Patent Application
20180319523
The present invention relates to a packaging apparatus comprising an evacuation station and to a packaging process using an evacuation station. The packaging process includes evacuation of packages in a continuous vacuum system having a fixed-gap vacuum chamber.
A packaging apparatus can be used to package a food product. The product can be a bare product or a product pre-loaded onto a tray. A tube of plastic wrap can be continuously fed through a bag/package forming, filling and sealing apparatus. The film and the product are joined, for example the product is deposited on the film or the film is wrapped around the product. In some examples, the bare product is fed through an infeed belt. A tube is created around the product by joining together and sealing opposite longitudinal edges of the film. Alternatively, the product is placed in the tube and a leading edge (at the downstream end) of the packaging material is sealed. Then the tube is sealed at the trailing edge (at the upstream end) of the package and is severed from the continuously moving tube of packaging material.
In some embodiments, the tube can be provided as a tube, or be formed from two films or webs sealed longitudinally at two longitudinal edges, or from a single film that is folded over and sealed along its longitudinal edges. In other embodiments, products are loaded into pre-formed bags, which are then supplied to an evacuation station and to a sealing station. Further, some embodiments can facilitate evacuation of multiple packages at the same time in the same process step. The latter can be realized, for example, by processing multiple bags using a single vacuum system.
Sealing bars or sealing rolls can be used to create seals in the packaging material. If sealing bars are employed, a lower bar and an upper bar are moved with respect to one another in order to contact each other while squeezing the packaging material between the bars and providing one or more seals, for example by heat-sealing. Actuating sealing bars in this manner requires the sealing bars being stationary relative to the package, for example moving the sealing bars along with the package located on a conveyor or intermittently stopping the conveyor during the actuation of the sealing bars. Sealing rolls can be employed in order to maintain a continuous motion of packages on a conveyor belt. In some examples, packages are placed on a conveyor belt in an orientation where an unsealed end of the package, for example the open edge of a bag holding a product, is located laterally on the side of the conveyor with respect to a main movement direction of the conveyor. The open ends of the packages can then be fed through sealing rolls which perform, for example, heat sealing of the package material, without having to perform a complex synchronization of the movements of, for example, sealing bars with respect to the moving packages. The seals are typically transversally extending regions, stripes, or bands of packaging material that have been processed (e.g. heat-treated) to provide a seal between the inside of the packaging and the environment.
In the context of this document, whenever evacuation or vacuumization in terms of gas extraction is referred to, it is understood that the term “gas” can comprise an individual particular gas or a mixture of gases and can, for example, refer to air (i.e. consist of a mixture of gases corresponding to ambient air). In some embodiments, packages can be flushed with protective gas or gases (sometimes also referred to as “inert” gas). It is noted that any known protective gas or gas mixture can be employed, for example CO2.
Gas can be injected into the package in the space between the product and the film using known techniques. Remaining gas inside the package after gas or air has been evacuated therefrom and after the package has been sealed ensures a desired residual level of O2 inside the package. Reducing the level of residual O2 in the package is particularly beneficial when packaging perishable products (e.g. cheese with low gassing level during maturation). In some applications, a residual O2 level of 5% to 6% may be sufficient. In other applications, a residual O2 level lower than 5%, for example 1% or lower, may be desirable. It is noted that, using embodiments of the present invention, practically any residual O2 level necessary or desired for an individual packaging application may be set accordingly.
A packaging apparatus is typically used for numerous different products with respect to, for example, the type of product, size, weight, and composition. Some packaging machines employ one or more vacuum chambers, typically one of which is designed to house one or more entire products to be evacuated. Generally, such a setup may entail several limitations. For example, the complexity and cost for the equipment leaves room for improvement due to the many components required. Further, the sizes of products that can be processed are limited by the maximum size of the vacuum chamber holding the product during evacuation. In some applications, it is difficult to provide chambers of sufficient size due to structural limitation of some components (e.g. actuators, supports). Also, maintaining process reliability and durability of components may be difficult with increasing size of components (e.g. chambers, actuators, gaskets) as the size typically impacts wear and tear properties. Additionally, processing times may increase due to vacuumization of larger chambers taking comparably longer time.
An aim of the present invention is to provide a packaging process that facilitates efficient packaging of products of larger sizes using a (soft) vacuum system suitable for a wide variety of sizes of products. A further aim of the present invention is to provide a packaging process that facilitates evacuation of gas and/or air from a package in a continuous manner. In particular, it is an aim of the invention to provide a packaging apparatus capable of executing the packaging process of the invention.
According to the invention, in a 1st aspect there is provided a packaging process comprising providing a package containing a product to be packaged, the package being made from a film and having an open end, providing a vacuum chamber having an elongated opening, relatively moving one of the package and the vacuum chamber with respect to the other such that a terminal portion of the open end relatively moves within the vacuum chamber and a non-terminal portion of the open end relatively moves outside the vacuum chamber, an intermediate portion of the open end passing through the opening and relatively moving along a length thereof, the intermediate portion extending between the terminal portion and the non-terminal portion of the open end, creating, within the vacuum chamber, an internal vacuum pressure that is lower than an ambient pressure outside the vacuum chamber.
In a 2nd aspect according to the 1st aspect, the step of creating an internal vacuum pressure within the vacuum chamber further comprises selecting the internal vacuum pressure such as to determine a gas flow through the opening causing opposing layers of the film at the open end to maintain a substantially spaced-apart configuration.
In a 3rd aspect according to any one of aspects 1 or 2, the step of creating an internal vacuum pressure within the vacuum chamber further comprises selecting the internal vacuum pressure such as to aspirate both gas from inside the package and gas from an ambient atmosphere through the opening.
In another aspect in accordance with any one of aspects 1 to 3, the means for moving are provided with elongated recesses located on an upper side of an upper run of the means for moving, each elongated recess having one or more openings configured to facilitate aspiration of air from the upper side of the upper run through the one or more openings and to a lower side of the upper run, the process further comprising aspirating air from the upper side through the one or more openings to the lower side in order to cause the film of the package to conform to a shape of the upper side and, in particular, to cause ingress of the film into the elongated recesses, thereby forming elongated channels in the film material situated below the product to be packaged.
In a 4th aspect according to any one of the 1st aspect to the preceding aspect, the opening extends substantially parallel to a longitudinal axis of the vacuum chamber.
In a 5th aspect according to any one of aspects 1 to 4, the opening is provided with a first guide belt arranged along a length of the opening and configured to contact the intermediate portion of the open end when passing through the opening, the first guide belt having an inner surface and an outer surface, the process further comprising moving the first guide belt along the length of the opening, optionally at a speed substantially corresponding to the relative speed between the package and the vacuum chamber.
