EP1612145A1

EP1612145A1 - Apparatus to form a tubular bag of the type with corners reinforced by sealing

Info

Publication number: EP1612145A1
Application number: EP05011422A
Authority: EP
Inventors: Duilio Cavicchiolo; Michele Cusinato
Original assignee: MD Bag Forming Sets Srl
Current assignee: MD Bag Forming Sets Srl
Priority date: 2004-06-29
Filing date: 2005-05-26
Publication date: 2006-01-04
Also published as: ITTV20040074A1

Abstract

Apparatus suitable for the continuous flow formation of tubular bags, starting with a film, for example, made of heat-sealable plastic synthetic material, particularly for the packing of loose foodstuffs supplied by a pre-packed filling and forming pipe obtained from tubular bags of the type with the longitudinal corners reinforced by sealing, said film unwound from a coil or extrusor upstream of the apparatus is forced by means of a collar to be turned, in such a way as to wrap the vertical filling pipe, and in which the forming of the corners takes place starting with the film that first assumes a rectangular section generated by the collar, and then, by means of deforming plate components that make provision for the entry of four sides, generating the four corners with folded flaps that once folded and sealed form the four longitudinal reinforcements.

Description

The apparatus in question is suitable for forming a tubular bag particularly with a rectangular section, or otherwise a section that is assimilable with other polygons, for the packaging of pre-packed products of the type with the corners reinforced by sealing.
The bags conventionally used to package foodstuffs at random, thus not stacked or placed adjacently in an orderly way, e.g. those for biscuits and snacks, consist of a soft wrapping made up of a film opportunely folded as a container and closed in correspondence to at least the upper end by means of the overlapping and longitudinal sealing of the edges of said film.
The drawbacks of this type of packaging relate to the lack of suitable stability of form which derives from the absence of rigid wrapping that is also due to the effect of the material from which the film is obtained, as well to the rather contained thickness of the film itself. The lack of good stability of the wrapping or rather packaging, makes display impossible, in particular with reference to the vertical positioning of the product on the shelves. In other words, it is common that the absence of stability can cause the packaging to fall, leaving it lying in a position different to that which is correct and that should favour the visibility of the label. Furthermore, it must be underlined that the inability of the packaging and in particular of the wrapping to maintain a substantially stable form causes the progressive deterioration of said packaging, making the label more difficult to distinguish as well as other essential information that conditions the purchase on the part of the average consumer.

PRIOR ART

These problems have been partly solved by EP0197875 (Cazes) in which a bag made of soft synthetic material is described that comprises stiffening and stabilization means. The patent in question relates to a bag made of synthetic and flexible material of the type obtained by at least one strip of film formed in such a way as to define, by means of sealing, a base on which the bag rests, two lateral walls, an opening and grip area connected to the two lateral walls and a front facade similarly connected to the two frontal walls, said front face corresponding to the side which illustrates the content of the bag after it has been opened. The result is a bag that in correspondence to the front face is provided with stiffening and stabilization means of the bag.
Apparatuses for forming the bags are also known. For instance, in US4986054 (McMahon) a method and an apparatus is described to form bags of the type with a continuous sheet of thermoplastic film supplied behind and inverted above a forming pipe containing the product that must be contained in the bag and introduced through the pipe with the end of the film formed in a tubular bag being transversely sealed. The lower end of the supply pipe is constructed in such a way as to deform elastically and expand so as to provide sealing means that move laterally.

