WASHING AND CLEANING SYSTEM ON A PACKING MACHINE

Abstract: A washing and cleaning system on a packing machine (1) of the type which manufactures filled packing containers from prefabricated container cases and which within a substantially wholly closed machine housing (6) comprises a bottom-forming station (2) a filling station (3), a top-forming station (4) and a driven chain or band conveyor (5) for transporting the cases between and through the said machine stations. The system comprises a slide (17) movable to and fro along a guide bar (16) which carries a number of freely adjustable nozzles (18) connected to one or more vessels containing fluids necessary for the washing and cleaning. The nozzles (18), moreover, are adjusted and distributed so that at least the bulk of all the machine components and spaces within the machine housing (6) as well as the inside of this housing are accessible to the fluid issuing through the nozzles (18) during the reciprocating movement of the slide (17) along the guide bar (16). The system, furthermore, comprises supplementary nozzles (26 and 28,29 respectively), firmly mounted at the conveyor (5) and in conjunction with the bottom-forming station (2) which likewise are connected, or connectable, to the said fluid vessels and with the help of which a supplementary cleaning of these specially exposed machine components is made possible.

Description: The present invention relates to a washing and cleaning system on a packing machine of the type which finish-manufactures filled packing containers from prefabricated tubular container cases and which within a substantially wholly closed machine housing comprises a bottom-forming station, a filling station, a top-forming station and a driven chain or band conveyor for transporting the cases in turn and succession between the said machine stations. Liquid foodstuffs of the milk, juice etc. type are packed and conveyed at present in most cases in finished consumer packages of non-returnable character which are made from a laminated packing material consisting customarily of thermoplastic-coated paper. A very large group of these so-called non-returnable packages is manufactured either from prefabricated blanks or from tubular, flattened container cases or from a web of packing material with the help of modern high-capacity packing machines of the type which form, fill and close in a liquid-tight manner the finishes packages. A packing machine of the type which manufactures packages from prefabricated tubular container cases is found described extensively, for example, in Swedish patent no. 361 857 and, in order not to burden unnecessarily the present description with machine details known already, reference is made instead to the Swedish patent for closer details concerning the design of the machine. To facilitate, if possible, the understanding of the present invention it may be appropriate, though, to provide here at least a summary outline of the principle according to which the machine manufactures the packages. The flattened container cases, whilst being raised to open tubular shape, are fed from a magazine positioned close to the machine onto a movable conveyor band which transports the cases into a bottom-forming station at the input end of the machine. The bottom-forming station comprises one or more intermittently rotatable wheels with radial mandrels whereon the cases supplied are threaded up and transported through a number of forming and sealing stations located round the wheel in order to provide the cases with a liquid-tight bottom closure. From the mandrel-wheel the cases provided with bottoms are placed onto a synchronously driven chain or band conveyor on which the cases in turn and succession are conveyed to a filling station where the cases are filled with the intended contents, and a top-forming station where the filled cases are provided with a liquid-tight top closure by means of an appropriate forming and sealing operation. After the passage through the top-forming station the finished packages are discharged towards the discharge end of the machine for further distribution. For optimum utilization of the production capacity of the machine it is customary to operate machines of this type continuously every day of the week from early in the morning until late in the evening with stoppages only at night-time and during planned, regularly recurring periods for more extensive maintenance and service work. Machine stoppages naturally also occur when during normal working hours the machine is to be changed from the filling of one product to another. The demands on hygiene and cleanliness when handling foodstuffs naturally have to be set very high so that it should be possible for the foodstuffs to be stored without any risk of being destroyed or impaired during at least a certain guaranteed keeping period, but also so as to avoid or, as long as this is at all possible, minimize the risk of the foodstuff coming into contact with, or being contaminated by, harmful bacteria and similar microorganisms which could grow rapdily in the foodstuff and and thus become a serious source of the spreading of infections. To meet these demands on cleanliness it is necessary, therefore, that the packing machine should be