WO2011151661A1

WO2011151661A1 - Large-volume packing container for bitumen

Info

Publication number: WO2011151661A1
Application number: PCT/IB2010/001309
Authority: WO
Inventors: Spyridon Synanidis
Original assignee: Bitumen Applied Research Limited
Priority date: 2010-06-01
Filing date: 2010-06-01
Publication date: 2011-12-08
Also published as: EP2576395A1

Abstract

Large-volume packing container for bitumen, the container being made of flexible material and comprising trapezoidal fabric panels forming the lateral walls, adjoining fabric panels being connected to each other in connecting regions extending along their edges so as to form an approximately truncated pyramid-like basic shape prior to filling, wherein the container is closed at the top by a cover wall extending parallel to the bottom wall and having a preferably central filling opening, wherein stabilizing means are arranged in the lower region of the fabric panels forming the lateral walls in order to stabilize the woven fabric to forces occurring obliquely to the warp and weft. The stabilizing means comprise webbings (14) extending obliquely to the warp and weft, the webbings (14) being connected to the fabric panels forming the lateral walls (1,2,3,4) only in said connecting regions (7).

Description

Large-volume packing container for bitumen

The invention refers to a large-volume packing container for bitumen, the container being made of flexible material and comprising trapezoidal fabric panels forming the lateral walls, adjoining fabric panels being connected to each other in connecting regions extending along their edges so as to form an approximately truncated pyramid-like basic shape prior to filling, wherein the container is closed at the top by a cover wall extending parallel to the bottom wall and having a preferably central filling opening, wherein stabilizing means (14) are arranged in the lower region of the fabric panels forming the lateral walls (1,2,3,4) in order to stabilize the woven fabric to forces occurring obliquely to the warp and weft.

A packing container of this type has become known from WO 2009/043071 Al . Bitumen as charge is more difficult to handle insofar as it is a melt, which is liquid to viscous at higher temperatures and sets at lower temperatures. Solidified melts have the property, that even at low temperatures they are not completely rigid. Although bitumen exhibits strong cohesion at ambient temperature, it has a very low internal friction, such that it behaves as a very slow running mass when cooled. If bitumen is filled in a container that is not dimensionally stable, the bitumen dodges during transport or storage due to the plastic flow (slow flow) , which complicates stacking of such containers or makes it impossible. Therefore bitumen is stored in barrels or as small packs in cartons or plastic foil, which as such are dimensionally stable containers. The packing container disclosed in WO 2009/043071 Al comprises lateral walls made of a woven fabric, which in the temperature range from 100° to 110°C has a stretching capacity of 10 - 25%, preferably 15 - 20%, in the direction of the warp and weft, wherein stabilizing means, such as pleats, seams, strips or the like are drawn or sewn into the lower region of the fabric panels forming the lateral walls in order to stabilize the woven fabric to forces occurring obliquely to the warp and weft. Thus the fabric forming the walls can stretch within predetermined limits due to the temperature of the filled bitumen, which leads to a certain bulging of the container. So that the bulge is not too prominent and as well so that no sideways creeping of the container takes place the stabilizing means are inserted in the fabric panels forming the lateral walls. The stability or the prevention of unguided bulging of the container is insofar important, as such containers are loaded in so- called "ISO-Container". These "ISO-Container" are internationally also called "TEU", which stands for "Twenty Feet Equivalent Unit". In these freight containers two packing containers are each put on the floor next to each other and subsequently two further containers are stacked on top of these two packing containers. It has to be avoided, that due to a strong bulging of the containers these are wedged or jammed in the freight container, which could make the unloading of the containers from the freight container difficult or virtually impossible. In order to attain a stabilizing effect, the stabilizing means get stretched to a lesser extent than the fabric forming the lateral walls when the container gets filled with bitumen. In the design disclosed in WO 2009/043071 Al this, however, results in considerable shearing forces occurring between the stabilizing means and the material of the lateral walls, which entails the risk of overstressing the material of the lateral walls and thus the risk of ripping.