PRIOR ART CLOSEST TO THE INVENTION

Considering everything disclosed above, EP 0627355 (ROVEMA) intended to optimize services by means of improved apparatus. In more detail, it provides tubular packing and a process and forming apparatus that can be produced continuously and subsequently filled and that is capable of retaining good dimensions and stability in unfavourable circumstances. The apparatus in question consists of a device for the production of tubular bags made of resistant film with a collar for the transformation of a flat film strip into a coating matrix and a filling duct, in particular a pipe, wrapped in the coating matrix with expansion elements to deform the forming bag, as well as with sealing devices to carry out the heat sealing of the edge. The tubular packaging that has an angled cross section is provided in these corners with reinforcement edges in such a way as to impede the deformation of the walls and edges themselves. The reinforcements consist in a covering similar to a sealing that are produced by hot sealing means. The first claim, after a suitable reformulation, consists of a pre-characterizing part that consists of a device for the production of tubular bags made from resistant film with a collar for the transformation of a flat film strip in a coating matrix, into a filling duct wrapped by the covering matrix, with expansion elements for the expansion of the film pipe, as well as with sealing devices for the heat sealing of the longitudinal seal, as well as the transversal seal and of the enlarged edges of a tubular bag made from film. Differently, the characterizing part that intends to define the protective domain starts with the fact that the enlarged edges of a tubular bag made from film are marked in such a way that the crosscut of the filling duct adapts to the crosscut of the tubular bag made of film and is a little smaller than this, with the fact that the filling duct presents longitudinal edges and that on all the longitudinal edges of the filling duct expansion elements are fixed radially to the longitudinal edges, and in proximity the lateral walls of the tubular bag made from film are curved towards the exterior from their surface, and that the expansion elements end at such a distance from the longitudinal edges of the filling pipe that the walls in the area of their edges slide across the sealing device.
As a rule, the apparatus described above seems to solve some prvolems. However, according to the applicant the fact remains that it appears complex, with a difficult and onerous operation and would not allow for a developed working, or rather the optimized working of the packaging that should substantially be intended to improve stability.
From these introductory considerations, the case is presented for the need for companies of the sector to find significantly innovative solutions, capable of objectively improving the services of the apparatuses intended for packaging.

DRAWINGS

Figure 1, is a view of a packaging obtained from a tubular bag according to the apparatus in question.
Figure 2 is a side view of the filling and forming pipe of the packaging in Figure 1.
Figure 3 is a sectional view, according to the axis A-A of the filling and forming pipe in Figure 2.
Figure 4 is an additional side view of the filling and forming pipe as in Figures 2 and 3 for the production of a packaging as in Figure 1.

Finally Figure 5 is a view according to a transversal surface of the filling and forming pipe of the packaging with sealing means of the corners of the packaging obtained by means of the apparatus in question.

PRACTICAL EMBODIMENT OF THE INVENTION

The apparatus concerned includes a collar 1 placed in the proximity of the upper end 50 of the filling and forming pipe 5, that conveys and deforms the film 15, in this case of the heat-sealing type, originating from the supply coil 2 upstream. The collar 1 is obtained from a metallic sheet, with flat surfaces that are inclined and coincide with one of their ends, obtained in such a way as to offer to the film 15, that slides on the same collar 1, sharp cornered apexes 7 which print the first longitudinal folds corresponding to the four corners of the packaging 12. The film 15, cornveyed and deformed by the collar 1 is thus turned and folded around the filling and forming pipe 5, assimilating the film portion 15 to a rectangular section 4. The filling and forming pipe 5, that receives through the end 50 the supply of the loose foodstuffs, is connected by means of suitable structures 3, in support 6 of the collar 1 in such a way that said collar 1 is slightly separated from the filling and forming pipe 5 so that the film 15 provided with first longitudinal folds started by the collar 1 slides between said two components, touching the surfaces.
The shaping of the rectangular section of the tubular bag 120 that precedes packaging 12, starts from the sharp cornered apexes 7 that oblige the film 15 to assume, through deformation of the material, first folds as a corner in correspondence to the external vertices of the subsequent sealings carried out in correspondence to each turn 8 of the edges of the film 15 of the packaging 12 in formation.
A second forced passing of the film 15 is achieved by means of the deforming members, consisting of first pressure and adjustable foils 9, in two units, placed on two opposite sides 10 of the filling and forming pipe 5 orthogonal to the two support surfaces of the pairs of sealing bar elements 11. The length of the first pressure and adjustable foils 9 is substantially inferior to the longitudinal development of the plates 13 that control and accentuate the turns 8 and the overlapping of the longitudinal closing edges 80 of the film 15, respectively corresponding to the four corners of the packaging 12 where the reinforcing sealings are carried out. With respect to the width of the pressure and adjustable foils 9, they present inferior dimensions with respect to the width of sides 10 of the filling and forming pipe 5 in such a way as to allow, through the longitudinal openings 16, an expansion of the film 15 in excess that locally allows turning 8 and in correspondence to a corner of the packaging 12 being formed, the overlaying of the longitudinal closing flaps 80. In this case, moreover, it is observed that said first pressure and adjustable foils 9 are fixed to the collar 1 and thus sized in such a way as to form the film 15 and generate the sizes and the forms of the packaging 12.
The film 15 deformed in this way by the pressure and adjustable foils 9 in correspondence to the four longitudinal openings 16 is conveyed by the two plates 13, that in addition to checking and accentuating the reentrant effect of the first, unequivocally determine the cross-section of the packaging 12 and form the surface plates of the sealing bar elements 11.
The form taken by the film 15 before the sealing of the four corners of the packaging 12 that correspond to the turns 8 and the overlaying of the edges 80 in correspondence to the corners of the packaging 12 being formed, is held and accentuated by second pressure foils 14, each placed on the abutment side of the sealing elements 11, parallel and separated from the sides 100 of the filling and forming pipe 5, with the function of making the film 15 re-enter simultaneously with the action of the first pressure and forming foils 9.
Furthermore, it must be revealed that the junction for overlaying and sealing of the two longitudinal edges 80 of the film 15, providing the packaging 12 being formed with the tubular section (see Figure 5) occurs in correspondence to only one of the four corners of said packaging 12.
The apparatus described above is inserted into a complex machine that is equipped with the mechanical elements that complete the forming and production functions of the packaging 12, such as the pulling device of the film 15, as well as at least the device with movable elements for the transverse re-entry of the film 15 and the transverse sealing device of the film 15.

