A LINER HAVING MULTIPLE WALLS

Abstract

 The present invention pertains to a liner for inserting into a bulk bag to provide an additional protection for contents comprises at least two side walls (14); a heat seal (17) between each adjacent side wall (14) formed by a welding line (70, 72, 74, 76, 78) extending longitudinal length of the side walls (14). Each of said side walls (14) defined by tubular films (54, 56, 58, 60) or flat films (62) has at least two layers of material so that each wall (14) of the liner (10) is formed from at least two layers of material. Said liners (10, 100, 200) can be made in a variety of sizes and is suitable to contain a wide range of flowable materials including granular products, and can be folded generally flat when empty.

Description

Technical Field of the Invention

[0001] The present invention relates to a liner for a bulk bag, which is collapsible and formed of a plurality of tubular films of flexible material so that each wall of the liner has at least two layers of material.

Background of the Invention

[0002] Flexible intermediate bulk containers, also known as bulk bags or big bags, are daily used throughout industry to receive, store, transport and discharge a wide variety of materials. Some of these bulk bags are flexible, contain a liner, and when empty can be folded to a generally flat condition. Generally, liners are receivable in the respective bags wherein the liners are attachable to the bags. Bulk containers, especially bulk bags, include a number of flexible elements attached to each other along longitudinally extending seams.

[0003] Bulk bags are used for the storage and transportation of dry, granular or powder products and type of the stored materials in the large bulks are variable. The liners are inserted into bulk bags to provide additional protection for the contents. Because of the stored of large amount material, stiffness of the liner plays a crucial role for carrying said material and products.

[0004] All liners can be made from a variety of materials. Over the years, liners have been manufactured from a variety of materials and have been provided in a variety of configurations. Polyethylene liners are ideal for handling dry bulk materials, allowing fill and discharge with ease, and generally arranged to be fit in flexible intermediate bulk containers. Said liners are, mostly, are in a form of single layer and kept in roll form, and subjected to thermal treatment process for in the bulk bags. The bulk bags have a spout in one or both ends for filling and emptying the bags. When filing the inner bag, localized stresses may occur within the inner liner decreasing its effectiveness. One of the problems that one could face is that during the loading, the occurred localized stresses potentially lead to a rupture on the liner.

[0005] A prior art publication in the technical field of the present invention may be referred to as US5556205 (A) among others, the document disclosing a flexible intermediate bulk container includes a number of flexible elements sewn to each other along longitudinally extending seams, at least two of the elements being tubular. Stored materials in the liner also could lead to a puncture or leakage in time. In addition to this, being in the form of thin and monolayer of the liner may cause the liner to be affected negatively.

[0006] The liners often include inherent weak regions which lead to failure and the liner could be useless because of the in the course of heavy loading. At the same during the extrusion of the liner, pin holes can be occurred on the walls of the liner which can also lead to failure. In addition, the construction of connectors and the application of same to the liners has generally been a labor intensive process which increases manufacturing costs and manufacturing time. To maintain the integrity of the liner it is imperative that walls of the liners not be damaged, breached or broken during manufacture and assembly of the liner.

[0007] The present invention therefore provides an arrangement as to the liner having multiple walls, which is defined by the characterizing features as defined in Claim 1.

Objects of the Invention

[0008] Primary object of the present invention is to overcome the abovementioned shortcomings of the prior art.

[0009] Another object of the present invention is to provide the liner for bulk bags formed of a flexible material with multiple walls for enhancing stability with high tensile strength.

[0010] Another object of the present invention is to provide the liner affecting less from outer environment condition at the same by keeping at almost same condition of the stored material safely by proposing longer shelf life for stored materials.

[0011] Another object of the present invention is to provide the liner reducing rupture of any wall or seam by having multiple walls and not allowing transfer of moisture and water vapor to outer and inner environment, in a similar manner keeping stored materials safely and not allowing transfer of moisture and water from inner to outer environment.

[0012] Another object of the present invention is to provide the liner that facilitates the manufacture of liners having walls formed from two or more layers of material, is of relatively simple design and economical manufacture and assembly, and can be produced by a method which is substantially automated, efficient and relatively simple to perform.

Summary of the Invention

[0013] The present invention pertains to a liner for inserting into a bulk bag to provide an additional protection for contents comprises at least two side walls; a heat seal between each adjacent side wall formed by a welding line extending longitudinal length of the side walls. Each of said side walls defined by tubular films or flat films has at least two layers of material so that each wall of the liner is formed from at least two layers of material. Said liners can be made in a variety of sizes and is suitable to contain a wide range of flowable materials including granular products, and can be folded generally flat when empty.

Brief Description of the Figures

[0014] Accompanying drawings are given solely for the purpose of exemplifying a liner having multiple walls, whose advantages over prior art were outlined above and will be explained in brief hereinafter. The drawings are not meant to delimit the scope of protection as identified in the claims nor should they be referred to alone in an effort to interpret the scope identified in said claims without recourse to the technical disclosure in the description of the present invention.