subjected regularly to a cleaning and washing treatment which not only concerns the machine components which during the manufacture of the package come into contact with the contents but also the machine components which run the risk of coming into contact with the contents or which are located in the close surroundings of the production line. Such a more thorough cleaning and washing treatment of the machine was carried out up to now more or less manually and was not only time-consuming but also associated with difficulties in being able to reach and to clean also nooks and corners in the machine which occur plentifully in such complicated machine designs. In order not to disturb unnecessarily the production of packages, the cleaning work in general was arranged, therefore, to be carried out in periods when the machine is normally out of operation, for example in connection with a machine shutdown for night stoppage. Cleaning work naturally is carried out also in connection with a machine being changed from one product to another. A washing and cleaning system for filling machines in accordance with the opening part of claim 1 is described in US-A-4 024 896. However this prior art machine concerns the filling of bottles and the washing nozzles are used for washing and cleaning the individual filling nozzles. The washing nozzles are mounted each on an individual guide bar. Many nozzles and guide bars are mounted on a revolving machine. However this machine does not allow the washing of machine parts others than filling nozzles. It is an object of the present invention to provide a washing and cleaning system by means of which the packing machine, with the least possible contribution of manual labour, can be washed and cleaned effectively during only a fraction of the time which has been necessary up to now for a corresponding manual washing and cleaning operation. This object is achieved in accordance with the present invention through a washing and cleaning system which has been given the characteristic that it comprises a number of freely adjustable nozzles arranged round the slide which are connected to one or more vessels containing fluids required for the washing and cleaning and which are distributed and aligned so that at least the main pat of all the machine components and spaces present within the machine housing as well as the inside of the surrounding machine housing are accessible to the fluid issuing through the nozzles during a reciprocating movement of the slide. With the help of the movable slide provided with nozzles, which thus substantially wholly replaces the previous manual washing and cleaning treatment, a corresponding treatment can be carried out with only a minimum of manual interventions being required, e.g. at the setting into operation and stopping of the the treatment, which is not only a labour-saving advantage but also means that the treatment can be carried out in appreciably shorter time than has been possible previously. In order to supplement the treatment carried out with the help of the slide equipped with nozzles, for example on particularly inaccessible or hidden spaces and machine components or on machine components which are specially exposed to the splashing of contents or which come into contact with the inside of the container cases which are to be filled, the washing and cleaning system may also comprise a number of further supplementary nozzles, firmly mounted on such spaces or machine components, which likewise are connected to the said vessels containing washing and cleaning fluids and are aligned so that they make possible a concentration of this fluid to the said regions of the machine. In accordance with a further embodiment the system can be connected to an electric control circuit comprising a preprogrammed microprocessor with the help of which the system can perform its intended washing and cleaning treatment in accordance with a predetermined working schedule. In the following the invention will be described in greater detail with special reference to the attached drawings, wherein Figure 1 shows schematically a packing machine, known in itself, provided with a washing and cleaning system in accordance with the invention, and Figure 2 shows a part of the system in greater detail. Figure 1 thus shows a packing machine of the type which has been described above and which from prefabricated, tubular, flattened container cases manufactures finished, filled packing containers for liquid foodstuffs, e.g. milk. The machine which has been given the general reference designation 1 comprises in turn and succession from the input end of the machine (to the right in Figure 1) a bottom-forming station 2, a filling station 3 and a top-forming station 4 and a driven chain or band conveyor 5 for the transporting of cases through the said stations and further, out through the discharge end of the machine (to the left in Figure 1) for further handling and distribution. To avoid or reduce the effect of possible pollutions in the surrounding atmosphere of the machine, and at the same time limit splashing of contents and the like during the operation of the machine, all the stations are covered by a common, essentially wholly closed, machine housing 6 which also contributes