The object of the invention is to create a large-volume packing container of the initially mentioned kind, which is self-stabilizing during filling of the bitumen and even when the bitumen stiffened, under stress from above, stands freely. It is also an object of the invention to create a large-volume packing container that substantially maintains its shape even after having been filled with bitumen. Further, it is an object of the invention to prevent ripping of the material of the lateral walls or of the stabilizing means due to shearing forces. Further, it is an object of the invention to enhance the security in handling the packing container. According to the invention this object is solved in that the stabilizing means comprise webbings extending obliquely to the warp and weft, the webbings being connected to the fabric panels forming the lateral walls only in said connecting regions. Webbing is a strong fabric woven as a flat strip or tube of varying width and fibers often used in place of rope. Modern webbing is often made from exceptionally high-strength material, such as nylon, polyester, Kevlar, cotton, polypropylene or flax. Within the scope of the invention polypropylene is preferred. In particular, the webbing is woven from monoaxially drawn polyolefin, preferably polypropylene, tapes. Generally, webbing is both light and strong, with high breaking strengths available. The webbing used according to this invention preferably has a width of approximately 3-6 cm, more preferably approximately 4 cm. The webbings extend from one side edge of the fabric panels forming the lateral walls to the opposite side edge thereof and according to the invention are connected to the fabric panels forming the lateral walls only in said connecting regions extending along the wall edges. Because the webbings are connected to the lateral walls only at said connecting regions, i.e. at the edges of the container where two adjoining lateral walls are connected to each other, the webbings are loosely contacting the lateral walls over their entire length between the connecting regions so that no shearing forces can occur. Thus, the stabilizing effect of the webbings is enhanced. In particular, the stabilizing effect of the webbings is not in any way inhibited by any shearing forces or by the risk of ripping.

In an advantageous manner, two webbings crossing each other are arranged at each lateral wall, the two webbings crossing each other preferably form an "X". In this way, the stabilizing effect is further enhanced and bulging of the container is effectively limited.

According to a preferred embodiment of the invention the webbings are connected to the edges of the fabric panels by sewing. This guarantees a particularly stable connection that can withstand high loads and high temperatures. Further, the container is preferably devised such that adjoining fabric panels are connected to each other along their overlapping edges by a seam, which seam also serves to connect the webbings to the fabric panels. Thus, a single seam holds two adjoining woven fabric panels together and connects the webbings to the edge of the panels. In order to attain an improved stability and to effectively limit bulging of the container the webbings preferably have a breaking strength in longitudinal direction of at least 1000 kg, preferably at least 1300 kg.

In a preferred manner the webbings are provided in the lower half, preferably lower third, of the height of the container. Due to this measure a bulging can be prevented in a particularly effective way, as the stabilizing means are mounted in just the region of the greatest bulging.

Further, it is preferred that in the temperature range from 100° to 110°C the woven fabric forming the walls (1, 2, 3, 4, 5, 6) has a stretching capacity of 10 - 25%, preferably 15 - 20%, in the direction of the warp and weft.

Advantageously a separate inner container of a plastic stable to approximately 100 - 105°C with a melting point of approximately 130 - 150 °C is used. Thereby it is prevented that bitumen sticks to the container and subsequently cannot be detached from the container at the processing place. The inner container is due to its melting point meltable during the processing of the bitumen, whereby due to the small amount of material of the inner container in relation to the overall mass of the bitumen contained in the container no changes in the bitumen quality are to be expected.

The woven fabric used for the walls, in particular the lateral walls, of the packing container preferably is a fabric of monoaxially drawn polyolefin, preferably polypropylene, tapes. These tapes are produced by stretching polyolefin sheets to four to ten times their original length, whereby the molecule chains in the tapes' longitudinal direction are oriented and thus have a strength in this direction which is about 6 to 10 times higher compared to the original sheet. The tape width is usually about 1.5 to 10 mm and the thickness 20-80 pm. Transverse strains cleave the tapes, which is why they are woven into flat fabric made of weft and warp layers about perpendicular to each other. The fabric then has uniformly high tensile strength in all directions. In order to achieve dust and moisture proofness and to prevent the layers of tapes from sliding, a melt coating, which preferably consists or the same material as the tapes, can be applied to, and pressed into, the material on one or both sides thereof. The fabric, in particular the polypropylene fabric, forming the walls can further be stabilized by a coating, in particular a polypropylene coating, wherewith both the stretching ability and the deformation due to forces occurring obliquely to the warp and weft can be prevented in a particularly effective manner.

