RU2588187C2 - Packing machine and method of producing sealed packages for food products from packing material web - Google Patents

Abstract

FIELD: packaging industry.

SUBSTANCE: packing machine for production of sealed packages from a packing material web for fluid food products contains an aseptic chamber, through which the said web is fed and inside which the sterilising agent is applied on the said web; a workstation located downstream of the said aseptic chamber and into which, during use, a pipe is supplied made from the said web, as well as a sealing element, which divides the chamber and the workstation. Packing machine comprises a transfer device, which is communicated, by the fluid medium, with the said workstation and can also carry out residues of the said sterilising substance from the said workstation. Method of production of sealed packages for a fluid food product from a packing material web comprises feeding of the web through an aseptic chamber, application of a sterilising agent on the web inside the aseptic chamber, supply of a pipe of web inside a workstation of the packing machine, arrangement of sealing medium between the chamber and the first workstation, a stage of transportation of sterilising agent residues from the workstation.

EFFECT: use of this group of inventions allows to reduce concentration of peroxide at workstations of a packing machine.

15 cl, 3 dwg

Description

Technical field

The present invention relates to a packaging machine and to a method for manufacturing sealed food packages from a web of packaging material.

State of the art

As you know, many food products, such as fruit juice, pasteurized or ultra-pasteurized milk, wine, tomato sauce, etc., are sold in packages obtained from sterilized packaging material.

A typical example of this type of packaging is a parallelepiped packaging for liquid or flowable food products, known as Tetra Brik Aseptic (registered trademark), which is made by folding and sealing a laminated tape packaging material.

The packaging material has a multilayer structure, essentially containing a base layer for stiffness and strength, which can be formed by a layer of fibrous material, such as paper, or mineral-filled polypropylene material; and a number of layers of heat-sealable plastic material, for example a plastic film covering both sides of the base layer.

In the case of aseptic packaging for long-term storage products such as ultra-pasteurized milk, the packaging material also contains a layer of gas and light impervious material, such as aluminum foil or a film of polyvinyl alcohol (EVOH), which is applied to a layer of heat sealable plastic material, and which in turn covered with another layer of heat-sealable plastic material, forming the inner surface of the package, ultimately in contact with the food product.

As you know, this kind of packaging is made on fully automatic packaging machines, on which the pipe is continuously formed from the supplied web of packaging material. More specifically, the web of packaging material is unwound from a roll and fed through a workstation for applying a sealing tape of heat-sealable plastic material and then through an aseptic chamber on a packaging machine, where it is sterilized, for example, by applying a sterilizing substance such as hydrogen peroxide, which then evaporates by heating and / or irradiating the packaging material with radiation of an appropriate wavelength and intensity.

The web of packaging material is then fed through a forming unit with bending components that interact with the packaging material so that it is gradually bent from the shape of the strip into the shape of a pipe.

More specifically, the first portion of the sealing tape is applied to the first longitudinal edge of the packaging material, on the surface of the material ultimately forming the inner side of the packages, with the second portion of the sealing tape protruding from the first longitudinal edge.

The bending components are arranged in series and contain roller bending elements forming passages for the packaging material, gradually changing in cross section from a C-shape to a substantially circular shape.

Interacting with the bending elements, the second longitudinal edge is laid on the outside of the first longitudinal edge with respect to the axis of the formed pipe. More specifically, the sealing tape is placed completely inside the pipe, with the surface of the second longitudinal edge facing the axis of the pipe partially overlapping the second portion of the sealing tape and partially on the surface of the first longitudinal edge located on the opposite side to the first workstation of the sealing tape.

Packaging machines of the above type are known in which the first and second longitudinal edges are heat-sealed inside an aseptic chamber to form a longitudinal seam along the pipe, which is then filled with a sterilized or pasteurized food product.

In addition, the packaging machines of the above type contain a forming unit in which the tube is sealed and cut along the cross section through equally spaced intervals to form a pillow-type package.

