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(11) | EP 0 043 875 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Packaging machine |
| (57) The machine comprises a first feeder cyclically operable to feed predetermined quantities
of particulate material to a receiving chamber 17. Discharge means is provided and
is operable to cause or allow the discharge of each quantity of particulate material
into an individual packaging receptacle 18 for bulk filling at a first station. A
second feeder is operable to feed a selected supplementary quantity of the material
to each bulk filled receptacle 18 at a second station concurrently with operation
of the first feeder and discharge means to bulk feed subsequent receptacles. |
[0001] The present invention relates to a packaging machine for packaging particulate material, especially powdered foodstuffs such as milk powder.
[0002] There exists in the packaging industry concerned with these materials a need for packaging equipment capable of bulk filling of packaging receptacles such as bags both quickly and accurately. Such equipment should desirably package the material with the minimum of handling operations and should have an essentially simple design with low maintenance requirements and a low demand on ancillary services. The number of personnel required to operate and control the equipment should be kept to a minimum. In the case of powdered foods, the handling of the material to be packaged should be carried out with due regard to hygiene, and if the filled packaging bags are to be closed by heat sealing it is advantageous if the filling process provides scope for deaeration of the filled bags.
[0003] It is therefore the primary object of the present invention'to provide a packaging machine which may enable rapid and accurate filling of receptacles with particulate material.
[0004] A supplementary object of the invention in a preferred embodiment thereof is the provision of a packaging machine of the kind referred to which is economic in its construction and operational and maintenance requirements and which enables hygienic handling of materials to be packaged.
[0005] Other objects and advantages of the invention will be apparent from the following description.
[0006] In accordance with the present invention, therefore, there is provided a packaging machine for the packaging of particulate material, the machine comprising in combination a packaging machine for the packaging of particulate material, the machine comprising in combination first feeder means cyclically operable to feed predetermined quantities of particulate material to a receiving chamber of the machine, discharge means operable to cause or allow discharge of each such quantity into an individual packaging receptacle for bulk filling thereof at a first station, and a second feeder means operable to feed a selectable supplementary quantity of the material to each bulk filled receptacle at a second station concurrently with operation of the first feeder means and discharge means to bulk fill subsequent receptacles.
[0007] Preferably, the discharge means comprises closure means operable to open or close an outlet of the receiving chamber, and for preference the machine further comprises feed control means for varying the quantities of material fed by the first feeder means.
[0008] In one preferred embodiment of the invention the first feeder means comprises an augur which may be controlled to rotate a selectable number of times and/or at a selectable speed in each feed cycle. In another embodiment, the first feeder means comprises a vibratory feeder operable to feed the material along a downwardly inclined chute. In the latter embodiment, sensing means may be provided to sense the weight or volume of material fed by the vibratory feeder and to stop the feeder when a predetermined weight or volume has been fed. In addition, the vibration amplitude of the feeder may be variable to correspondingly vary the feed rate and a shut-off gate can be provided to prevent flow of material into the receiving chamber. A flow regulating gate can also be provided to regulate the flow of material along the chute.
[0009] For preference, the machine further comprises a weight sensing means adapted to sense the weight of each bulk filled receptacle and to control the second feeder means to feed to the receptacle a supplementary quantity of material equal in weight to the difference between the sensed weight and a reference weight. The second feeder means conveniently comprises an augur or vibratory feeder.
[0010] With this machine, after conclusion of each discharge into a packaging.receptacle at the first station the discharge means can operate to prevent further discharge from the receiving chamber so that feeding into the receiving chamber can immediately recommence. Each receptacle once bulk filled can be replaced at the first station by an empty receptacle to receive the next discharge from the receiving chamber, the shutdown of the main feeder, namely the first feeder, between cycles thus being kept to a minimum by this system. The bulk filled receptacle is transferred to the second station for introduction, if required, of a topping-up quantity, which enables consistently accurate filling of the receptacles and which can be quickly carried out during each bulk filling cycle.
