FI62031B - FLEXIBEL LOESGODSBEHAOLLARE AV VAEVT TYG - Google Patents

Description

E3CT1 M „„ KUUUTUSJU1.KAI * U

jSpS M <11> utläccnincsskiiift OiiUil K C (45) Patent granted 10 11 1932

Patent meddelat y (51) Kv.ik.Wa3 B 65 D 33/02 FINLAND — FINLAND (2.1) P »unttlh> h« nu «—hummwehntnf 8029 ^ 1 (22) H» k * ml * pUvi — An »etaln | wUf 18.09.80 (23) AlkupUvt — GlMghutadag 0ll.08.78 (41) Gotten stuck - Graters oKMI | 18/9/80

Patanttl · and rakistarihallitiM / 44) NUittvIluIpMon ju kuLLPublic date——

Patent · och regittarrtyralsan '' AmMum uttafd och uti ^ kriftun pubikurmd 30.07.82 (32) (33) (31) Pyy *** / «uoikuiit — a« sird prior * · * 06.08.77 26.08.77, 18.11.77 , 31.05.78, 31.05.78, 3i.O5.78 United Kingdom-Storbritannien (GB) 33076/77, 36051/77, 1 + 8179/77, 25798/78, 25799/78, 258ΟΟ / 78 (71) Tay Textiles Limited, Park Mill, Dundee DDI 9NA, Scotland, United Kingdom-Storbritannien (GB) (72) Allan MacFarlane Sandeman, Dundee, Scotland, James Duncan Bell,

Dundee, Scotland, United Kingdom-Storbritannien (GB) (7! +) Berggren Oy Ab (5I1) Flexible bulk container of woven fabric - Flexibel lösgodsbe-hällare av vävt tyg (62) Divided by application 782 ^ 10 (patent 61169) ~

This invention relates to a flexible bulk container of woven fabric formed by a sack having sidewalls and a base, the sidewalls alternatively consisting of a tubular fabric, preferably a continuous piece of fabric, four or more connected into a tube, , an interconnected body in which the warp yarns run vertically in the fabric of which the side walls are formed and in which the side walls have areas where the strength of the warp yarns per unit width is greater than at least the majority of the remaining parts of the side walls, the lifting members being attached to said areas.

Such containers can be used for the storage and transport of granular, powdery and other particulate substances such as chemicals, food, cement, etc. Containers are usually large bags or sacks. They often have to withstand loads that weigh a ton or more. Above this workload, there should preferably be a considerable safety margin.

Such known sacks are often made of a woven fabric, e.g. woven polypropylene or other suitable synthetic material. There are often seams between adjacent parts of the tank. It has been found that in use, these parts can form areas with a high concentration of tension, whereby the fabric tends to tear easily next to the seams. It is also known to attach lifting eyes or the like to the main body of the container, and the attachment points can likewise form areas where the concentration of tension is high.

Several methods have been proposed for making such sacks in areas where the stress concentration becomes high, but several of these proposals require the use of an additional reinforcing agent and more and more manufacturing steps. This can prolong manufacturing time and increase costs, which is not desirable, especially if the containers are intended for single use.

Finnish patent application No. 780043, which has become public after the priority date of the present application, discloses a sack whose wall is reinforced with an additive and whose lifting members are attached to these reinforced areas.

However, it is an object of the present invention to provide a sack which can be manufactured in a simple manner, in which the attachment points of the lifting members are even stronger. According to the invention, this has been achieved in the sack shown in the introduction, in that flanges of at least twice the material thickness are formed in the reinforced areas and that the lifting members are attached to these flanges.

The container can be made of several fabric parts or of a single strip of fabric which is folded suitably and the different parts of which form side walls. In general, it is desirable to have an area of greater warp strength adjacent to each flap of the fabric portion or strip.

The container is preferably structured in such a way that as many of its seams as possible run along the ridges, or at least those seams which are subjected to the greatest concentration of stress during use.

