US3269079A

US3269079A - Method of and apparatus for sterile packaging of sterile consumer goods

Info

Publication number: US3269079A
Application number: US271771A
Authority: US
Inventors: Schmied Rudolf
Original assignee: Alpura AG
Current assignee: Alpura AG
Priority date: 1962-04-12
Filing date: 1963-04-09
Publication date: 1966-08-30
Anticipated expiration: 1983-08-30
Also published as: DK111406B; GB1034416A; CH399287A

Description

Aug. 3Q, 1966 R. SCHMIED 3,269,079

METHOD OF AND APPARATUS FOR STERILE PACKAGING OF STERILE CONSUMER GOODS 2 Sheets-Sheet 1 Filed April 9, 1963 Jnvenlor iiapazrfimmmo Aug. 30, 1966 R. SCHMIED 3,269,079

METHOD OF AND APPARATUS FOR STERILE PACKAGING OF STERILE CONSUMER GOODS Filed April 9, 1963 2 Sheets-Sheet 2 92 7/1 venfor: Run; Jam/0 fir K 1% M firraR/vzy United States Patent 3,269,079 METHOD OF AND APPARATUS FOR STERILE PACKAGING 61E STERILE CONSUMER GOQDS Rudolf Schmied, Tonisbach, Konolfingen, Switzerland,

assignor to Alpura A.G., Bern, Switzerland, a corporation of Switzerland Filed Apr. 9, 1963, Ser. No. 271,771 Claims priority, application Switzerland, Apr. 12, 1962,

4,472/62 12 (Ilaims. (Cl. 5328) The invention relates to a method of and apparatus for sterile packaging of sterile consumer goods wherein a tube is formed from a packaging material in a filling and packaging machine; the tube is partly filled with the goods to be packaged, and thereupon compressed transversely of its length to form closed receptacles, the inside of the formed tube being sterilized by heat at a location above the goods.

With the system according to the invention sterilization of the packaging material prior to formation of the tube may be omitted. This considerably simplifies the entire filling and packing operation as compared with methods wherein the packing material is completely sterilized before introduction into the tube forming and filling machine and a sterile atmosphere must be maintained along the path of the packaging material into the machine and until the closed receptacle has been formed, for instance, by production of a sterile atmosphere at a slight positive pressure inside a chamber which surrounds the path traveled by the packing material and the parts for forming and filling the receptacles or containers.

In a conventional apparatus for performing the aforesaid method, heating means are disposed inside of the tube and above the goods filled thereinto, for heating the inside of the tube to sterilization temperature. The heating means may be, for example, in the form of an electric radiator.

In the method according to the invention, however, the energy required to heat the inside of the tube is transmitted from the outside of the tube through the wall thereof. Therefore, no heating means are required in the interior of the tube, a feature which is very advantageous in the preparation of small containers which are made from a small diameter tube. Another advantage of the system of the invention is the much greater freedom in choosing the type of heating and the medium used as heat carrier. In addition, in the system according to the invention the size of the heating means is not restricted to tube diameter.

It is of advantage to heat the outside of the tube by heat radiation; in certain cases it may be of advantage to heat the outside of the tube by means of a flowable heat carrier which is brought into contact with the out side surface of the tube. Alternatively, electric heating means, for example, a high-frequency electric field may be used.

In a Variation of the system according to the invention, supplemental heating of the inside of the tube is provided. In this case the intensity of the heat applied to the outside of the tube can be reduced. For the same reason at least the side of the packing material which subsequently forms the inside of the tube may be treated with a chemical agent detrimental to germs or microbes which may be present.

The apparatus for performing the method according to the invention comprises tube-forming elements, a filling pipe for the material to be packaged which pipe extends into the formed tube, and pressing elements for compressing the filled tube, and is characterized in that a source of heat energy is placed outside the tube above the goods filled thereinto, for heating the inside of the tube.

3,269,079 Patented August 30, 1966 The aforesaid energy source may be in the form of a heat radiator; alternatively, the energy source may comprise means for applying a flowable heat carrier to the outer wall of the tube. If desired, heating may be electric, for example, by providing means producing a highfrequency electric field extending through the tube wall. Additional heating means may be placed inside the tube; since the internal heating means do not have to provide the entire heat required, the additional heating means may be of suitably small size.

If initial chemical treatment is desired, means may be provided for applying a chemically active substance at least to that side of the packaging material which will subsequently form the inside of the containers.