In a 6th aspect according to the 5th aspect, the outer surface of the first guide belt is provided with a contoured shape comprising recesses, optionally wherein the recesses extend over the outer surface in a direction perpendicular to a longitudinal extension of the first guide belt; and/or the recesses are spaced from one another at regular intervals along the longitudinal extension of the first guide belt, the intervals preferably being between 2 mm and 20 mm, more preferably between 5 mm and 15 mm, most preferably about 10 mm; and/or the recesses have a depth of between 0.2 mm and 2 mm, preferably between 0.5 mm and 1.5 mm, most preferably about 1 mm; and/or the recesses have a length along the longitudinal extension of the first guide belt of between 2 mm and 10 mm, more preferably between 3 mm and 8 mm, most preferably about 5 mm.
In a 7th aspect according to the 6th aspect, the regular intervals are about 10 mm, the recesses have a depth of about 1 mm, and the recesses have a length along the longitudinal extension of the first guide belt of about 5 mm.
In an 8th aspect according to any one of aspects 5 to 7, the first guide belt has the form of a closed loop running around first and second deflection rolls and along the length of the opening.
In a 9th aspect according to any one of aspects 1 to 8, the opening is provided with a second guide belt arranged along a length of the opening and configured to contact the intermediate portion of the open end when passing through the opening, the second guide belt having an inner surface and an outer surface, the process further comprising moving the second guide belt along the length of the opening, optionally at a speed substantially corresponding to the relative speed between the package and the vacuum chamber.
In a 10th aspect according to the 9th aspect, the outer surface of the second guide belt is provided with a substantially smooth shape.
In an 11th aspect according to any one of aspects 8 or 9, the second guide belt has the form of a closed loop running around first and second deflection rolls and along the length of the opening.
In a 12th aspect according to any one of aspects 5 to 8 and any one of aspects 9 to 11, the inner surface of the first guide belt extends along an upper edge of the opening and the outer surface of the first guide belt is configured to contact the intermediate portion from above, and the inner surface of the second guide belt extends along a lower edge of the opening and the outer surface of the second guide belt is configured to contact the intermediate portion from below.
In a 13th aspect according to any one of aspects 1 to 12, relatively moving one of the package and the vacuum chamber with respect to the other comprises relatively moving one of the package and the vacuum chamber with respect to the other at a relative speed of between 5 m/min and 30 m/min, preferably between 10 m/min and 20 m/min.
In a 14th aspect according to any one of aspects 1 to 13, relatively moving one of the package and the vacuum chamber comprises relatively moving one of the package and the vacuum chamber along a movement direction substantially parallel to the longitudinal axis of the vacuum chamber.
In a 15th aspect according to any one of aspects 1 to 14, the process further comprises creating a seal on the package at the open end, thereby forming a sealed package containing the product and having a sealed end; optionally the step of creating the seal on the package being performed when aspirating gas from inside the package has been substantially concluded.
In a 16th aspect according to any one of aspects 1 to 15, the step of providing the package comprises positioning a tubular film around the product to be packaged, and creating, at a sealing station, a first seal on the tubular film, thereby forming the package containing the product to be packaged, and optionally creating a longitudinal seal along a film in order to obtain the tubular film.
In a 17th aspect according to any one of aspects 1 to 16, the step of providing the package comprises creating the open end by one or more of perforating the package in the region of the terminal portion of the open end; cutting the package in the region of the terminal portion of the open end; and creating an aperture in the package in the region of the terminal portion of the open end.
In an 18th aspect according to the 17th aspect, the process further comprises the step of flushing the inside of the package with gas or a mixture of gases; optionally wherein the gas or mixture of gases comprise an inert gas; further optionally wherein the gas substantially consists of or comprises CO2.
In a 19th aspect according to any one of aspects 1 to 18, the process further comprises providing the opening with a height of 8 to 20 times a thickness of the film, or providing the opening with a height of 1.0 mm or less, preferably 0.8 mm or less, most preferably 0.5 mm or less, or providing the opening with a height of between 0.3 mm and 1.0 mm, preferably between 0.3 mm and 0.8 mm, most preferably between 0.3 mm and 0.5 mm.
In a 20th aspect according to any one of aspects 1 to 19, the vacuum chamber is provided with upper and lower rollers, each roller having a substantially cylindrical shape and being arranged to be able to rotate about a respective longitudinal axis thereof, the upper and lower rollers being relatively positioned with respect to one another such that the upper and lower rollers contact each other along an elongated contact area on their respective lateral surfaces, thereby providing the rollers with a substantially air-tight seal along the contact area, the contact area extending substantially parallel to the respective longitudinal axis of the upper and lower rollers, wherein a first set of rollers is arranged at an upstream end of the vacuum chamber and configured to provide the vacuum chamber with a substantially air-tight seal at the upstream end thereof; and/or a second set of rollers is arranged at a downstream end of the vacuum chamber and configured to provide the vacuum chamber with a substantially air-tight seal at the downstream end thereof, downstream being defined with respect to the main movement direction.
In a 21st aspect according to any one of aspects 1 to 20, creating the internal vacuum pressure within the vacuum chamber comprises creating an internal vacuum pressure of between 950 mbar and 500 mbar, preferably between 800 mbar and 525 mbar, most preferably between 700 mbar and 550 mbar.
In a 22nd aspect according to any one of aspects 1 to 21, the vacuum chamber comprises a first sub-chamber and a second sub-chamber.
In a 23rd aspect according to the 22nd aspect, the process further comprises providing the first sub-chamber with a first pressure and providing the second sub-chamber with a second pressure different from the first pressure, optionally wherein the second pressure comprises a lower absolute pressure value than the first pressure, or the first pressure comprises an absolute pressure value lower than the ambient pressure and the second pressure comprises an absolute pressure value substantially equal to or higher than the ambient pressure.
In a 24th aspect according to any one of aspects 22 or 23, the vacuum chamber comprises a third sub-chamber, the process further comprising providing the third sub-chamber with a third pressure different from the first and second pressures, optionally the third pressure comprising a lower absolute pressure value than each of the first and second pressures.
In a 25th aspect according to the 2th aspect and any one of aspects 22 to 24, the vacuum chamber comprises one or more additional sets of rollers, each additional set of rollers being arranged between adjacent sub-chambers.
In a 26th aspect according to any one of aspects 1 to 25, the process further comprises a first stretch belt arranged at the downstream end of the vacuum chamber and configured to receive the intermediate portion of the open end when exiting the opening, optionally the process further comprising controlling an operating speed of the first stretch belt to be higher than the relative speed between the package and the vacuum chamber, the operating speed preferably being about 2% to 30% higher than the relative speed between the package and the vacuum chamber, the operating speed more preferably being about 3% to 12% higher than the relative speed between the package and the vacuum chamber.
