded inwardly to form a hem 218 around the top of the bag. A narrow webbing 220 is attached to the outside of the hem and secured thereto by a double row of stitching 222 using heavy duty polyester twine.

Bag 210 includes four lifting members 225. Like the lifting members 15 and 115 of the previously described embodiments, each lifting member 225 is formed from an elongated strip of the same type of woven material as is used in the panels of the bag body, folded longitudinally at least twice to form a multi-layered strip 225 as shown in enlarged cross-section in Fig. 12 of the drawings. The overall strip length may be thirty-six inches or more. Strips of narrow webbing 226, similar to webbing 220, may be positioned on one side of each lifting member 225 along each longitudinal edge thereof and attached to the loops as by longitudinal stitching 227. Two rows of stitching 227 are shown at the open side of the three layered loop while a single row of stitching 227 is shown along the other side of the loop.In bag 210, each elongated strip used to form a lifting member 225 should have a width WS (Fig. 5) of at least about twelve inches and the effective width W of each lifting loop member 225 is preferably about four inches or more.

The lifting members 225 are inherently much stiffer than conventional webbing loops, due to their multi-ply construction. Lifting member stiffness is also increased by the strips of webbing 226 when employed. The stiffness of these lifting members causes them to tend to stand upright, providing high, wide openings 230 to receive the tines of a forklift truck. The wide openings are obtained by fastening the ends of the lifting members to the side panels 211, 212 and 214 of the bag at points displaced from the corners of the bag by distances S which are substantially greater than the widths of the loops. As is shown most clearly in Figs. 10 and 11 the edge of one end of a lifting member 225, which is approximately four inches wide in this embodiment, is positioned at a spacing S approximately six to ten inches from the corner of the bag.The opposite end of the lifting member is attached to the adjacent panel of the bag with its edge also positioned approximately six to ten inches from the corner of the bag. This spacing of the ends of each lifting member from the bag corner provides an opening of substantial height which is more than six inches wide, from virtually any angle, for the insertion of a forklift tine.

In attaching lifting members 225 to side panels 211, 212 and 214, the ends of each lifting member are preferably placed between webbing 220 and the outer faces of the side panels. At one end of each lifting member 225, as shown in Fig. 12, webbing strips 226 on the lifting member engage the side panel. However, the lifting members can be secured to the inner surfaces of the side panels, rather than the outer surfaces as shown, if desired.

Each lifting member 225 is twisted, as shown in detail in Figs. 10 and 11, so that the strips 226 of webbing face outwardly from the side panel of the bag when this end of the loop is fastened to the side panel. That is, each lifting member 225 is twisted so that one surface 251 is on the outside of the bag at the end of the lifting member secured to one panel whereas the other surface 252 is on the outside of the end secured to the other panel (see Figs. 10 and 11). Fastening of the ends of the lifting members is preferably accomplished by zig-zag anchor stitching 232 applied throughout essentially all of the height H of each end portion of each lifting member 225, with H preferably being approximately six inches or more.

One reason for twisting each lifting member 225 is to obtain more even distribution of the stresses which are applied to the side panels when the transport bag 210 is lifted by members 225. If a lifting member is attached in the conventional manner with the same sides facing the side panels at both ends, the edge of the lifting member which is remote from the corner of the bag will be required to sustain virtually all stress when the bag is lifted; the edge of the lifting member closer to the corner will carry virtually no stress. By twisting each lifting member, the edge farthest from the corner at one end of the lifting member becomes the edge closest to the corner at the opposite end of the lifting member, thus distributing stress throughout the width of the lifting member at both ends. The twist in each lifting member 225 also increases its rigidity, enabling it to stand more erectly. Thus, the twisted, spread lifting member construction of Figs. 9-12 affords a stronger, more durable bag construction that also facilitates engagement of the lifting members by a lift truck fork without damage to the lifting members. Twisted webbing loops have sometimes been used in the past, but with a limp webbing loop secured directly to the bag corners these advantages are not achieved.