Figure 1 demonstrates a perspective view of the liner for a bulk bag according to the present invention.

Figure 2 demonstrates a top view of a liner for a bulk bag according to the present invention.

Figure 3 demonstrates a perspective view of another embodiment of a liner according to the present invention.

Figure 4 is an end view of a plurality of tubular films positioned to form a multiple walled liner.

Figure 5 is an end view as in figure 4 illustrating the plurality of tubular films of figure 4 joined together by welding line.

Fig. 6a demonstrates a perspective view of another embodiment of a liner according to the present invention.

Fig 6b demonstrates a perspective view of another embodiment of a liner according to the present invention.

Detailed Description of the Invention

[0015] Referring now to the figures outlined above, the present invention is detailedly described hereinbelow. The reference numbers used in the figures are as follows:

10.

Liner

11.

Top wall

12.

Bottom wall

14.

Side wall

15.

Spout

17.

Heat seal

20.

Inclined welding line

21.

Inclined welding line

22.

Inclined welding line

23.

Inclined welding line

30.

First line

31.

Second line

50.

Metal frame

52.

Welding head

54.

Tubular film

56.

Tubular film

58.

Tubular film

60

Tubular film

62.

Flat film

70.

Welding line

72.

Welding line

74.

Welding line

76.

Welding line

78

Welding line

80.

Outer edge

82.

Outer edge

84.

Outer edge

86.

Outer edge

100.

Liner

200.

Liner

[0016] The present invention relates to a liner (10, 100, 200) comprising at least two substantially rectangular side walls (14) having at least two layers of material so that each wall (14) of the liner (10) is formed from at least two layers of material, and a heat seal (17) between each adjacent side wall (14) formed by a welding line (70, 72, 74, 76, 78) extending longitudinal length of the side walls (14).

[0017] In a preferred embodiment, the liner (10), preferably facing to flexible intermediate bulk containers, comprises generally in a form of rectangular top wall (11) and bottom wall (12), with each wall (11, 12, 14) formed from at least two layers of material.

[0018] As it can be seen in fig. 1, a spout (15) can be provided on the top wall (11) and in another embodiment, figure 3, the spout (15) can be provided in both of the top and bottom walls (11, 12). Said spout (15) can be welded or heated onto the one end of the walls (14) or both ends of the walls (14). When the spout (15) is welded for combining with the walls (14), the production process is simplified, the production efficiency is enhanced, and the liner is arranged properly for filling and discharging. Referring to the fig. 6, another embodiment of a liner (200) is shown. Said spout (15) can be welded are heated onto the liner (200) at the open ends of the walls (14).

[0019] In a preferred embodiment, the liner (10) is generally formed from a flexible plastic sheet material which is mostly impervious to liquid as desired for a particular application. Said liner (10) may be made in a variety of sizes and is suitable to contain a wide range of flowable materials including granular products and liquids, and can be folded generally flat when empty.

[0020] Referring to fig. 4 and 5, the liner (10) can be formed from polyethylene (PE)-based films to capture numerous packaging applications due to their performance and economic advantage. A plurality of tubular films (54, 56, 58, and 60) of material is used to form the liner (10). Each tubular film (54, 56, 58, and 60) is preferably circumferentially continuous and elongate so that a plurality of liners (10) may be formed from an elongate tubular films of material with the liners (10) interconnected in end to end relation in the web. The tubular films (54, 56, 58, and 60) may also be used separated for forming individual bags.

[0021] Again referring to the figure 4 and 5, a first pair of tubular films (56, 58) are folded in half and are disposed between a second pair of generally flat tubular films (54, 60). The folded tubular films (56, 58) are preferably mirror images of each other and define a generally U-shaped facing in generally opposed directions. Each folded portions of one of the flat tubular film (54) is heat sealed at its outer edges (80) to the corresponding outer edges (82) of the overlying U-shaped tubular films (56, 58). In a similar manner, each folded portions of the other flat tubular film (58) is heat sealed at its outer edges (86) to the corresponding outer edges (84) of the U-shaped tubular films (56, 58). Specifically, edges (80) are sealed to edges (82) along welding line (70). Referring to the fig. 2, first and second lines (30, 31) of borders where the liner has double layers can be seen.

[0022] A metal frame (50), an object having low thermal conductivity, is disposed in each u-shaped tubular films (56, 58) in the area of a welding head (52) to prevent the adjacent portions of the U-shaped tubular films (56, 58) from being heat sealed to each other. When connected in this fashion, a circumferentially continuous film is formed with the flat tubular films (54, 60) arranged to define a pair of opposed side walls of the liner (10) and the U-shaped tubular films (56, 58) arranged to define a second pair of opposed side walls of the liner (10) when filled. The juncture or connection between each adjacent side wall (14) is formed by a heat seal (17) extending the full length of the side walls (14).

