LINER FOR A BULK BAG, BULK BAG WITH INNER LINER AND METHOD OF

MAKING THE SAME

TECHNICAL FIELD

The present invention relates to a method for manufacturing bulk bag, comprising the steps of forming a bottom of a tubular liner and fixing said liner to an outer bag. The invention also relates to a method for manufacturing a liner for a bulk bag, and the bulk bag and liner.

BACKGROUND ART

In many fields of technology, bulk bags are used for collecting, transporting and storing materials, mostly free-flowing materials such as chemicals, plastics, cement, flour, grains, fertiliser and the like. One commonly used bulk bag system is Portabulk, others are disclosed by patent documents US222425 (Smith), FR2795387 (Frutipack) and EP0079155 (Hokkai Can). Often, the bulk bags are supplied with a suspended liner in the form of an inner bag from a plastic film material inserted into the bulk bag.

When emptying the bulk bag by cutting open the bottom, however, it is generally difficult to extract all the free-flowing material without additional operations such as shaking the bag, due to the fact that material often gets stuck in folds and crevices of the liner. Also, parts of the liner can fall off through the cutting operation and fall down into the material being emptied from the bulk bag, requiring removal by hand to avoid contamination of the material. This is generally undesired from the economic as well as the ergonomic points of view.

One solution to the problem is presented by the use of a dispenser such as the Raimo Big Bag Dispenser provided by OBS Enviro, where the dispenser is screwed into the bulk bag and acts as a valve, onto which a tube is mounted for controlled extraction of the material. This solution is, however, costly in that it requires the separate dispenser system and also time-consuming since it needs to be carefully screwed into place and fixed by a separate operation.

Several other similar solutions are available on the market, but generally require the presence of additional devices or systems to empty the bulk bag, thereby being more cumbersome and costly compared to simply cutting the bulk bag open by hand. There is thus a need for a more convenient, efficient and cost-effective bulk bag that can be emptied without additional dispensers or the like.

DISCLOSURE OF THE INVENTION

The object of the present invention is to eliminate or at least to minimize the problems described above. This is achieved through a bulk bag and a method for manufacturing such a bulk bag according to the appended independent claims, using a liner with a bottom fixed to the outer bag along at least two sides of said bottom so that the liner is held securely against the outer bag. Thereby, the cutting of the bottom of the bulk bag will result in a neat cutting of the liner as well and prevent additional material from the liner from falling down from the bulk bag, as well as material being stuck inside the liner.

' Preferably, the liner is fixed to the outer bag along opposing sides, more preferably along the flange seams. Thereby, the liner is securely held so that the bottom of the liner extends along the bottom of the outer bag without being displaced or crumpled regardless of how the bulk bag is filled and handled.

According to one aspect of the invention, the flanges themselves are removed before the liner is fixed to the outer bag. Thereby, the amount of excess fabric of the liner is decreased so that the risk of liner falling from the bag when opened by cutting can be further minimized. Alternatively, the flanges can be folded and fixed to the flange seams or the outer bag to achieve the same advantage.

Further advantages of the present invention will be apparent in view of the detailed description below.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail with reference to the appended drawings, wherein:

Fig. 1 shows a first step of manufacturing a liner for a bulk bag according to a preferred embodiment of the present invention;

Fig. 2 shows a second step of manufacturing the liner of Fig. 1 ;

Fig. 3 shows a third step of manufacturing the liner of Fig. 1 ;

Fig. 4 shows a fourth step of manufacturing the liner of Fig. 1 ;

Fig. 5a shows a bulk bag comprising the liner of Fig. 1-4;

Fig. 5b shows an enlarged view of a section of the bulk bag of Fig. 5a with the liner fixed to the outer bag; Fig. 6a shows a first step of manufacturing a liner for a bulk bag according to the second embodiment of the present invention;

Fig. 6b shows a second step of manufacturing the liner of Fig. 6a;

Fig. 6c shows a third step of manufacturing the liner of Fig. 6a;

Fig. 6d shows a fourth step of manufacturing the liner of Fig. 6a;

Fig. 6e shows a bulk bag comprising the liner of Fig. 6a-d;

Fig. 6f shows an enlarged view of a section of the bulk bag of Fig. 6e with the liner fixed to the outer bag;