3 62031

In a structure using several fabric parts, which may be of the same width to facilitate manufacture, the parts can be joined together along their flaps to form an open bag-like structure at the top, the seamed flaps of which run mainly vertically. One such structure may comprise three parts, one of which is U-shaped and the other two are connected across the ends of the U-shaped part, the bend of the U-part forming the bottom of the container.

The fabric parts can be joined in any suitable way, such as by welding or sewing. The stitch can, for example, be used as a unitary helix, in which case each thread passes through areas with higher warp strength. Alternatively, parallel rows of stitches can be stitched through areas with higher warp strength.

Areas adjacent to the seams with higher warp strength not only improve the tear strength of the fabric, but also form suitably reinforced areas for lifting means, such as fabric loops, to be attached to the container. These are sewn or otherwise attached to flanges formed in areas of higher warp strength with at least twice the material strength. These flanges formed in the stronger areas absorb the stresses caused by the lifting of the tank loops.

The lifting loops are attached to the body portion, for example, by attaching the ends of the loop fabric strips to the radially projecting flanges of the body portion formed by pinching regions of higher warp strength of the body portion, the ends of the loops preferably being attached to opposite outer surfaces of the collapsed portions.

The body part can be closed from the bottom end by fitting a round base piece to the body part, which is attached to it, e.g. by sewing the sides together.

There are no longitudinal seams in the body that would be weak points. Its manufacture is simple due to the small number of sewing steps.

4,62031

Areas with higher warp strength can be obtained by using warp yarns with higher density or higher toughness, or by using a combination of these. The low toughness warp yarns may be in the form of a flat polypropylene tape and the higher toughness warp yarns in the form of twisted polypropylene yarn, R.E.F. yarns ("roll embossed film") or high tenacity multifilament yarns. In a preferred construction, the low tenacity yarns are in the form of a flat strip and the higher tenacity yarns are e.g. R.E.F. polypropylene yarns or filaments of round cross section. Both types of yarns can be of different materials, in which case, for example, yarns with lower toughness are polypropylene and yarns with higher toughness are polyester or nylon.

The fabric used to make the container may be, for example, in the form of a strip with stronger warp areas adjacent to each weft, or e.g. in the form of a tube woven in a circular weaving machine with suitable areas of higher warp strength.

Two embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which Figure 1 is a perspective view of a container according to the invention, Figure 2 is a portion of a seam between two fabric panels of a container and Figure 3 is a perspective view of another embodiment of a container.

Figure 1 of the drawings shows a flexible bulk container in which a maximum of 1 tonne of material can be placed and which has a safety factor of at least five times its weight. The container comprises a bag part 1 to which four lifting loops 2 are attached. The bag is made of a woven fabric, e.g. woven polypropylene, but also polyethylene tetraphthalate, rayon, nylon, etc. could be used. The preferred fabric structure is about 6x5 yarns / cm of woven polypropylene tape having a denier of 2000.

The fabric can be sealed with a polypropylene coating or laminated polyethylene.

s 62031

The loops 2 are preferably made of fabric, e.g. woven polyethylene tetraftlate with a width of about 5 cm.

The bag 1 comprises three pieces of fabric, namely a substantially u-shaped part 3 forming two sides and a bottom of the bag, and two rectangular pieces 4 and 5 forming the other two sides of the bag. The pieces of fabric are arranged so that their warp yarns run vertically along the sides of the bag. The pieces are joined by sewing along the seams, e.g. with notch stitches using polypropylene yarn. The flaps of the pieces of fabric 3, 4 and 5 run vertically along the seams except at the bottom of the bag. There is a stitch 6 around the top of the bag to prevent the fabric from wearing. The seam structure and the attachment end of the loops to the bag are shown more clearly in Figure 2. The two pieces of fabric 3 and 4 are sewn together along the seam 7 with polypropylene yarn 8.