Claims

Apparatus to form a tubular bag particularly for the packaging of pre-packed products of the type with corners reinforced by sealing, including at east one means 2 for supplying a film 15 made of heat-sealable material and a filling and forming pipe 5 of the tubular bag and in correspondence to said filling and forming pipe 5 a forming collar 1 and deformation members of the film 15 are provided characterized in that the deformation members are made up of first pressure foils 9 and second pressure foils 14.
Apparatus to form a tubular bag particularly for packaging according to claim 1, characterized in that the first pressure foils 9 are placed adjacent to the filling and forming pipe 5 in correspondence to the two opposite sides 10 orthogonal to the two support surfaces of the pairs of sealing rod elements 11.
Apparatus to form a tubular bag particularly for packaging according to claims 1 and 2, characterized in that the second pressure foils 14 are placed adjacent to the filling and forming pipe 5 in correspondence the two opposite sides 100 orthogonal to the two sides 10 of the forming and filling pipe 5.
Apparatus to form a tubular bag particularly for packaging according to the previous claims, characterized in that along the perimeter of the filling and forming pipe 5 longitudinal openings 16 are provided for the expansion of the film 15 in excess.
Apparatus to form a tubular bag particularly for packaging according to the previous claims, characterized in that the width of each of the pressure and adjustable foils 9, has smaller dimensions with respect to the width of sides 10 of the filling and forming pipe 5.
Apparatus to form a tubular bag particularly for packaging according to the previous claims, characterized in that the conjunction for overlaying and sealing of the two longitudinal edges 80 of the film 15, giving to the packaging 12 being formed the tubular section that is obtained in correspondence to only one of the four corners of said packaging 12.
Apparatus to form a tubular bag particularly for packaging according to the previous claims, characterized in that the collar 1 placed in the proximity of the upper end 50 of the filling and forming pipe 5 conveys and deforms the film 15, originating from the supply coil 2 positioned upstream, said collar 1 being obtained from a metallic sheet, with flat surfaces that are inclined and coincide with one of their ends, obtained in such a way as to offer to the film 15 that slides on said collar 1 sharp cornered apexes 7, printing the first longitudinal folds corresponding to the four corners of the packaging 12.
Apparatus to form a tubular bag particularly for packaging according to the previous claims, characterized in that the film 15, conveyed and deformed by the collar 1 is tumed-up and folded around the filling and shaping pipe 5, assimilating the film portion 15 to a rectangular section 4 which corresponds the section of said filling and shaping pipe 5.