The forming unit contains two or more clamping elements (clamps), which cyclically interact with the pipe in order to seal it.

Packages of the “pillow” type are then mechanically folded to form corresponding packages on the forming unit, which are located downstream of the movable components of the forming unit.

In detail, the forming unit is located downstream of the aseptic chamber with respect to the direction of advancement of the pipe.

In addition, the seal separates the aseptic chamber from the forming unit in a fluid tight manner, exerting pressure on the tube of packaging material.

However, some peroxide residues inevitably pass through the seal, especially when the packaging material web is provided with a plurality of closing devices openable, which are applied by injection of the plastic material directly onto the fabric.

In essence, the opening device, moving along with the pipe, moves the seal from the outside diameter of the pipe, thereby reducing the effectiveness of the seal in a fluid-tight compartment of the aseptic chamber.

This situation is complicated by the fact that the high speed with which the pipe is fed makes the gap between the passages of the two subsequent opening devices very short with respect to the seal. Accordingly, the time period during which the seal is effectively pressed against the pipe is reduced.

Peroxide residues can impair the wear resistance of the mechanical components of the forming and bending assemblies, such as clamps.

Accordingly, in industry there is a need to reduce, as far as possible, the amount of peroxide that can pass through the seal and possibly come in contact with the forming unit or other downstream components of packaging machines.

In addition, the operator usually has access to the bending unit.

In European regulatory documents, there is a requirement that peroxide residues in the air be below a certain limit at the work places of the packaging machine, to which the operator has access, for example, in forming and bending units.

Therefore, there is a need to reduce, as far as possible, the concentration of peroxide in the workplaces of the packaging machines, which the operator has access to and which are located downstream from the compaction.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a packaging machine for the manufacture of sealed packages for fluid food products from a web of packaging material, designed to directly meet at least one of the above needs.

This problem is solved by means of a packaging machine according to claim 1.

The present invention also relates to a method for manufacturing sealed food packages from a web of packaging material, as claimed in claim 10.

Brief Description of the Drawings

A preferred and non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a packaging machine according to the invention;

Figure 2 is an enlarged front view of some components of the packaging machine of Figure 1 with parts removed for clarity;

Figure 3 - additional components of the packaging machine of Figure 1 with the parts removed for clarity.

Description of a preferred embodiment of the invention

Reference numeral 1 to FIG. 1-3 indicates a packaging machine for the continuous production of sealed food packages 9 from a web 3 of packaging material that is unwound from a roll 4 and fed along the manufacturing path P.

Preferably, packaging 9 for fluid food products, such as pasteurized or ultra-pasteurized milk, fruit juices, wine, peas, legumes, etc., is made on machine 1.

The machine 1 can also produce sealed packages 9 for a food product that is fluid in the manufacture of packages 9 and cures after the packages 9 are sealed. One example of such a food product is a serving of cheese, which melts in the manufacture of packages 9 and then hardens as needed after the packages 9 are sealed.

The packaging material has a multilayer structure essentially containing a base layer for stiffness and strength, which can be formed by a layer of fibrous material, for example paper, or a mineral-filled polypropylene material and a number of layers of heat-sealable plastic material, for example a polyethylene film covering both sides of the main layer.

More specifically, as shown in FIG. 3, the web 3 is fed along the path P by means of guide elements 5, for example, rollers or the like, and sequentially through a number of workstations, of which are schematically shown: workstation 6 for applying a sealing tape to the web 3; a forming workstation 7 for forming a pipe 10 from packaging material having an axis A, and a workstation 8 for heat sealing a longitudinal seam 14 along the pipe 10.

In a preferred embodiment of the invention, the web 3 comprises a plurality of closingable opening devices 70 and directly obtained by injection molding.

The machine 1 also includes a filling device 12 for continuous filling into the pipe 10 from the packaging material of a sterilized or sterile processed food product.

