Field of the invention

The invention relates to a powder filling device comprising:

a first powder supply station having a dispensing opening,

a transport device having dosing cavities with a predetermined volume, movable past the dispensing opening to a filling position, and

- a filling station comprising a container transport member for moving a container along the filling position.

The invention also relates to a method of filling a container with a powder or granular material, comprising the steps of:

- supplying a first volume of powder or granular material from a first powder supply station into a dosing cavity of a transport device, via a dispensing opening, transporting the filled dosing cavities of the transport device to a filling position and

dispensing the contents of the dosing cavity into a container.

Background of the invention

Such apparatus and method are known from US patent no. 8,122,893. In this document, a rotating indexing disc having a plurality of cavities is rotated past a hopper from which each of the cavities is filled with a predetermined quantity of tobacco. The indexing disc rotates to a transfer station at which successive portions of tobacco are ejected from the cavities by means of a mechanical push rod into a tubular pouch that is produced in a vertical form fill sealing machine. The volume of tobacco that is entered into the cavities is determined by the cavity size. The tobacco falls under influence of gravity from the hopper into the cavity, while excess tobacco is removed by a skimming device located downstream of the hopper. WO 2015/056127 describes method for filling containing elements of single-use capsules for extraction or infusion beverages with a dose of product, the method comprising the following steps:

moving a succession of containing elements(2) along a first movement path (P); - rotating about a respective axis of rotation (X4) at least one first rotating element

(40a) to create a feeding flow of product which intercepts a first containing seat

(S1 ) to be filled;

releasing a dose (33) of product in the first containing seat (S1 ) movable along a second movement path (P1 ) in a region (R1 ) for forming the dose;

- moving the first containing seat (S1 ) from the dose forming region (R1 ) to a dose transfer region (R2);

transferring, at the dose transfer region (R2), the dose (33) of product from the first containing seat (S1 ) to a second containing seat (S2) movable along a third movement path (P2);

- moving the second containing seat (S2) from the dose transfer region (R2) to a dose release region (R3),

transferring, at the dose release region (R3), the dose (33) of product from the second containing seat (S2) to a containing element (2) advancing along the first movement path (P) and positioned at the dose release region (R3).

The use of the indexing disc in the known apparatus has an advantage over directly dispensing into the pouch in that by use of the push rod, a very rapid filling of the pouch can be achieved that is independent of the dosing speed of the hopper. The known system has as a drawback that the dosing of the contents into the cavities is not very accurate and that some loss of product occurs upon removal by the skimming device. Furthermore, the filling volume is determined by the size of the cavities, so that an adjustment in filling volume will have to be accompanied by a change out of the indexing disc. As the cavities are completely filled with product, there is a risk that at high indexing speeds, product may leave the cavities upon moving from the hopper to the transfer station. Also the use of the push rod for substances other than tobacco may lead to product leaving the cavity or dusting taking place during product ejection.

It is therefore an object of the present invention to provide a filling device and method in which rapid and accurate dosing and dispensing of powder or granular material can be achieved. It is a further object to provide a filling device and method that are versatile and allow easy adjustment of the dosed and dispensed volumes. It is finally an object of the invention to provide a filling device and method that allows rapid and accurate dosing and filling of a variety of different powders or granular materials.

Summary of the invention

Hereto a filling device in accordance with the invention is characterized in that the powder supply station comprises a screw-feeding device adapted to dispense a predetermined volume of powder or granular material that is smaller than the volume of the dosing cavities.

By the use of the screw-feeding device, accurate volumes of powder or granular material can be dosed into the cavities. By use of the screw-feeding device, the dosing volume is no longer determined by the volume of the cavities but is controlled by the number of rotations of the conveyor screw. Hereby easy switching between different dosed volumes of product is possible without exchange of the dosing cavities.

Furthermore, the controlled dosing in the cavities via the screw-feeding device allows different products such as free-flowing powders and non-free flowing or "sticky" powders to be accurately and rapidly dosed into the cavities.

Because the cavities are not completely filled, product spillage upon transport and upon ejection or compression is reduced in view of improved containment of the product deeper in the cavity.

Finally, controlled filling of only a part of the cavities allows improved accuracy of filling by a staged filling process using multiple filling stations or the use of mixed ingredients by filling each cavity with different products at different supply stations. With the term "powder" as used herein is meant a bulk substance of particles having a size between 0.01 μηη and 2000μηι that may either be dry and free-flowing or moist and sticky or clumpy. The powder may be formed of a single substance, such as starch, flour, talcum, spray dried ingredients such as milk powder, crystals such as salt or sugar, or a coarse powder such as for instance milled air-dried vegetables. The powder may also comprise a mixture of different particle sizes and may include anti- caking agents or flow aids like silicon dioxide or silicates. Mixtures of powders further include for instance dried savoury powders (e.g. seasonings, bouillons, soups, sauces/gravies, dressings, mealmakers/etc.) or other foodstuff. Further examples of powders include coffee, flour, powdered milk, personal care products, cosmetics, pharmaceuticals, lemonade powder, detergent powder and the like.

