Patent Description:
The present invention also relates to a packaging assembly for forming and sealing a plurality of packages containing a pourable product, preferably a pourable food product.

In particular, the present invention relates to a packaging assembly configured to fill, form, seal, cut and fold packages containing the pourable product starting from a tube of packaging material.

As it is generally known, many pourable food products, such as fruit juice, UHT (ultra-high temperature-treated) milk, wine, tomato sauce, etc., are sold in packages made of sterilized packaging material.

A typical example is the parallelepiped-shaped package for pourable food products known as Tetra Brik Aseptic (registered trademark), which is made by folding and sealing a laminated web of packaging material. The packaging material has a multilayer structure comprising a base layer, e.g. made of paper, covered on both sides with layers of heat-seal plastic material, e.g. polyethylene.

In the case of aseptic packages for long-storage products, such as UHT milk, the packaging material also comprises a layer of oxygen-barrier material, e.g. an aluminum foil, 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 usually produced in fully automatic packaging assemblies, in which a continuous tube is formed starting from a web of packaging material initially wound in a reel and fed through a plurality of unwinding rollers of such packaging assembly. The web of packaging material is sterilized in the packaging assembly, e.g. by applying a chemical sterilizing agent, such as hydrogen peroxide solution, which, once sterilization is completed, is removed from the surfaces of the packaging material, e.g. evaporated by heating. The web so sterilized is then maintained in a closed, sterile environment, and, advanced by the aforementioned unwinding rollers, is folded and sealed longitudinally to form the tube by means of a known web folding device.

The tube is fed continuously along a first direction, normally a straight vertical direction, is filled with the sterilized food product from above and is formed, sealed and subsequently cut along equally spaced transversal cross-sections extending along a second direction, normally a direction orthogonal to the first direction. So-called pillow packs are obtained thereby, which have a longitudinal sealing band, a top transversal sealing band and a bottom transversal sealing band. The pillow packs are then cut at the cross-sections to be separated from one another and directed to a folding device of the packaging assembly for the final folding thereof.

In order to perform the forming and sealing operations, the known packaging assemblies comprise a forming device configured to form the tube, so as to give an external shape to the tube corresponding to the desired shape of the package, and a sealing device configured to seal the tube at equally spaced cross-sections orthogonal to the tube advancement direction.

A packaging assembly of the above type is known from <CIT>. Such packaging assembly comprises a pair of alternately movable forming and sealing jaws which are controllable with a reciprocating movement in the first direction and in a third direction orthogonal to the first direction and second direction to interact with the tube at successive portions thereof.

In particular, the jaws are guided and driven by a pair of driving and guiding rods to which the tube runs parallel.

The forming device comprises at least one pair of forming members, typically in the form of shells (or half-shells), arranged at opposite lateral sides of the tube of packaging material, facing one another and cyclically surrounding, in use, successive portions of the tube to sequentially impart or transfer the predetermined external shape to these portions.

For each jaw, the sealing device is arranged operatively downstream of the forming device, with respect to the first direction, and comprises at least one pair of sealing elements, typically in the form of clamps, arranged at opposite lateral sides of the tube of packaging material facing one another and cyclically gripping between them, in use, successive equally spaced transversal cross-sections of the tube to seal the tube at these transversal cross-sections, thereby forming the pillow packs.

In detail, the sealing device comprises two sealing elements: a sealing member carrying heating means and a countersealing member defining an abutment surface for the heating means to abut against.

In greater detail, each tube portion gripped between the sealing elements is heat-sealed by the heating means, which locally melt, in use, the heat-sealable plastic material in the gripped region.

In some embodiments in which the layer of barrier material is defined by a sheet of electrically conductive material, e.g. a sheet of aluminum, the heat-sealing is obtained by means of induction. In such a case, the heating means comprise an inductor which is carried by the sealing member, is supplied by a highfrequency current generator, and is substantially defined by a coil comprising one or more induction bars made of electrically conductive material, extending parallel to the second direction, and which interact with and induce an electric current in the packaging material to heat the packaging material to the required heat-seal temperature.

In other embodiments, the heat-sealing is obtained by providing ultrasounds for locally melting the plastic material. In such cases, the heating means comprise a sonotrode carried by the sealing member.