Very briefly, the sealing tape prevents the absorption of the food product by the edge 11, as soon as the pipe 10 and the seam 14 are made on the pipe, and also improves the gas tightness and physical strength of the seam 14.

Station 7 contains a number of forming units 13 located sequentially along the trajectory P and which gradually interact with the web 3 in order to bend it into a pipe shape.

More specifically, the forming devices 13 comprise an appropriate number of rollers, performing the corresponding mandatory passes of the packaging material, the corresponding sections of which gradually change their shape from a C-shape to a substantially circular shape.

More specifically, machine 1 comprises (FIG. 1) a frame 20, which essentially comprises:

- base 26, resting on the floor (soil);

- platform 27 parallel to the base 26;

- upper compartment 29 located on the platform 27; and

- lower compartment 28 located between the base 26 and the platform 27 and accessible to the operator.

Compartment 29 accommodates:

- an aseptic chamber 21, where the web 3 is sterilized and a tube 10 is formed from the web 3; and

- a workplace 22, through which serves the pipe 10.

Compartment 28 accommodates the forming and bending unit 23, where the tube 10 is sealed and cut into individual pillow-shaped bags 2, which are subsequently bent to form the respective packages 9, a lower zone 24 and a bending workplace not shown, on which the bags 2 are bent to obtain appropriate processed packages 9.

The web 3 is sterilized inside the aseptic chamber 21 using a sterilizing agent, hydrogen peroxide in the shown embodiment of the present invention, which is subsequently vaporized by heating and / or by exposing the packaging material to radiation having an appropriate wavelength and intensity.

Workplaces 6, 7, 8 are located inside the chamber 21.

The machine 1 also contains a seal 25 located between the chamber 21 and the workstation 22 and configured to prevent the flow of the sterilizing substance towards the workstation 22, the forming and bending unit 23 and zone 24 (Figure 2).

The seal 25 is coaxial with respect to the pipe 10, while the inner diameter of the seal 25 is in contact with the outer diameter of the pipe 10.

As shown in FIG. 2, the seal 25 is located between the flange 31 and the fixed structure 32, which forms the lower end of the aseptic chamber 21.

The forming and bending unit 23 is configured to:

- firstly, gripping, sealing and cutting the pipe 10 along cross-sections spaced at equal distances to form a sequence of packages 2; and

- then folding the packages 2 with the formation of the respective packages 9.

The forming and bending unit 23 is shown only in part of two clamps 36, which cyclically move between:

- the open position in which they are disconnected from the pipe, and

- a closed position in which they surround the pipe 10 and heat seal it along its cross section.

The frame 20 comprises a plurality of windows (not shown) that make the forming and bending assembly 23 and the bending components accessible to the operator.

Preferably, the machine 1 comprises a conveying means 30 fluidly connected to the workstation 22 and adapted to transport the remainder of the sterilizing substance outward from the workplace 22 (FIG. 2).

More specifically, the conveyance means 30 essentially contains:

a liquid circuit 40 having an inlet end 41 fluidly connected to the workstation 22 and an outlet end 42 opposite the end 41 which is fluidly connected to the lower zone 24;

- a pump 45 located along the circuit 40 and configured to pump air from the workplace 22 along with the remains of the sterilizing substance; and

- a separation element 46 inserted along the contour 40.

In detail, circuit 40 receives air with a sterilizing substance at an inlet end 41 and discharges purified air at an outlet end 42.

Circuit 40, in particular, contains:

- a pipe 43 forming an end 41 and extending between the end 41 and the dividing element 46; and

- a pipe 44, forming an end 42, along which a pump 45 is inserted, and extending between the separation element 46 and the end 42.

Pump 45 is inserted along circuit 40 between separation member 46 and end 42, while separation member 46 is inserted along circuit 40 between end 41 and pump 45.

In the shown embodiment of the present invention, the separation element 46 is a gas scrubber.