The loop 2 has two branches 9 and 10. The fabric near the seam 7 is compressed to form a flange, and the branches 9 and 10 are sewn to the flange so that they cover it. Each stitch passes through the branches 9 and 10 of the loop and the two thicknesses of the bag fabric.

Although not shown, the warp yarns are turned back, for example, by 1.3 mm next to the weft of the pieces of fabric. In this way, a certain reinforcement can be obtained next to the seam. However, according to the invention, additional reinforcement is provided by denser warp yarns. For example, in the areas generally denoted by reference numerals 11 and 12, the warp yarns are denser next to the hem of the fabric pieces 3 and 4, i.e. the yarns are compressed closer to each other, and / or stronger warp yarns are used. Thus, most warp yarns could be polypropylene tape with a strength of perhaps 4-6 g / denier. In the regions 11 and 12 adjacent to the hul, the warp yarns may be R.E.F. polypropylene yarns having a strength of 5-7 g / denier or multifilament polypropylene yarns. The widths of the regions 11 and 12 are such that the branches of the loop can fit in them, and the regions run along the length of the ridges.

Figure 3 shows another preferred embodiment of the invention, in which the container comprises a one-piece, tubular main body part 13 with a round base 14 sewn in. Four loops 2 are attached to the top of the bag and arranged evenly around it. At the point of attachment of the loop 2, the sack fabric is pinched together so that a flange is formed near the top of the sack. The branches of the loop pass over the flange and are sewn into it as in the previous embodiment.

The attachment points of the loops 2 are in areas 15 where the warp yarns have a higher toughness and density and run vertically in the bag. Higher toughness and density can be achieved as described above. In other respects, e.g. with respect to the materials used, the bag is similar in structure to that described above.

It is thus found that a container is obtained which, in terms of simple construction, is even stronger and more reliable and in which the reinforced areas shift the lifting loads downwards along the container when the container is lifted from the loops. The method by which the fabric of the sack is made and the sack is formed enables even greater production efficiency.

It has been found that a particularly preferred arrangement combines the use of R.E.F. yarns with a "folding" effect in the areas adjacent to the ridges. Thus, R.E.F. polypropylene warp yarns are woven in pairs. In order to facilitate the weaving step, it is then advantageous for the warp yarns to pass over and under two weft yarns at a time. The resulting tank has significantly better strength and is capable of carrying loads of 8-10 tons.

Claims (6)

A flexible container for woven fabric for bulk goods in the form of a sack (1) with side walls (3, 4, 5) and a bottom, the side walls alternatively consisting of a tubular fabric (13), a continuous piece of fabric, joined to a tube, or of two or more, preferably four parts joined together, and the warp trees of the fabric, of which the side walls are made, extend in the vertical direction of the bag and the side walls comprise zones (11, 12, 15) where the warp strength per width unit is greater than it is at least in most of the residual portions of the fabric parts, and with lifting means (2) attached to said zones, characterized in that flanges of at least double material thickness are formed in these zones and that the lifting means (2) are attached to these flanges. Container according to claim 1, characterized in that each flange is formed by a zone pair (11, 12), in which each zone is located at the city edge of the side wall. Container according to claim 2 with four joined side walls (3, 4, 5), characterized in that one (11) of the two zones forming the flange passes without interruption from the bottom end of the one side wall (3), above the bottom of the container. , to the lower end of the opposing side wall (3) city edge, along the reinforced city edge to the continuous piece of fabric forming the opposing side walls, and along the bottom edges of the two other side walls (4, 5). Container according to claim 2 or 3, characterized in that the lifting means (2) are fixed in the flanges (7) formed in the four corners of the bag, in the joints of the fabric pieces (7). 5.; Container according to any of the preceding claims, characterized in that each lifting member (2) consists of a Loop with two branches (9, 10) which are attached, on each side of the flange with a seam that pierces both the branches and the flange.