Fig. 7a shows a first step of manufacturing a liner for a bulk bag according to the the third embodiment of the present invention;

Fig. 7b shows a second step of manufacturing the liner of Fig. 7a;

Fig. 7c shows a third step of manufacturing the liner of Fig. 7a;

Fig. 7dshows a fourth step of manufacturing the liner of Fig. 7a;

Fig. 7e shows a bulk bag comprising the liner of Fig. 7a-7d;

Fig. 7f shows an enlarged view of a section of the bulk bag of Fig. 7e with the liner fixed to the outer bag;

Fig. 8a shows a first step of manufacturing a liner for a bulk bag according to the fourth embodiment of the present invention;

Fig. 8b shows a second step of manufacturing the liner of Fig. 8a;

Fig. 8c shows a third step of manufacturing the liner of Fig. 8a;

Fig. 8d shows a fourth step of manufacturing the liner of Fig. 8a;

Fig. 8e shows a bulk bag comprising the liner of Fig. 8a-8d;

Fig. 8f shows an enlarged view of a section of the bulk bag of Fig. 8e with the liner fixed to the outer bag. DETAILED DESCRIPTION OF THE INVENTION

Fig. 1 shows a tubular liner 1 for a bulk bag according to a preferred embodiment of the present invention, with a tubular surface 4. Through a bottom seam 5, the tubular liner 1 is formed into a bag-like shape. The liner 1 can be made from a PE film material but other materials can of course also be used, depending on what is suitable for the present application of the bulk bag.

In Fig. 2, the liner 1 has been folded to create a bottom 2, across which the bottom seam 5 runs, and two flanges 3 have been created on opposite sides. In Fig. 3, flange seams 6 have been added that run across each flange 3 along the nearest side of the bottom 2, and in Fig. 4 the flanges 3 have been folded towards the flange seams 6. Alternatively, they can be cut off to decrease the amount of material of the liner present inside the bulk bag.

In Fig. 5a and the close-up in Fig. 5b, the liner is shown inside an outer bag 10 with fixing seams 11, along which the liner 1 has been fixed to the outer bag 10. These fixing seams 11 preferably run alongside the flange seams 6, but can alternatively be placed along the other sides of the bottom 2, i.e. along opposite sides of the bottom 2, said sides being the sides without the flange seams 6. It is advantageous to fix the liner 1 to the outer bag 10 along fixing seams 11 rather than pointwise and for the seams to be placed on opposite sides of the bottom 2, since this aids in getting the bottom 2 of the liner 1 to lie flat against a bottom of the outer bag 10, avoiding folds or creases of excess material of the liner 1 that may prevent material contained in the bulk bag from exiting through a rip or tear along the bottom or may result in such excess material falling out of the rip or tear to contaminate the material. The outer bag 10 is provided with handles 12 for easy handling and transport of the bulk bag.

The method of manufacturing the bulk bag with the liner 1 will now be described in more detail.

A sheet of film material, such as for instance a PE material, is made into a liner 1 with a tubular shape and a surface 4, and a bottom seam 5 is produced, preferably by welding or sewing, along one end of the tube to yield a bag-like shape with an opening at an upper end. Then, a bottom 2 is produced by folding the liner 1 , preferably in accordance with markings previously made on the liner 1. By holding the surface 4 of the bag-shaped liner in such a way that four perpendicular sides are created, excess fabric is pushed out into the shape of two flanges 3 on opposite sides of the bottom 2 and the bottom seam 5 runs across the centre of the bottom 2 so that the liner 1 is symmetrical along the bottom seam 5. Then, flange seams 6 are produced, again preferably by sewing or welding, so that the shape of each flange 3 is fixed and the bottom surface 2 is defined by the flange seams 6, and the flanges 3 are removed by cutting or are folded towards the flange seams 6 to prevent undesired folds or creases of liner material and also to add stability to the sides of the bottom surface 2.

In a final step, the liner 1 is fixed to an outer bag 10 along fixing seams 11, again preferably sewn or welded, so that the liner 1 is firmly held with the bottom 2 along a bottom of the outer bag 10. It is advantageous to fix the liner 1 along the flange seams 6 to prevent liner material of the folded flanges 3 from being displaced to run along the bottom of the outer bag 10 and possibly be cut through during an opening of the bulk bag being formed by the liner 1 and the outer bag 10. The liner is generally also fixed to the outer bag 10 along the opening at the upper end, and this can be made in any suitable way.

