PACK

Abstract: A pack for an epoxy adhesive and a hardener comprises two compartments (4, 6) disposed on opposite sides of a labyrinth member (14). Squeezing the compartments (4, 6) forces both the epoxy adhesive and hardener through a tortuous passageway defined by the labyrinth member (14). The epoxy adhesive and hardener mix while travelling along the passageway and exit the nozzle (20) as a mixed adhesive product.

Description: Pack The present invention relates to a pack for a two- component product, such as an adhesive formed from an epoxy resin and a hardener. Traditionally, epoxy adhesives have been sold with the resin and the hardener packaged in separate tubes, so that the resin and the hardener do not react before the product is to be used. The user dispenses equal amounts of the resin and hardener from the respective tubes and mixes the two components with an appropriate implement to form the adhesive. The mixing process is often messy and requires the provision of a mixing implement and mixing surface or container by the user. A pack for a two-component product, primarily a pharmaceutical product, has been proposed in GB-A- 2002316. This pack comprises two stacked compartments for the respective products separated by a barrier layer which can be ruptured by an internal projection when it is desired to mix the components . Mixing of the components is carried out by the user shaking or kneading the pack and this may not achieve satisfactory mixing in all cases. US-A-4795265 discloses a method of mixing two liquid or paste-like liquid components in which the components are forced out of separate storage compartments in a plastics bag by a roller. The components pass through a series of pockets, each of which is arranged to break explosively under the pressure of the roller and thereby pass the components into the next pocket, the explosive breakage being intended to provide a mixing action. Downstream of the series of pockets, a discharge pocket (Figure 3 of US-A- 4795265) may be provided, such discharge pocket having oblique internal walls defining a meander-shaped discharge path. Thus the entire length of the device is defined by the combined lengths of the initial storage compartments, the series of breakable pockets and the discharge pocket. This can result in a device of substantial length. In an alternative proposal disclosed in Figure 13 of US-A-4795265, a bag having a number of transverse partitions is provided instead of the series of breakable pockets to force the components to be deflected sideways and thus to promote a mixing effect. Viewed from a first aspect, the invention provides a pack for a two-component product, the pack comprising two compartments for respective components of the product, the compartments being disposed in mutually facing relation, and a passageway disposed between the compartments, through which, in use, both components are supplied to an outlet of the pack. The passageway is disposed between the compartments to provide a particularly compact design, without excessive length. The two components of the pack are forced to pass through the same passageway in order to exit the pack, thereby causing the components to mix without the need for intervention by the user. Mixing of the components will thus take place as they pass through the passageway. Preferably, however, the passageway has a tortuous or labyrinthine form to promote mixing of the components as they travel through the passageway. For example, the passageway may have an undulating or zig-zag form. In one arrangement, the passageway is defined by a labyrinth member which has a peripheral barrier and a series of inwardly projecting barriers which overlap alternately to partially block the path of the components from the compartments to the outlet. The labyrinth member, or other member defining the passageway may be, for example, an injection moulded plastics member. Alternatively, the passageway may be defined by bonded sheet material, for example of plastics . In general, it is desirable for the components to be separated in the pack before mixing is required. This may be achieved in any suitable manner. For example, an over-pressure may be generated in the passageway on filling which is maintained in the sealed pack such that the pressure in the passageway prevents the components entering the passageway until the outlet of the pack is opened. There will generally be an inlet to the passageway from each compartment, disposed remote from the pack outlet. Thus, when it is desired for the components to be mixed and dispensed, for example by applying external pressure to the pack, the components in the compartments will travel generally away from the outlet of the pack before entering the passageway and then travelling generally towards the outlet . In a preferred arrangement, a rupturable seal is provided between at least one compartment and the passageway. Such a seal can be ruptured when it desired for the components to enter the passageway. The rupturable seal may be one or more slits cut into a wall of the compartment and arranged to rupture and open up when desired. In general, a respective rupturable seal may be provided between each compartment and the passageway. The or each seal may be arranged to be rupturable when external pressure is applied to the or each compartment by a user. The outlet of the passageway preferably forms a nozzle through which the mixed product may be dispensed. In general, the outlet of the passageway will be provided with a closure. The closure may be a re-usable closure, such as a cap or the like. However, in the case of a product such as an epoxy adhesive, the product must be used shortly after the components have been mixed, and thus a re-usable closure is not required. Thus, a rupturable or frangible closure may be provided. In one arrangement, the outlet end of the passageway is in the form of a blind duct. The closed end of the duct may be cut, twisted, broken or otherwise separated from the passageway to provide the outlet, e.g. a nozzle, from which the mixed product may be dispensed. Preferably, the duct has a weakened portion to aid the removal of the end of the duct . Advantageously, the duct is connected to an extended portion of the pack which the user may grip when removing the end of the duct and which may be removed with the duct . The pack may be constructed in any suitable manner. In one simple arrangement the pack comprises four stacked layers of material bonded to each other at their periphery. In this case, one compartment is defined between layers one and two, the other compartment is defined between layers three and four, and the passageway is defined between layers two and three. Apertures, or rupturable seals, are provided in layers two and three to allow the compartments to communicate with the passageway when required. A passageway defining member, such as the labyrinth member described above, may be disposed between layers two and three. Such a passageway defining member may also define the outlet of the passageway and, optionally, the closure therefor. The layers may be composed of any suitable material, for example plastics film or a laminate. In one arrangement, layers one and four are in the form of plastics mouldings, for example thermoformings, having formed therein depressions or wells which partially define the respective compartments. In a particularly convenient arrangement layers one and four are formed from a single piece of material and layers two and three are also formed from a single piece of material . The pack is formed by folding the layers together to form the stacked arrangement . In general, in the preferred embodiments, the passageway is sandwiched between the compartments. An embodiment of the invention will now be described by way of example only and with reference to the accompanying figures, in which: Figure 1 shows an view exploded of the construction of a pack according to the invention; Figure 2 shows a perspective, partially transparent view of the assembled pack of figure 1; and Figure 3 shows the pack of figure 1 in use. Referring to figure 1, a pack for an epoxy adhesive and a hardener comprises a polypropylene thermoforming 2 having formed therein two wells 4,6 which partially define respective compartments for the epoxy adhesive and hardener. A metallised polypropylene laminate sheet 8 is kiss-cut in two regions to form a respective rupturable seal 10,12 for each compartment. An injection moulded plastics labyrinth member 14 has two complementary halves connected by a central hinge. Each half comprises a peripheral barrier 16 from which project transverse barriers 18. To construct the pack, the compartments 4,6 of the thermoforming 2 are filled respectively with the epoxy adhesive and the hardener. The laminate sheet 8 is bonded to the thermoforming 2 to seal each compartment. The labyrinth member 14 is placed on the laminate sheet 8 and the thermoforming 2 is folded up in the manner of a clam shell, to form the pack shown in figure 2. On folding, the transverse barriers 18 of the halves of the labyrinth member interconnect to form a labyrinthine passageway through from the rupturable seals 10,12 to a nozzle 20 which is also formed by the halves of the labyrinthine member. The adhesive is dispensed by twisting-off a tab portion 22 of the thermoforming 2 which breaks off the end of the nozzle 20 to provide an outlet from the passageway. The pack is then squeezed by the user, as shown in figure 3, which increases the pressure in each compartment causing the seals 10,12 to break and allow the epoxy adhesive and hardener to pass from their respective compartments 4,6 into the passageway. Both components pass together through the passageway under the pressure of continued squeezing, and the tortuous path causes the components to mix effectively. Thus, a mixed adhesive product exits the nozzle 20 as shown in figure 3. Although the invention has been described herein with particular reference to epoxy adhesives, it will be appreciated that the invention may be applied to other two-component products, such as pharmaceutical preparations, toothpastes and the like. Furthermore, the invention is also of application to products comprising more than two components.

