WO1997001496A1

WO1997001496A1 - Container liners

Info

Publication number: WO1997001496A1
Application number: PCT/GB1996/001513
Authority: WO
Inventors: Andrew Stephen Paul Tisi
Original assignee: Philton Polythene Converters Limited
Priority date: 1995-06-24
Filing date: 1996-06-21
Publication date: 1997-01-16
Also published as: GB9512916D0

Abstract

A liner (16) is disclosed for the bulk transport of flowable particular products in a cargo container (10) having a pair of corner fillet boards (20) extending diagonally across two lower corner regions at one end of the container. The liner (16) is in the form of a bag fabricated from flexible plastics sheet material, so as to fit closely within the container (10). The two portions (21) of the liner which, when the liner is installed in a container, are disposed generally in said corner regions are pre-shaped closely to follow the three-dimensional topology of the container and the fillet boards (20) extending across the corner regions. The fillet boards (20) may be received in pockets (26) pre-formed in said portions (21) of the liner (16).

Description

CONTAINER LINERS

This invention relates to container liners, and also to the combination of a container liner suspended within a container, for the bulk transport of flowable particulate products. Containers of standardised sizes are ever more being used for the transport of products. The products may be packaged appropriately and then the packages loaded into the container, or - depending upon the nature of the products - those products may be loaded directly into the container. In order to allow the direct loading of particulate products, such as powders, granules or the like, it is known to fit within a container a bag-like flexible liner for example of polyethylene which liner is provided with an inlet accessible when the liner has been fitted into a container, whereby a bulk product may be loaded into the liner for transport. A wide variety of particulate materials may be carried in bulk in this way, and in view of the isolation of the product from the ambient, even food products may conveniently be transported.

The conventional way of discharging a powder-like material carried in a liner within a container is to allow the material to run under gravity out of a discharge provided at one end of the liner, by tipping the container. The wall of the container in the region of the discharge may be provided with a hatch having a door which, when opened, gives access to the discharge of the liner. In an alternative arrangement, at the end of the container provided with the conventional doors, a bulkhead structure is provided within the container to retain the load and liner in position, the structure having an aperture giving access to the discharge. When the container is to be discharged, either a hatch in the container doors or the container doors themselves are opened, to gain access to the discharge through the aperture in the structure.

For some designs of liner, the discharge comprises a tube communicating with the interior of the liner and which tube is normally closed off, but which may be opened in order to allow product to run out of the liner. Such a tube may be closed with adhesive tape. In the alternative, a collector or funnel-like arrangement may be offered to the liner and the liner is then slit to allow product to run out of the liner into the collector or funnel-like arrangement. The liner may be pre-slit, during manufacture, and be held closed with adhesive tape or other fasteners, which may be released to open the slit, when the liner is to be discharged.

At the completion of a discharge operation, after the container has been tipped and product has been allowed to run out of the liner discharge, there is a tendency for the product to accumulate in the lower corner regions of the liner. Significant quantities of product may remain in the liner and steps may have to be taken to ensure the complete emptying of this remaining product. For example, not infrequently an operator has to thrust a suitable implement into the container, between the liner and the container wall, physically to man-handle the liner to move product remaining within the liner, towards the discharge.

In a case where a structure is provided within the container at the discharge end, it is known to mount triangular fillets in the lower corner regions at the discharge end of the container, to minimise the likeli¬ hood of product accumulating in those regions during a discharge operation. Despite that and depending upon the angle of repose of the product, significant quantities of product may still remain in the liner. Research has shown that this is in part due to the creasing and folding of the liner which occurs to allow the liner to lie over the corner fillets, so preventing free flow of the product.

It is a principal aim of the present invention to address the above problem, associated with the discharge of a liner when fitted to a container having corner fillets at the discharge end thereof.

