HERMETICALLY SEALED PACKAGE AND MANUFACTURING METHOD THEREOF

Abstract: The package is realised using a first section (2) of wrapping material, made of tinfoil, or of thin aluminium foil treated with products (lakes) which make it heat-weldable, or obtained from a film of heat-weldable material; said section is formed into a bag inside a pit-shaped forming hopper (3), by means of a piston (5) able to confer a cup shape (4) to said first section of wrapping material in concurrence with the walls of said forming hopper, which are structured so that the sides of said cup are obtained by folding and mutually superimposing peripheral portions, mutually contiguous, of said first section; the subject method provides for the use of welding means (8) preferably associated with said hopper, to weld in a permanent manner the overlapping portions of the wrapping material which define the sides (4b) of said cup in the phase wherein, by means of said piston, the container is made to pass through the outlet (3c) of said forming hopper; the package is completed, after filling the cup with the product to be packaged, using a second section of wrapping material, preferably obtained from the same material as the first, brought to close the cup with its own peripheral border folded outwards and facing the top border of said cup; and the subject method entails hermetically sealing the cup by providing for the mutual welding of said borders of the cup and of the second section of wrapping material.

Description: Description HERMEΗCALLY SEALED PACKAGE AND MANUFACTURING METHOD THEREOF Technical Field The present invention relates to a package for products of pasty consistency, such as products derived from milk, as are portions of cheese, of solid or pasty final consistency, obtained by dropping a pre-set quantity of melted cheese inside a cup shaped as a wedge or as a polygonal solid, obtained by folding back or forming into a bag a section of wrapping material inside a pit-shaped forming hopper, cup which is subsequently closed with a second section of wrapping material to define the final package of the product. The present invention further relates to the method for obtaining said package shaped as a wedge, or as a polygonal solid, for instance shaped as a parallelepiped, in automatic machines for dosing, dispensing and packaging said products of the kind indicated above. Background Art For the packaging of portions of melted cheese, the use of sections of material obtained from metal foils (for instance made of aluminium) is universally known. In order to obtain wedge-shaped or parallelepiped-shaped portions, such sections of material are formed into bags (or folded) to form a cup container, open at its top, within which is injected the dosed quantity of product to be packaged. The containers are formed into cups using automatic machines that provide for feeding individual sections of material to a hopper for forming the open container, subsequently transferring said open container inside a pocket presented by a conveyor, which transfers it to a filling station, where a device for dispensing the dosed product is located, and subsequently along a closure line, wherefrom the package is then extracted. On this closure line operate devices that position on the filled cup a small lid obtained from a second section of wrapping material and whose border is permanently joined to the border of the cup itself. Folding devices then fix the joined borders to adhere to the outer surface of the small lid thereby giving rise to the definitive conformation of the package. In the forming phase of the cup inside the forming hopper, it occurs that peripheral parts of the section of wrapping material, which is shaped into a bag inside the hopper, are subjected to folds, which involve the sides of the cup, and to a mutual superimposition in close adherence one to the other. It has been observed that between the different folded portions, interstices may be originated which determine extremely small fissures which when the package is closed may compromise the seal of the package. Disclosure of the Invention The Applicant has intuited that by exploiting the characteristics of the wrapping material, or preventively and superficially treating the wrapping material with materials compatible with food hygiene and able to confer heat-weldability characteristics to the wrapping material, during the phase wherein the cup container is formed it would have been possible to eliminate the aforesaid interstices and consequently any possible fissure able to compromise the hermetic seal of the package of the products in question. Therefore the package constituting the subject of the present invention is characterised in that it is obtained from a first section of wrapping material presenting heat-weldability characteristics, peripherally folded or shaped into a bag to form a cup conformed as a wedge or as a polygonal solid, and with the sides of the cup defined at least in part by the mutual welding of contiguous peripheral parts of said section of wrapping material folded and mutually superimposed; and it is further characterised in that it is closed by a second section of wrapping material presenting, preferably, the same characteristics as the first section used to form the cup and whose peripheral border is joined by welding to the border of said cup. The Applicant has further intuited that by providing an appropriate combination of devices associated to the forming hopper and to the package closure line it was possible to obtain the aforesaid package with an operative method of extreme simplicity and safety of operation, able to be carried out on machines known in the art and by means of which the wedge-shaped or solid polygonal-shaped packages are obtained. Subjects of the present invention therefore are both the package, and the method for obtaining it as they are defined in the claims that follow. The solution idea constituting the basis of the method of the present invention consists in the fact that: in order to realise the cup, which is part of the package, a section of foil wrapping material is used which presents, at least superficially, characteristics of heat-weldability; the peripheral part of said section is formed into a bag inside a pit- shaped forming hopper whose section and shape are the same as the section and shape of the desired package, using a piston able to move axially, in the two directions, inside the hopper and whose cross section shape matches the cross section of the pit of the hopper; said piston is used as a bearing element for the folding elements presented by