In a 27th aspect according to the 26th aspect and any one of aspects 5 to 8, the first stretch belt is arranged in a plane parallel to an operating plane of the first guide belt and in partial overlap with an operating region of the first guide belt.
In a 28th aspect according to any one of aspects 26 or 27, the process further comprises a second stretch belt arranged opposite to and in contact with the first stretch belt at the downstream end of the vacuum chamber, the first and second stretch belts being configured to receive, between one another, the intermediate portion of the open end when exiting the opening, optionally the process further comprising controlling an operating speed of the second stretch belt to be higher than the relative speed between the package and the vacuum chamber, the operating speed preferably being about 2% to 30% higher than the relative speed between the package and the vacuum chamber, the operating speed more preferably being about 3% to 12% higher than the relative speed between the package and the vacuum chamber.
In a 29th aspect according to the 28th aspect and any one of aspects 9 to 11, the second stretch belt is arranged in a plane parallel to an operating plane of the second guide belt and in partial overlap with an operating region of the second guide belt.
In a 30th aspect according to any one of aspects 1 to 29, the vacuum chamber further comprises a set of stretch rollers arranged at the downstream end of the vacuum chamber and configured to receive the intermediate portion of the open end when exiting the opening, optionally the process further comprising controlling an operating speed of the stretch rollers to be higher than the relative speed between the package and the vacuum chamber, the operating speed preferably being about 2% to 30% higher than the relative speed between the package and the vacuum chamber, the operating speed more preferably being about 3% to 12% higher than the relative speed between the package and the vacuum chamber.
According to the invention, in a 31st aspect, there is provided a device for evacuating gas from a package in a packaging apparatus, the package having an open end, the open end having a terminal portion, a non-terminal portion, and an intermediate portion located between the terminal portion and the non-terminal portion of the open end, the device comprising a vacuum chamber having an elongated opening extending along a longitudinal axis of the vacuum chamber, an evacuation means configured for providing the vacuum chamber with an internal vacuum pressure that is lower than an ambient pressure outside the vacuum chamber, a means for moving a package relative to the vacuum chamber, and a control unit programmed for controlling the means for moving to relatively move a package to be evacuated with respect to the vacuum chamber, the package and the means for moving each being arranged with respect to the vacuum chamber so that a main movement direction of packages placed on the means for moving and the longitudinal axis of the vacuum chamber are substantially parallel to one another, the package to be evacuated being positioned so that, during the relative movement of the package with respect to the vacuum chamber, a terminal portion of the open end of the package relatively moves within the vacuum chamber and a non-terminal portion of the open end relatively moves outside the vacuum chamber, an intermediate portion of the open end passing through and relatively moving along the opening, and activating the evacuation means to provide the vacuum chamber with the internal vacuum pressure.
In a 32nd aspect according to the 31st aspect, the control unit is further programmed to control the internal vacuum pressure for allowing a gas flow through the opening causing opposing layers of film at the open end to maintain a substantially spaced-apart configuration.
In a 33rd aspect according to any one of aspects 31 or 32, the control unit is further programmed to control the internal vacuum pressure for aspirating both gas from inside the package and gas from an ambient atmosphere through the opening.
In another aspect in accordance with any one of aspects 31 to 33, the means for moving are provided with elongated recesses located on an upper side of an upper run of the means for moving, each elongated recess having one or more openings configured to facilitate aspiration of air from the upper side of the upper run through the one or more openings and to a lower side of the upper run.
In a 34th aspect according to any one of the 33rd aspect or the preceding aspect, the opening extends substantially parallel to a longitudinal axis of the vacuum chamber.
In a 35th aspect according to any one of aspects 31 to 34, the device further comprises a first guide belt arranged along a length of the opening and configured to contact the intermediate portion of the open end when passing through the opening, the first guide belt having an inner surface and an outer surface, and a first drive configured to act on the first guide belt, wherein the control unit is further programmed to control the first drive to move the first guide belt in the movement direction along the length of the opening, optionally, at a speed substantially corresponding to optionally at a speed substantially corresponding to the relative speed between the package and the vacuum chamber.
In a 36th aspect according to the 35th aspect, the outer surface of the first guide belt is provided with a contoured shape comprising recesses, optionally wherein the recesses extend over the outer surface in a direction perpendicular to a longitudinal extension of the first guide belt; and/or the recesses are spaced from one another at regular intervals along the longitudinal extension of the first guide belt, the intervals preferably being between 2 mm and 20 mm, more preferably between 5 mm and 15 mm, most preferably about 10 mm; and/or the recesses have a depth of between 0.2 mm and 2 mm, preferably between 0.5 mm and 1.5 mm, most preferably about 1 mm; and/or the recesses have a length along the longitudinal extension of the first guide belt of between 2 mm and 10 mm, more preferably between 3 mm and 8 mm, most preferably about 5 mm.
In a 37th aspect according to the 36th aspect, the regular intervals are about 10 mm, the recesses have a depth of about 1 mm, and the recesses have a length along the longitudinal extension of the first guide belt of about 5 mm.
In a 38th aspect according to any one of aspects 35 to 37, the first guide belt has the form of a closed loop running around first and second deflection rolls and along the length of the opening.
In a 39th aspect according to any one of aspects 35 to 38, the device further comprises a second guide belt arranged along a length of the opening and configured to contact the intermediate portion of the open end when passing through the opening, the second guide belt having an inner surface and an outer surface, and a second drive configured to act on the second guide belt, wherein the control unit is further programmed to control the second drive to move the second guide belt in the movement direction along the length of the opening, optionally at a speed substantially corresponding to the relative speed between the package and the vacuum chamber.
In a 40th aspect according to the 39th aspect, the outer surface of the second guide belt is provided with a substantially even shape.
In a 41th aspect according to any one of aspects 39 to 40, the second guide belt has the form of a closed loop running around first and second deflection rolls and along the length of the opening.
In a 42nd aspect according to any one of aspects 35 to 38 and any one of aspects 39 to 41, the inner surface of the first guide belt extends along an upper edge of the opening and the outer surface of the first guide belt is configured to contact the intermediate portion from above, and the inner surface of the second guide belt extends along a lower edge of the opening and the outer surface of the second guide belt is configured to contact the intermediate portion from below.
In a 43th aspect according to any one of aspects 31 to 42, the control unit is further programmed for controlling the means for moving to relatively move a package to be evacuated at a relative speed of between 5 m/min and 30 m/min, preferably between 10 m/min and 20 m/min.