In addition to the filling pipe for introducing the goods to be packaged, a second pipe may be extended through the open end of the tube, the second pipe terminating above the goods filled into the tube, and means being provided for introducing a sterile gaseous medium through the second pipe into the interior of the tube. This arrangement produces a gas current which prevents ambient air from entering the interior of the tube.

The novel features which are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, and additional objects and advantages thereof will best be understood from the following description of embodiments thereof when read in connection with the accompanying drawing wherein:

FIG. 1 is a schematic sectional view of a filling and packing machine according to the invention.

FIG. 2 is a schematic cross-sectional view of a portion of a heating device forming part of the machine illustrated in FIG. 1.

FIG. 3 is a schematic part-sectional view of a filling and packing machine corresponding to that illustrated in FIG. 1 and provided with a modified heating system.

FIG. 4 illustrates means, cooperating with an apparatus according to the invention, for pretreating the packing material.

FIG. 5 is a schematic part sectional view of a portion of a modified apparatus according to the invention provided with additional heating means inside the tube.

FIG. 6 is a schematic cross-sectional view of a dielectric heating arrangement suitable for use in the system according to the invention.

Referring more particularly to FIGS. 1 and 2 of the drawing, the filling and packing machine comprises a casing 1 on which a support member 2 is mounted. Striplike material 5 is continuously unwound from a reel, not

shown, and supplied to the packing machine. The packing material 5 is in the form of paper type strip coated on one side with a plastic film made, for example, of polyethylene, and is so guided into a ring 3 that a tube 5 is formed, the coated side of the paper forming the inner wall of the tube. The lateral marginal portions of the material 5 overlap and form a longitudinal portion of the tube after it is formed. A heating element 7 secured to a support 6 is pressed against the overlapping portions of the material 5 and binds the overlapping portions together by fusing the plastic film. Inside the formed tube, the overlapping portions bear against a roller, not shown, opposite the heating element 7 which is electrically heated.

Transverse heat sealing means for compressing the tube 5 at intervals are provided inside the casing 1. The transverse heat sealing means comprise electrically heated pairs of

pressing jaws

10, 11 which are secured to

endless chains

12, 13 and move therewith when the device is in operation. The

chains

12, 13 run around

guide wheels

14, 15 and 16, 17, respectively. The wheels 14 a and 17 are rotated by driving means, not shown, in the direction indicated by

arrows

18 and 19, respectively. Additional pairs of pressing jaws, not shown, are moved in a plane normal to the plane of the drawing so that the continuously descending tube is compressed alternately in two directions perpendicular to one another. Movement of the pressing jaws, when in the operative position, causes a downward movement of the material 5 and tube 5. The compression of the tube 5 by the heated pressing jaws subdivides the tube 5 into closed receptacles 20. The goods to be packaged, for example, milk which has been sterilized in a manner not described, is supplied to the apparatus through a filling pipe 21. The latter is secured to a member 4 in a manner which will be described later. A part of the length of pipe 21 is surrounded by heat insulation 26. The supply of milk is controlled by means of a float 9 in the conventional manner for maintaining a constant liquid level 22 within the tube 5.

In the unfilled top part of the tube is a closure member 33 which, when the apparatus is in operation, engages With the inner tube wall. The member 33 is supported by a jacket member 37 which extends through the top of the tube 5' and is secured to the filling pipe 21. The closure member 33 is formed with a recess 38 where the filling pipe 21 extends through the member 33. The recess 38 intercepts condensation water forming on the outside of the filling pipe 21. The jacket member 37 is secured to the member 4.

According to the invention, a heating device 61 is placed outside the tube 5 and is operative upon the outside of the tube above the liquid level 22. The heating device comprises a quartz tube 62 provided with passages 63 longitudinal of the tube 62 and accommodating electric heating coils 64. Current is supplied thereto through a conduit 65. FIG. 2 is a cross-section through a portion of the quartz tube 62 and of the tube 5.

Prior to starting normal operation of the apparatus the material 5 is formed into the tube 5 which is compressed at intervals by the

jaws

10, 11 to form a plurality of empty receptacles. The heating device 61 is operative during this time and heats the outside of the tube in order to raise the temperature of the inside of the tube to sterilization temperature. While there is no supply of goods to be packaged, hot air or another suitable heat carrier is temporarily passed through the pipe 21 from a source, not shown. The pipe 21 and the elements in side the tube, such as the float 9, the closure member 33, and the jacket member 37, are sterilized by the hot air which escapes through a clearance between the member 33 and the tube 5' and through the top of the apparatus. The hot air destroys microbes which may be present in the air in the tube 5'.

