HK1169090A - Method for moving a reel of packaging material from a storage station to a supply station of a packaging unit for producing sealed packages of food product, and clamping unit for clamping such reel - Google Patents

Description

Method for moving a web of packaging material from a storage station to a supply station of a packaging unit for producing sealed packages of a food product, and a gripping unit for gripping such a web

Technical Field

The present invention relates to a method for moving a web of packaging material from a storage station to a supply station of a packaging unit for producing sealed packages of a food product.

Furthermore, the invention relates to a clamping unit for clamping a roll of packaging material.

Background

Many food products, such as fruit juice, pasteurized or UHT (ultra high temperature treated) milk, wine, tomato sauce, etc., are sold in packages made of sterilized packaging material.

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

The packaging material has a multilayer structure mainly comprising: a base layer for providing stiffness and strength, which may be defined by a layer of fibrous material (e.g. paper) or a layer of mineral-filled polypropylene material; and a plurality of heat-seal plastic material layers, such as polyethylene films, covering both sides of the base layer.

In the case of aseptic packages for long-storage products, such as UHT milk, the packaging material also comprises a layer of gas-and light-barrier material, for example aluminium foil or ethylene/ethylene ethyl alcohol (EVOH) film, which is superimposed on a layer of heat-seal plastic material, and is in turn covered with another layer of heat-seal plastic material forming the inner face of the package eventually contacting the food product.

Such packages are known to be produced on fully automatic packaging units having a supply station fed with a roll of packaging material.

In particular, a continuous tube is formed in the packaging unit from a web supply of packaging material; the web of packaging material is sterilized, for example by applying a chemical sterilizing agent, for example a hydrogen peroxide solution, in the packaging unit, whereafter the sterilizing agent is removed from the surface of the packaging material, for example by heating and evaporation.

The sterilized web is maintained in a closed, sterile environment, and is folded longitudinally into a cylinder and sealed to form a tube.

The tube is fed in a first vertical direction parallel to its axis and is continuously filled with the sterilized or sterile-processed food product and is heat-sealed at equally spaced cross sections by two pairs of jaws to form pillow packs, each having top and bottom transverse sealing bands, i.e. bands extending in a second direction orthogonal to the first direction. The pillow packs are separated by cutting the respective sealing strips and are then fed to a folding station where they are folded to form respective packages.

The rolls of packaging material are usually stored on trays at a storage station, and are subsequently taken out of such trays and loaded into a supply station of the packaging unit.

More precisely, the first robot takes out the reel from the storage station, and the second robot takes out the reel in a state where its axis is in the horizontal direction and feeds such reel to the supply station. The second robot comprises a loading device which correctly positions the rolls inside the supply station of the packaging unit.

There is a need in the industry to streamline as much as possible the removal of the rolls from the trays and the subsequent loading of the rolls onto the supply table.

Also, there is a need within the industry to reduce as far as possible the risk of damaging the outer layer of the packaging material when loading the roll onto the supply station.

Finally, there is a need in the industry to facilitate loading of the roll onto the supply table due to space limitations within the supply table.

Disclosure of Invention

It is an object of the present invention to provide a method for moving a web of packaging material and a gripping unit for gripping such a web of packaging material, designed to fulfill at least one of the above-mentioned requirements in a simple and cost-effective manner.

According to the present invention, there is provided a method of moving a web of packaging material from a storage station to a supply station of a packaging unit for producing sealed packages of a food product as claimed in claim 1.

The invention also relates to a gripping unit for gripping a roll of packaging material as claimed in claim 9.

Drawings

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

fig. 1 is a perspective view of a clamping unit according to the present invention;

fig. 2 to 5 are perspective views of the clamping unit of fig. 1 in respective operating positions;

fig. 6 is a side view, on a reduced scale, of the gripping unit and the supply station of the packaging unit of fig. 1 to 5 in a further operating position; and

fig. 7 is a perspective view of the clamping unit of fig. 1 to 6 when coupled with a spindle.

Detailed Description

Number 1 in fig. 1 to 7 indicates as a whole a gripping unit for moving a web 2 of packaging material from a storage station 3 (only schematically shown in fig. 2) to a supply station 4 (fig. 6) of a packaging unit 5 for producing sealed packages of food products from a tube of sheet packaging material.