In order to further enhance the stability and to decrease the risk of ripping the container is preferably devised such that the fabric forming the lateral walls is designed as a double layer woven fabric. Thereby, the inner layer of the double layer woven fabric serves as a security layer in case the outer layer gets damaged due to a possible mishandling of the container. Further, the inner layer is a further means to maintain the shape of the filled container.

In particularly advantageous manner, the outer layer of the double layer woven fabric is configured as a sandwich type fabric comprising two layers of woven polypropylene fabric connected to each other by an intermediate layer of a polypropylene film. The intermediate layer is preferably devised as a lamination and sticks the two layers of the sandwich type fabric together. Due to the intermediate layer the fabric is resistant to rain. Further, the intermediate layer can have ultra-violet radiation protective properties. Advantageously, the outer layer of the sandwich type fabric has a higher density than the inner layer of the sandwich type fabric. In particular, the outer layer of the sandwich type fabric can have a density of at least 100 gr/m², preferably 130 - 140 gr/m², and the inner layer of the sandwich type fabric can have a density of 50 - 100 gr/m², preferably 65 - 85 gr/m². The lower density of the inner layer results in a reduction of the production costs and prevents that the container gets too stiff while still adding to the stability of the container.

In a preferred manner, the webbings are arranged between the outer layer and the inner layer of the double layer fabric. In this way, the webbings are protected from external impacts and other harmful influences.

For easy loading on the one hand and for the hanging of the containers inside the freight container two corner welds lying next to each other of the walls can be connected by straps running roughly parallel to each other.

An embodiment of the invention is schematically shown in the drawing .

Fig. 1 shows a depiction of the container.

Fig. 2 is a section according to line II-II. Fig. 3 is a section of the lateral wall according to line III-III .

The container consists of a truncated cone formed by four trapezoidal lateral walls 1, 2, 3, 4, a floor 5 and a top surface 6, whereby the lateral walls 1, 2, 3, 4 are connected to each other by seams extending along the edges of the later walls in the connecting regions 7, the bottom edge of the lateral walls to the floor by seams 8 and the upper edge of the lateral walls with the top surface 6 by seams 9. The top surface 6 has a filling opening 10, through which the internal lining 11 protrudes, which is closable by a strip 11' or similar.

The inclination of the lateral walls to the floor (see Fig.2, lateral wall 2 and floor 5) is, as indicated for angle a, between 70° and 85°, preferably between 75° and 83°. As already mentioned, this leads to an optimization of the filling volume on the one hand and a corresponding ability to straighten up by itself on the other hand, as when tilting of the container the floor 5 is lifted partially off the setting-up surface, whereby then due to the internal pressure of the filled in bitumen the lifted- off part of the floor is pressed down onto the setting-up surface, whereby due to the tensile rigid connection across the lateral walls (such as wall 4) and the top surface 6 the opposite lateral wall 2 is straightened up, such that a stable structure is achieved. Along the seams 7, 8, 9 the edges of neighboring walls adjoining each other are beaded and in the upper part of the seams 7 the straps 13 are co- sewed, whereby a very strong stitching is effected. In the lower half in the lateral walls 1-4 the stabilizing webbings 14 are arranged. Two webbings 14 crossing each other are arranged at each lateral wall 1-4. These stabilizing means form an "X" and run aslant from one edge of the walls, in particular from the corner area of the walls 1-4, upwards to the opposite edge. The end portions of the webbings 14 are attached to the walls 1-4 at the connecting regions 7. Preferably, the end portions of the webbings 14 are co-sewn with the seams connecting two adjoining lateral walls 1-4. The middle portion of the webbings, i.e. the portion extending between the end portions that are connected to the later walls, is not connected to the later wall at all.