Thereupon supply of hot air to the pipe 21 is stopped and the goods to be packaged, for example, sterile milk is introduced through the pipe 21 into the tube 5. The containers sealed closed by the

pressing jaws

10, 11 are filled completely with the goods.

Because of the heat supplied by the heating device 61 to the outside of the tube, heat flows through the tube Wall to the inside wall of the tube and increases the temperature of the inside wall, which subsequently is in contact with the goods, for destroying any microbes on the inside wall of the tube. The inside wall of the tube must be heated to, for example, between 100 C. and 300 C., depending upon the speed at which the tube is moving through the device.

The air trapped between the closure member 33 and the liquid level 22 is so heated while the apparatus is in operation that any microbes which may enter through the upper end 36 of the tube and between the inside wall of the tube and the closure member 33 are destroyed.

FIG. 3 illustrates a packing and filling machine similar to the apparatus illustrated in FIG. 1, like elements being designated by like numerals. In the embodiment shown in FIG. 3, however, the outside of the tube is not heated by radiation but by engagement with a fiowable heat carrier. To this end, a tubular jacket 28 surrounds the tube 5' when the apparatus is in operation, a clearance 29 being provided between the jacket 28 and the tube 5'. An aperture 30 is provided in the jacket 28. Around the aperture 30 is an annular distributing channel 31 to which a pipe 32 is connected. The latter is provided with a valve 43 and connected to a blower 44 which draws air from the atmosphere. A heating means, for example an electric heating coil 45, is disposed in the pipe 32. Downstream of the heating means 45 a filter 47 is provided which retains microbes carried along by the air. When the apparatus is in operation, air which has been heated to a temperature of, for instance, 300 C. is introduced into the clearance 29 between the tube 5 and the jacket 23. Due to the outside heating of the tube 5 heat travels through the wall of the tube 5 so that the inside thereof is sufficiently heated for sterilization.

Since the jacket 28 extends downwardly beyond the end of the filling pipe 21 into the area where the

jaws

10, 11 operate, the bottom part of the jacket tube 28 is preferably made of flexible material. To this end, a hose 28b is secured to a sleeve 28c screwed onto the metallic top part 28a of the jacket 28. The hose 28b is preferably made of a heat-resistant plastic material, for example, of a polymerization product of tetrafluoroethylene.

The filling pipe 21 is surrounded by a tube 53 whose bottom end is open and which is connected by a pipe 54 to the pipe 32.. The pipe 54 is provided with a valve 55, a filter 57 for retaining germs and an electric heating device 56. The pipe 54 is also connected to the filling pipe 21 by means of a conduit 58 provided with a valve 59. The filling pipe 21 is provided with a valve 51.

When preparing the apparatus shown in FIG. 3 for normal operation heated and sterile air of a temperature of, for example 300 C., is supplied through the pipe 32 to the jacket 28. A portion of the air supplied by the blower 44 is heated in the device 56 and conducted through the pipe 5 1 to the filling pipe 21 and to the tube 53. In this way the inside of the filling pipe 21 and of the tube 53 and also the parts inside the jacket 28, namely the outside of the lower portion of the filling pipe 21 and the float 9 and apparatus connected therewith, are sterilized.

When the surfaces of all parts which are inside the tube 5 are sterilized the heating element '7 is started and the strip 5 is introduced into the apparatus and pushed downward inside the jacket 28 until the tube is gripped by the rotating

jaws

10, 11 and pulled thereby through the apparatus. The overlapping longitudinal marginal portions of the strip 5 are welded together as described in connection with the embodiment of the invention shown in FIG. 1. The tube 5 is in connection with the surrounding atmosphere only at its starting point 36.

The initially formed containers are filled with air. In order to prevent drawing of contaminated air into the tube 5' the heater 56 is stopped so that when the

valves

59 and 60 are open cold air sterilized in the filter 57 flows into the pipe 54 and through the pipe 21 and the tube 53 into the interior of the tube 5'. The initially formed containers are therefore filled with cold sterile air. The excess sterile air flows upward toward the starting point 36 of the tube 5. In this way a gas current is provided which prevents entry of ambient air into the tube 5. By manipulation of the valve 60 the rate of flow of air supplied to the tube 53 can be so controlled that during normal operation the velocity of the air current between the outside surface of the tube 53 and the inside surface of the tube 5 is low and the inside of the tube 5 is not excessively cooled. If desired, the heating device 56 may be so controlled that a desired temperature of the air supplied to the interior of the tube 53 is maintained.