More specifically, the separation element 46 cleans the mixture of air and a sterilizing substance by contacting the mixture with a washing solution.

Very briefly, the separation element 46 injects the washing solution in the first direction, while the mixture of air and sterilizing substance moves in the second direction opposite to the first direction.

In more detail, the dividing element 46 contains:

- the input end 50, through which the element receives a mixture of air and a sterilizing substance with the help of the circuit 40 through the pipe 43;

- an output end 51 through which the element discharges purified air, and

- the output end 53, through which he discharges the washing solution along with the remains of the sterilizing substance.

The purified air advances in a second direction (directed from end 50 to end 51) as it passes through end 51.

The remainder of the sterilizing substance is advanced with the washing solution in the first direction (sent from end 51 to end 50) when they pass through end 53.

The end 53 of the separation element is fluidly connected through a conduit 47 to a reservoir 55.

The tank 55 is located inside the compartment 28.

In the illustrated embodiment, the wash solution is water.

Preferably, the wash solution is water at a temperature that is lower than the temperature of the mixture of air and oxygen peroxide. Thus, the solubility of oxygen peroxide in water increases.

The workplace 22 also contains a hollow casing 60, through which passes the section 61 of the pipe 10 (Figure 2).

In more detail, the casing 60 surrounds the portion 61 of the pipe 10 and contains:

- hollow upper case 64;

- hollow lower case 65;

- a hollow intermediate housing 66 inserted axially between the housings 64, 65.

Cases 64, 65 are cylindrical and extend around axis B parallel and separate from axis A.

Case 66 contains:

a connector 71, which is connected to the end 41 of the pipe 43 using the clamp 63; and

- a cylindrical element 67, which extends around the axis C, parallel and separate from axis A, B.

In other words, the element 67 is eccentric with respect to the housings 64, 65, which are in turn eccentric with respect to the pipe 10.

More specifically, the axis A is located between the axes B, C. In addition, the axis B is located in the radial direction between the axes A, C.

In addition, the axis C is located on the opposite side of the pipe 43 with respect to axis A.

As a result, the element 66 protrudes in a radial direction from the housings 64, 65 on the opposite side of the pipe 43 with the formation of the compartment 75 with the side of the pipe 10 opposite the pipe 43.

In addition, the axis A is closer to the side surfaces of the housings 64, 65 from the compartment 75 than from the pipeline 43.

The housing 65 rests, on the opposite side of the element 66, on an annular element 69, which in turn rests on a rubber ring 68.

Housing 65 is also welded to member 69.

In actual use, the web 3 is unwound from the roll 4 and fed along the path R.

More specifically, the web 3 is fed using guide elements 5 along the path P and through the aseptic chamber 21.

The web 3 is sterilized inside the aseptic chamber 21 using a sterilizing substance, hydrogen peroxide in the shown embodiment of the invention.

The sterilizing substance is subsequently evaporated by heating and / or by exposing the packaging material to radiation having an appropriate wavelength and intensity.

As shown in FIG. 3, the web 3 passes through successive sections 6, 7, 8, within which a seal 14 is made, with the tape being applied to the packaging material.

Then the web 3 gradually interacts with the forming nodes 13, bends with the imposition of the edges 11, 15 and the formation of the pipe 10, while not sealed in the longitudinal direction.

In section 8, edge 15 is heated to melt the polyethylene layer, while heat is transferred, for example, due to heat conduction from edge 15 to edge 11 and the sealing tape, in order to melt the polyethylene layer of edge 11 and the heat-sealing material of tape 9.

Alternatively, other heat transfer means may be used for the heated edge 11 and the sealing tape.

Then, the edges 11, 15 and the tape are compressed between the rollers in order to mix the polyethylene layer of the edges 11, 15 and the heat-sealable material of the tape and thus create molecular bonds forming the seam 14 of the treated pipe 10.