The countersealing member comprises a pressure arrangement, preferably two pressure pads made of elastomeric material in the case of induction heat-sealing, or a pressure anvil made of metal in the case of ultrasonic sealing, having respective front contact surfaces defining the above-mentioned abutment surface.

Once the heat-sealing operation is completed, a cutting member carried by one of the two sealing elements, normally the countersealing member, is activated, thereby interacting with the tube of packaging material to cut the tube along the respective previously-created sealing band, and so separating (cutting) a pillow pack from the bottom end of the tube of packaging material. Typically, the cutting member is extracted from a slot of the countersealing member to engage a corresponding recess of the sealing member.

Once the cutting operation is completed, the sealing member and the countersealing member are moved away from one another to be ready to grip another subsequent portion of the tube. A lightweight forming device with outer reinforcement structures is known from <CIT>.

Although the known forming devices and packaging assemblies are functionally valid, the Applicant has observed that they are prone to further improvements, in particular as per the total number of components, their overall weight, the maintenance, assembly and production thereof, and their flexibility and adaptability to packages of different formats (e.g. shape/size).

It is therefore an object of the present invention to provide a forming device, and a packaging assembly, which are designed to meet at least one of the above-mentioned needs in a straightforward and low-cost manner.

This object is achieved by a forming device, and a packaging assembly, as claimed in the appended claims.

With reference to <FIG>, number <NUM> indicates as a whole a packaging assembly for producing a plurality of sealed packages <NUM> containing a pourable product, preferably a pourable food product such as pasteurized or UHT milk, water, fruit juice, wine, peas, beans, etc. starting from a tube <NUM> of packaging material.

In detail, packaging assembly <NUM> is configured to form tube <NUM> starting from a web-like sheet <NUM> of packaging material, which is unwound off a reel <NUM> and fed along a forming path.

In greater detail, packaging assembly <NUM> is configured to form and seal a plurality of pillow packs 2a containing the pourable product starting from tube <NUM> and then to fold pillow packs 2a for obtaining the aforementioned formed, sealed and folded packages <NUM> containing pourable product.

Preferably, the packaging material has a multilayer structure (not shown), and comprises a layer of fibrous material, e.g. paper, covered on both sides with respective layers of heat-seal plastic material, e.g. polyethylene.

In the case of aseptic packages <NUM> for long-storage products, such as UHT milk, the packaging material also comprises a layer of gas-and-light barrier material, e.g. aluminum foil or ethylene vinyl 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, the latter forming the inner face of package <NUM> eventually contacting the pourable product.

Conveniently, after being unwound off reel <NUM> and before being formed into tube <NUM>, sheet <NUM> of packaging material is sterilized, e.g. by applying a chemical sterilizing agent, such as hydrogen peroxide solution, which, once sterilization is completed, is removed from the surfaces of the packaging material, e.g. evaporated by heating.

Then, packaging assembly <NUM> is configured to perform, sequentially, the following operations:.

Conveniently, packaging assembly <NUM> comprise an isolation chamber <NUM> defining an inner environment, in particular an inner sterile environment containing a sterile gas and separated from an outer environment. Advantageously, the operations of longitudinally sealing tube <NUM> and forming tube <NUM> are carried out within the isolation chamber <NUM>.

Packaging assembly <NUM> comprises a forming and sealing apparatus for forming and sealing pillow packs 2a and having a longitudinal axis X along which tube <NUM> is fed.

That is, in use, tube <NUM> is fed continuously along a first direction A parallel to axis X, in particular a straight vertical direction.

While being fed along axis X, tube <NUM> is filled from above with the pourable product, in a manner known and not described in detail.

As visible in <FIG>, the forming and sealing apparatus comprises a forming device <NUM> and a sealing device <NUM>.

Forming device <NUM> comprises at least one pair of forming members <NUM>, preferably embodied as forming shells <NUM> arranged facing one another at opposite sides of axis X, i.e. at opposite sides of tube <NUM>, in use.

According to a manner known and not described in detail herein, forming shells <NUM> are repeatedly movable towards and away from one another (and towards and away from tube <NUM>) to cyclically cooperate with tube <NUM> for imparting or transferring a predetermined external shape thereto.