According to one aspect of the present invention, there is provided a liner for the bulk transport of flowable particulate products in a container which has in use a pair of corner fillets extending diagonally across two lower corner regions at one end of the container, which liner comprises a bag fabricated from flexible plastics sheet and adapted for location within the container, the two portions of the liner which are in use to be disposed in said corner regions being pre¬ shaped closely to follow the three-dimensional topology of the container and the fillets extending across the corner regions thereof. By pre-shaping the container liner during the fabrication thereof so as closely to follow the topology of the container and the corner fillets, the liner when in use and loaded with a product will not have creased or folded portions overlying the corner fillets. Consequently, there will be a reduced tendency for product to accumulate over those corner fillets and better emptying of the container can be assured.

The liner may be fabricated to have, at each of two said portions, a panel of substantially the same shape and size as the fillet over which said panel is to lie, the panel being disposed with respect to the adjacent areas of the liner such that in use, the panel and the adjacent areas are all substantially crease- free. To ensure this, each of said adjacent areas should be of essentially rectangular shape, of substantially the same size as the container walls against which those areas lie, when in use.

Each said portion of the liner may be formed with a respective pocket, in which may be received at least in part, but preferably substantially wholly, the associated corner fillet of the container. Each fillet may be disposed in its respective pocket before the liner is fitted to the container, so that the fillet is in its required position within the container only immediately before the container is to be loaded. In this case, the fillet may be sealed in the pocket, by closing the pocket for example with adhesive tape. Alternatively, the fillet may be fitted to the container and subsequently, as the liner is located therein, the liner may be pulled over the fillet so that the fillet is received in the pocket.

In view of the foregoing, a second but closely related aspect of the present invention provides a liner for the bulk transport of flowable particulate products in a container, which liner comprises a bag fabricated from flexible plastics sheet and adapted for location within the container, the two portions of the liner which are in use to be disposed in two lower corner regions at one end of the container being pre- shaped to define a panel which in use will extend diagonally across said two lower corner regions, the liner defining in conjunction with each said panel a pocket in which may be disposed a substantially rigid triangular fillet to extend in use diagonally across the respective lower corner region of the container.

In a preferred liner of this invention, the region thereof adjacent the outlet is configured to hold at least one substantially rigid board which, in use, may bear on a bulkhead within the container to support the liner and a contained load. Alternatively, that region is configured to hold a pair of substantially rigid boards, one to each side respectively of the outlet, which boards, in use, may bear on a bulkhead within the container to support the liner and a contained load. In this arrangement, each of the pair of boards may be of triangular form, so that an edge of each board lies closely adjacent an edge of the adjacent triangular plate which forms the corner fillet. These boards thus serve to support the lower corner region of the liner, towards the central discharge. Advantageously, the liner defines a pocket for receiving the or each substantially rigid board, though the board could be held in place on the liner by any other suitable technique, such as by using double-sided adhesive tape.

The location of the liner within a container may be performed in an essentially conventional manner. Thus, the liner may have side and top wall areas with suspension means, such as a plurality of spaced tension members, provided along the edge regions between the side and top wall areas. In another arrangement, the liner may simply be placed in the container, and then inflated prior to the filling of the container.

Discharging of a loaded liner of this invention may also be essentially conventional. The liner may have discharge means provided between the pre-shaped regions, such as an outlet pipe or a panel intended to be slit to allow products to flow out of the liner into a funnel, tundish or the like. Also, the liner may have an inlet arranged conventionally, to permit loading of product. At least the discharge region of the liner of this invention may be reinforced with a panel of a flexible material which overlies the material of the liner. Such a reinforcing panel may be of a plastics material sheet similar to that of the liner itself, or may be of a sheet of greater strength. When the liner is to be discharged, such a panel may be slit through together with the liner, to allow the outflow of contained product. Alternatively, and particularly where the liner has a discharge tube or other outlet pre-formed therein, the reinforcing panel may be pre-slit and then held closed by suitable means such as adhesive tape, a clasp-fastener or the like. The slits in the reinforcing panel may then be opened when discharge is to occur. Another possibility would be for the reinforcing panel to have defined lines of weakness (for example by perforating) and for the panel to be torn along those lines when discharge is to occur.