Specifically, the roll 2 includes an outer circumferential edge 6, a central through hole 7 radially inward with respect to the outer circumferential edge 6, and a pair of top surfaces 9 opposite each other and extending from the hole 7 to the outer circumferential edge 6. The hole 7 is also coaxial with the roll 2 (fig. 2).

Also, the rolls 2 are preferably stacked on trays at the storage table 3 with the axis extending in a vertical direction (fig. 2).

Differently, each roll 2 is fed to the supply table 4 in a state in which the respective axis extends in the horizontal direction (fig. 6).

With reference to fig. 6, the supply station 4 mainly comprises a frame 11 defining a compartment 12, into which compartment 12 the roll 2 is fitted.

More precisely, the roll 2 is supported inside the compartment 12 by the spindle 18 in a manner able to rotate about its own axis.

In particular, the spindle 18 (fig. 4 and 5) comprises a pair of cylindrical central portions 20 (only one of which is shown in fig. 7) coaxially housed within the bore 7 of the roll 2, and a pair of cylindrical projections 23 extending on respective opposite sides of the portions 20.

Each projection 23 has a diameter smaller than that of the portion 20 and comprises an annular groove 24 and an end 26 arranged on the opposite side of the groove 24 with respect to the corresponding portion 20.

The packaging unit 5 preferably produces sealed packages of pourable food products, such as pasteurized or UHT milk, fruit juice, wine, etc.

The packaging unit 5 may also produce sealed packages of food products that can be filled into tubes when producing the packages and which solidify after sealing the packages. An example of such a food product is a portion of cheese, which melts when the package is produced and solidifies after the package is sealed.

The packaging material has a multilayer structure (not shown) and comprises a layer of fibrous material, usually paper, covered on both sides with layers of heat-seal plastic material, for example polyethylene. In the case of aseptic packages for long-storage products, such as UHT milk, the packaging material also comprises a layer of gas-and light-barrier material, for example aluminium foil or ethylene/ethylene ethyl alcohol (EVOH) film, which is superimposed on a layer of heat-seal plastic material, and is in turn covered by another layer of heat-seal plastic material forming the inner face of the package eventually contacting the food product.

The tube is formed in a known manner by longitudinally folding and sealing a web (not shown) of heat-seal sheet material, filled with a filling tube (not shown) of sterilized or sterile-processed food product for packaging, and fed along a vertical path in a known manner not shown, and heat-sealed and cut at equally spaced cross sections.

The gripping unit 1 is preferably carried by a lift truck 8 shown in fig. 6.

The gripping unit 1 advantageously comprises a pair of gripping arms 10 which are movable with respect to each other along a direction X (horizontal in fig. 1, 2, 6 and 7, vertical in fig. 3 to 5) to any one of the following positions: an open position in which they are separated from the roll 2, a first clamping position (fig. 2 to 5) in which they are at a first distance and cooperate with the edge 6 of the roll 2, and a second clamping position (fig. 6) in which they are at a second distance smaller than said first distance and clamp the spindle 18 engaged with the hole 7 of the roll 2; the gripper arms 10 are able to rotate integrally with each other about a direction Y transverse to the direction X.

In particular, the first distance is equal to the diameter of the roll 2.

When the clamp arms 10 are in the open position, they are at a third distance greater than the first distance.

The gripper arms 10 are substantially parallel. And gripping arms 10 are able to move integrally with each other along a direction Z which is vertical in use and transverse to direction X, Y.

Direction Y, Z is fixed relative to movement of clamp arm 10 between the open position, the first clamp position, and the second clamp position.

Direction X is integral with the gripping arm 10 and orthogonal to direction Y, Z (fig. 2 and 6) when the axis of the gripped roll 2 is horizontal; when the axis of the gripped roll 2 is vertical, the direction X is parallel to the direction Z and orthogonal to the direction Y (fig. 3 to 5).

In more detail, the grip unit 1 mainly includes:

a pair of vertical guides 15 fitted to the lifting vehicle 8;

a sliding portion 16 that can slide onto the guide portion 15 along the direction Z;

a support table 17 which can rotate about direction Y with respect to the slide 16 and which protrudingly bears the gripping arm 10 on the opposite side of the guide 15 and of the slide 16.