The longitudinally sealed pipe 10 is continuously filled with the fluid product 12 using the device 12 and then fed through the workstation 22.

At this stage, the longitudinally sealed pipe 10 passes through the seal 25 and enters the workstation 22.

A certain amount of peroxide residues can pass through the seal 25 together with the pipe 10.

The passage of the directly molded opening devices 70 through the seal 25 disconnects the inner diameter of the seal 25 from the outer diameter of the pipe 10, thereby increasing the amount of sterilizing substance that reaches the workstation 22.

The transporting means 30 removes air along with the remains of the sterilizing substance from the workplace 22.

In more detail, air and residues are pumped out by means of a pump 45 from the casing 60 and the workplace 22 and pass through the end 41 and the pipe 43.

In addition, due to the presence of the compartment 75, a situation is prevented in which residues are caught within the side of the casing 60, which is opposite to the pipe 43.

After this, the mixture of air and residues reaches the separation element 46. Here, the washing solution is injected into the mixture.

As a result, the wash solution and peroxide residues are transported through line 47 to tank 55.

In addition, the purified air is transported through a pipe 44 to the lower zone 24.

The pipe 10 is then transported to the forming and bending unit 23, where it is gripped, sealed and cut along equidistant cross sections to form a sequence of bags 2, which are subsequently bent to obtain the corresponding packages 9.

The advantages of machine 1 and the method according to the present invention will be clear from the following description.

In particular, the transporting means 30 significantly reduces the amount of sterilizing substance that reaches the forming unit 22.

Thus, the risk that the sterilizing agent can reduce the wear resistance of mechanical components such as clamps 36 and the forming and bending assembly 23 is significantly reduced.

In addition, when accessing the forming and bending unit 23, the operator is exposed to greatly reduced amounts of sterilizing substance, thereby reducing the health hazard to the operator.

More specifically, the Applicant has found that the conveyor 30 ensures that the machine 1 meets European requirements for the level of peroxide in those places that are accessible to the operator, such as the forming and bending unit 23.

In more detail, the Applicant has found that the air in the forming and bending unit 23 in the vicinity with clamps 36 contains less than 0.4 ppm of hydrogen peroxide.

In addition, the purified air is transported to zone 24, that is, to the zone of machine 1, which is not directly accessible to the operator.

In this case, moreover, the Applicant found that the cleaned air transported to zone 24 was in compliance with European regulations. In more detail, the applicant has found that the purified air transported to zone 24 contains less than 1 part per million hydrogen peroxide.

The applicant also found that the air transported by transporting means 30 to zone 24 contains 0.3 ppm after 1 hour, starting from the moment the machine 1 started operating; 0.4 ppm after 2 hours, starting from the moment the machine 1 started operating; and 0.5 ppm after 3 or 4 hours from the start of operation of machine 1.

The applicant also found that on the bending components of the bending and forming unit 23, the air contains hydrogen peroxide in an amount of 0.5 ppm.

Finally, the casing 60 allows the transporting means 30 to pump out from the workplace 22 also the remains of the sterilizing substance that has already reached the forming and bending node 23.

In other words, the casing 6 creates a stream of air and residues that travels upward from the forming and bending unit 23 in the direction of the conveying means 30.

Compartment 75 creates a space that is effective in preventing the remainder of the sterilizing substance from entering between the casing 60 and the pipe 10.

It is clear that changes can be made in machine 1, as well as in the method as they are described and illustrated in this description, without departing, however, from the scope of the invention defined by the accompanying claims.

In particular, the casing 60 may taper towards the aseptic chamber 21.