This invention extends to the combination of a container having a pair of corner fillets extending diagonally across two lower corner regions at one end of the container and a liner of this invention as described above, which liner is located within the container with said portions overlying said corner regions of the container.

By way of example only, one specific embodiment of container liner of this invention and intended for use with a container for the bulk transport of particulate product will now be described in detail, reference being made to the accompanying drawings, in which:-

Figure 1 is an end view on a container including corner fillets and having suspended therein a liner of this invention; and

Figure 2 is a detailed view on a modified form of the lower left-hand corner region of the arrangement shown in Figure 1. In the drawings, there is shown a conventional container 10 having a floor 11, a pair of side walls 12 and a top 13. The further end of the container is closed, but the end shown in the drawings is provided with a pair of doors 14. Those doors may be provided with an hatch (not shown) having a further door which when opened allows access to be gained to the lower central end region 15 of a liner 16, suspended within the container. Such access is required when the doors of the container have been closed and the liner has been filled with product, to allow discharge of the product from the liner. In the alternative, a bulkhead structure (not shown) may be provided within the container to support the end of the liner even when loaded and the doors 14 have been opened. Suitable bulkhead assemblies are known in the art, or a bulkhead assembly as described in our co-pending International Patent Application No. PCT/GB96/ , filed simul¬ taneously herewith, may be employed.

The liner 16 is fabricated from a flexible plastics material such as sheet polyethylene, which may be in tubular form. The liner is bag-like and of generally rectangular cross-sectional shape, both horizontally and vertically, such that the liner when loaded with product bears against and is supported by the floor and side walls of the container, and also by the closed end wall (not shown) and the closed doors 14. The liner is suspended from the edges thereof along the junctions between the two side walls of the liner and the top thereof, by means of tapes suitably secured to the liner and attached to the upper corner regions of the container.

In a manner known per se, the container of Figure 1 is provided with a pair of substantially rigid corner fillet boards 20, each of triangular shape and arranged so as to extend substantially diagonally across the corner regions of the container. The boards may be attached in position within the container for example by means of self-adhesive tapes, or by being nailed directly to the floor of the container, when that is made of a material such as wood. The liner 16 has the portions 21 thereof, which directly overlie the boards 20, suitably shaped so as to be of essentially the same topology as the corner regions of the container, with the fillets in place. Thus, the two lower corner regions of the liner each have a panel of essentially the same shape let thereinto with the excess material of the liner being trimmed away. That panel may be of the same material as that of the main part of the liner and may be secured in position for example with double-sided adhesive tape, by a chemical welding or bonding process, by using an adhesive, or by a heat-welding process.

With the two lower corner regions of the liner shaped closely to fit the internal topology of the container at the lower corner regions thereof adjacent the doors, when the liner is loaded with product, there will be no creasing and folding in those corner regions, to accommodate excess material. The liner thus presents a smooth internal surface for the product which may consequently flow easily thereover. In this way, accumulation of product in the corner regions at the discharge end of the container may be avoided, when discharging products.

Figure 2 shows a modified lower corner region of the liner 16. Here, a second sheet 25 of the material from which the liner is made is secured in position to overlie the triangular panel let into the main part of the liner. This forms a pocket 26 in the corner region, in which pocket 26 is received the corner fillet board 20. In the illustrated arrangement of Figure 2, the opening to the pocket is along edge 27, though alternatively that edge could be bonded to the liner and the opening provided along the diagonal edge 28.

With the arrangement of Figure 2, the corner fillet board 20 need not be securely attached to the container itself. Instead, the board 20 may be located in the pocket 26 in the liner as the liner 16 is being suspended within the container, or may even be located in that pocket beforehand, prior to the liner being situated within the container. The liner itself may give sufficient support for the board, though for greater security each corner region of the liner may be secured to the floor of the container, for example by using adhesive tapes 29 (Figure 2).