Upon completion of the aforedescribed initial sterilization, the valve 59 is closed and the valve 51 is opened. The goods to be packaged, for example milk, now flows through the pipe 21. During normal operation of the apparatus the containers sealed closed by the

jaws

10, 11 are completely filled with the goods to be packaged. Entry of germs is prevented by the sterile air leaving the bottomv end of the tube 53 and moving upward inside the tube 5. Instead of air, nitrogen or another inert gas which does not react unfavorably with the goods to be packaged may be introduced into the tube 5' through the tube 53. The specific gravity of nitrogen at room temperature is greater than that of the ambient air so that the tube 5 will be permanently filled by the relatively heavy gas. v

The method according to the invention requires a certain resistivity of the packing material against elevated temperatures. Particularly suitable is a packing material formed of a thin metal foil or of paper to one side of which a metal foil is applied, or by placing a metal foil between two layers of paper. Very sensitive packing materials, for example certain types of paper, may be adversely affected by the required heating. In that case a chemical pretreatment of the packing material as illustrated in FIG. 4 may be desirable. The striplike packing material 71 passes through a bath 72 before it enters the filling and packing machine 73. The bath 72 consists of a chemical solution, for example a 15% hydrogen peroxide solution, which is detrimental to germs. Therefore, a lower temperature is needed for completely destroying the germs than is required without the chemical pretreatment of the packing material.

In lieu of the aforedescribed chemical pretreatment an additional heating device may be provided inside the tube 5' which supplements the heating of the inside of the tube which is effected by penetration of energy from the outside of the tube to the inside thereof. An arrangement of this type is shown in FIG. 5. A jacket 28 is provided as in the embodiment shown in FIG. 3, the inside of the jacket, i.e. the clearance 29 between the jacket 28 and the tube 5', being supplied with hot air or another suitable heat carrier by means of a conduit 32. The device for supplementally heating the inside of the tube 5' is formed by an electric radiator 86 surrounding the filling pipe 21, In this way the inside of the tube 5' is directly exposed to the radiation from the device 86. Current is supplied to the radiator 86 through conduits 87 which extend through the opening 36 of the tube 5'. Since the heater 86 must supply only a part of the heat required for sterilization the heater may be small so that it can be easily accommodated within the tube 5'.

FIG. 6 is a diagrammatic illustration of another modification of the device for heating the tube 5'. The tube is surrounded by two

semicylindrical elements

91 and 92 made of electric conductive material. The

elements

91 and 92 are connected by

conduits

93 and 94, respectively, to a high-frequency electric generator so that a high-frequency condenser field is produced between the

elements

91 and 92. The frequency may amount to 15,000 cycles per second. In this way a dielectric heating of the tube 5 and therefore of the inside of the tube is effected by electric energy transport from the outside of the tube. In lieu of the two semicylindrical elements 91 and 92 a hollow cylinder may be arranged concentric with the tube 5' and an electrode may be provided inside of the tube. The filling pipe 21 may be used to form this inside electrode.

The invention is not limited to the described and il lustrated examples. Different types of heating devices may be placed at the outside of the tube 5 and different heat carriers may be used. If the packing material from which the packing tube is formed includes a metal foil in addition to a paper and/or synthetic films, the packing tube may be heated inductively, for example, by surrounding the tube with a coil which produces an electric field of medium or high frequency. In this case eddy currents are produced within the metal foil which effect heating of the foil.

The apparatus according to the invention can be used for packaging any fiowable goods aside from milk, for example, for packaging fiowable powders. The invention is not limited to apparatus forming a tube from striplike material; it can be applied to apparatus whereby a tube is produced by extrusion of synthetic plastic packing material, aluminum, or the like, through an annular nozzle.

I claim:

1. A method of sterile packing sterile consumer goods, comprising:

continuously forming a tube from longitudinally moving striplike material,

compressing the tube in a direction normal to the longitudinal axis of the tube for closing one end of the tube,

partly filling the tube with the sterile goods,

compressing the tube in a direction normal to the longitudinal axis of the tube and in spaced relation to the closed end of the tube for forming a closed container enveloping the goods,

partly filling the tube beyond said last formed container,

compressing the tube in a direction normal to the longitudinal axis of the tube and in spaced relation to the last compression of the tube for forming a new container enveloping the goods,

continuing said filling and compressing steps to continuously form containers containing the goods, and continuously transporting energy through the wall of said tube from the outside to the inside thereof at a location beyond the goods filled into the tube and where the tube is empty, said energy being capable of being transformed into heat at the inside of the tube for heating and sterilizing the inside of the tube prior to coming in contact with the sterile goods.