Each gripping arm 10 comprises a substantially trapezoidal portion 13 adjacent to the table 17 and a free portion 14 opposite to the trapezoidal portion 13 with respect to the table 17.

The free portion 14 is generally rectangular with seats 19 configured to couple with opposing grooves 24 of the spindle 18. Preferably, the seat 19 is through and U-shaped.

The free portion 14 of each gripping arm 10 also comprises an elastic pad 21 suitable for cooperating with the edge 6 of the roll 2.

In particular, the pad 21 is located on the side of the free portion 14 of each gripping arm 10 facing the other gripping arm 10.

The pad 21 of each gripping arm 10 is also arranged along the direction Y between the respective trapezoidal portion 13 and the respective seat 19.

The gripping unit 1 further comprises a pair of variable-length actuators 22, each variable-length actuator 22 being arranged between the ends of the respective trapezoidal portion 11 adjacent to the table 17.

The actuator 22 extends substantially parallel to the table 17 and orthogonal to the gripper arm 10 and is operated to vary the distance of the gripper arm 10 along the direction X.

More precisely, when the length of the actuator 22 is extended, the gripping arms 10 move away from each other along the direction X. Differently, when the length of the actuator 22 is shortened, the gripper arms 10 approach each other along the direction X.

The operation of the gripping unit 1 will be described starting from the configuration shown in figure 2, in which the gripping unit 1 carried by the lift truck 8 removes the reel 2 from the storage table 3.

More precisely, the roll 2 is stored at the storage table 3 in a state in which its axis is horizontal.

When the gripper unit 1 removes the roll 2 from the storage table 3, the gripper arm 10 moves from the open position to the first gripping position and engages with the edge 6 of the roll 2.

In this position, direction X is horizontal and orthogonal to direction Y, Z (fig. 2).

Thereafter, the gripping arms 10 are rotated integrally by an angle of 90 degrees in a first direction about the axis Y together with each other and with the roll 2. At the end of the rotation, the axis of the roll 2 is horizontal and the direction X is parallel to the direction Z and orthogonal to the direction Y. In other words, the direction X is vertical.

At this stage, the portion 20 is manually inserted into the hole 7 of the roll 2, so that the projections 23 extend on opposite sides of the hole 7 (fig. 3).

The gripping arm 10 is then lowered along the direction Z (fig. 4) together with the roll 2 until the roll 2 is supported by the support 30 (fig. 5).

More precisely, the support 30 mainly comprises a horizontal base 35 and a pair of projections 36 projecting upwards from the base 35. The projections 36 define respective recesses 37.

The groove 37 is engaged by the end 26 of the spindle 18 when the roll 2 is supported by the support 30.

Gripper arm 10 is then moved to the open position and rotated 90 degrees about axis Y relative to roll 2 in a second direction opposite to the first direction. At the end of the rotation, the direction X is horizontal.

In turn, the clamp arm 10 is moved to the second clamping position and the abutment 19 engages the recess 24 of the spindle 18.

Thereafter, the gripping arm 10 is raised along the direction Z and the roll 2 is raised together with the spindle 18. Lift truck 8 moves roll 2 to supply station 4 of packaging unit 5 and is then inserted into compartment 12 (fig. 6).

Finally, roll 2 is mounted on a support in compartment 12, together with spindle 18, with gripper arms 10 moved to the open position and lift truck 8 moved away from supply table 4.

The advantages of the gripping unit 1 and of the method of moving a roll according to the invention will be clear from the above description.

In particular, the gripping unit 1 uses the same gripping arm 10 both for taking a roll 2 from the storage table 3 and for feeding such a roll 2 to the supply table 4.

As a result, the movement of the roll 2 from the storage table 3 to the supply table 4 is highly streamlined.

Also, when the roll 2 is fed to the supply station 4, the spindle 18 is gripped by the gripping arm 10, while the edge 6 of the roll 2 is not gripped.

Thus, there is substantially no risk of damaging the outer layer of packaging material defining the edge 6 during insertion of the roll 2.

Also, centering of the roll 2 in the compartment 12 is facilitated, since the spindle 18 is inserted into the hole 7 of the roll 2.