Apart from the above difference, the modified arrangement of Figure 2 is essentially the same as that described above with reference to Figure 1 and offers the same advantages in relation to the discharge of product.

Though not shown in the drawings, either embodiment of liner may be provided with a reinforcing panel which overlies the illustrated end region of the liner. Such a panel may be of a stronger sheet plastics material than the liner, and be adhered to the liner so as to extend over at least the discharge end of the liner.

Claims

1. A liner for the bulk transport of flowable particulate products in a container which has in use a pair of corner fillets extending diagonally across two lower corner regions at one end of the container, which liner comprises a bag fabricated from flexible plastics sheet and adapted for location within the container, the two portions of the liner which are in use to be disposed in said corner regions being pre-shaped closely to follow the three-dimensional topology of the container and the fillets extending across the corner regions.

2. A liner as claimed in claim 1, wherein the liner has, at each of said two portions, a panel of substantially the same shape and size as the fillet over which said panel is to lie, the panel being disposed with respect to the adjacent areas of the liner such that in use the panel and adjacent areas are substantially crease-free.

3. A liner as claimed in claim 2, wherein each of said adjacent areas is of essentially rectangular shape, of substantially the same size as the container walls against which those areas lie in use.

4. A liner as claimed in any of the preceding claims, wherein each said portion of the liner is formed with a respective pocket to receive at least in part the associated fillet of the container.

5. A liner as claimed in claim 4, wherein each fillet is substantially wholly received in its associated pocket and is located within the container at the required position by the liner.

6. A liner as claimed in claim 5, wherein each fillet is sealed within its respective pocket in the liner.

7. A liner for the bulk transport of flowable particulate products in a container, which liner comprises a bag fabricated from a flexible plastics sheet and adapted for location within the container, the two portions of the liner which are in use to be disposed in two lower corner regions at one end of the container being pre-shaped to define a panel which in use will extend diagonally across said two lower corner regions, the liner defining in conjunction with each said panel a pocket in which may be located a substantially rigid triangular fillet to extend in use diagonally across the respective lower corner region of the container.

8. A liner as claimed in claim 7, wherein in each pocket there is provided a respective triangular plate which, when the liner is in use in a container, will form a corner fillet across the lower corners of the container at the discharge end thereof.

9. A liner as claimed in any of the preceding claims, wherein the region of the liner adjacent the outlet is configured to hold at least one substantially rigid board which, in use, may bear on a bulkhead within the container to support the liner and a contained load.

10. A liner as claimed in any of claims 1 to 8, wherein said region of the liner adjacent the outlet is configured to hold a pair of substantially rigid boards, one to each side respectively of the outlet, which boards, in use, may bear on a bulkhead within the container to support the liner and a contained load.

11. A liner as claimed in claim 8 and claim 10, wherein each of the pair of boards may be of triangular form, so that an edge of each board lies closely adjacent an edge of the adjacent triangular plate which forms the corner fillet.

12. A liner as claimed in any of claims 9 to 11, wherein the liner defines a pocket for receiving the or each substantially rigid board.

13. A liner as claimed in any of the preceding claims, wherein the liner has side wall areas and a top wall area, with suspension means being provided along the edge regions between the side wall areas and the top wall area.

14. A liner as claimed in claim 13, wherein the suspension means comprises a plurality of spaced tension members secured to the liner along each of said edge regions.

15. A liner as claimed in any of the preceding claims, wherein the end of the liner having the pre- shaped regions is provided with outlet means adapted to allow the discharge of the loaded liner therethrough on raising the other end of the container.

16. A liner as claimed in any of the preceding claims, wherein a flexible reinforcing panel is attached to and overlies at least the discharge region of the liner.

17. The combination of a container having a pair of corner fillets extending diagonally across two lower corner regions at one end of the container and a liner as claimed in any of the preceding claims, which liner is suspended within the container with said portions overlying said corner regions of the container.