Patent Description:
The present invention further relates to a method to provide folds in a web.

The present invention relates to a vertical flow-wrapper as it is for example disclosed in<CIT>or<CIT>. A vertical flow-wrapper, also called vertical flow wrapping machine, is a packaging machine that receives a plane continuous web, for example a film of plastic material, e.g., a thermoplastic material, a paper- or a cardboard-material or a combination of these materials, which is transported, preferably continuously, and passed downwardly over a form shoulder and a vertical form-fill tube and is thereby shaped into a tubular form, i.e. into a tubular web, by being wrapped around the vertical form-fill tube of the flow-wrapper. After being wrapped around the vertical form-fill tube, the web is longitudinally closed by means of a longitudinally extending seal, which is applied to the web especially by heat sealing the lateral/longitudinal margins of the web or by heat sealing in the vicinity of these margins thereby joining them. This is carried out by so called longitudinal-sealing means. The tubular web has conventionally a rectangular, elliptical or a circular cross-sectional area, but may also have any other regular or irregular cross-section. The tubular web is closed by cross-sealing means, preferably in a direction perpendicular to the transport direction of the web, i.e. transversely. Thereby, individual packages are defined out of the continuous tubular web. A product, such as a foodstuff, is introduced into the packages by dropping the product through the form-fill tube and into the tubular web surrounding the form-fill-tube. During and/or after filling, the tubular web is transversely open at its upper end, i.e. not cross-sealed. Simultaneously to the filling and/or thereafter, the tubular web together with the product is moved downwardly and then a top cross-seal is formed above the product and thereby a hermetically closed package is produced. As a last step or simultaneously to the application of the top seal, the package is separated from the tubular web by cutting means. The vertical flow-wrapper also comprises a folding- and preferably a sealing unit upstream from the form shoulder. The forming unit forms folds into the plane web, which improve the stability and/or the appearance for the produced package. There is a constant need to improve the flow-wrapper, particularly make it suitable for sustainable packaging material, like paper or cardboard.

The purpose is attained by providing a vertical flow-wrapper comprising:.

wherein, each set of folding means comprises at least one rotating object.

The disclosure regarding this embodiment of the present invention also applies to the other embodiments of the present invention and vice versa. Subject matters disclosed regarding this embodiment of the present invention can also be combined with other subject matters disclosed regarding this and/or other embodiments of the present invention and vice versa.

The present invention relates to a, preferably continuously, operating vertical flow-wrapper. A vertical flow-wrapper is a packaging machine that receives a continuous plane web, for example a film of plastic material, e.g., a thermoplastic material, a paper- or a cardboard-material or a combination of these materials and forms it into packages. The web is transported, preferably continuously, and passed downwardly over a form shoulder and a vertical form-fill tube and is thereby shaped into a tubular form, i.e. into a tubular web, by being wrapped around the vertical form-fill tube of the flow-wrapper. After being wrapped around the vertical form-fill tube, the web is longitudinally closed by means of a longitudinally extending seal, which is applied to the web especially by heat sealing the lateral/longitudinal margins of the web or by heat sealing in the vicinity of these margins thereby joining them. This is carried out by so called longitudinal-sealing means. The tubular web has conventionally a rectangular, elliptical or a circular cross-sectional area, but may also have any other regular or irregular cross-section. The tubular web is closed by cross-sealing means, preferably in a direction perpendicular to the direction of flow of the web, i.e. transversely to the web transport direction. Thereby, individual packages are defined out of the continuous tubular web. A product, such as a foodstuff, is introduced into the packages by dropping the product through a form-fill tube and into the tubular web. During filling, the tubular web is transversely open at its upper end, i.e. not cross-sealed. Simultaneously to and/or after the filling, the tubular web together with the product is moved downwardly and then a top cross-seal is formed above the product and thereby a hermetically closed package is produced. As a last step or simultaneously to the application of the top seal, each package is separated from the tubular web by cutting means. The cutting means are preferably part of the cross-sealing means.

The inventive vertical flow wrapper also comprises, upstream from the form shoulder at least one folding unit for forming at least one fold in the moving web of packaging material. Preferably, the flow-wrapper comprises a multitude of folding units, particularly two, three, four or more. Each folding unit comprises two or at least two, preferably exactly two sets of folding means, each folding means comprising at least one rotating object. The web is passed along the rotating objects and is thereby folded, particularly by their circumferences. The passing web rotate the rotating objects. The at least two rotating objects of one folding unit cooperate in providing one fold to the web.

