GB2239444A - Lined containers - Google Patents

Abstract

A container suitable for hazardous liquids, e.g. agrochemical concentrates, comprises a protective shock-absorbing outer (1) made from compressed recycled cellulose fibre material and a blow-moulded snap-fitting plastics liner (3) chosen to be impermeable to the liquid to be stored. The density of the fibre material is chosen to give the required strength and shock-absorption. The process for making the outer is adapted to give a relatively smooth inside surface (21) but rough outer surface (19) to facilitate handling and improve shock-absorption. The container is stackable and has a heat-sealed plastics/foil laminate lid. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO CONTAINERS The present invention relates to containers and in particular to containers suitable for storing hazardous products, e.g. liquid concentrates.

At present most hazardous liquids are stored in metal drums or, where smaller quantities are required, plastics containers. Such plastics containers clearly have to be made from a material which is impermeable and resistant to the liquid to be stored but also have to be made sufficiently thick to withstand mechanical shocks which frequently occur during transport, storage and use.

Once the contents have been used, however, it is necessary to dispose of the container and while traditionally such containers would be disposed of by burning or dumping, this is becoming increasingly difficult because many of the plastics used are not bio-degradable and can give off noxious fumes when burnt. For these reasons the use and manner of disposal of certain plastics, e.g.

polypropylene and PVC is being restricted in many countries.

According to the present invention there is provided a container comprising a protective outer made from compressed fibre material and retained therein, a rigid or semi-rigid plastics liner conforming to the inside of the protective outer and adapted to be resistant to its intended contents.

The fibre outer supports the plastic liner and is shock-absorbant to protect the plastics liner against mechanical shocks. It also acts to some extent as a temperature insulator thus preventing sudden changes in the temperature of the surroundings being transmitted quickly to the contents. This can be important because some substances can be degraded by sudden temperature changes. The presence of the supportive and protective container outer means that the plastics used for the liner can be thinner than in the all-plastics containers formerly used. Thus there is less plastic to dispose of, and also as the liner is not providing the main structural support of the container the plastics simply needs to be chosen to be resistant to the contents rather than to provide strength.This gives greater freedom of choice of plastics to be used and may allow a more environmentally-friendly plastic to be used.

Where the container is for a liquid the liner should, of course, be impermeable to the liquid. The liner may be gas impermeable to prevent passage of noxious fumes from the contents or damaging gas or vapour to the contents.

The liner may be retained in the container outer by snap-fitting, e.g. by providing the outer with lugs or a rim onto which the liner is snapped. As further security the liner may also be glued into the outer. Alternatively the outer may have a plain open end, i.e. without a rim, the liner simply wrapping over the top plain edge.

The compressed fibre material may be bio-degradable, preferably compostable, e.g. recycled cellulose fibre produced from waste paper and this further eases the problems of disposal because the bulk of the container is made from an environmentally-friendly material.

The liner may have a closed end, side walls extending from the closed end to an open end surrounded by a rim formed by turning the side walls outwardly, the rim providing an attachment surface for a lid which may be a metal foil/plastics laminate lid heat-sealed to the rim.

The container outers are preferably adapted to be restable, and may be adapted to allow easy stacking of complete containers e.g. by providing in the underneath of the container a recess which can accept the top of another of the containers.

The containers may also be made into a "clutch" connected by strips of the fibrous material and from which the individual containers can be torn as desired. This can be achieved by forming all of the outers of the containers integrally with each other. The strips connecting the containers may be adapted to facilitate the division of the containers, e.g. by making the strips suitably thin or by perforating the strips.

The container may further comprise a water-soluble or dispersible envelope for containing the contents, the envelope simply resting in the container so that it can be tipped out by inverting the container. To avoid puncturing the envelope the inside surface of the plastics liner can be made smooth. The provision of the envelope is particularly useful where the container is used for harmful solids or liquid concentrates which are to be added to a water-diluent, because the presence of the water soluble or dispersible envelope reduces the chances of the user accidentally coming into contact with the concentrate.

The container may be divided into several compartments by at least one wall of the compressed fibre material, one plastics liner extending through all compartments or separate liners being provided for each.

The compartments may be different sizes.

The container is particularly useful for storing hazardous materials and particularly liquid agro-chemicals such as liquid fertilizers or biocides.

The invention will be further described by way of non-limitative example with reference to the accompanying drawings, in which: Fig. 1 is a diagrammatic cross-sectional view of an embodiment of the invention; Fig. 1A shows part of an alternative embodiment; Fig. 2 is a side view of a second embodiment of the invention; and Fig. 3 is a diagrammatic cross-sectional view of a third embodiment of the invention.

As can be seen from Fig. 1 the container comprises an outer 1 of approximately cylindrical shape but which flares steadily from a closed bottom towards an open top.

The outer is made from a compressed cellulose fibre material made from recycled paper and in the production process, which is described below, the inside surface 21 is made to be smooth compared to the outside surface 19 which is rough.

This exterior roughness increases the shock-absorbing properties of the outer and also makes for easier handling of the container. The flaring of the container outer allows empty outers to be nested for easy storage and transport.