[0011] Embodiments of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which:-
Fig. 1 is a schematic side elevation of a milk powder packaging machine according to a first embodiment of the invention;
Fig. 2 is a schematic front elevation of the machine of Fig. 1; and
Fig. 3 is a schematic side elevation of a milk powder packaging machine according to a second embodiment of the invention.
[0012] Referring now to Figs. 1 and 2 of the drawings, there is shown a milk powder packaging machine 10 for packaging, for example, 25 kilogram quantities of the powder into plastic bags. Other particulate materials, whether foodstuffs or not, different packaging quantities and other types of packaging receptacles are all within the scope of the operation of the machine.
[0013] The machine comprises an enclosed feed hopper 11 mounted on a frame (not shown) and having at its uppermost side an inlet communicating with a vibratory delivery device 12. The device 12 in turn communicates with a bulk delivery funnel 13 for the reception of bulk loads of milk powder, the device 12 being operable to assist displacement under gravity of the powder down into the feed hopper 11. Inter- . posed between the hopper 11 and device 12 is an isolation valve (not shown), for isolating the hopper from the delivery funnel so as to enable inspection or maintenance to be carried out downstream of the device 12. The hopper 11 has an inspection hatch 14 arranged at one of its sides for access to its interior.
[0014] Feeding of powder from the hopper 11 is carried out by a first feeder means which consists of a cyclically driven horizontal augur (not shown) housed in an enclosed conduit 15 extending horizontally from the base region of the hopper, the augur extending into the hopper and being driven by an electric motor 16, for example a 1.5 kilowatt clutch/brake motor. The augur is controlled by means of a presettable electronic counter to rotate a predetermined number of times in each cycle, the number of augur revolutions per cycle being selected in accordance with the quantity of powder to be delivered in each cycle. In the case of the present embodiment which provides 25 kilogram fillings, the first , feeder means is preferably controlled to provide 90% of this filling. This proportion may be varied by appropriate adjustment of the counter setting.
[0015] The operating speed of the augur can also be varied, for example between 100 and 150 r.p.m., for corresponding variation in the rate of feed of the powder.
[0016] At a point remote from the hopper 11, the conduit 15 communicates with an enclosed housing 17 defining a receiving chamber for receiving powder fed by the augur. At its lowermost end the receiving chamber has a downwardly tapering outlet neck. A discharge means, for example a gate (not shown), is provided for discharging successive quantities of the powder from the receiving chamber through the outlet neck.
[0017] The area below the outlet neck of the housing 17 constitutes a bulk filling station for bulk filling of individual plastic bags 18, each of the bags being supported at the station on a transfer conveyor 19. The conveyor 19 has a V shaped support bed (Figs. 1 and 2) or a flat support bed (Fig. 3) for supporting each bag so that its neck can be engaged with the outlet neck of the housing 17.
[0018] Also arranged at the bulk filling station are two sintered plastic deaeration probes 20 which are inserted into each bag during the bulk filling process in order to remove entrained air, the probes being withdrawn after a predetermined time.
[0019] For topping up of the bulk filled bags there is provided a second feeder means for feeding supplementary quantities of the powder to the bags at a supplementary feed station down-stream of the bulk filling station. The second feeder means consists of a second variable speed augur (not shown) arranged in a horizontal conduit 23 extending from the base of a reservoir unit 22, the reservoir unit being supplied by an inclined chute 21 extending down from the top of the feed hopper 11. The second augur is driven by an electric motor 24, for example a 0.6 Kilowatt clutch/brake motor, at a speed of between, for example, 100 to 200 r.p.m. in dependence on the desired feed rate.
[0021] The conduit 23 terminates in an outlet shroud 26 for the discharge of a supplementary quantity of the powder into each bulk filled bag at the supplementary feeding station, each bag being supported at this station on a weighing mechanism 27 electrically connected to control means for controlling the augur drive motor 24. In dependence on the measured weight of each bag, the augur is correspondingly driven to feed a supplementary quantity of powder to the bag via the shroud 26 to complete the requisite 25 kilogram filling. A digital display of the measured weight is also included in the weighing mechanism 27.