the hopper and provided to form the sides of the cup by folding contiguous peripheral portions of said section of wrapping material one on the other; said folded and superimposed portions are mutually welded immediately after performing the aforesaid folding operations and before the cup is ejected from the forming hopper by the action of said piston; for the welding operation, welding devices are employed which are comprised in the forming hopper and which use the lateral surface of the piston as a bearing element for welding said folded and superimposed portions. By operating in this manner, one has the certainty that the folded and superimposed parts that are joined together by means of welding constantly maintain their proper position and that the cup that is ejected from the forming hopper has its sides perfectly formed and hermetically sealed over their entire height. The essential characteristics of the present invention shall now be better described with reference to an exemplifying embodiment of the method constituting the subject of the present invention, with reference to the accompanying drawings, purely indicative and non-limiting, wherein: - Figure 1 shows a package of the subject type and wedge-shaped, in an axonometric view; - Figure 2 shows the package as per Figure 1 in the phase wherein the cup is formed; - Figure 3 shows, schematically and in a section view some parts of the pit- shaped forming hopper for the realisation of the method of the present invention; - Figure 4 schematically shows the operative station that allows to put in place the closure lid of the subject package and according to the operative method constituting the subject of the present invention; - Figure 5 schematically shows the devices that allow to fold on the closure lid of the package the borders of the lid itself and of the cup previously joined by welding according to the method constituting the subject of the present invention; - Figure 6 schematically shows the phase wherein the package is ejected from the closure line of a machine wherein all the operative phases of the previous figures have been completed; - Figures 7 and 8 schematically show two other types of package according to the present invention and obtainable with the subject method; - Figure 9 shows, by way of example, the package as per Figure 1 in a phase of its opening for the consumption of the product contained therein. The subject package may be realised in automatic machines of any kind suitable for dosing and dispensing the products whereto the invention refers. For example the machines may be of the type with turntable, where the forming hopper, the device for dosing and dispensing the product and the devices for closing and ejecting the package are positioned fastened to the periphery of said turntable in correspondence with stopping stations of pockets for the containment of the cups as they are formed and ejected from the forming hopper. Said machines may also be of the type with continuous linear conveyor and of the type with multiple forming hoppers aligned transversely above said conveyor, arranged according to one or more rows. With reference to Figures 1 and 2 an embodiment of the subject package is indicated as 1, is shaped as a wedge and is obtainable from a first section 2 of foil wrapping material with heat-weldability characteristics. By way of example it is indicated that the section 2 can be obtained from a sheet of tin foil, or of aluminium, whereof at least the surface destined to remain inside the cup has been preventively treated with lakes able to confer heat- weldability characteristics to said surface. The section 2 could also be obtained from a film of heat-weldable plastic material. By means of the hopper 3, as shall be more fully described hereafter and according to known techniques, the section 2 is folded as shown schematically in Figure 2; in practice the peripheral part of the section 2 is shaped into a bag to form an open cup container 4, whereof the bottom 4a is defined as well as the sides 4b and 4c. The main structure of said hopper is of a known type and normally used in machines for manufacturing packages, also known in the art, and shaped as wedges or as parallelepipeds for the products in question. The hopper 3 presents along the walls that define the sides 4b of the cup container 4 helicoidal folding devices (not shown in the drawings) by means of which the peripheral part of the section 2 is shaped into a bag or folded thereby allowing the formation of the cup 4 by means of the folding and mutual superimposition of parts of contiguous sections of said peripheral portion of the section 2. The section 2 is inserted in the hopper 3 by a piston 5 able to move axially, in the two directions, inside the hopper 3. The piston 5 presents a shape and a section to copy those of the hopper 3 and also to copy the cross section shape of the cup 4. Said piston 5 is movable from a first position wherein it is outside and raised with respect to the inlet 3e of the hopper 3, to a second position wherein, with its lower part, it projects from the outlet 3d of the hopper 3, subsequently to return to the starting position. The piston 5, in its second position, penetrates inside one of the pockets 6 presented by a conveyor 7 which is positioned below the hopper 3 and which in one of its stopping positions carries a pocket 6 aligned axially with the hopper 3 and thus with the piston 5. The pocket 6, according to the prior art in the machines indicated above, is closed at the bottom by a piston 10, described below, which follows the pocket 6 in the transfer of the cup container 4 to the ejection from the machine of the fully defined package. The aforesaid conveyor 7 may assume, in practice, the structure and the shape of a rotating platform, along whose periphery the pockets 6 are uniformly distributed. Said conveyor 7 may also assume the form of a continuous, linear conveyor on whose conveying surface the pockets 6 are uniformly distributed. For the realisation of the operative method constituting the subject of the present invention, the hopper 3 is equipped, downstream of its section 3a for folding the sides 4b and 4c, with a section 3b wherein operate welding devices 8 constituted by heated plates against which are pressed, by the piston 5, the sides 4b and 4c of the cup being formed, during the motion of the cup 4 itself towards the outlet of the forming hopper 3. With this solution, when, with the descent of the piston 5, a section 2 is inserted in the hopper 3, and the container 4 progressively traverses the outlet 3c of the hopper 3, to be inserted in