The container is also provided with a plastics liner 3 which snap-fits inside the outer 1 by interengagement of a rolled-over rim 11 on the liner and a lip 13 provided around the top of the outer. The annular upper surface 5 of the rolled-over rim of the liner is smoothly curved or flat to allow a lid 7, which is metal foil and plastics laminate, to be heat-sealed to it after filling of the container. A tab 9 is provided around the periphery of the lid which can be used to remove the lid.

In an alternative embodiment shown in Figure 1(A) the upper edge of the outer 1 is plain, i.e. has no rim, the liner 3 simply extending over the edge. The lid is then heat sealed to the top edge of the liner as before.

The plastics liner 3 is rigid or semi-rigid so that it is self-supporting in the outer i.e. does not collapse as the container is emptied. In order to assist maintaining it in position the bottom of the liner 3 is attached with glue 15 to the floor of the outer 1. The material of the liner is chosen according to the liquid to be stored to be impermeable and resistant to that liquid. Typical materials are: P.V.A., polyethylene, polypropylene, polyamide (Nylon Reg. Trade Mark), PET, PVDC or PVC. It may be made by blow-moulding or any other suitable process.

The outer 1 is made from recycled cellulose fibre obtained from waste paper by mulching the paper with water, aluminium sulphate (as a pH adjuster) and rosin by drawing it through a coarse mesh. The rosin helps bind the fibres together and increases the rigidity and water resistance of the final product. A deflacker may be used to assist fibre break-up. The slurry so produced is drained on a belt and applied to a fine wire-mesh mould against which it is compressed to expel the liquid. In this embodiment the mould is formed into the shape of the inside of the container outer 1 and this results in a relatively smooth inside impressed with the pattern of the mesh used. The outside is left somewhat rougher.The amount of compaction applied in the moulding process and also the fineness of the mesh used to chop the paper into fibres affect the density of the product and thus its rigidity and shock absorption properties. A denser material can be used to increase strength but this reduces the effectiveness of the shock absorption and the final result is a selected compromise between the two to give the required result for the particular application.

Figure 2 shows a further example of the invention in which the containers may be made into a "clutch" for ease of handling and storage by forming the container outers 1 integrally with each other so as to be connected by strips of material 25. These may be at the top as shown or positioned differently as is convenient. The strips 25 can be adapted to facilitate division of the containers by making the strips suitably thin or by perforating them.

The container may also comprise a water soluble or dispersable envelope for the contents and which is filled, sealed and simply placed in the container before sealing by the lid. In order to avoid puncturing the envelope the plastics liner 3 should be formed with a smooth inside. On use the lid can be removed and the envelope easily tipped out, e.g. into a tank of water diluent for use. This container is particularly suitable for hazardous concentrates of, for example, agro-chemicals, because the chances of the user coming into contact with the concentrate are reduced. The sealed envelope is simply tipped into the water whereupon it disappears leaving the concentrate to mix with the diluent.

The container is made in a number of sizes, e.g. 1 litre, 2 litres and 3 litres which are chosen to be "unit-quantity" sizes i.e. quantities such that the entire contents are used at one go. This avoids the user retaining half-full containers which can constitute a hazard.

In a further embodiment shown in Figure 3 the container may be constructed to have several compartments, e.g. 31 and 33, each with a liner and sealed over the top with a lid (not shown), so that multi-component products can be stored, one component to each compartment. The compartments may be sized to contain the appropriate proportions of the components.

Claims (14)

1. A container comprising a protective outer made from compressed fibre material and retained therein, a rigid or semi-rigid plastics liner conforming to the inside of the protective outer and adapted to be resistant to its intended contents.

2. A container according to claim 1 wherein said compressed fibre material is bio-degradable.

3. A container according to claim 1 or 2 wherein said liner is retained in the outer by snap-fitting.

4. A container according to claim 3 wherein the outer is provided with lugs onto which the liner is snap-fitted.

5. A container according to claim 1, 2, 3 or 4 wherein said liner is glued into the outer.

6. A container according to any one of the preceding claims wherein said compressed fibre material is compostable.

7. A container according to any one of the preceding claims wherein said compressed fibre material is recycled cellulose fibre.

8. A container according to any one of the preceding claims wherein the liner has a closed end, side-walls extending from the closed end to an open end surrounded by a rim formed by turning side walls outwardly, said rim providing an attachment surface for a lid.

9. A container according to claim 8 comprising a lid heat-sealed to the rim.

10. A clutch of containers each in accordance with any one of the preceding claims, the outers of the containers being formed integrally with each other so as to be connected by strips of said compressed fibre material of such a thickness and strength that individual containers can be manually torn from the clutch.

11. A container according to any one of the preceding claims further comprising a water soluble or dispersible envelope for containing the contents and slidable out of the container by inverting the container.

12. A container according to any one of the preceding claims divided into a plurality of compartments by at least one wall of said compressed fibre material, each compartment being lined with a plastics liner.

13. A container constructed substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

14. An agro-chemical pack comprising a container according to any one of the preceding claims containing as an agro-chemical, preferably liquid, fertilizer or biocide.