Claims: Claims 1. A pack for a two-component product, the pack comprising two compartments for respective components of the product, the compartments being disposed in mutually facing relation, and a passageway disposed between the compartments, through which, in use, both components are supplied to an outlet of the pack. 2. A pack as claimed in claim 1, wherein the passageway has a labyrinthine form to promote mixing of the components as they travel through the passageway. 3. A pack as claimed in claim 1 or 2 , wherein a rupturable seal is provided between at least one compartment and the passageway. 4. A pack as claimed in claim 3 , wherein the rupturable seal is a slit cut into a wall of at least one compartment. 5. A pack as claimed in claim 3 or 4 , wherein the seal is arranged to be rupturable when external pressure is applied to the at least one compartment by a user. 6. A pack as claimed in any preceding claim, wherein the outlet end of the passageway is in the form of a blind duct part of which may be separated from the rest of the passageway to form the outlet of the pack. 7. A pack for a two-component product, substantially as hereinbefore described with reference to the accompanying drawings .

Inventors: BARNARDO CHRISTOPHER JOHN ANDR, TYLDESLEY FRANK, BARNARDO, CHRISTOPHER, JOHN, ANDREW, TYLDESLEY, FRANK
Applicants: BARNARDO CHRISTOPHER JOHN ANDR, CIBA SC HOLDING AG, TYLDESLEY FRANK, BARNARDO, CHRISTOPHER, JOHN, ANDREW, CIBA SPECIALTY CHEMICALS HOLDING INC., TYLDESLEY, FRANK
Application year: 1999
Main classification: B65D81
IPC codes: B65D30, B65D75, B65D81, B65D85