In a 44th aspect according to any one of aspects 31 to 43, the device further comprises multiple sets of upper and lower rollers, each roller having a substantially cylindrical shape and being arranged to be able to rotate about a respective longitudinal axis thereof, the upper and lower rollers being relatively positioned with respect to one another such that the upper and lower rollers contact each other along an elongated contact area on their respective lateral surfaces, thereby providing the rollers with a substantially air-tight seal along the contact area, the contact area extending substantially parallel to the respective longitudinal axis of the upper and lower rollers, wherein a first set of rollers is arranged at an upstream end of the vacuum chamber and configured to provide the vacuum chamber with a substantially air-tight seal at the upstream end thereof; and/or a second set of rollers is arranged at a downstream end of the vacuum chamber and configured to provide the vacuum chamber with a substantially air-tight seal at the downstream end thereof, downstream being defined with respect to the main movement direction.
In a 45th aspect according to any one of aspects 31 to 44, the vacuum chamber comprises a first sub-chamber and a second sub-chamber.
In a 46th aspect according to the 45th aspect, the control unit is further programmed to provide the first sub-chamber with a first pressure and to provide the second sub-chamber with a second pressure different from the first pressure, optionally wherein the second pressure comprises a lower absolute pressure value than the first pressure, or the first pressure comprises an absolute pressure value lower than the ambient pressure and the second pressure comprises an absolute pressure value substantially equal to or higher than the ambient pressure.
In a 47th aspect according to any one of aspects 45 and 46, the vacuum chamber comprises a third sub-chamber, the control unit further being programmed to provide the third sub-chamber with a third pressure different from the first and second pressures, optionally the third pressure comprising a lower absolute pressure value than each of the first and second pressures.
In a 48th aspect according to the 44th aspect and any one of aspects 45 to 47, the vacuum chamber comprises one or more additional sets of rollers, each additional set of rollers being arranged between adjacent sub-chambers.
In a 49th aspect according to any one of aspects 31 to 48, the device further comprises a first stretch belt arranged at the downstream end of the vacuum chamber and configured to receive the intermediate portion of the open end when exiting the opening, optionally the control unit being configured to control an operating speed of the first stretch belt to be higher than the relative speed between the package and the vacuum chamber, the operating speed preferably being about 2% to 30% higher than the relative speed between the package and the vacuum chamber, the operating speed more preferably being about 3% to 12% higher than the relative speed between the package and the vacuum chamber.
In a 50th aspect according to the 49th aspect and any one of aspects 35 to 38, the first stretch belt is arranged in a plane parallel to an operating plane of the first guide belt and in partial overlap with an operating region of the first guide belt.
In a 51st aspect according to any one of aspects 49 to 50, the device further comprises a second stretch belt arranged opposite to and in contact with the first stretch belt at the downstream end of the vacuum chamber, the first and second stretch belts being configured to receive, between one another, the intermediate portion of the open end when exiting the opening, optionally the control unit being configured to control an operating speed of the second stretch belt to be higher than the relative speed between the package and the vacuum chamber, the operating speed preferably being about 2% to 30% higher than the relative speed between the package and the vacuum chamber, the operating speed more preferably being about 3% to 12% higher than the relative speed between the package and the vacuum chamber.
In a 52nd aspect according to the 51st aspect and any one of aspects 39 to 41, the second stretch belt is arranged in a plane parallel to an operating plane of the second guide belt and in partial overlap with an operating region of the second guide belt.
In a 53rd aspect according to any one of aspects 31 to 48, the device further comprises a set of stretch rollers arranged at the downstream end of the vacuum chamber and configured to receive the intermediate portion of the open end when exiting the opening, optionally the control unit being configured to control an operating speed of the stretch rollers to be higher than the relative speed between the package and the vacuum chamber, the operating speed preferably being about 2% to 30% higher than the relative speed between the package and the vacuum chamber, the operating speed more preferably being about 3% to 12% higher than the relative speed between the package and the vacuum chamber.
In a 54th aspect according to any one of aspects 31 to 53, the device further comprises sealing means configured to provide a package being relatively moved with respect to the vacuum chamber with a seal; optionally the sealing means being configured to provide the seal in the region of the non-terminal portion, and/or the sealing means comprising one of a trimmer and a knife roll.
In a 55th aspect according to the 54th aspect, the sealing means are arranged at a downstream end of the vacuum chamber.
In a 56th aspect according to any one of aspects 54 or 55, the control unit is further programmed for controlling the sealing means to provide a package being relatively moved with respect to the vacuum chamber with the seal.
In a 57th aspect according to the 56th aspect, the device further comprises cutting means configured to cut excess film material from a package being relatively moved with respect to the vacuum chamber; optionally the package being cut in the region of the intermediate portion or the excess film material substantially comprising the terminal portion and the intermediate portion.
In a 58th aspect according to the 57th aspect, the cutting means are arranged at a downstream end of the vacuum chamber.
In a 59th aspect according to any one of aspects 57 or 58, the control unit is further programmed for controlling the cutting means to cause cutting of excess film material.
In a 60th aspect according to any one of aspects 31 to 59, the opening has a height of 8 to 20 times a thickness of the film, or the opening has a height of 10 times a thickness of the film or less; or the opening has a height of between 0.3 mm and 1.0 mm, optionally the opening having a height of 1.0 mm or less, preferably 0.8 mm or less, most preferably 0.5 mm or less.
In a 61st aspect according to any one of aspects 31 to 60, the opening has a depth of 50 mm or less, preferably 20 mm or less, and more preferably 12 mm or less. In a 62nd aspect according to any one of aspects 31 to 61, the control unit is programmed for controlling the evacuation means to create an internal vacuum pressure of between 950 mbar and 500 mbar, preferably between 800 mbar and 525 mbar, most preferably between 700 mbar and 550 mbar.
In another aspect according to any one of aspects 31 to 62 in combination with aspect 36, the device further comprises one or more flusher assemblies, each of the one or more flusher assemblies comprising a flusher support rotatably carrying a nozzle head, the nozzle head having a plurality of nozzles. Each nozzle of the plurality of nozzles is configured to engage and disengage a respective recess of the recesses during movement of the first guide belt, thereby being positioned, when engaged, at least partially within the open end of the package. The flusher support further comprises a conduit configured to direct a flow of controlled gas towards the respective nozzle or nozzles of the plurality of nozzles while engaging a corresponding recess of the recesses. The conduit may further be configured to prevent a supply of controlled gas to the respective nozzle or nozzles of the plurality of nozzles while not engaging a corresponding recess of the recesses.
According to the invention, in a 63rd aspect there is provided a packaging apparatus comprising an evacuation station coupled to the control unit and an output station. The control unit is configured to control the means for moving to move one or more packages, each containing a product to be packaged, towards and through the evacuation station, and towards the output station; wherein the evacuation station comprises a device for evacuating according to any one of aspects 31 to 62.
In a 64th aspect according to the 63rd aspect, the apparatus further comprises a loading station coupled to the control unit, the control unit being configured to control the loading station to position a tubular film around products to be packaged; and a sealing station coupled to the control unit, the control unit being configured to control the sealing station to create one or more seals on the tubular film, thereby creating the one or more packages, each containing one of the products to be packaged, wherein the control unit is configured to control the means for moving to move the one or more packages from the loading station towards and through the sealing station.
