TECHNICAL FIELD

The invention relates to a method for use in connection with the introduction of a viscous material into a container, for example a tube, and to a filling nozzle intended for use in the method. The invention relates in particular to methods that make use of those nozzles which comprise more than one duct in order to be able to introduce at least two different types of substances into the same container, in such a way that a lasting pattern is formed by the different substances introduced into the container. The invention also relates to a tube filling machine for performing the method, comprising a filling nozzle as described herein, and to the use of such a filling nozzle.

BACKGROUND ART

The use of filling nozzles having multiple ducts for simultaneously introducing a plurality of substances into a tube or container is already known in the art. One area in which the use of this type of filling nozzles is particularly common is that of toothpaste which is to be introduced into tubes. Such a nozzle is described in US 6,418,986, in which an inner, circular duct for the introduction of a first substance is surrounded by a second annular duct for the introduction of a second substance. The ducts are arranged concentrically. The nozzle may be coupled to a manifold pipe, which in turn may be coupled to containers for the required substances, for example white and red toothpaste. It is also described how, at its orifice, the nozzle is provided with a valve for shutting off the flow from the ducts.

The object of filling toothpaste tubes and such products which contain

relatively highly viscous pastes and creams in this way is to create a lasting pattern formed from the different substances. When the product is introduced into the tube there are consequently two largely unmixed substances in the tube. In the example in US 6,418,986 the tube will therefore contain two separate white and red substances, which will give a red-white striped paste when the toothpaste is squeezed out of the tube.

In order to successfully fill tubes with toothpaste of different colours, for example, and to be able to control the filling of the tube in order to produce a desired pattern, it is necessary to be able to reliably control the flows. When introducing toothpaste of different colours the different flows have in conventional machines been controlled by regulating the pressure and rates of flow by means of piston pumps. The flows from the pumps have been coupled to inlet ducts in the upper part of the filling nozzle. The differently coloured substances have then flowed through separate ducts in the nozzle. Near the outlet end of the nozzle the separate ducts have then converged into one larger common duct. One problem with this type of filling is getting the filled substances to detach from the nozzle so that they do not run or drip. It is also important that this be done in a controlled way, so that the filling quantity is equal each time.

Certain substances have conventionally been made to detach from the nozzle in that the piston in the pump makes a rapid movement backwards on completion of a pump stroke before the pump valve closes. As a result the product in the nozzle is sucked backwards into the nozzle. This procedure is primarily used for substances having a high viscosity which are not sticky. When this method is used for introducing differently coloured substances, the problem arises that the differently coloured substances, which flow together at the end of the nozzle, are not sucked up into the same duct from which they came. This means that the differently coloured substances are mixed and the first flow which emerges at the next filling operation is mixed.

The most common method of getting a substance to detach from the nozzle after filling is to use a valve at the outlet end of the nozzle. The valve usually comprises a valve cone located on a spindle inside the nozzle. The valve is opened and closed by the spindle moving to and fro in the axial direction of the nozzle. It has conventionally been most common for the ducts in the nozzle to constitute sectors of the nozzle cross section. The spindle and its valve cone have been arranged at the centre of the cross section. When the coloured substances emerged from the separate ducts and ran together in the lower part of the nozzle, they continued to form sectors around the spindle and the valve cone. When the valve cone was closed, therefore, the substances were not mixed. In nozzles with one duct arranged inside another duct, for example a pipe with one coloured substance at the centre of the nozzle surrounded by another pipe containing a substance of a different colour, a problem arose in the lower part of the nozzle. When the coloured substances emerge from the separate ducts they surround the spindle and the valve cone on all sides, the one substance nearest the centre of the nozzle and the other substance outside. When the valve cone is closed against the nozzle opening, each part of the closing surface of the cone will cut off both the inner and the outer colour, with the result that the substances become mixed. At the next filling, therefore, the first flow to emerge from the nozzle will be mixed. In addition turbulence occurs around the valve cone and the different substances will not come out evenly but will have a tendency to mix when they emerge from the nozzle. The colour distribution over the flow cross-section emerging from the nozzle will therefore vary.