Claims (15)

1. A packaging machine (1) for the manufacture of sealed packages (9) from a web (3) of packaging material for fluid food products, comprising:
- an aseptic chamber (21) through which the aforementioned web (3) is supplied and inside which a sterilizing substance is applied to the aforementioned web (3);
- a workstation (22) located along the aforementioned aseptic chamber (21), to which, in use, a pipe (10) is made of said web (3), and
- sealing means (25) that separates said chamber and said workplace (22);
characterized in that it comprises a transporting means (30) fluidly connected to said workstation (22) and configured to discharge the remnants of said sterilizing substance from said workplace (22). 2. A packaging machine according to claim 1, characterized in that said conveyance means comprises:
- a circuit (40) located in a fluid between said workstation (22) and zone (24) of said packaging machine (1); and
- separation means (46) located along said circuit (40) and configured to separate said residues from said air stream;
- moreover, in use, said circuit (40) receives said air stream with said residues by said workplace (22) and, in use, supplies a stream of purified air to said zone (24). 3. A packaging machine according to claim 2, characterized in that the separation means (46) comprises a source of flushing fluid and means for injecting said flushing fluid into said air stream containing said residues. 4. A packaging machine according to claim 1, characterized in that said conveying means (30) comprises pressure means (45) located along said circuit (40) for pumping an air stream containing said residues from said working place (22). 5. A packaging machine according to claim 2, characterized in that it comprises a reservoir (55) fluidly coupled to said release agent (46) and, in use, provided with said release agent (46) a mixture containing said residues. 6. A packaging machine according to claim 1, characterized in that it comprises a casing (60) fluidly coupled to said transporting means (30) located inside said workplace (22) and surrounding, when using at least one part said pipe (10). 7. A packaging machine according to claim 6, characterized in that said casing (60) comprises at least one casing (64, 65) and a compartment (75) protruding in the radial direction from said casing (64, 65) from the opposite side said transport means (30). 8. A packaging machine according to claim 7, characterized in that at least one first casing (64, 65) extends around a first axis (B), which, when used, is parallel and separate from the second axis (A) of said pipe (10) wherein said casing (60) further comprises a second housing (66) fluidly coupled to said conveying means (30) and forms said compartment (75);
wherein said second body (66) extends around a third axis (C), which is parallel and, when used, is separate from the two said first and second axes (B, A). 9. A packaging machine according to claim 2, characterized in that it comprises a forming and bending unit (23) for creating, when used, from the said pipe (10) a plurality of packets (2) and for folding the said packets (2) to form the corresponding packages (9);
moreover, said forming and bending unit (23) is accessible to the operator and is located downstream of said first workstation (22) with respect to the direction of advancement of said packaging material; said forming and bending unit (23) is, when used, placed above said zone (24). 10. A method of manufacturing a sealed package (9) for a fluid food product from a web (3) of packaging material, comprising the steps of:
- feeding said web (3) through an aseptic chamber (21) of the packaging machine (1);
- applying a sterilizing substance to said web (3) inside said aseptic chamber (21);
- feeding a pipe (3) obtained from said web inside a workplace (22) of said packaging machine (1); and
- the location of the sealing means (25) between the aseptic chamber (21) and said first workstation (22);
characterized in that it includes the step of transporting the remains of said sterilizing substance from said workplace (22). 11. The method according to p. 10, characterized in that the said stage of transportation includes the stages of:
- supply to the circuit (40) a stream of air along with the mentioned residues;
- separating said air stream from said residues;
- supply to the zone (24) of said packaging machine (1) a stream of purified air. 12. The method according to p. 11, characterized in that said separation step comprises the step of injecting a washing solution into said air stream containing said residues. 13. The method according to p. 12, characterized in that the said injection stage includes the stage of injection of the washing solution at a temperature below the temperature of the air stream. 14. The method according to p. 10, characterized in that said stage of transportation includes the stage of pumping said air stream with said residues from said first workstation (22). 15. The method according to p. 10, characterized in that it includes the stage of formation and folding of the aforementioned packages (9) at the second workstation (23) of the said packaging machine (1), which is accessible to the operator and located along the said first workplace (22) carried out in the direction of advancement of said pipe (10); and said first workstation (22) is located, when used, above said zone (24).

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