In a 65th aspect there is provided a packaging process for use with a device according to any one of aspects 31 to 62 for evacuating gas from a package in a packaging apparatus, the process comprising providing a package containing a product to be packaged, the package being made from a film and having an open end, providing a vacuum chamber having an elongated opening, relatively moving one of the package and the vacuum chamber with respect to the other such that a terminal portion of the open end relatively moves within the vacuum chamber and a non-terminal portion of the open end relatively moves outside the vacuum chamber, an intermediate portion of the open end passing through the opening and relatively moving along a length thereof, the intermediate portion extending between the terminal portion and the non-terminal portion of the open end, creating, within the vacuum chamber, an internal vacuum pressure that is lower than an ambient pressure outside the vacuum chamber.
In a 66th aspect according to the 65th aspect, the step of providing the package comprises creating the open end by one or more of perforating the package in the region of the terminal portion of the open end; cutting the package in the region of the terminal portion of the open end; and creating an aperture in the package in the region of the terminal portion of the open end. Alternatively or additionally, the process further comprises the step of flushing the inside of the package with gas or a mixture of gases; optionally wherein the gas or mixture of gases comprises an inert gas; further optionally wherein the gas substantially consists of or comprises CO2.
In a 67th aspect according to any one of aspects 65 or 66, the step of creating an internal vacuum pressure within the vacuum chamber further comprises selecting the internal vacuum pressure such as to determine a gas flow through the opening causing opposing layers of the film at the open end in order to maintain a substantially spaced-apart configuration; and/or aspirate both gas from inside the package and gas from an ambient atmosphere through the opening.
In a 68th aspect according to any one of aspects 65 to 67, the process further comprises guiding the intermediate portion of the open end along a length of the opening while relatively moving one of the package and the vacuum chamber with respect to the other; and/or creating wrinkles in the film at the open end of the package, optionally substantially within a region where the intermediate portion of the open end enters the vacuum chamber, further optionally maintaining the wrinkles in the film substantially throughout the moving of the intermediate portion along the length of the opening; and/or removing wrinkles from and/or flattening the film at the open end of the package, optionally substantially within a region where the intermediate portion of the open end exits the vacuum chamber; and/or creating elongated wrinkles in the film an area of the package substantially in contact with the means for moving.
In a 69th aspect according to any one of aspects 65 to 68, the process further comprises allowing lateral movement of the package and/or of the film material at the open end of the package in a direction perpendicular to the movement direction such that a change in volume of the package and/or a change in the shape of the film of the package while relatively moving one of the package and the vacuum chamber with respect to the other can be accommodated.
Advantages of the packaging process and the packaging apparatus include that the packaging process can be performed using a relatively small vacuum chamber having a fixed gap allowing movement of a portion of the package (e.g. bag neck, unsealed end of package). Evacuating a smaller chamber and maintaining a vacuum within a smaller chamber can be significantly more efficient than evacuating larger chambers designed to house the entire product/package during vacuumization. Further improvements entail lower costs and less space requirements at the same processing rate (e.g. m2/1 ppm).
Advantages of the packaging process and the packaging apparatus further include that packages can be evacuated continuously and in a serial manner, thereby reducing complexity of the vacuum system. This can also entail a reduction in processing times and/or processing costs due to continuous processing as opposed to batch processing.
Advantages of the packaging process and the packaging apparatus further include that products of larger and/or variable sizes can be efficiently packaged irrespective of the size of the vacuum chamber. For example, products having a same height but varying length and width can be processed without any changes to the packaging apparatus or process. The size of the vacuum chamber does not limit the size of the packages that can be processed. Additionally, the packaging apparatus can be easily adapted for processing products of a different height.
Advantages of the packaging process and the packaging apparatus also include that wrinkle generation (beneficial, e.g., for vacuumization) and flattening (beneficial, e.g., for sealing) can be integrated into the continuous processing as the products/packages are in motion during these stages.
Advantages of the packaging process and the packaging apparatus further include that monitoring the process (e.g. vacuumization) can be performed more easily due to the products/packages being freely accessible as opposed to being enclosed in a vacuum chamber.
Advantages of the packaging process and the packaging apparatus additionally include that the packaging apparatus can be easily adapted to individual applications. For example, the width of the main conveyor belt can be changed in order to accommodate products of particular length. Further, processing speed and evacuation time can be changed by adapting the operation speed of the main conveyor and/or by employing a longer or shorter vacuum chamber.
Advantages of the packaging process and the packaging apparatus further include that the risk of deterioration of the products (e.g. molding caused by residual oxygen) can be reduced by providing the packages with a protective gas, prior to evacuation of gas or air.
The packaging process may also facilitate full integration and automation with a vertical or horizontal form, fill, and seal (VFFS, HFFS) apparatus.
Evacuation station 1 includes a main conveyor belt 30 and infeed 34 and outfeed 36 areas in order to facilitate the introduction of packages 50 into a working zone of evacuation station 1 and to transport the packages 50 through and away from the evacuation station 1. Alongside the main conveyor belt 30, an evacuation chamber 10 is located. The evacuation chamber has an elongated opening 14 extending substantially parallel to a longitudinal axis of the evacuation chamber 10 along a sidewall thereof. The opening 14 defines a fixed gap (e.g. having a height that is substantially fixed along the length of the vacuum chamber 10) extending substantially parallel to the movement direction 40. At an upstream end of the evacuation chamber 10 (upstream being defined with respect to movement direction 40 of packages 50 through evacuation station 1), a bag neck guide 16 and/or a belt guide 12 is/are provided in order to reliably introduce the bag necks of packages 50 (e.g. film material in correspondence of the open end 55 of each package 50) into the fixed-gap opening 14. At the downstream end of the evacuation chamber 10, sealing rolls 24 can be provided, including a corresponding sealing roll motor, knife rolls 22, and/or a trimmer for trimming excess material. It is noted that the terms “upstream” and “downstream” are defined with respect to the main movement direction 40 of products through the packaging apparatus.
In some embodiments, the packages 50 are provided as packages having sealed ends (e.g. a first sealed end and a second sealed end). Before evacuation, a sealed end of a respective package 50 can be perforated or provided with an aperture in order to provide the package 50 with the open end 55. The perforation or aperture is provided in the terminal portion 54 of the open end 55, such that the terminal portion 54 of the open end 55 and, thus, the perforation or aperture, is guided through the vacuum chamber 10. In other embodiments, a seal present at the terminal portion 54 (e.g. a seal extending along an edge of the package 50, can be cut in order to create the open end 55. Similarly, the cut is provided in the terminal portion 54 of the open end 55, such that the terminal portion 54 of the open end 55 and, thus, the opening created by the cut, is guided through the vacuum chamber 10.