In hitherto known nozzles there is therefore an immediate risk of substances from different ducts becoming mixed. This means firstly that the control of the flows will not be as precise as is desirable and that in such a case the different substances, such as toothpaste of different colours, will not be introduced into the container with the desired pattern.

There is therefore an outstanding need for an improved method and device for controlling the simultaneous introduction of multiple different substances into a container, such as a tube, in order to fill the tube with substances so that a desired, lasting pattern is obtained. There is in particular a need to be able to control the flow of substances without the different substances becoming mixed at the end of the nozzle and to create a pattern which does not vary when dispensing the substances from the nozzle.

DISCLOSURE OF INVENTION

The present invention, however, has provided a method for the introduction of a highly viscous substance into a container using a filing nozzle of the type referred to in the introductory part, which substantially eliminates the problems that have been associated with such previously known methods. The invention therefore relates to a method and a filling nozzle intended for filling a container with at least two types of substances. This is a common occurrence when introducing toothpaste of different colours into tubes. In order that the substances will retain a pattern when they have been introduced into the container, one requirement is that these must not run together. This is suitably achieved in that the viscosity of at least one of the substances is not less than 10,000 cps (centipoises) or 10 PAs (Pascal seconds), preferably not less than 30,000 cps or 30 PAs and most preferably not less than 40,000 cps or 40 PAs, with the result that the highly viscous substance will retain its configuration when it has being introduced into the container. The term highly viscous substances is here therefore intended to refer to substances having a viscosity in excess of 10,000 cps or 10 PAs at 20 degrees Celsius and normal atmospheric pressure.

It is not necessary for the second or any further substances to have a similarly high viscosity, since they can be kept in place by being supported by the more high viscous substance(s). It is normally desirable, however, for the viscosity of the different substances to be approximately equal in order

that they can be removed equally from the container, for example by squeezing a tube. If the difference in viscosity between the different substances forming the content of the tube is too great, there is a serious risk that those with a significantly lower viscosity will be squeezed or will run out first.

The filling nozzle is. provided with at least two ducts, which extend in the longitudinal direction of the filling nozzle. The ducts in the nozzle further comprise some type of coupling or connection to feed ducts, which are in turn connected to different stocks of each required substance. The ducts which extend along the longitudinal axis of the nozzle open out at basically the same point at a remote outlet end of the nozzle. The invention is further characterized in that the first duct is provided at its orifice with a first valve, intended to regulate the flow in the first duct, and that the second duct is provided at its orifice with a second valve intended to regulate the flow in the second duct. This design makes it possible to control the respective flow from each of the different ducts accurately and precisely. Locating the actual valve function at the orifice reduces the risk of an unwanted substance dripping or being entrained down into the container.

Consequently the different valves must preferably be separately controllable, that is to say at the orifice of the filling nozzle the different valves for each duct must be capable of being opened and closed independently of one another. There may be occasions, however, when it is desirable for the opening and closing of the different valves to be synchronized. If so, it may be feasible to mechanically link the different control devices for the different valves together and to control these by means of a common control command.

According to one embodiment of the invention the valves are controlled by means of so-called spindles. It is not essential to the actual idea of the invention, however, what type of valves or control devices are used, the use

of spindles being only one of many possible detailed technical embodiments within the scope of the invention.

According to a further embodiment of the invention the first duct and the second duct are separated from one another over their extent in the filling nozzle, from their connections to respective feed ducts to their orifices at the remote end of the nozzle. The flows of the different substances, which are to be introduced into the container, are therefore separated all the way up to where the ducts open out close to the remote end of the nozzle. In most cases the actual idea in providing the nozzle with different ducts is that the flows are separated until they leave the nozzle orifice and in this way are endowed with a desired pattern in the filled substance.

In certain cases, however, there may be contact between the different ducts in the nozzle upstream of the orifices of the respective ducts. In these cases it may be, for example, that a certain admixture of a substance is possible, and is desirable. It is therefore also possible to use the valve arrangement described herein for such a type of nozzle in which ducts intended for different types of substances are designed so that they communicate with one another over their length in the nozzle, so that the different substances come into contact with one another as they flow through the nozzle. The different ducts may communicate with one another, for example, through openings in the dividing walls between the ducts.