More specifically, each forming shell <NUM> is defined by a half-shell having a substantially C-shaped cross section, so that forming members <NUM> are configured to cyclically surround, by means of said movement, successive portions of tube <NUM>, thereby sequentially imparting the predetermined external shape to such portions of tube <NUM>.

In particular, forming shells <NUM> are movable towards one another along a second direction B transversal, more in particular orthogonal, to first direction A and axis X.

Furthermore, forming shells <NUM> are movable in a reciprocate manner along the first direction A so as to follow the advancement of tube <NUM> along axis X.

Conveniently, the forming and sealing apparatus comprises two forming devices <NUM>, that is two pairs of forming shells <NUM>, each pair being movable in the aforementioned reciprocate manner.

More precisely, the speed of each pair of forming shells <NUM> along first direction A matches, in use, the advancing speed of tube <NUM> along axis X, so that the forming shells <NUM> of each pair can surround the respective portion, cyclically and correctly impart or transfer the desired shape thereon.

In detail, tube <NUM> is fed along axis X downwards. Hence, forming shells <NUM> are moved downwards to follow and surround one portion of tube <NUM>.

Then, once the forming is completed, forming shells <NUM> detach from such tube portion and are moved upwards and then follow a subsequent tube portion to repeat the forming operation thereon.

The two pairs of forming shells <NUM> perform the above operation in an alternate manner, thereby forming successive portions of tube <NUM>.

Sealing device <NUM> is configured to repeatedly seal tube <NUM> at equally spaced cross-sections thereof which are orthogonal to the tube advancement direction, i.e. orthogonal to axis X and first direction A.

In detail, as schematically shown in <FIG>, sealing device <NUM> has a sealing member <NUM> and a countersealing member <NUM> arranged at opposite sides of axis X, in particular at opposite sides of tube <NUM>, and facing one another.

According to a known manner, sealing member <NUM> and countersealing member <NUM> are repeatedly movable towards and away from one another to cyclically cooperate with one another thereby clamping tube <NUM> in a jaw-like manner at said cross-sections for sealing tube <NUM> and defining transversal sealing bands which extend along a third direction C orthogonal to both first direction A and second direction B.

Conveniently, the forming and sealing apparatus comprises two sealing devices <NUM>, each one of which is integral in motion along axis X (and first direction A) with a respective pair of forming shells <NUM>.

In detail, for each sealing device <NUM> and for each pair of forming shells <NUM>, sealing member <NUM> is integral with one forming shell <NUM> and preferably arranged below forming shell <NUM>, and countersealing member <NUM> is integral with the other forming shell <NUM> and preferably arranged below forming shell <NUM>.

To this end, packaging assembly <NUM> comprises at least one, in particular two pairs of arms <NUM>. The arms <NUM> of each pair of arms <NUM> are arranged at opposite sides of axis X, in particular at opposite sides of tube <NUM> and carry one pair of forming shells <NUM> and one sealing device <NUM>. In particular, one arm <NUM> of each pair of arms <NUM> carries one forming shell <NUM> and sealing member <NUM> of sealing device <NUM> and the other arm <NUM> of each pair of arms <NUM> carries the other forming shell <NUM> and countersealing element <NUM> of sealing device <NUM>.

Such kind of reciprocating, alternate and cyclical movement of arms <NUM>, and of forming shells <NUM>, sealing member <NUM> and countersealing member <NUM> is well-known and described, for example, in <CIT>.

In this way, arms <NUM> of each pair control and determine the movement of the respective pair of forming shells <NUM> and the movement of the respective sealing device <NUM>.

In practice, arms <NUM> define alternately movable forming and sealing jaws, which are controllable with a reciprocating movement in first direction A and in second direction B to interact with tube <NUM> at successive portions thereof.

For the sake of brevity, reference will be made in the following to a single forming shell <NUM>. However, the functional and structural features of such forming shell <NUM> are equally applicable to each forming shell <NUM> of forming device <NUM>.

According to the invention, and as visible in <FIG>, <FIG> and <FIG>, forming shell <NUM> comprises:.