The straps 13 co-sewed along the side edges are formed as loop handles 13', wherein two loop handles running roughly parallel to each other are provided, and wherein the loop handles 13' can serve not only for the lifting via a forklift but as well for the fixation of the container inside of a standard container. This results, as mentioned earlier, in a stable, tensile rigid frame for interposed container walls. In Fig.2 it is indicated, how the separate inner container 11 is introduced in the container, whereby it is essential that the inner container at least in the region of the seams 8 is connected with the walls of the container to prevent that an inwards folding or other deformation of the inner container results, which prevents that the container can be fully filled.

In Fig.3 the different layers of the wall panels can be seen. The walls consists of a double layer woven fabric, the outer layer of which is designated by 15 and the inner layer of which is designated by 19. The outer layer 15 is made of a sandwich type fabric formed comprising an outer layer 16 and an inner layer 17 connected to each other by an intermediate film 18. The inner layer 19 of the double layer woven fabric carries a coating 20 made of a polypropylene film. The webbings 14 are arranged between the two layers of the double layer woven fabric, i.e. between the sandwich type layer 15 and the inner layer 19.

The present container is designed for liquid or viscous or creepable charges like bitumen, whereby it has been discovered, that due to the design the container has a high degree of self stabilizations.

Claims

Claims :

1. Large-volume packing container for bitumen, the container being made of flexible material and comprising trapezoidal fabric panels forming the lateral walls, adjoining fabric panels being connected to each other in connecting regions extending along their edges so as to form an approximately truncated pyramid-like basic shape prior to filling, wherein the container is closed at the top by a cover wall extending parallel to the bottom wall and having a preferably central filling opening, wherein stabilizing means are arranged in the lower region of the fabric panels forming the lateral walls in order to stabilize the woven fabric to forces occurring obliquely to the warp and weft, characterised in that the stabilizing means comprise webbings (14) extending obliquely to the warp and weft, the webbings (14) being connected to the fabric panels forming the lateral walls (1,2,3,4) only in said connecting regions (7) .

2. Packing container according to claim 1, characterized in that two webbings (14) crossing each other are arranged at each lateral wall (1,2,3,4).

3. Packing container according to claim 1 or 2, characterized in that the webbings (14) are connected to the edges of the fabric panels by sewing. 4. Packing container according to claim 3, characterized in that adjoining fabric panels are connected to each other along their overlapping edges by a seam (7,8,9), which seam also serves to connect the webbings (14) to the fabric panels .

5. Packing container according to any one of claims 1 to 4, characterized in that the webbings (14) have a breaking strength in longitudinal direction of at least 1000 kg, preferably at least 1300 kg.

6. Packing container according to any one of claims 1 to 5, characterized in that the webbings (14) are provided in the lower half, preferably lower third, of the height of the container .

7. Packing container according to any one of claims 1 to 6, characterized in that in the temperature range from 100° to

110°C the woven fabric forming the walls (1, 2, 3, 4, 5, 6) has a stretching capacity of 10 - 25%, preferably 15 - 20%, in the direction of the warp and weft. 8. Packing container according to any one of claims 1 to 7 , characterized in that a separate inner container (11) of a plastic stable to approximately 100 - 105°C with a melting point of approximately 130 - 150°C is used. 9. Packing container according to any one of claims 1 to 9, characterized in that the woven fabric is made of monoaxially drawn polyolefine, preferably polypropylene tapes . 10. Packing container according to any one of claims 1 to 9, characterized in that the polypropylene fabric forming the walls (1, 2, 3, 4, 5, 6) is stabilised by a polypropylene coating .

11. Packing container according to any one of claims 1 to 10, characterized in that the fabric forming the lateral walls (1,2,3,4) is designed as a double layer woven fabric.

12. Packing container according to claim 11, characterized in that the outer layer (15) of the double layer woven fabric is configured as a sandwich type fabric comprising two layers (16,17) of woven polypropylene fabric connected to each other by an intermediate layer (18) of a polypropylene film.

13. Packing container according to claim 12, characterized in that the outer layer (16) of the sandwich type fabric (15) has a higher density than the inner layer (17) of the sandwich type fabric (15).

14. Packing container according to any on of claims 11 to 13, characterized in that the webbings (14) are arranged between the outer layer (15) and the inner layer (19) of the double layer fabric.