With the term "granular material" as used herein, larger particles sizes are intended from 2 mm to 50mm. Granular materials may include dried tea leaves, granules or pieces of chocolate, shredded herb leaves, dried fruit or vegetables, croutons etc.

The invention also includes mixtures of powdery and granular materials, in the dry or moist state. The flowability index (ffc) measured via the Ring Shear Tester is in the range of 1-17, preferably in range of 1 -4. A suitable method of measuring flowability via the Ring Shear Tester is given in ASTM 6773.

A suitable screw-feeding device for use in the present invention may for instance be formed by an Auger Filler obtainable from All-Fill, USA.

The containers that are filled according to the invention may comprise rigid containers such as rectangular or cylindrical boxes, tins, jars and the like, as well as flexible pouches, horizontal or vertical form fill sealing containers. The size of the containers may be such as to contain between 10g and 5 kg of product.

The transport device according to the present invention may be any device suitable for transporting the dosing cavities from the dispensing opening of the screw feed device to the filling position, such as a chain carrying the dosing cavities, moving arms, indexing linear or hinged sliding gates, continuous belt driven dosing cups, indexing or continuous horizontal axis rotating wheel transport mechanisms, and the like.

In a preferred embodiment, the transport device is formed by an indexing disc, which may be of circular, oval, rectangular, polygonal or any other suitable shape. An embodiment of a powder filling device comprises a second powder supply station, downstream from the first powder supply station, adapted to filling a dosing cavity after it has been filled with a first volume of powder or granular material from the first powder supply station, with a second volume of powder or granular material.

By partly filling of the dosing cavities at the first powder supply station, a second volume can be added in the downstream part of the dosing process from the second supply station. One embodiment includes supplying a relatively large first volume of substance, for instance between 60 and 95 % of the total dosing volume, followed by and accurate smaller volume of for instance 40%-5% of the total dosing volume, to obtain a very accurate total dosing volume. The first powder supply station may comprise a relatively large diameter screw, while the second powder supply station comprises a smaller diameter screw running at a higher speed having an increased accuracy in view of the smaller volume of product supplied.

Alternatively, or in addition, a weighing device may be employed in each cavity. The weighing device determines the weight of product that has been supplied by the first powder supply station. This value is read into the control unit and is used as an input parameter for driving the second supply station to top up the dosing cavity with a varying amount of product, until the desired pre-set total weight is received in the dosing cavity.

Another embodiment includes supplying a first type of substance from the first powder supply station and a second type of substance from a second supply station, in particular from a second powder supply station. In this manner it is possible to keep multiple components separate up to the moment of filling of the container, such that product quality of each ingredient can be optimal. Bigger granular pieces or fragile products (like herbs or compacted powders) that are less compatible with the first dosing step, can be supplied by the second supply station.

According to the invention it is possible to separately supply multiple ingredients to the dosing cavity in order to maintain optimal flow properties and hence rapid filling, for each separate substance while maintaining high product quality and preventing damage to for instance fragile products.

An example of the first product may be a base for dried savory powders, while the second product may comprise a mix of granular additives such as dried vegetables, noodles, dried meat etc. Another possibility is supply oils or oil-based ingredients, or liquid flavours to the dosing cavity via the second supply station.

It is also possible to supply via the second supply station a micro dose of for instance vitamins, minerals, flavours or colorants. This ensures proper dosing of such additives.

The second supply station may comprise any type of feed device, such as a hopper or sliding gate. In a preferred embodiment the second supply station is a powder supply station and comprises a screw-feeding device.

In another embodiment of a powder filling device according to the invention, a plunger device is provided downstream from the first powder supply station, the plunger device comprising a movable plunger member for entering into the cavities. Provision of a plunger or push rod can be utilized for instance prior to ejection of the product from the dosing cavities into the container in order to achieve a compression of the product inside the cavities. Upon filling of the container, the compressed product will drop out of the dosing cavities in the form of a pellet that disintegrates when contacting the container.

In another embodiment, the plunger or push rod is used at ejection of the product from the dosing cavity into the container for rapid ejection.

Because the dosing cavities are not completely filled, there is some headspace available above the powder in the cavity, such that upon entering of the plunger, the product will remain contained in the cavity and dusting or spillage is reduced to a minimum. The plunger member may have a cross section corresponding to a cross- section of the cavities. In a further embodiment of a filling device according to the invention, the screw-feeding member of the first dispensing device is adapted to dispense within a time of between 50ms and 500ms a volume of powder material that is smaller than the volume of the dosing cavities by between 1 % and 80%. Depending on the cavity size and the flow characteristics of the material, the screw member of the screw-feeding device is designed to have an optimal flow performance in terms of shear stress, accuracy or speed. In another embodiment, the cavities are adapted to move from the powder supply station to the filling station in an index time of between 10ms and 250ms. As the cavities according to the invention are only partly filled, the high inertia forces upon acceleration and deceleration during indexing, can be taken up while the product remains adequately contained in the cavities, allowing high-speed transport from the supply station to the filling station.