Evacuation chamber 10 further has a fluid connector 11 configured to be attached to a vacuum source (e.g. a vacuum pump; not shown). In this manner, gas or air can be evacuated from evacuation chamber 10 through fluid connector 11 and, thus, the vacuum chamber can be provided with an internal vacuum pressure that is below ambient pressure. A suitable vacuum source is a vacuum pump operating at, for example, about 1200 m3/h and 500 mbar of absolute pressure.
Typically, products are loaded onto a continuously supplied film, for example supplied from a roll of film, the film being subsequently longitudinally sealed in order to create a sequence of packages 50, i.e. products placed in the tubular film. This can be performed at a loading station (not shown in
It is assumed that once packages 50 reach evacuation station 1 along movement direction 40 as shown in
It is noted that each of the packages 50 can have different dimensions, in particular with respect to length l and width w, as compared to other packages 50 being processed in the same packaging apparatus. The length l of a package 50 refers to the extension of the package 50 parallel to the surface of the main conveyor 30 and perpendicular to the movement direction 40. The width w of a package refers to the extension of the package 50 parallel to the surface of the main conveyor 30 and in the direction of the movement direction 40. Packages 50 are placed and positioned such that the open ends 55 of the packages 50 are lined up with respect to the side of the main conveyor belt 30 facing the vacuum chamber 10, so that the series of open ends 55 is arranged parallel to the movement direction 40 and in alignment with the opening 14 of the vacuum chamber 10.
In
A packaging apparatus, for example an apparatus including an evacuation station such as evacuation station 1, typically comprises a control unit. The control unit and individual connections to components of the packaging apparatus are not shown for clarity. It is understood that the control unit is connected to one or more components of the packaging apparatus, for example one or more of a loading station, a sealing station, and a flusher. A flusher may be provided in order to flush the inside of the packaging film 21 with a protective gas or mixture of gases. The control unit is further connected to evacuation station 1 and to the main conveyor belt 30. At the evacuation station 1, gas or air is evacuated from the packages 50.
The control unit may further be connected to additional components, such as a hot air or shrink tunnel, where the film material around packaged products 50 can additionally undergo heat-shrinking after the packages 50 having been evacuated and sealed. It is understood that the packaging apparatus can comprise common connection means for connecting the control unit to any components controlled, for example electrical, optical, or other connections and/or leads.
The control unit can be configured for controlling the transport of packages 50 along a predefined path, for example by controlling a motor associated with main conveyor belt 30. The control unit can further control the actuators of different components, for example, in order to create seals on the tubular film or in order to control sealing bars (e.g. sealing bars 26, 27; see below), sealing rolls (e.g. sealing rolls 24; see below), knife rolls, vacuum pumps, etc. The control unit is configured to send and/or receive control signals to/from the vacuum source (e.g. a vacuum pump). The control unit can further be configured to control the vacuum pump to provide an internal vacuum pressure to vacuum chamber 10. To this aim, the control unit can be configured to control a power driving the vacuum pump connected to vacuum chamber 10. The control unit is further configured to control the main conveyor 30. For example, the control unit can be configured to increase or decrease an operating speed of the main conveyor belt 30. The control unit can further be configured to control the operating speed of the main conveyor 30 depending on a position of products 50 with respect to different components of the packaging apparatus. In embodiments in which the packages 50 are moved relative to the vacuum chamber 10, the main conveyor belt 30 can be controlled to move the packages 50 relative to the vacuum chamber 10 at a predetermined relative speed, for example between about 5 m/min to about 30 m/min, preferably between about 10 m/min to about 20 m/min.
The control unit can comprise a digital processor (CPU) with memory (or memories), an analogical type circuit, or a combination of one or more digital processing units with one or more analogical processing circuits. In the present description and in the claims it is indicated that the control unit is “configured” or “programmed” to execute certain steps. This may be achieved in practice by any means, which allow for configuring or programming the control unit. For instance, in case of a control unit comprising one or more CPUs, one or more programs are stored in an appropriate memory. The program or programs contain instructions, which, when executed by the control unit, cause the control unit to execute the steps described and/or claimed in connection with the control unit. Alternatively, if the control unit is of an analogical type, then the circuitry of the control unit is designed to include circuitry configured, in use, to process electric signals such as to execute the control unit steps herein disclosed.
With respect to both
Vertical positioning of the open end 55 of packages 50 can be achieved by relatively adjusting the vertical spatial relationship (i.e. vertical as seen in
Packages 50 are positioned and the vertical position of vacuum chamber 10 or main conveyor 30 is adjusted so that open ends 55 of packages 50 are substantially positioned within an operating region of guides 16 and/or belts 12 in a longitudinal extension of vacuum chamber 10 and opening 14. This facilitates introduction of the open ends 55 into and through vacuum chamber 10 during movement of packages 50 along direction 40 into and through evacuation station 1.
While open ends 55 are guided into opening 14 and moved along the length thereof, vacuum pressure applied to vacuum chamber 10 causes aspiration of gas or air through opening 14 from inside packages 50 and from around ambient air outside packages 50 as indicated by arrows in
The length of vacuum chamber 10 along movement direction 40 (see
In one example, evacuation station 1 can be configured in accordance with the following parameters. Evacuation station 1 is configured to accommodate and process products of up to 1500 mm in length (e.g. based on a width of main conveyor 30). The desired evacuation time is set at a minimum of 5 seconds and the operating speed of main conveyor is set at a maximum of 20 m/min (i.e. 0.33 m/s). Vacuum chamber 10, thus, has to be provided with a length of at least 1.7 m in order to provide the minimum evacuation time taking into account the operating speed of main conveyor 30. Not including infeed (guides 16, belts 12) and outfeed areas, or an operating area for the sealing rolls and the knife rolls, vacuum chamber has a length of about 2 m. In this example, opening 14 is provided with a size (opening height) of 0.5 mm. Further, vacuum chamber 10 is provided with an absolute pressure of 600 mbar. The desired air speed in opening 14 is set at 250 m/s, necessitating an air flow rate from chamber 10 of about 1125 m3/h. Air flow rate is calculated based on the air speed (250 m/s; see above)×gap width (0.5 mm; see above)×gap length (estimated to be 2.5 m). In the present example: 250 m/s×0.0005 m×2.5 m=0.3125 m3/s=1125 m3/h. It is understood that these exemplary values can be modified in accordance with the individual application in order to account for different processing times, different film material, etc.
