FLUID CONTAINER

Abstract: A container for a liquid such as herbicide comprises a rigid casing (2) having a transparent or translucent wall. The interior of the casing (2) is divided into two compartments (14) and (16) by a flexible partition (8). The liquid in one of the compartments (14) has a colour or shade which contrasts visually with the material of the flexible partition (8) so that any leakage of the liquid across the partition (8) can be visually detected.

Description: This invention relates to fluid containers for herbicides. A recent development in the packaging of herbicides is a fluid container of the type having a rigid casing of which the interior is divided into two compartments by a flexible partition, such as a collapsible bag or flexible membrane. The fluid can then be contained in one compartment of the container where it may be isolated from the atmosphere. A vent hole is provided in the rigid casing, or other provision made, for air to be introduced into the casing on the other side of the partition from the fluid as the fluid is dispersed. As the fluid flows out of the container the flexible partition deflects thereby reducing the volume of the part of the container in which the fluid is contained. A problem associated with such containers is that, if the flexible partition has a hole or tear, liquid can leak out of its enclosure into the other part of the casing, and thence through the vent hole to the surroundings. This is undesirable, particularly if the contents is a herbicide or other hazardous material. Even where the rigid casing is transparent or translucent, it will not be easy, or possible, to detect visually whether or not the liquid has leaked through the flexible partition. According to the present invention there is provided a liquid-filled container for herbicide having a transparent or translucent rigid casing, the interior of which is divided into two compartments by a flexible partition, one of which compartments contains the liquid, and in which during emptying of the container, the other compartment is vented to the exterior, such that emptying of the container is accompanied by movement of the flexible partition, characterised in that the other compartment is vented to the exterior through an initially closed vent hole which is provided in the rigid casing, and in that the flexible partition is of a colour or shade which contrasts visually with the liquid. A container according to the present invention is useful as it is possible to detect whether the liquid contained in the container has leaked out of its compartment through the flexible partition merely by looking through the rigid casing. If the liquid has so leaked it will be clearly visible as it will form a contrast against the flexible partition. The flexible partition is preferably opaque and also darker in colour than the liquid, so that it is easily visible through the rigid casing, as will be the contrast between it and any liquid, which will be lighter in colour, which has leaked out of the enclosure. In a preferred embodiment, the container is adapted for use with hand-held delivery lances for herbicides, e.g. it is in the form of a disposable cartridge for use with such a lance. The flexible partition is preferably made of a plastics material. A pigment may be incorporated in the plastics material to provide the flexible membrane with its colouring or shading. The fluid container is provided with means for allowing air to flow into the container as liquid flows out of the enclosure. This means preferably takes the form of a hole, or plurality of holes, provided in the rigid casing. For a better understanding of the present invention, and to show how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 shows a herbicide container; and Figure 2 is a diagrammatic sectional view of the container of Figure 1. The container shown in Figures 1 and 2 comprises a rigid casing 2 made up of two casing parts 4, 6 between which is provided a flexible partition 8. The casing part 6 has an outlet fitting 10 through which the container may be filled, and through which, in use, the contents of the container are dispensed. The other casing part 4 has a projecting spigot 12 which is hollow, but which is closed at its end away from the interior of the container. Normally, the partition 8 provides a leak-proof barrier, dividing the interior of the container into two compartments 14, 16. When the container is full, the compartment 14 occupies substantially the whole of the interior of the casing 2, and the partition 8 lies against the interior of the casing part 4. When the container is to be used to dispense the contents, the spigot 12 is broken off, so that air can pass through the resulting hole into the compartment 16, to allow the partition 8 to move away from the casing part 4 as liquid flows from the compartment 14. It will be appreciated that, in normal use, no liquid will cross the partition 8 into the compartment 16, and so there is no possibility that the liquid can flow through the hole left when the spigot 12 is broken off to the outside. However, should a leak appear in the partition 8, as represented by a hole 18 in Figures 1 and 2, liquid can flow from the compartment 14 to the compartment 16 and, when the spigot 12 is broken off, the accumulated liquid in the compartment 16 can flow to the outside. This is highly undesirable where the contents of the container is a herbicide or other potentially harmful substance. To avoid the danger of such unintentional leakage, the rigid casing 2, or at least the casing part 4, is formed from a translucent plastics material, and the material of the partition 8 has a colour or shade which contrasts visually with that of the fluid 14. For example, where the fluid 14 has a relatively light shade, the material of the partition 8 is relatively dark. Consequently, if leakage across the partition 8 occurs, this will be evident as a light stain 20 on the relatively dark background seen through the translucent casing part 4. Herbicides for application direct from the container, without dilution, need to be formulated very carefully to ensure that they have the desired physical properties to enable them to be distributed as desired. Also, such herbicides may be pigmented, for example with a white pigment, so that they will show up on the ground or on plants, so that the operator can see where droplets of the herbicide have landed. Consequently, it will normally be undesirable to tamper further with the pigmentation or dyeing of the herbicide, and so the preferred course will be to select the colour and shade of the partition 8 to contrast with the previously determined colour or shade of the herbicide. By providing the visual contrast between the fluid and the material of the partition 8, it is possible to detect containers in which the partition 8 is leaking before the spigot 12 is broken off, i.e. before there is any possibility of the leaking fluid reaching the outside of the container. Consequently, containers in which the partition 8 is leaking can be rejected as unsuitable for use before there is any danger of contamination by the possibly harmful contents.

Claims: A liquid-filled container for herbicide having a transparent or translucent rigid casing (2), the interior of which is divided into two compartments (14,16) by a flexible partition (8), one (14) of which compartments contains the liquid, and in which during emptying of the container, the other compartment (16) is vented to the exterior, such that emptying of the contained is accompanied by movement of the flexible partition (8), characterised in that the other compartment (16) is vented to the exterior through an initially closed vent hole which is provided in the rigid casing, and in that the flexible partition (8) is of a colour or shade which contrasts visually with the liquid. A liquid-filled container as claimed in claim 1, characterised in that the liquid is of a lighter shade than the flexible partition (8). A liquid-filled container as claimed in claim 2, characterised in that the flexible partition (8) is black. A liquid-filled container as claimed in any preceding claims, characterised in that the vent hole is closed by a removable closure (12).

Inventors: GILL, DAVID CHARLES
Applicants: NOMIX-CHIPMAN LIMITED
Application year: 1990
Main classification: B65D81
IPC codes: B65D85, B65D25, B65D79, B65D81