Finally, the gripping unit 1 does not require the presence of loading devices to correctly position the roll 2 inside the compartment 12.

Clearly, changes may be made to the gripping unit 1 and to the method of moving a roll as described and illustrated herein without, however, departing from the scope of the present invention as defined in the accompanying claims.

Claims (15)

1. A method for moving a web (2) of packaging material from a storage station (3) to a supply station (4) of a packaging unit (5), characterized by comprising the steps of:

-clamping the peripheral edge (6) of the roll (2) by using a pair of clamping elements (10) of a clamping unit (1);

-rotating the gripping element (10) with respect to the roll (2); and

-supporting the roll (2) on the pair of gripping elements (10) by interacting with a portion (7) of the roll (2) radially inward with respect to the circumferential edge (6).

2. A method as claimed in claim 1, characterized by comprising, after said step of gripping the circumferential edge (6) of said roll (2) and before said step of rotating said gripping element (10), the step of supporting said roll (2) on a support (30).

3. Method according to claim 1 or 2, characterized in that it comprises a step of taking said reel (2) from said storage station (3) and a step of feeding said reel (2) to said supply station (5);

said step of removing said roll (2) comprises said step of pinching a circumferential edge (6);

said feeding step being carried out in a condition of supporting said roll (2) by interaction with said portion (7).

4. A method as claimed in claim 2 or 3, comprising the step of inserting a mandrel (18) into a hole (7) of the roll (2) radially inwards with respect to the peripheral edge (6); said insertion step being carried out before the step of supporting said roll (2) by interacting with said portion (7); said step of supporting said roll (2) by interacting with said portion (7) comprises the step of clamping said spindle (18) by means of said clamping element (10).

5. Method according to claim 4, characterized in that said step of inserting is carried out before said step of supporting said roll (2) on said support (30).

6. The method according to claim 4 or 5, characterized in that said step of inserting the mandrel (18) is carried out manually.

7. Method according to any one of claims 4 to 6, characterized in that said step of feeding said supply station (4) with said roll (2) comprises the step of feeding said supply station (4) with said roll (2) and with said spindle (18).

8. A method as claimed in any one of the preceding claims, characterized by comprising, after said step of clamping the circumferential edge (6) and before said step of rotating the clamping element (10) with respect to the roll (2), a step of rotating the clamping element (10) integrally with the roll (2).

9. A gripping unit (1) for gripping a web (2) of packaging material, characterized by comprising a pair of gripping elements (10) movable with respect to each other along a first direction (X) to any one of the following positions:

-an open position in which they are separated from the roll (2);

-a first clamping position in which they are at a first distance and clamp, in use, the peripheral edge (6) of the roll (2), and

-they are at a second distance smaller than said first distance and support, in use, a second gripping position of said roll (2) by interacting with a portion (7) radially inward with respect to said circumferential edge (6);

the gripping elements (10) are integrally rotatable with respect to each other about a second direction (Y) transverse to the first direction (X).

10. Clamping unit as claimed in claim 9, characterized in that said clamping elements (10) are slidable integrally with each other along a third direction (Z) transversal to said second direction (Y).

11. Clamping unit according to claim 9 or 10, characterized in that each of the clamping elements (10) comprises:

-a first portion (21) which, in said first gripping position, can cooperate with said peripheral edge (6) of said roll (2);

-a second portion (19) defining a seat (19) configured to be engageable by a spindle (18) housed within a hole (7) of the roll (2) in the second gripping position.

12. Clamping unit according to claim 11, wherein the first part (21) comprises an elastic gasket (21).

13. Clamping unit according to claim 11 or 12, characterized in that the abutment (19) is U-shaped.

14. The clamping unit of any one of claims 10 to 13, comprising:

-at least one guide (15);

-at least one sliding portion (16) movable along the third direction (Z) with respect to the guide portion (15); and

-a support table (17) rotatable with respect to said slide (16) about said second direction (Y) and supporting said gripping element (10) in a movable manner with respect to said first direction (X).

15. A lift truck (8) for moving a roll (2) of packaging material from a storage station (3) to a supply station (4) of a packaging unit (5), characterized by comprising a gripping unit (1) according to any one of claims 9 to 14.