More specifically, forming shell <NUM> is defined by a hollow, C-shaped half-shell <NUM> internally delimiting cavity <NUM>, with structure <NUM> arranged within cavity <NUM>.

According to a known embodiment, forming shell <NUM> has a main wall and two side walls projecting orthogonally from the main wall, thereby defining the aforementioned C-shape.

Reinforcing inner structure <NUM> comprises a lattice structure distributed within cavity <NUM>.

In particular, structure <NUM> comprises a lattice macro-structure, i.e. a lattice structure having an appreciable percentage of voids over solids, in particular appreciable to the naked eye.

Advantageously, the lattice structure has a plurality of beams <NUM> extending within cavity <NUM>.

In detail, cavity <NUM> extends within hollow body <NUM> longitudinally with respect to axis X and first direction A, and beams <NUM> extend within cavity <NUM> longitudinally with respect to axis X and first direction A.

More specifically, hollow body <NUM> comprises:.

Each beam <NUM> extends transversally within cavity <NUM> from first inner surface 19b up to second inner surface 20a.

That is, each beam <NUM> extends transversally between first inner surface 19b and second inner surface 20a.

Thanks to this configuration, structural stiffness of hollow body <NUM> is ensured, while providing for a forming shell <NUM> of lesser weight.

According to this preferred embodiment, first wall <NUM> is a front wall of forming shell <NUM> and second wall <NUM> is a rear wall of forming shell <NUM>, with respect to axis X or tube <NUM>.

Both first wall <NUM> and second wall <NUM> have a C-shaped profile, for defining said C-shape of forming shell <NUM>.

As visible in <FIG>, <FIG> and <FIG>, beams <NUM> are defined by elongated plates extending (longitudinally) within cavity <NUM> to define a plurality of longitudinal passages (or chambers, or cells, or voids) <NUM> each having a prismatic cross-section.

In detail, for each passage <NUM>, two sides of the respective prismatic cross-section are defined by a pair of opposite beams <NUM>.

In light of the above, beams <NUM> extend within cavity <NUM> intersecting with first wall <NUM> and second wall <NUM> of hollow body <NUM>, and without intersecting with one another.

According to an alternative embodiment not shown, beams <NUM> extend within cavity <NUM> intersecting with first wall <NUM>, second wall <NUM> and with one another, as to form a reticulate inner structure.

Preferably, passages <NUM> are separated from one another.

As visible in <FIG> and <FIG>, reinforcing inner structure <NUM> further comprises a plurality of ribs <NUM> extending on first inner surface 19b and protruding therefrom towards cavity <NUM>.

Conveniently, ribs <NUM> are arranged to define a raised lattice that extends on first inner surface 19b, as shown in <FIG> and <FIG>.

In this way, hollow body <NUM> is further reinforced in its most stressed part, i.e. where the forming shell <NUM> cooperates in contact with tube <NUM>.

Preferably, reinforcing inner structure <NUM> comprises a further plurality of ribs (not shown) extending on second inner surface 20a and protruding therefrom towards cavity <NUM>.

Conveniently, also the ribs of said further plurality of ribs are arranged to define a raised lattice that extends on second inner surface 20a.

In this way, hollow body <NUM> is even more reinforced and thus able to better withstand the loads exerted, in use, thereon.

Advantageously, the density of reinforcing inner structure <NUM>, both of lattice structure (i.e. beams <NUM>) and ribs <NUM>, is variable (non-constant) within cavity <NUM>.

For example, such density is higher at the most stressed points and lower at the least stressed points, thereby saving material and reducing weight while ensuring appropriate mechanical properties.

According to an important aspect of the invention, hollow body <NUM> and reinforcing inner structure <NUM> are formed in one piece without solution of continuity, so that forming shell <NUM> is formed in one piece without solution of continuity.

Advantageously, forming shell <NUM> is obtained by additive manufacturing.

In a preferred embodiment, forming shell <NUM> is made of metal, such as titanium or stainless steel.

Conveniently, forming device <NUM> comprises, for each forming shell <NUM>, at least one cam follower <NUM> coupled to the respective forming shell <NUM> for cooperating with a cam surface (known per se and not shown) of packaging assembly <NUM> to control the movement of forming shells <NUM> towards and away from one another.