In one embodiment of the invention the first duct and the second duct in the filling nozzle are arranged concentrically about an axis in the longitudinal direction of the nozzle. In this case the nozzle may be provided with a first duct in the form of a circular pipe, which is surrounded and separated by a dividing wall from a second duct in the form of an annular duct. The form of the ducts has here been specified as being circular or annular. These forms are advantageous partly with a view to the desired pattern, for example when introducing toothpaste of different colours into tubes, and partly in respect of

the overall design of the nozzle and valves. It is possible, however, for the walls of the ducts to have other geometric shapes, for example rectangular or hexagonal, or to provide the orifices of the ducts with different geometric shapes in order to obtain a desired pattern in the substance introduced into the container.

For most embodiments it is advantageous to arrange the first duct and the second duct concentrically in the nozzle. This is not essential to the invention, however, it being possible, if so desired, to use non-concentric arrangements in order to obtain special filling patterns, for example.

The valves arranged at the orifice may be of a number of different types and have different functions. According to one embodiment the valves may be largely designed to be adjustable only between a first position in which the valve is open, and a second position in which the valve is closed. In this case the quantities of the different substances from each duct, which are to be introduced into the containers, are basically controlled, for example, by controlling the flows in any of the inlet pipes coupled to the nozzle.

According to another embodiment the valves at the orifice of the filling nozzle are designed so that they can be set to be opened to different degrees. In this case the valves may either have a number of predefined positions, so that the degree of opening of the valves can only be adjusted in stages, or they may be continuously adjustable so that they are set to the desired, analogous position. In this embodiment the control of the flows can be regulated solely or predominantly through adjustment of the orifice valves.

In the embodiments described above the invention has been described solely for nozzles having two separate ducts for different substances. It is naturally possible to connect both a third duct and additional further ducts if so required.

Nor is it essential to the invention that the ducts have a circular cross- sectional shape, it being possible to use any other suitable shape, for example a square, triangular, polygonal, oval or other shape.

The invention also relates to a machine for filling containers such as tubes and dispensers comprising a filling nozzle according to the embodiments described above. The filling machine according to the invention may advantageously be used for filling toothpaste tubes and pump-action dispensers for multicoloured toothpaste. Other types of dispensers, such as squeeze bottles and the like can also be used. The substances filled may alternatively be different types of viscous cosmetic products, such as creams and lotions, or viscous foodstuffs such as jam or marmalade, sauces, pastes, caviar, soft cheese or the like.

The invention also relates to the use of a nozzle such as that described herein for introducing different types of viscous substances into the same container, at least one of the substances being a highly viscous substance, in such a way that a lasting pattern is formed by the different substances introduced into the container.

There is therefore a multiplicity of arrangements and methods which fall within the scope of the idea according to the invention of providing a filling nozzle with at least two ducts, intended for different substances, provided with separate valves arranged at the orifices of the ducts.

BRIEF DESCRIPTION OF DRAWINGS

The invention will be described in more detail below with reference to the figures shown in the drawings attached, in which:

Fig. 1 shows a filling nozzle according to one embodiment of the invention, viewed in cross section in the longitudinal direction

of the filling nozzle

Fig. 2a-d shows an enlargement of the remote end of the filling nozzle shown in Fig. 1 , in which various positions are shown for valves arranged in the orifice.