[0023] Referring to fig. 1, to provide substantially rectangular top wall (11) when the liner (10) is expanded, the liner (10) is heat sealed along inclined welding lines (20, 22, 24, and 26) extending from the welding lines (70, 72, 74, and 76). To provide a square walls, the inclined welding lines (20, 22, 24, and 26) extend at an included angle of 45° relative to the side edges of the film defined by the welding lines (70, 72, 74, and 76). Referring to figure 3, there is shown a liner (10) comprising another embodiment of the invention. The liner (10) is substantially identical in construction and functions to the liner (10), illustrated in figure 1, .The difference is that the liner (10) is provided with spout (15) both of the top and bottom walls (11, 12).

[0024] Instead of tubular films (54, 56, 58, and 60) flat films (62) can also be used for defining side walls (14). Another embodiment of a liner (100) can be seen in figure 6a; two interconnected side walls (14) defined by flat films (62) are sealed each other by heat seal (17). One of the important advantages of the flat film (62) is that allowing the selecting from a variety of materials. Using flat films for liner helps to the producer choose different kind of materials.

[0025] Another embodiment of a liner (200) can be seen in fig. 6b; in this embodiment the liner (200) has no spout (15) or top wall (11). On the other hand, said spout (15) can be welded to the upper end of the liner (200). Again referring to the fig. 6b, the user can fill and discharge the liner (200) with ease, and two interconnected side walls (14) having at least two layers of material, are sealed each other. In addition to this, the liner (10) is heat sealed along welding lines (78) extending longitudinal length of the side walls for defining a heat seal (17).

[0026] While the embodiments of this invention have been described with reference to liners having walls formed of two or three layers of material, modifications or variations will be readily apparent to those skilled in the art. For instance, a liner with each wall having four layers of material can be formed as well. Other combinations of tubular films to provide still further additional layers of material of each wall of the liner are also possible and will be readily recognized by those skilled in the art. Still further, while the lines of connection between the films used to form the liner have been described herein as heat seals, other methods of connection, including but not limited to stitching, stapling and joining with adhesive, may also be employed as desired.

[0027] Although preferred embodiments of the invention have been illustrated in the accompanying drawings and described in the foregoing detailed description, it will be understood that the invention is not limited to the embodiments disclosed, but is capable of numerous rearrangements, modifications, and substitutions of parts and elements without departing from the spirit of the invention.

Claims

1. A liner (10, 100, 200) for inserting into a bulk bag to provide an additional protection for contents comprising:

at least two side walls (14);

a heat seal (17) between each adjacent side wall (14) formed by a welding line (70, 72, 74, 76, 78) extending longitudinal length of the side walls (14)
characterized in that

each of said side walls (14) has at least two layers of material so that each wall (14) of the liner (10) is formed from at least two layers of material.

2. A liner (10, 100, 200) as set forth in Claim 1 wherein said liner comprises four interconnected rectangular side walls (14).

3. A liner (10, 100, 200) as set forth in Claim 1 wherein each of said four side walls (14) is defined by a one of four tubular films (54, 56, 58, 60).

4. A liner (10, 100, 200) as set forth in Claim 1 wherein each of said walls (14) is defined by flat film (62).

5. A liner (10, 100, 200) as set forth in Claim 1 wherein said liner (10, 100, 200) comprises top and bottom walls (11, 12) disposed on opposed ends of the side walls.

6. A liner (10, 100, 200) as set forth in Claim 1 wherein said liner comprises at least one spout (15) provided on one or both of the top and bottom walls (11, 12).

7. A liner (10, 100, 200) as set forth in Claim 6 wherein said at least one spout (15) is welded or heated onto the liner (10, 100, 200) for filling or discharging properly.

8. A liner (10, 100, 200) as set forth in Claim 6 wherein the top and/or bottom walls (11, 12) are defined by inclined lines (20, 21, 22, 23) of connection joining together adjacent portions of the side walls (14).

9. A liner (10, 100, 200) as set forth in Claim 3 wherein each tubular film (54, 56, 58, 60) are formed from a flexible plastic sheet material which is impervious to liquid.

10. A liner (10, 100, 200) as set forth in Claim 3 wherein a first pair of tubular films (56, 58) is folded in half and disposed between a second pair of flat tubular films (54, 60).

11. A liner (10, 100, 200) as set forth in Claim 3 wherein said folded tubular films (56, 58) are preferably mirror images of each other and define a U-shaped facing in opposed directions.

12. A liner (10, 100, 200) as set forth in Claim 3 wherein each folded portions of one of the flat tubular films (54, 60) is heat sealed at its outer edges (80, 86) to the corresponding outer edges (82, 84) of the overlying U-shaped tubular films (56, 58).

13. A liner (10, 100, 200) as set forth in Claim 1 wherein the heat seal (17) extends full length of the side walls (14).

Drawing