In particular, each forming shell <NUM> carries two cam followers <NUM> at respective lateral portions <NUM> thereof extending from hollow body <NUM> in opposite directions along third direction C.

Expediently, forming shell <NUM> comprises at least one, in particular two, lubrication ducts <NUM> for conveying a lubricating medium towards the respective cam follower <NUM>. In detail, each lubrication channel <NUM> is configured to receive the lubricating medium from a known source thereof and to convey the received lubricating medium at the respective cam follower <NUM>.

According to one aspect of the invention, each lubrication duct <NUM> is formed in one piece, without solution of continuity, with hollow body <NUM>.

In particular, each lateral portion <NUM> internally defines one lubrication duct <NUM>, as visible in <FIG>.

Advantageously, each lateral portion <NUM> is formed in one piece, without solution of continuity, with hollow body <NUM>.

More specifically, lateral portions <NUM> are formed together with hollow body <NUM> by additive manufacturing, so that lubrication ducts <NUM> are formed together with hollow body <NUM>, thereby defining further inner cavities of the hollow body <NUM> itself, distinct and separated from cavity <NUM>.

The operation of packaging assembly <NUM> is described hereinafter with reference to a single pair of arms <NUM> and starting from a condition in which arms <NUM> are moving downward along first direction A to match the advancing speed of tube <NUM>.

In this condition, forming shells <NUM> start to move towards one another, as well as sealing member <NUM> and countersealing member <NUM>.

Sealing member <NUM> and countersealing member <NUM> grip tube <NUM> thereby sealing it and creating a transversal sealing band along third direction C.

Soon after, forming shells <NUM> surround tube <NUM> imparting the desired external shape thereto.

Once forming and sealing are finished, forming shells <NUM> are moved away from one another, as well as sealing member <NUM> and countersealing member <NUM>.

The advantages of forming device <NUM> and packaging assembly <NUM> according to the present invention will be clear from the foregoing description.

In particular, thanks to the peculiar configuration of forming shells <NUM>, i.e. being hollow and internally reinforced, the weight of forming device <NUM> is substantially reduced, while ensuring an appropriate stiffness and resistance.

Also, the total number of components is heavily reduced, since each forming shell <NUM> is now defined by a single component, also including lubrication ducts <NUM>, instead of a large number of parts and fastening elements for coupling such parts together. Accordingly, maintenance, assembly and production thereof are largely eased.

Moreover, flexibility and adaptability of forming device <NUM> to packages <NUM> of different formats is improved, since it is sufficient to vary the conformation of reinforcing inner structure <NUM> (such as shape, dimension and/or density of beams <NUM>) to different types of load profiles exerted by different packages <NUM> being formed, during production.

Also, density of reinforcing inner structure <NUM>, both of lattice structure (i.e. beams <NUM>) and ribs <NUM>, could be non-constant within cavity <NUM>, for example being higher at the most stressed points and lower at the least stressed points, thereby saving material, reducing weight while ensuring appropriate mechanical properties.

The reduced weight also determines lower stress on the servomotors configured to move arms <NUM> and a smoother torque trend thereon.

The presence of ribs <NUM> allows for a thinner first wall <NUM> and second wall <NUM>, while ensuring sufficient stiffness of such walls.

Claim 1:
Forming device (<NUM>) for a packaging assembly (<NUM>) configured to form and seal a plurality of packages (<NUM>) containing a pourable product starting from a tube (<NUM>) of packaging material,
the forming device (<NUM>) comprising a pair of forming members (<NUM>) facing one another and movable towards and away from one another to cyclically cooperate in contact with successive portions of the tube (<NUM>) for imparting or transferring a predetermined external shape thereto;
characterized in that each forming member (<NUM>) comprises:
- a hollow body (<NUM>) configured to externally cooperate in contact with the tube (<NUM>) and internally delimiting an inner cavity (<NUM>); and
- a reinforcing inner structure (<NUM>) housed in the cavity (<NUM>) and surrounded by the hollow body (<NUM>) to reinforce the hollow body (<NUM>).