Brief description of the drawings

A number embodiments of a filling device and filling method according to the present invention will by way of non-limiting example be described in detail with reference to the accompanying drawings. In the drawings:

Fig. 1 shows a schematic view of a first embodiment of a filling device according to the present invention including an ejection plunger,

Fig. 2 shows an embodiment in which two supply stations are placed in series, filling taking place under gravity flow conditions, and

Fig. 3 shows an embodiment of a filling device comprising a compacting plunger. Detailed description of the invention

Fig. 1 shows a filling device 1 according to the invention, comprising a powder supply station 2, a transport device 3 and a filling station 4. The powder supply station 2 comprises a screw-feed device 5 with a screw 6, which may for instance be formed by an Auger Filler such as available the firm All-Fill. The screw feed device 5 has a dispensing opening 7 from which powder or granular product can be dosed into dosing cavities 8,9 of the transport device 3 by rotation of the screw 6. The transport device 3 is in this embodiment formed by an indexing disc having a rotating disc 14 that along its circumference is provided with dosing cavities 8,9 which may have a volume of between 1 cm ³ and 1000 cm ³ . The partly filled cavities 8,9 -the level of the powder in the cavities has been indicated by a dashed line- are moved by rotation of the disc 14 along stationary disc 15 to a filling position 10 at which the stationary disc 15 comprises an opening and in which the cavity is situated above a container 1 1 that has been moved to the filling position 10 via transport member 12. At the filling position, the cavities can be opened and closed by a gate device 16, such that the contents of the cavity are transferred into the container 1 1 . A plunger 17 may be driven by an actuator 18 to press the product from the cavity and to obtain a product acceleration upon filling of the container 1 1 . The operation of the screw feed device 5, the transport device 3, the actuator 18 of the plunger 17, the gate device 16 and the transport members 12 of the container 1 1 is controlled by a control unit 20 that is connected to the respective machine parts via schematically indicated electrical signal lines 21 ,22,23,24,25.

The control unit 20 drives the screw-feed device 5 to dose a predetermined volume of product into each cavity via the dispensing opening 7 by controlling the rotation of the screw 6. The volume of powder that is dispensed may be for instance 100 cm ³ in 200ms. As the volume dispensed is smaller than the cavity volume, the level of the powder in the cavity is below the peripheral edge 27 of each cavity opening 26. At the time one cavity is filled by the screw-feed device 5, another cavity at the filling station may simultaneously be emptied at the filling position 10 so that rapid operation is warranted.

After partly filling a cavity 8 to for instance between 10% and 90% of the volume of the cavity 8, the indexing disc 14 is rotated under control of the control unit 20 to the filling position 10 in a time of about 150ms. At the filling station 10, the actuator 18 is activated by the control unit 20 such that the plunger 17, which is of a cross-section of similar size and shape to the opening 26 of the cavities 8,9 and that closely fits into the cavity, is pressed into the opening. At the same time, the sliding gate device 16 at the filling position is opened so that product is accelerated into the container 1 1 in a filling time of about 350ms.

In fig. 2 an embodiment is shown in which two powder supply stations 2, 2' are placed in series for each supplying to a cavity a part of the product volume that is transferred from the cavity into the container 1 1 . The second supply station 2' may be formed by a hopper or sliding gate but is preferably formed by a screw feed device 5'. The screw feed device 5'may be of a smaller size than screw feed device 5 such hat between 10% and 20 % of the total product that is dispensed at the filling station 10, is supplied by the screw feed device 5' for accurate dosing. As an option, it has been illustrated in Fig. 2 that at the bottom of cavity 8 a weighing device 30 may be provided which inputs the weight of the powder supplied into the cavity 8 by supply station 2 to the control unit 20 via schematically indicated signal line 31 . Depending on the measured weight, the control unit 20 drives screw-feed device 5' via signal line 32 to complete the dosed amount in the cavity, by topping up the cavity 8 when it is underneath the supply station 2' to a predetermined amount of product.

In the embodiment shown in fig. 2, the filling of the container 1 1 takes place under gravity flow conditions after opening of the gate 16 at the filling position 10 without a plunger being present.

In the embodiment of fig. 3, a plunger 17 is placed between the supply station 2 and the filling position 10 for compression of the product in the cavities. In this way a pellet of compressed product is formed that allows for rapid dispensing by the pellet dropping into the container 1 1 without a powder trail being formed.