[0022] As can be seen in Fig. 2, downstream of the supplementary feed station there is arranged a conveyor 28 for conveying filled bags to a heat sealing unit for closure of the bags.
[0023] Referring now to Fig. 3, there is shown a packaging machine 30 that differs from the machine 10 essentially only in the nature of the first and second feeder means, the otherwise corresponding features of the machines being identified by the same numerals.
[0024] The first feeder means in this case consists of a slightly downwardly inclined chute 31 extending from the base of the feed hopper 11 to the housing 17, and a vibratory feeder 32 arranged in the bottom of the hopper 11. The feeder 32 is driven by an electromagnetic drive unit 33, such a drive being preferred to a vibratory motor in order to ensure an immediate "on"-"off" response. As in the case of the main feed augur of the machine 10, the vibratory feeder 32 is driven in cycles to feed predetermined quantities of the powder, measurement of the quantity and consequently stopping and starting of the drive unit 33 being achieved either volumetrically by a level control or gravimetrically by mechanical or electronic weighing equipment.
[0025] To control the flow rate of the powder and to prevent overrun of the feed the chute 31 is provided at its inlet end with a rate control gate 34 and at its outlet end with a shut-off gate 35. The former is adjustable through angular positions ranging from 0° - 900, while the latter has only open and closed positions. The gates 34 and 35 can be operated together so that both are entirely closed at the end of each feeding cycle.
[0026] The flow rate of the powder is additionally controllable by amplitude adjustment of the vibratory feeder.
[0027] The second feeder means consists of a second vibratory feeder 37 and drive-unit 38, and is supplied by a chute 36 which includes a rate control gate and a shut-off gate similar to the gates 34 and 35.
[0028] By comparison with the machine 10, the machine 30 is primarily,suitable for more granular and less dusty powders, and it may be found expedient in the case of the machine 10, when utilised to package powders of this consistency, to employ a vibratory feeder in the second feeder means rather than an augur.
[0029] In use of the packaging machine 10 or 30, milk powder is unloaded into the bulk delivery funnel 13 and delivered under gravity, with the assistance of the vibratory delivery device 12, to the feed hopper 11. The augur or vibratory feeder of the first feeder means is set into cyclic operation to feed, in each cycle thereof, a selected quantity of the powder to the receiving chamber in the housing 17, the discharge means being set to allow material to accumulate in the receiving chamber. A bag 18 is positioned below the outlet neck of the housing 17.
[0030] At the end of each feeding cycle the augur or vibratory feeder is stopped and, in the case of the vibratory feeder, the rate control and shut-off gates 34 and 35 are closed. The gate or other closure element of the discharge means is operated to allow the material accumulated in the receiving chamber to discharge in bulk into the bag 18.
[0031] Simultaneously with the bulk discharge the deaeration probes 20 enter the bag for removal of air entrained with the powder, and are withdrawn after a predetermined time. The partial deaeration of the bulk-filled bag facilitates later heat sealing of the bags.
[0032] At the end of the bulk discharge, the gate or other closure element of the discharge means closes off the outlet of the housing 17 and a further feeding cycle of the augur or vibratory feeder immediately commences, the shutdown of the augur or vibratory feeder thus being for only as long as it takes to complete the discharge of the material from the receiving chamber and then close the chamber outlet.
[0033] While the next feeding cycle is in progress, the bulk filled bag is transferred to the supplementary feeding station and a fresh, empty bag is placed on the conveyor 19 at the bulk filling station. When the empty bag is in place, the discharge means opens the receiving chamber outlet. Meanwhile, the bulk filled bag at the supplementary feeding station is weighed by the weighing mechanism 27 and, in dependence on the measured shortfall of the weight of the bag in relation to a reference weight, the second augur or vibratory feeder of the second feeder means is set into operation to feed to the bag a topping-up quantity of powder sufficient to achieve the reference weight. When the reference weight is reached, the filled bag is transferred to the conveyor 28 for conveying to the heat sealing unit. As only a relatively small topping-up quantity is required, the entire topping-up process can be carried out during a feeding cycle of the first feeder means, so that the packaging rate of the machine is determined essentially only by the feed cycle time of the first feeder means plus the bulk discharge time.