The processing speed of evacuation station 1 can be calculated as follows. Processing packages containing products 56 having a width of 450 mm (and, e.g., length 500 mm, height 100 mm) and arranging the packages at a distance of 50 mm with respect to one another results in a throughput of 40 packages per minute (ppm), the evacuation time being 5 seconds. This is based on: conveyor speed/(width+spacing)=20 m/min/(0.45 m+0.05 m)=40 ppm. In another example, products 56 of 120 mm width (1200 mm length, 100 mm height) are processed, where the products are placed in bags (i.e. packages) of 250 mm width and the evacuation time is set at 10 seconds (i.e. operating speed of the main conveyor 30 of 10 m/min). The throughput in this latter example is: 10 m/min/(0.25 m+0.05 m)=33 ppm.
At the downstream end of vacuum chamber 10 a sealing roll assembly 24 is configured to seal the open ends 55 of packages 50 in a continuous manner, for example by heat-sealing. Here, sealing roll assemblies known in the art can be employed, for example those including two rolls carrying heating elements and being arranged to act upon film material from opposite sides, heat-sealing the film material as it is directed between the sealing rolls and through the sealing roll assembly. Subsequently, suitable cutting means, for example a knife roll, cuts excess film material from packages 50. Typically, packages 50 are sealed in the region of the non-terminal portion 52 and excess film material is cut in the region of the intermediate portion 53, optionally close to the non-terminal portion 52. In some embodiments, little or no excess film material is cut. If excess film material is cut, a corresponding container (not shown) receiving the cut material can be provided.
Additionally or alternatively to what is described in the previous paragraph, the grooves 32 can be provided with a number of openings (e.g. multiple openings spaced at regular intervals along the length of a single groove) and a vacuum can be applied to a predetermined area of the conveyor belt 30 from below. This can be achieved by providing the lower side of the upper run of the conveyor belt 30 with an aspiration element (e.g. a box-shaped nozzle having an open top portion positioned close to the lower surface of the upper run of the conveyor belt 30) and by applying a vacuum pressure to the aspiration element. In this manner, air can be aspirated through the openings in the upper run of the conveyor belt 30 and, thus, act on the film of packages placed on the conveyor belt 30. Consequently, the film material of the package can be pulled towards the conveyor belt 30 where the film material will adapt to the shape of the upper surface of the upper run of the conveyor belt 30. Thereby, the film is pulled into the grooves 32, forming plies or wrinkles in the film material.
This deformation of the film material entails several effects promoting efficient and effective evacuation of the package. First, the plies or wrinkles form channels below the product placed in the package and thereby facilitate evacuation of air in a region of the package difficult to evacuate, because it is often not or not entirely in fluid communication with the open end of the package due to the product being placed upon it. Further, even if the region is in fluid communication with the open end of the package, this might be only indirectly and/or through passages having a rather high resistance to fluid flow (e.g. due to complex and/or twisted shapes of the passages, small minimal or average diameter of the passages, points of constriction in the passages). The channels formed below the product conform to the straight shape and diameter of the grooves and, therefore, provide improved fluid communication. Second, the channels can provide an additional general region of fluid flow from the sealed end of the package towards the open end thereof, in addition to the regions at the top of the product and on either side thereof, where the packaging film is typically spaced further from the product than at the bottom thereof. And third, the channels can carry over towards the open end and through the opening 14 into the vacuum chamber 10, such that the channels promote the overall evacuation of the package by ensuring that opposite layers of film do not adhere too closely to one another in the region where the film material extends through the opening 14 into the vacuum chamber 10.
After exiting evacuation station 1, packages 50′ have been evacuated and sealed along the previously unsealed edge 21′, thereby being provided with a sealed edge 21″. Subsequently, packages 50′ can be separated further downstream of evacuation station 1, for example at a corresponding cutting station (not shown). In some applications, it is desired to keep packages 50′ connected to one another. In such applications, instead of separating the packages 50′ using a cutter, merely a perforation is provided between two adjacent seals, so that products 50′ may be separated manually by ripping the film material 21 along the perforation.
Upper guide belt 70 and lower guide belt 72 are guided along the vacuum chamber 10 in correspondence of and along the opening 14 in respective grooves or notches 70′ and 72′ (not shown in
Evacuation station 1 is configured to move package 50 from the intake section 100 through each of operating sections 200, 200′, and 200″, and subsequently through outlet section 300 in a manner that allows for the neck of packages 50 to be introduced into vacuum chamber 10, and through each of sections 10-1, 10-2, and 10-3. The sections 10-1, 10-2, and 10-3 are separated by upper rollers 90 and lower rollers 92 (lower rollers are not shown in
Corresponding actuators are configured to actuate rollers 90 and 92 are substantially in sync with belts 70 and 72, as well as conveyor belt 30, such that packages 50 move along conveyor belt 30 at substantially the same speed as the necks of the packages 50 are guided between the upper and lower rollers 90 and 92, as well as between the upper and lower belts 70 and 72 along opening 14. It is understood that both conveyor 30, belts 70 and 72, and rollers 90 and 92 are provided with one or more actuators connected to a control unit configured to control the one or more actuators in order to a desired synchronous or substantially synchronous movement, or any movement required during operation of evacuation station 1. In some embodiments, belts 70 and 72, and rollers 90 and 92 are actuated by a single common drive motor. In other embodiments, belts 70 and 72, and rollers 90 and 92 are driven by two or more actuators commonly controlled by the control unit.
Generally, the conveyor belt 30 includes from about 20% to about 50% projections 30p and from about 80% to about 50% recesses 30r per surface unit. A ratio of surface area covered by the recesses 30r to surface area covered by the projections 30p ranges from about 1:1 to about 1:5. In a preferred embodiment of the conveyor belt 30 as shown in
Further, the rear of evacuation station 1 is provided with three separate fluid connectors 11-1, 11-2, and 11-3, each of the fluid connectors being configured to connect to a vacuum source. It is noted that in some embodiments each fluid connector can be connected to a separate vacuum source providing a specific vacuum pressure different from one another. In other embodiments, all fluid connectors can be connected to a single vacuum source via a respective conduit, each conduit optionally including a flow controller configured to supply the fluid connector with a respective and/or predetermined vacuum pressure. In this manner, the first section 10-1 of evacuation chamber 10 can be supplied with a vacuum pressure different from that supplied to the second and/or third sections of the vacuum chamber 10. It is noted that some applications require a progressive evacuation of the package 50, during which each package is evacuated in several stages, each stage providing a package with a vacuum pressure higher than previous stages. In other applications, one of the sections 10-1, 10-2, or 10-3 can be provided not with a vacuum pressure but instead with a positive pressure and a suitable gas (e.g. an inert gas such as CO2) in order to facilitate flushing the package with the gas before evacuation or between evacuations.