the pocket 6 of the conveyor 7, the heated plates 8, in concurrence with the outer lateral surface of the piston 5, join by welding the folded and superimposed parts present on the sides 4b of the cup container 4. If necessary, the piston 5 stops during its descent to allow the cup container 4 to remain, for an instant, stopped in contact with the heated plates 8. Alternatively the piston 5 may be slowed in its descent run to allow a longer contact time of the sides of the cup 4 with the heated plates 8. According to a further possibility, the entire walls of the forming hopper 3 could be heated in order to obtain the welding of the parts progressively folded and superimposed of the sides of the cup 4. With the insertion of the cup container in the pocket 6 of the conveyor 7 an with the return of the piston 5 to the starting position, the transfer begins of th container 4 to a filling station, where a dosing-dispensing device (not shown in th drawings) injects therein a wanted and proportional dose of product. Subsequently the filled cup 4 is transferred to a line for the closure of th package 1 which shall now be described according to the embodiments shown i Figures 4, 5 and 6 of the accompanying drawings. With reference to Figure 4, the aforesaid closure line of the package comprises an operative station SI which allows to put in place the small closure 11 9 of the package 1 according to the subject operative method. The cup container 4, stopped in the station SI, presents its upper border 4ι projecting from the plane whereon the mouth of the related containment pocket « opens. The border 4d of the cup container 4 finds itself surrounded by weldin: elements 11 positioned above the conveyor 7 and sustained in such a way as to movable, in the two directions, closer and, respectively, farther away with respect h the pocket 6, hence with respect to the cup container 4. In the station SI, in correspondence with the stopped position of a cu{ container 4, a hopper 12 is vertically aligned, positioned above the welding element: 1 1 and provided for the formation of the lid 9 starting from a second section o: wrapping material presenting, preferably, the same characteristics of heat weldabilit} as section 2. The hopper 12 presents an opening shaped to copy the shape of the cup 4 anc it can be traversed by a correlated piston 13, which is movable, in the two directions from a raised position, wherein it is outside and above the hopper 12, to a lowered position, wherein it is substantially on the same plane as the welding element 11. During the descent of the piston 13, a section of wrapping material, destined to form the lid 9 and previously positioned on the inlet of the hopper 12, is forced inside the hopper 12 itself, so that its perimeter border 9b is folded upward to face the border 4d of the cup 4, when the piston 13 reaches its descent stop position. With the piston 13 stopped in said descent stop position there is the activation of the welding elements 11, which are thrust forward to press the borders 4d-9b against each other in concurrence with the outer lateral surface of the piston 13; in this way said borders are joined by welding. Subsequently the welding elements 11 return to the initial position, as does the piston 13, and the package, hermetically sealed, is transferred to a successive operative station (see Figure 5) where folding devices 14 fix the welded borders 4d-9b above and in adherence to the outer surface of the lid 9 bringing them to the condition shown in Figure 1. The package 1 thus completely defined reaches the ejection station (see Figure 6) where the piston 10 extracts it from the respective pocket 6 to carry it on the trajectory of a further extractor 15 which sends the package 1 to subsequent lines for encasing or other processing. As shown by way of example in Figures 7 and 8 the subject package may also assume different forms from those shown in Figures 1 and 2. As shown in Figure 7, the subject package may present the folds of peripheral parts of the sheet of wrapping material used to form the cup 4 only in correspondence with the rear side of the cup; whilst as shown in Figure 8 the cup may have parallelepiped shape, with square or rectangular base, without thereby changing the operating phases of welding the folded and superimposed parts that are on the sides of the package and without thereby changing the welding of the border 9b of the lid 9 to the border 4d of the cup container 4, operative phases which allow to obtain a hermetically sealed package, in accordance with the purpose that the Applicant had intended to attain. Advantageously it has been experimentally observed that as an effect of the frame defined by the mutual welding of the borders 9b-4d the package 1 constituting the subject of the present invention does not need rip-away strips to be opened in order to allow consumption of the product. By lifting the borders 9b-4d, fixed to adhere to the outer surface of the lid 9, one has the possibility of using them as if they were rip-away strips, thanks to their greater resistance, due to the mutual junction by welding, than the remainder of the cup container 4. Also advantageously it has been experimentally observed that, thanks to its hermetic seal characteristics, there is the possibility of dosing very fluid products inside the subject package 1 without the risk of spillage or releases; moreover, there is an absolute hygienic protection of the product thanks to the impossibility of contamination by external agents. With the subject operative method a greater cost efficiency is also obtained in the production of the subject packages especially due to the fact that, since rip-away strips are not necessary to open the package, the method allows to eliminate all apparatuses needed today for the application of said rip-away strip (one or more) in the non hermetically sealed packages with shapes corresponding to those whereto the present invention refers. From the above description it is clear that the Applicant with the solution constituting the subject of the present invention has fully attained its intended goal and aim. The invention thus conceived in its solution idea can be used for packaging products of pasty consistency, in particular, as foregoing disclosed, cheese, but also butter, margarine and others. It can be subject to numerous modifications and variations of the constructive forms of the devices for the realisation of the illustrated method, so that all technical details described above may be replaced, in the practical realisation of the subject method, with technically equivalent elements.