MODE(S) FOR CARRYING OUT THE INVENTION

Fig. 1 shows a filling nozzle 1 according to one embodiment of the invention. The filling nozzle 1 is shown in cross-section along the central axis of the nozzle 1 in the longitudinal direction thereof. The nozzle 1 comprises a first, inner duct 2 and a second, outer duct 3. These ducts 2, 3 are annular and in the embodiment shown are arranged concentrically around the central axis of the filling nozzle 1. The filling nozzle 1 further comprises an inner spindle 4, which is arranged in the first, inner duct 2 and constitutes an inner wall for the inner duct 2. The filling nozzle 1 further comprises an outer spindle 5, which is arranged between the first, inner duct 2 and the second, outer duct 3 so that it constitutes an outer wall of the inner duct 2 and an inner wall of the outer duct 3. Outside the outer duct the filling nozzle 1 is provided with a casing 6, which constitutes an outer wall of the second, outer duct 3. The top, or the remote end, of the inner spindle 4 is designed to function as a first, inner valve 7 and is geometrically designed to match the orifice 8 of the inner duct, in order to be able to restrict the flow in the inner duct 2. The inner valve 7 can switch from an open position to a closed position through displacement of the inner spindle 4 relative to the outer spindle 5, which comprises the orifice 8 of the inner duct, along the central axis of the filling nozzle 1. Similarly the top of the outer spindle 5 is designed to function as a second, outer valve 9 designed to match the orifice 10 of the outer duct, in order to be able to restrict the flow in the outer duct 2. In the same way as for the inner valve 7, the outer valve 9 can be closed or opened through displacement of the outer spindle 5 relative to the casing 6, which comprises the orifice 10 of the outer duct, along the central axis of the filling nozzle 1.

The first, inner duct 2 of the filling nozzle 1 is further provided with a first connection 11 , which can be coupled to a first feed duct for delivering a first substance, which is to be introduced into a container. Similarly, the second, outer duct 3 is provided with a second connection 12, which can be coupled to a second feed duct for delivering a second substance. As shown in the drawings, the inner duct 2 and the outer duct 3 are separated over their entire common length, from the connections 11 , 12 to the orifices 8, 10 at the remote end 13 of the filling nozzle 1.

Fig. 2 a-d shows an enlargement of the remote end 13 of the filling nozzle 1. Fig. 2a shows how both the inner valve 7 and the outer valve 9 are in the open position. This is attained in that both the inner spindle 4 and the outer spindle 5 are displaced along the central axis of the nozzle 1 in the longitudinal direction thereof, in a direction opposed to the direction of flow of the substance when filling a container. In this way both the inner orifice 8 and the outer orifice 10 are left open and both of the substances can therefore flow and fill the container simultaneously.

In Fig. 2b the position has changed compared to that in Fig. 2a in that the inner spindle 4 has been displaced along the central axis of the nozzle 1 in the longitudinal direction thereof in a direction parallel to the direction of flow of a substance when filling a container. The orifice 8 of the inner duct is thereby closed and during filling a substance will only be introduced into the container through the outer duct 3.

In Fig. 2c the position has changed compared to that in Fig. 2b in that the outer spindle 5 has been displaced along the central axis of the nozzle 1 in the longitudinal direction thereof in a direction parallel to the direction of flow of a substance when filling a container. This will have produced two changes in the valve positions for both ducts 2, 3. Since the outer spindle 5 constitutes the outer wall of the inner duct 2 and comprises the orifice 8 of the inner duct, the shift in the position of the outer spindle 5 will mean that

the inner valve 7, which consists of the top of the inner spindle 4, is displaced relative to the inner opening, so that the inner duct 2 is opened. The orifice 10 of the outer duct on the other hand will be closed by the displacement of the outer spindle 5, comprising the outer valve 9, so that only the substance from the inner duct 2 will fill the container.

In Fig. 2d the position has changed compared to that in Fig. 2c in that the inner spindle 4 has been displaced along the central axis of the nozzle 1 in the longitudinal direction thereof in a direction parallel to the direction of flow of a substance when filling a container. The orifice 10 of the inner duct is thereby also closed and no filling of a container can therefore take place.

The embodiment of a filling nozzle according to the invention described in Fig. 1 and 2 is only one example and must not be regarded as limiting alternative embodiments of the invention. In the example shown it will be seen, for instance, that the outer spindle constitutes both a valve for the outer duct and an outer wall and orifice of the inner duct. In design terms it is feasible to separate these functions so that the dividing wall between the ducts is fixed and that the valve arrangement is achieved either through a moveable spindle, which slides along the fixed wall, or through the use of another type of valve. Furthermore, the examples shown here largely show only valve positions which are either open or closed. As already pointed under the heading "Disclosure of invention", it is possible, without departing from the scope of the idea of the invention, to control the valve positions so that the magnitude of the flows varies.