2. A method as defined in claim 1 wherein said energy is in the form of heat radiated onto the outside of the tube.

3. A method as defined in claim 1 wherein a hot fluid is moved relative to and in contact with the outside of the tube.

4. A method as defined in claim 1 wherein said energy is in the form of a high frequency electric current.

5. A method as defined in claim 1 wherein additional heat is applied to the inside of the tube before the tube comes into contact with the goods filled into the tube.

6. In combination with the method defined in claim 1, the steps of continuously applying, prior to formation of the tube, a chemical agent which is harmful to germs to at least the side of the longitudinally moving striplike material which side forms the inside of the subsequently formed tube.

7. In an apparatus for continuously forming sterile containers for packaging sterile goods from a continuously longitudinally moving striplike packaging material by continuously forming a tube from said material, sealing the end of the tube, partly filling the tube with the goods to be packaged, and consecutively compressing the tube in a direction normal to the longitudinal axis thereof and in spaced relation for forming a continuous string of sealed containers:

heating means disposed solely on the outside of the tube for continuously heating the empty tube beyond the goods filled thereinto for heating the inside thereof to at least sterilization temperature.

8. In an apparatus as defined in claim 7 wherein said heating means includes heat radiation means radiating heat onto the outside of the tube.

9. In an apparatus as defined in claim 7 wherein said heating means includes a source of hot fiuid and means for moving the hot fluid in contact with the outside of the tube.

10. In an apparatus as defined in claim 7 wherein said heating means includes means for producing a high frequency electric field penetrating the tube.

11. In an apparatus as defined in claim 7 means for applying, prior to formation of the tube, a chemical agent harmful to germs to at least the side of the longitudinally moving packaging material which side forms the inside of the subsequently formed tube.

12. In an apparatus as defined in claim 7 a pipe extending into the tube for conducting the sterile goods into the tube, a second pipe placed adjacent to said first pipe and terminating in said tube upstream of the level of the goods filled into said tube, and means for producing a sterile said sterile gas filling the empty tube beyond the sterile goods and preventing ambient air from entering the tube.

References Cited by the Examiner UNITED STATES PATENTS 2,889,673 6/1959 Rockland et a1 531l2 2,918,770 12/1959 Stocker 53-18O 2,928,219 3/1960 Gubler 53-180 3,055,731 9/ 1962- Loliger.

3,063,211 11/1962 Graves 53-180 3,163,971 1/1965 Loliger et al 53180 XR 3,164,936 1/1965 Loliger 53180 FRANK E. BAILEY, Primary Examiner.

gas and conducting the sterile gas into said second pipe, 15 S ABEND Assistant Examiner

Claims

1. A METHOD OF STERILE PACKING STERILE CONSUMER GOODS, COMPRISING: CONTINUOUSLY FORMING A TUBE FROM LONGITUDINALLY MOVING STRIPLIKE MATERIAL, COMPRESSING THE TUBE IN A DIRECTION NORMAL TO THE LONGITUDINAL AXIS OF THE TUBE FOR CLOSING ONE END OF THE TUBE, PARTLY FILLING THE TUBE WITH THE STERILE GOODS, COMPRESSING THE TUBE IN A DIRECTION NORMAL TO THE LONGITUDINAL AXIS OF THE TUBE AND IN SPACED RELATION TO THE CLOSED END OF THE TUBE FOR FORMING A CLOSED CONTAINER ENVELOPING THE GOODS, PARTLY FILLING THE TUBE BEYOND SAID LAST FORMED CONTAINER, COMPRESSING THE TUBE IN A DIRECTION NORMAL TO THE LONGITUDINAL AXIS OF THE TUBE AND IN SPACED RELATION TO THE LAST COMPRESSION OF THE TUBE FOR FORMING A NEW CONTAINER ENVELOPING THE GOODS, CONTINUING SAID FILLING AND COMPRESSING STEPS TO CONTINUOUSLY FORM CONTAINERS CONTAINING THE GOODS, AND CONTINUOUSLY TRANSPORTING ENERGY THROUGH THE WALL OF SAID TUBE FROM THE OUTSIDE TO THE INSIDE THEREOF AT A LOCATION BEYOND THE GOODS FILLED INTO THE TUBE AND WHERE THE TUBE IS EMPTY, SAID ENERGY BEING CAPABLE OF BEING TRANSFORMED INTO HEAT AT THE INSIDE OF THE TUBE FOR HEATING AND STERILIZING THE INSIDE OF THE TUBE PRIOR TO COMING IN CONTACT WITH THE STERILE GOODS.