[0034] The machine 10 or 30 is preferably constructed in such a manner as to enable easy cleaning of the various parts between changes in the type of material handled by the machine. Stainless steel can be used extensively to ensure a high standard of hygiene, and enclosure of the various components provides a substantially dust-free operation and minimises ingress of foreign matter. The requirements imposed on energy media, such as electric power and compressed air, may be relatively low. A gentle handling of the material, especially agglommerated powders, may be ensured by features such as the comparatively low-speed operation of the bulk feed augur of the machine 10 and absence of backpressures in the augur feed.
[0035] The bulk feeding and topping-up systems of the machine 10 or 30 may allow accuracy tolerances of, for example ± 1.25% and - 0.125% of, respectively, the predetermined bulk filling weight and the predetermined total filling weight of each bag.
[0036] Additional features may be incorporated in the machine 10 or 30, for example a bag magazine with automatic dispensing, the bags being sequentially coded, sampler means for sampling the packaged material, and dust collection means. In the case of the machine 10, a fluidising ring may be associated with the bulk feed augur to enhance the handling of the material by the augur.
1. A packaging machine for the packaging of particulate material, the machine comprising
in combination first feeder means (15) cyclically operable to feed predetermined quantities
of particulate material to a receiving chamber (17) of the machine, discharge means
operable to cause or allow discharge of each such quantity into an individual packaging
receptacle (18) for bulk filling thereof at a first station, and a second feeder means
(23) operable to feed a selectable supplementary quantity of the material to each
bulk filled receptacle (18) at a second station concurrently with operation of the
first feeder means (15) and discharge means (26) to bulk fill subsequent receptacles.
2. A machine as claimed in claim 1, wherein the discharge means comprises closure
means operable to open or close an outlet of the receiving chamber (17).
3. A machine as claimed in claim 1 further comprising feed control means for varying
the quantities of material fed by the first feeder means (15).
4. A machine as claimed in any one of the preceding : claims, wherein the first feeder
means (15) comprises an augur.
5. A machine as claimed in claim 4, wherein the augur is controllable to rotate a
selectable number of times in each feed cycle.
6. A machine as claimed in either claim 4 or 5, wherein the augur is controllable
to rotate at a selectable speed in each feed cycle.
7. A machine as claimed in any one of claims 1 to 3, wherein the first feeder means
comprises a vibratory feeder (32) operable to feed the material along a downwardly
inclined chute (31).
8. A machine as claimed in claim 7, comprising sensing means adapted to sense the
weight or volume of material fed by the vibratory feeder (32) and to stop the feeder
when a predetermined weight or volume has been fed.
9. A machine as claimed in either claim 7 or claim 8, wherein the vibration amplitude
of the vibrating feeder (32) is variable to correspondingly vary the feed rate of
the feeder.
10. A machine as claimed in any one of claims 7 to 9, comprising a shut-off gate (35)
operable to prevent flow of material into the receiving chamber (17).
11. A machine as claimed in any one of claims 7 to 10, comprising a flow regulating
gate (34) operable to regulate the flow of material along the chute (31).
12. A machine as claimed in any one of the preceding claims, comprising weight sensing
means (27) adapted to sense the weight of each bulk filled receptacle (18) and to
control the second feeder means (23) to feed to the receptacle a supplementary quantity
of material equal in weight to the difference between the sensed weight and a reference
weight.
13. A machine as claimed in any one of the preceding claims, wherein the second feeder
means (23) comprises an augur or vibratory feeder.
14. A machine as claimed in any one of the preceding claims, comprising a hopper (11)
for storage of particulate material to be fed by the first feeder means (15).
15. A machine as claimed in claim 14, wherein the first feeder means (15) is disposed
at least partly in the base of the hopper (11).
16. A machine as claimed in any one of the preceding claims, comprising a reservoir
(22) for storage of particulate material to be fed by the second feeder means (23).
17. A machine as claimed in any one of the preceding claims, comprising deaeration
means (20) for deaeration of the receptacles (18) during bulk filling thereof.