to a dampening of the noise level of the machine. The bottom-forming station 2 in the present example of a machine comprises two synchronously operating, intermittently rotatable mandrel wheels 7, each of which carrying a number of radial mandrels 8 for the transporting of the tubular cases through a number of forming and sealing stations 9 located round the wheel. The filling station 3 comprises two filling pipes 10 which are connected to a common contents tank 11 from which the cases, provided with bottoms, moved forwards right below on the conveyor 5, are filled with a specified portion of contents with the help of a suitable metering arrangement, not shown, which controls the portioning out of contents through the downwardly directed filling pipes 10. It is also evident from the Figure 1 that the filling station 3 can be connected to a conditioning system 12 of a type known in itself so as to create an atmosphere of chilled, sterile air suitable for the filling station in the immediate vicinity of the filling pipe 10 and thereby minimize the risk of undesirable formation of condensation on the outsides of the filling pipes. The top-forming station 4 comprises two pressing-down and sealing devices 13, each of which comprising sealing jaws 14 movable towards one another, between which foldable, open top parts of the filled cases are sealed together with one another for the liquid-tight closing of the cases. With the help of the machine 1 described finished, filled packing containers are manufactured from prefabricated container cases which from a magazine positioned close to the input end of the machine are fed one by one with simultaneous raising up to open tubular shape onto a movable conveyor band which transports the raised container cases and threads them onto radial mandrels 8 of the wheel 7 at the bottom-forming station 2 of the machine. In the course of the intermittent rotation of the wheel 7 the threaded-on cases are led through a number of forming and sealing stations 9 located round the wheel for the closing of one, or bottom-forming, end of the cases. The cases provided with bottoms are drawn off the mandrels 8 and placed onto a driven chain or band conveyor 5 which in rhythm with the intermittent rotation of the wheel 7 advances the cases to the filling station 3 of the machine directly below the downwardly directed filling pipes 10 for the portioned filling with the intended contents. From the filling station 3 the filled cases are advanced further on the conveyor 5 into the top-forming station 4 of the machine where the upper open end of the cases is closed in liquid-tight manner with the help of the synchronously operating pressing-down and sealing device 13. From the top-forming station 4 finally the finished packages are discharged from the machine for further handling and distribution. As mentioned earlier, the machine has to be subjected regularly to an extensive cleaning and washing, for example in connection with a natural machine stoppage for the night or in connection with the machine being changed over from the filling of one product to another. For this purpose the machine 1 is provided with an automatic washing and cleaning system with the general reference designation 15. The system 15 comprises a guide bar 16 arranged straight above and parallel with the conveyor 5 which carries a slide 17 movable to and fro along the guide bar and which is driven with the help of a cylinder without piston rod or a linear motor of a type known in itself. The slide 17 has a number of nozzles 18 distributed round the slide in connection with a flexible tube 19 which through a main duct 20 and branch pipes 21 and 22 (Figure 2) connected to the main duct is in connection with vessels 23 and 24 respectively containing fluids required for the washing and cleaning. The nozzles 18, moreover, are distributed and aligned so that the fluid, which with the help of a pump 25 (Figure 2) provided in the main duct 20 is made to issue through them from the respective vessel, reaches and covers substantially all machine components situated within the machine housing 6, including the inside of this housing, when the slide 17 is moved along the guide bar 16. To make possible a particularly thorough or supplementary washing and cleaning of specially exposed machine components or regions of the machine which are not readily accessible to the nozzles 18, the system 15 comprises, moreover, a number of further supplementary nozzles which are firmly mounted at such machine components or regions. In the embodiment shown the system thus has such a supplementary nozzle 26 especially aligned towards the conveyor 5 at the discharge end of the machine, which is in connection with the main duct 20 through a duct 27, and other such supplementary nozzles 28 and 29 are present on, and especially directed towards, the mandrels 8 on the respective mandrel wheel 7, which likewise are connected to the main duct 20 through ducts 30 and 31 respectively. To make possible an optional actuation of the nozzles, the respective nozzle ducts are provided with, or are individually controlled by, control valves 32-34 which together with a valve 35 in the pipe 21 and valve 36 in the pipe 22 may be connected to, and controlled by, an electric control circuit, not shown, comprising a preprogrammable microprocessor with whose help the connection of the nozzles with the vessels 23 and 24 as well as with an outer water duct 37 connected to the main duct 20 can be opened and interrupted according to a preprogrammed working schedule. To clean the machine 1 with the help of the washing and cleaning system 15 described, the procedure is as follows: The valves 33 and 34 are closed whilst the valve 32 is opened and the conveyor 5 is put into operation. The pump 25 is started at the same time as one of the valves 35 and 36 is opened, as a result of which washing and cleaning fluid is squirted under pressure (approx. 