A rotating object according to the present invention is any object that is axially symmetrical, that is provided rotatable and that preferably has an edge, preferably a pointed edge around which the web is folded. The rotating object preferably has two opposite ends, wherein more preferably one end of the object, particularly an end that is in contact with the web is preferably flat, i.e. disklike. The rotating object is for example a disk or a truncated cone with a circular cross section. The web is bent around the rotating object, preferably two rotating objects, and thereby folded.

Downstream from the folding unit, preferably a sealing unit is provided for sealing the formed fold. The sealing can be done with an adhesive and/or under the influence of heat and/or pressure.

Subsequently, the folded web is transported toward the form shoulder which forms the web into a tube.

Preferably, each set of folding means comprises a multitude of rotating objects. A circular shaped plane of each rotating object of one, preferably each, set of forming means is preferably provided in one single plane, which is preferably provided at an angle > <NUM>° and more preferably < <NUM>°, relative to a horizontal plane. These planes of the of rotating objects of two adjacent sets of folding means of one folding unit are preferably in parallel.

Preferably, the axis of rotation of the rotating objects of each set of folding means are provided along a line, preferably a straight line, a curved line or any other line-shape. More preferably, this line is provided at an angle relative to a transport direction of the web. More preferably, the angles of two sets of folding means which jointly form one fold, differ.

Preferably, two sets of folding means of one folding unit are vertically staggered. The two staggered folding means form a pair that folds one fold.

According to a preferred embodiment of the present invention, the outer circumference of the rotating objects of the two sets of folding means of one folding unit partially overlap.

Preferably, upstream from the folding unit, a first deformation edge is provided, which deforms the flat, 2D-shaped, web into a 3D-shape. This deforming means reduces the lateral extension of the web prior to folding.

Preferably, downstream from the folding unit and more preferably upstream from a preferred sealing unit that seals the fold, a second deformation edge is provided, which deforms the folded web, preferably back into an essentially flat shape with the exemption of the fold(s).

The upstream- and/or the downstream deforming edge is preferably a stationary part, with no rotating element, preferably a plate.

Another subject matter of the present invention is a method to provide folds into a plane moving web, wherein:.

According to this embodiment of the present invention, the initially flat, i.e. 2D-shaped, web is first shaped into a 3D-shape, for example by bending the web transversely to its transport direction. Thereby, the lateral extension of the web, in comparison to the flat state, is reduced. Subsequently, the at least one fold is provided in the 3D-shaped web. This is preferably done by the folding unit disclosed above. Finally, the folded web is retransferred into an at least essentially plane shape by a second deforming edge with the exemption of the fold(s).

Preferably, the fold is flattened as well, so that it is parallel to the web.

Further details, features and advantages of the present inventions are demonstrated by the Figures and by the following description of preferred embodiments on the basis of the drawings. The drawings illustrate only exemplary embodiments of the present invention, which do not restrict the essential idea of the invention.

In the different Figures the same parts are provided with the same reference signs.

In <FIG>, the flow-wrapper <NUM> according to the invention is schematically shown, which comprises a frame <NUM>. A web, here a film <NUM>, especially a weldable plastic film <NUM>, is preferably continuously supplied from a reel <NUM> to a form shoulder <NUM>, which shapes the web <NUM> into a tubular form around a form-fill tube <NUM>. In the context of the present invention, a "tubular form" of the packages <NUM> or of the web <NUM> means any cross-sectional form including a circular form or another form, and especially a square, rectangular- or generally a polygonal form. Longitudinal sealing means <NUM>, which are provided downstream from the form shoulder <NUM>, seal the edges of the tubular web <NUM> together along a longitudinal seal <NUM>. Cross sealing means <NUM> provide cross seals <NUM> to the tubular web <NUM> at the downstream end of each package <NUM> and subsequently, the package is filled with a packaging item. Finally, an upstream cross seal <NUM> is applied to the web tube <NUM> by means of the cross sealing means <NUM>, which hermetically closes each package <NUM>. The cross sealing means <NUM> preferably apply simultaneously an upstream cross-seal closing the top of the package <NUM> and a downstream cross-seal defining the bottom of the subsequent, upstream package <NUM>. The packages <NUM> are separated from one another by a cutting means <NUM>, which are preferably incorporated into the cross-sealing means <NUM>. For the application of each cross seal(s), the seal jaws are reciprocated from an open position, in which the seal jaws are spaced apart to a sealing position, in which the seal jaws are pressed together and apply a pressure on the film tube.