The twist used in the lifting members 225 of bag 210, Figs. 9-12, can also be used to advantage in the lifting loops 25 of bag 10, Figs. 1-7. The edgeto-edge stress distribution function of the twist in loops like those of bag 10 is less critical because the lifting member legs are immediately adjacent each other, but the stiffening effect of the twist is quite advantageous.

Claims (11)

1. A semi-bulk transport bag having a volumetric capacity of the order of at least twenty cubic feet and a weight capacity of the order of at least about two thousand pounds, comprising a bottom panel and four side panels with the side panels stitched at their edges to the bottom panel and to each other, the bag having a plurality of lifting members anchored to the top of the bag, the side panels and bottom panel all being formed of a woven panel material of high tensile strength, in which:: each lifting loop comprises an elongated strip of at least three superimposed layers of the same type of woven material as the panel material, stitched longitudinally to form a loop member having a width W of at least about three inches, and each lifting member has two end portions, each end portion having a height H of at least about six inches and each secured to a top portion of a different side panel of the bag by anchor stitching extending throughout the surface area of the lifting member end portion to distribute the transfer of lifting stress from the lifting member to an area of the side panels having a total width of approximately 2W and height H.

2. A semi-bulk transport bag according to Claim 1 in which each lifting member is formed from a single, integral strip of the woven bag material, folded longitudinally at least twice to afford three or more layers in the completed lifting member.

3. A semi-bulk transport bag according to Claim 2, including four lifting members of loop configuration each located at a respective corner of the bag, in which the edges of the end portions of each lifting member are overlapped at the bag corner by an overlap width much smaller than W, and in which the overlapped edges of the lifting loop member end portions are tacked to the bag corner by the stitching joining the bag side panels.

4. A semi-bulk transport bag according to Claim 3 in which each lifting member loop has a single twist to increase the stiffness of the loop.

5. A semi-bulk transport bag according to Claim 2, in which the bottom panel and two side panels are formed by a continuous U-shaped body member and the remaining side panels are formed by two additional side panel members, and which includes only two lifting members each having a width W of at least about five inches, each lifting member extending from one corner of the bag to another, with each lifting member anchored only to two opposed side panel members.

6. A semi-bulk transport bag according to Claim 5 in which the woven material for the two side panels to which the lifting members are anchored is substantially heavier and stronger than the woven material for the other two side panels.

7. A semi-bulk transport bag according to Claim 6, in which each of the two side panels to which the lifting members are anchored includes a vertical hem having a width greater than W, and in which the end portions of each lifting member are inserted into and anchored in the top of one of the side panel hems.

8. A semi-bulk transport bag according to Claim 5 in which a strip of protective webbing is folded over and sewn to the outer edge cf each lifting member.

9. A semi-bulk transport bag of the kind having a volumetric capacity of the order of at least twenty cubic feet and a weight capacity of the order of at least about two thousand pounds, comprising a bottom panel and four side panels stitched together at their edges to form a bag body of generally rectangular cross sectional configuration, the bag having a plurality of lifting members anchored to the bag body adjacent its top corners, the side panels and bottom panel all being formed of a woven panel material of high tensile strength, in which:: each lifting member comprises an elongated strip of stiff high-strength material having its opposite ends secured to the top portions of two adjacent side panels of the bag body but spaced from the corner formed by such side panels by a distance of at least six inches, each lifting member having a single twist therein to equalize load stress, when used to lift the bag, across the full width of the lifting member at the juncture between the lifting member and each of the two side panels to which it is secured.

10. A semi-bulk transport bag according to Claim 9 in which: each lifting member is formed as an elongated strip of at least three superimposed layers of the same type of woven material as the panel material, stitched together longitudinally and having a width W, and each lifting member has an end portion having a height H of at least about six inches at each end of the lifting member anchored to a side panel of the bag body by anchor stitching extending throughout a major portion of the surface area of the lifting member end portion to distribute the transfer of lifting stress from the lifting member to an area of that side panel having a total area of WxH.

11. A semi-bulk transport bag according to Claim 10 in which the lifting member width W is at least about three inches.