70 bar) through the nozzle 26 towards the conveyor 5 passing by. After approx. 1 minute the conveyor 5 is stopped and the valve 32 is closed. The valve 33 is opened and the slide 17 is actuated to perform a reciprocating movement along the guide bar 16. During this movement the washing and cleaning fluid issuing through the nozzles 18 will sweep over and cover essentially all machine components present within the machine housing 6, including the inside of this housing, and after approx. 1 minute the connection between the nozzles 18 and the source of washing and cleaning fluid is broken owing to the open valves 35 or 36 being closed and the slide 17 being stopped. The fluid squirted out is allowed to work for approx. 10 minutes, whereafter the slide 17 is actuated again to perform a reciprocating movement along the guide bar 16. During this movement the connection between the nozzles 18 and the outer water duct 37 is opened, as a result of which a thorough flushing out of the cleaning fluid squirted out earlier is provided. After approx. 10 minutes of flushing the connection to the water duct 36 is interrupted and the slide 17 is stopped. The valve 34 and one of the valves 35 and 36 are opened at the same time as the wheel 7 is actuated and the mandrels 8 are rinsed with washing and cleaning fluid during the passage past the nozzles 28 and 29. After a final flushing with water the wheel 7 is stopped and the pump 25 is halted, whereupon the machine is washed and cleaned and ready for a new manufacture and filling of packing containers. As mentioned already, the regulation of the valves as well as the actuation of the conveyor 5 and the mandrel 7 may take place wholly automatically with the help of a microprocessor which appreciably reduces the number of manual interventions necessary and which, therefore, in practice can be limited so as to comprise merely the actual setting into operation of the washing and cleaning procedure. The automatic process also entails the further advantage that the consumption of chemicals as well as of water can be kept very low without the demand on a high, optimum cleaning effectiveness being neglected.

Claims: A washing and cleaning system for filling machines comprising a filling station (3) for filling containers and a top-closing station for closing the containers and a driven chain or band conveyor (5) for transporting the containers in turn and succession between said machine stations, and comprising a sliding device being movable to and from along a guide bar (16) and carrying washing nozzles (18) which are connected to one or more vessels (23 and 24) containing washing fluids, characterized in that - for the purpose of washing and cleaning prefabricated tubular packing containers within a closed housing (6) of a packing machine which comprises a bottom-forming station (2) and a top-forming station (4) - the sliding device is a slide (17) which carries a number of the washing nozzles (18) which are freely adjustable and arranged arround the slide (17) and which are distributed and aligned so that at least the bulk of all the machine components and spaces present within the machine housing (6) as well as the inside of the surrounding machine housing are accessible to fluid issuing through the nozzles (18) during the reciprocating movement of the slide (17) along the guide bar (16). A washing and cleaning system in accordance with claim 1, characterized in that it also comprises supplementary nozzles (26 and 28,29 respectively), firmly mounted at the conveyor (5) and in conjunction with the bottom-forming station, which likewise are connected, or are connectable, to the said vessels (23 and 24). A washing and cleaning system in accordance with claim 1 or 2 characterized in that the guide bar (16) is arranged above, and parallel with, the conveyor (5). A washing and cleaning system in accordance with claim 2 or 3 characterized in that the nozzles (18) as well as each one of the supplementary nozzles (26 and 28-29) are freely actuable in relation to one another. A washing and cleaning system in accordance with anyone of the preceding claims. characterized in that the slide (17) is driven with the help of a cylinder without piston rod or a so-called linear motor of a type known in itself. A washing and cleaning system in accordance with anyone of the preceding claims, characterized in that it is controlled with the help of a microprocessor.

Inventors: LINDGREN, CHRISTER, SCHILDT, ROLF
Applicants: TETRA ALFA HOLDINGS S.A.
Application year: 1989
Main classification: B08B3
IPC codes: B08B3, B65B59, B65B55