Claims: Claims 1. Hermetically sealed package for products of pasty consistency, in particular for products derived from milk, such as portions of melted cheese, of the type shaped as a wedge or as a polygonal solid, obtained from a first sheet or section of wrapping material, folded peripherally to form a cup for the containment of the product, and from a second sheet or section of wrapping material positioned to cover the product as a lid for the closure of the package, characterised in that said first and second section of wrapping material present characteristics of heat-weldability; in that said cup presents its sides composed by peripheral parts of said first sheet of wrapping material, belonging to contiguous sides of said first sheet, mutually folded, superimposed facing one another and joined together by heat welding; and in that said small lid presents its entire border joined by heat welding to the entire upper border of said cup. 2. Hermetically sealed package, according to claim 1, characterised in that said borders of the cup and of the lid for the closure of the package joined by heat welding form a frame usable manually for ripping open the package. 3. Method for the realisation of a hermetically sealed package for products of pasty consistency, in particular for products derived from milk, such as portions of melted cheese, of the type shaped as a wedge or as a polygonal solid, obtained from a first sheet or section of wrapping material, folded peripherally to form a cup for the containment of the product, and from a second sheet or section of wrapping material positioned to cover the product as a lid for the closure of the package, characterised in that it comprises: realising said cup using a first sheet or section of wrapping material presenting characteristics of heat weldability, shaping into a bag the peripheral portion of said section, to form the sides of the cup, inside a pit-shaped forming hopper and in concurrence with a piston that provides the bearing for a series of folding elements comprised in said forming hopper; joining by heat welding the folded and superimposed parts of said peripheral portion of the first sheet of wrapping material and which form, at least partially, the sides of the cup, by means of welding devices that belong to at least one section of said forming hopper; forming a small closure lid of said cup starting from a second sheet or section of wrapping material, presenting characteristics of heat weldability, by means of a hopper positioned downstream of the devices for dosing and dropping the product inside the cup, and positioned along the route followed by the cup on the line of closure of the package; said forming comprising the phase wherein a peripheral border of said lid is realised, destined to face the upper border of said cup; introducing the lid inside the cup filled with product until its peripheral border is brought to a position facing the upper border of the cup; joining by heat welding the entire border of said lid to the entire border of said cup. 4. Method for the realisation of a hermetically sealed package for products of pasty consistency, according to claim 3, characterised in that the junction by heat welding of the entire border of said lid to the entire border of said cup is effected using welding elements that realise a frame usable manually by the consumer of the product to rip the package open. 5. Method for the realisation of a hermetically sealed package for products of pasty consistency, according to claim 3, characterised in that the phase of joining by heat welding the folded and superimposed parts of said peripheral portion of the first sheet of wrapping material and which form, at least partially, the sides of the cup, comprises an arrest of the cup being formed in correspondence with said welding devices and the utilisation of the lateral surface of said piston as an element that operates together with said welding devices to maintain in mutual contact the parts of the sides of the cup subjected to the action of the welding devices themselves. 6. Method for the realisation of a hermetically sealed package for products of pasty consistency, according to claim 3, characterised in that the phase of joining by heat welding the folded and superimposed parts of said peripheral portion of the first sheet of wrapping material and which form, at least partially, the sides of the cup, comprises a slow down of the descent velocity of the piston inside the forming hopper.

Inventors: GRAZIA ALESSANDRO, GRAZIA, ALESSANDRO
Applicants: CORAZZA NATALINO SPA, GRAZIA ALESSANDRO, GRAZIA, ALESSANDRO, OFFICINE MECCANICHE NATALINO CORAZZA S.P.A.
Application year: 1998
Main classification: B65D85
IPC codes: B65B25, B65D85