The bulk bag can be used in various different fields of technology, especially for collecting, transporting and storing free-flowing materials such as chemicals, plastics, cement, flour or fertiliser. After such a material has been placed into the liner 1 of the bulk bag, said bag is closed in a secure manner to allow for handling and transport. When it is desired to remove the material again, the bulk bag can be placed in a hanging position and the bottom can be slit by use of a knife or other sharp object. This allows the free-flowing material to exit the bulk bag in a convenient manner and thanks to the liner 1 provided in accordance with the invention, the contamination of the free-flowing material by parts of the liner can be avoided, while at the same time preventing material from getting stuck in folds or creases of the liner. Thus, an efficient emptying of the bulk bag can be performed.

Fig. 6a-6f discloses a second embodiment according to the present invention, with a liner Γ differing from the one previously described by having a spout 8' provided in the bottom 2' to allow for a convenient emptying of the bulk bag 10'. Said spout 8' is manufactured by using a spout seam 7' in two parts that run across the end of the liner 1 'and also serve to create the bottom 2' (shown in Fig. 6a). The steps of manufacturing the liner 1 ' are described by Fig. 6a, 6b, 6c and 6d, respectively, and correspond to the steps disclosed by Fig. 1, 2, 3 and 4 and described above. The difference lies in the presence of the spout 8' in the bottom 2' that creates a connection between an interior and exterior of the liner without requiring a cutting of the bottom 2' itself.

In Fig. 6e, the bulk bag 10' is disclosed together with the liner 1 ' mounted inside, and showing the spout 8' of the liner inside a corresponding outer spout 13' of the outer bag 10' allowing for a smooth flow of material from inside the bulk bag and out. Handles 12' allow for easy handling and transporting of the bulk bag. Fig. 6f shows a close-up of a corner of the bottom 2' of the liner placed inside the outer bag 10' and secured by fixing seams 11 '.

The use of the bulk bag with the liner according to the alternative embodiment differs from that described through the preferred embodiment above mainly in that the emptying of the bulk bag and the distribution of the material stored inside is facilitated through the use of the spout 8' and outer spout 13'. At the same time, the bottom 2' shows the same stability as that described above, since the flanges 3' and flange seams 6' serve to give stability without the presence of folds or creases of material that would risk trapping material inside. Of course, the spout 8' and outer spout 13' can be sealed during transport or storage to prevent an undesired leakage from the bulk bag.

Fig. 7a- 7f discloses the third embodiment according to the present invention, with a liner 301 differing from the previously described in the first embodiment by having grooves 314 and the opening 315 at the top of the liner 301 to allow for a convenient in conveying the material into the liner 301 as well as facilitate in sealing and closing the top of the liner for carrying and transportation. The opening 315 manufactured by using a groove seam 316 in two parts that run from the top of the line 301 along the groove 314 to the side of the liner 301.

The steps of manufacturing the liner 301 are described by Fig. 7a, 7b, 7c and 7d, respectively, and correspond to the steps disclosed by Fig. 1, 2, 3 and 4 and described above.

In Fig 7e, another embodiment of the outer bag 310 according to the present invention comprising one handle 312.

Fig. 8a-8f discloses the fourth embodiment according to the present invention, with a liner 401 differing from the previously described in the second embodiment by having grooves 414 and the opening 415 at the top of the liner 401 to allow for a convenient in conveying the material into the liner 301 as well as facilitate in sealing and closing the top of the liner for carrying and transportation. The opening 415 manufactured by using a groove seam 416 in two parts that run from the top of the line 401 along the groove 414 to the side of the liner 401.

The steps of manufacturing the liner 301 are described by Fig. 8a, 8b, 8c and 8d, respectively, and correspond to the steps disclosed by Fig. 6a, 6b, 6c and 6d and described above.

The invention is not to be seen as limited by the embodiments described above but can be varied within the scope of the appended claims, as will be readily understood by the person skilled in the art. For instance, the liner and outer bag can be manufactured in different materials and their dimensions can vary according to what is suitable at a given application. Different methods of joining the liner and outer bag to each other, as well as creating the bottom seam or flange seams of the liner can also be employed, such as by use of an adhesive or the like.