Upstream from the form shoulder <NUM> at least one folding unit <NUM> is provided, for forming at least one fold <NUM> in the moving web <NUM> of packaging material. Between the folding unit <NUM> and the form shoulder, a sealing unit (not depicted) may be provided for sealing the legs <NUM> of the formed fold <NUM> together. The sealing can be done with an adhesive and/or under the influence of heat and/or pressure.

<FIG> depicts a package <NUM>, that can be produced with the inventive flow-wrapper. In the present case the package comprises <NUM> corner folds; i.e. in the present case four folding units <NUM>, provided side by side and in parallel are needed to produce these corner folds. The corner folds <NUM> may contribute to the stability and/or the outer appearance of the package <NUM>. Parallel to the corner folds <NUM>, a longitudinal seal <NUM> is provided and at its top and its bottom, the package <NUM> comprises a cross seal <NUM>, respectively.

<FIG> and <FIG> show details of the folding unit <NUM>, in the present case two folding units <NUM>, which are located side by side, each producing a fold <NUM>, respectively. For the production of the package according to <FIG>, four of these folding units <NUM> are required side by side. A web <NUM> is transported past the folding unit(s) in a transport direction <NUM>. All folding units <NUM> forming the folds of one package are preferably provided at the same angle of inclination. During folding, the path of the web is preferably parallel to this angle of inclination.

Each folding unit <NUM> has at least two adjacent sets of folding means16, <NUM>, each set of folding means <NUM>, <NUM> comprising at least one rotating object <NUM>, here five rotating objects <NUM> per set of folding means <NUM>, <NUM>. The rotating objects <NUM> of each set of folding means <NUM>, <NUM> are provided at a support <NUM>, respectively. The rotating objects <NUM> of two adjacent sets of folding means <NUM>, <NUM> cooperate in forming one fold <NUM>.

The pivot axis of all rotating objects <NUM> of each set of folding means <NUM>, <NUM> are preferably provided along a line <NUM>, here a straight line <NUM>. Relative to the transport direction <NUM> of the film, the line <NUM> of the rotating objects of the set of folding means <NUM> has a different angle of inclination α than the line <NUM> of the rotating objects of the adjacent set of folding means <NUM>.

The rotating objects <NUM> of each set of folding means <NUM>, <NUM> each comprise a circular plane at one end, the end facing the web. These circular ends are preferably provided in one plane, respectively. In the present case, the circular planes of rotating objects <NUM> of the set of folding means <NUM> is located vertically above the circular planes of rotating objects <NUM> of the set of folding means <NUM>.

As can be particularly seen from <FIG>, some rotating objects <NUM> of two adjacent sets of folding means <NUM>, <NUM>, may overlap, particularly the downstream rotating object(s), here, relative to the transport direction <NUM>, the last two rotating objects of the sets of folding means overlap.

Upstream from the folding units <NUM>, a first deforming edge <NUM> is provided, which deforms the plane web into a bent shape. Downstream from the folding units, a second deforming edge <NUM> is provided, which flattens, the bent web again. The deforming edges <NUM>, <NUM>, here plates with no moving parts, are provided transverse to the transport direction of the web <NUM>.

For folding, the web is transported along the first deforming edge <NUM>, then passes the folding units <NUM> and is finally move along the second deforming edge <NUM>. During folding, the web is passed along the rotating objects <NUM> of each folding unit <NUM> which cooperate in providing one fold to the web. The passing web rotate the rotating objects. The rotating objects are preferably not driven by a motor.

Claim 1:
Vertical flow-wrapper (<NUM>) comprising:
- a folding unit (<NUM>) for forming at least one fold (<NUM>) in a moving web of packaging material, the folding unit (<NUM>) comprising at least two sets of folding means (<NUM>, <NUM>),
- preferably a sealing station downstream from the folding unit for sealing the formed folds,
- a web feed, which, preferably continuously, feeds the web (<NUM>) via the folding unit (<NUM>) and the preferred sealing station to a form-shoulder (<NUM>) and a form-fill tube (<NUM>), which form the web (<NUM>) into a web-tube,
- longitudinal sealing-means (<NUM>) to seal the longitudinal edges of the web tube together and
- cross sealing means (<NUM>) to provide a cross-seal to the web tube to produce individual packages,
characterized in, that each set of folding means (<NUM>, <NUM>) comprises at least one object (<NUM>) that rotates and that the axis of rotation (<NUM>) of the rotating objects (<NUM>) of each set of folding means (<NUM>, <NUM>) are provided along a line (<NUM>) and that the line (<NUM>) is provided at an angle (α) relative to a transport direction (<NUM>) of the web (<NUM>).