Supports 101 and 101′ and/or rollers 90 and 92 are configured to maintain the contact surfaces of rollers 90 and 92 substantially in contact with one another, without excessive pressure being created between the contact surfaces. Preferably, the supports 101 and 101′ and/or rollers 90 and 92 are configured to keep the contact surfaces in contact with one another with sufficient contact force in order to provide the interface extending between and along the contact surfaces (e.g. an elongated area extending along the side walls of the substantially cylindrically-shaped rollers 90 and 92 and substantially parallel to the longitudinal axes thereof) with an air-tight seal, while the contact force is minimized in order to allow the film 21 of the neck of a package 50 to pass between rollers 90 and 92.
Further, gears 104 and 104′ are configured to bring belts 70 and 72 as close together as possible without bringing respective contact surfaces of the belts 70 and 72 into direct contact with one another. Generally, vacuum chamber 10 and respective gears 104 and 104′ arranged along the length of the vacuum chamber 10 are configured to position adjacent longitudinally extending portions of belts 70 and 72 substantially parallel to one another. Preferably, the adjacent portions of belts 70 and 72 are spaced apart from one another at a distance of 0.8 mm or less, more preferably at a distance of 0.5 mm or less, and most preferably at a distance of 0.3 mm or less.
Further, gears 104 and 104′ are shown as sprockets or gears having teeth engaging a corresponding profile present in belts 70 and 72, respectively. Gears 104 and 104′ may be configured to impart motion transferred to them from a drive motor (e.g. from drive motor 95, possibly via transfer belts or chains; see
The wheels 25 and 25′ shown on the right side of
As shown in
In order to facilitate and/or to promote the formation of wrinkles during introduction of necks of packages 50 into evacuation station 1 it has proven beneficial to provide the outer surface 70o of the belt 70 with a contoured shape as described above (preferably with recesses having a depth of about 1 mm and a length of 5 mm, with a distance of 10 mm between successive recesses), while the outer surface 72o of the belt 72 is provided with a substantially flat contour. This configuration provides channels 73 as shown in
As shown in
Limited vertical movement of the belts 70 and 72 can be beneficial in accommodating films 21 of different thicknesses without exerting excess pressure (e.g. substantially no pressure) upon layers of film 21 (not shown in
Channels 74 provided in supports 101 and 101′ can be employed in order to adjust a pressure exerted between adjacent portions of the belts 70 and 72. As described above, generally the adjacent portions of the belts 70 and 72 should exert little or no pressure on layers of film 21 positioned between the belts 70 and 72. However, in some applications and/or some stages of evacuation, it can be beneficial to enhance the sealing contact between the adjacent portions of the belts 70 and 72, for example during flushing, in order to minimize loss of inert gas. In order to enhance the sealing contact, pressurized air can be introduced through channels 74, thereby forcing the adjacent portions of the belts 70 and 72 against one another, depending upon the pressure of the air provided. As each channel 74 has a rather local effect on a respective section of one of the belts 70 and 72 (e.g. being effective along a section of 5 to 10 cm), the individual pressure and/or duration can be set and/or modulated as desired.
The flusher chamber 10-xf includes one or more nozzles 120 configured to provide the flusher chamber 10-xf with an inert gas from a corresponding source (not shown). The flusher chamber 10-xf can further include a fluid connector 11-x configured to connect to a suitable conduit and/or further components (e.g. a vacuum source, a pump) in order to facilitate selective aspiration of gas or air from the flusher chamber 10-xf, for example when venting superfluous gas from the flusher or when providing a controlled outflow of gas from flusher chamber 10-xf. Nozzles 120 can be fixedly integrated into the flusher chamber 10-xf or the nozzles 120 can be movable towards and away from the opening 14 (i.e. laterally with respect to movement direction 40) in order to improve the efficiency and/or effectiveness of the flushing step. In embodiments having movable nozzles 120, corresponding actuators (not shown) can move the nozzles 120 closer to the opening 14 and, preferably, into the open end 55 of a package 50 in order to introduce inert gas directly into the package 50 (as opposed to supplying the inert gas first to the flusher chamber 10-xf and subsequently transferring the inert gas into the package 50 by overpressure in the flusher chamber 10-xf and/or aspiration exerted from an expanding package 50, expanding outside the flusher chamber 10-xf.
It is noted that the flusher chamber 10-xf may be provided with an internal pressure substantially corresponding to ambient pressure, in which case a previously (partly) evacuated package 50 can aspirate inert gas from the flusher chamber 10-xf by the film material relaxing from it (partially) evacuated configuration due to the lack of a significant pressure differential between the flusher chamber 10-xf and the ambient pressure). To this aim, the flusher chamber 10-xf can be provided with additional sensors (not shown) configured to detect the open end of a package 50 and to provide a signal based on the detection to the control unit, the control unit being configured to control the actuator(s) of the nozzle(s) based on the signal provided by the sensor(s). The Rollers 90 and 92 are provided at either side of the flusher chamber 10-xf in order to substantially seal the flusher chamber 10-xf from adjacent chambers (e.g. chambers 10-1 and 10-3; see
Evacuation chamber 10-xv further includes sub-chambers 10-xv-1, 10-xv-2, and 10-xv-3 separated by dividers 96. Dividers 96 are configured to facilitate a controlled fluid flow between the different sides of the divider, offering a desired resistance to the fluid flow such that a pressure differential between two adjacent sub-chambers can be created and maintained while the evacuation chamber 10-xv is provided with only a single fluid connector 11-x providing the evacuation chamber 10-xv with a general vacuum pressure. Further, the dividers 96 are configured to allow film 21 at the neck of packages 50 being moved through the evacuation chamber 10-xv to pass through the dividers without excessive friction or wear and tear on the materials involved (e.g. curtains of divider 96 or film 21). This configuration of the evacuation chamber 10-xv allows for a single evacuation chamber to provide different pressure differentials. In one embodiment, the pressure in the first sub-chamber 10-xv-1 is between 800 and 900 mbar, the pressure in the second sub-chamber 10-xv-2 is between 700 and 800 mbar, and the pressure in the third sub-chamber 10-xv-3 is between 600 and 700 mbar, thereby providing an increasing pressure differential. Such an increasing pressure differential can be beneficial when evacuating packages 50 containing a product 56 or products 56 easily affected by vacuumization (e.g. loose material or bulk goods that could interfere with evacuation), because of the gradual increase in vacuum pressure. It is noted that other intervals of increasing pressure differentials can be chosen, which have a substantially similar effect.
The sealing rollers 24 are configured to provide the neck of each package 50 exiting the vacuum chamber 10 with a seal. Sealing is performed in a continuous manner as packages 50 exit evacuation station 1. Pushers 105 and 105′ are configured to act upon the stretch belts 80 and 82 ensure that in the final stage before sealing substantially no or very little air or gas can enter the evacuated packages 50. Pushers 105 and 105′ can be mechanical pushers (e.g. based on one or more springs pushing a contact element on the belts 80 and 82) or based on a pneumatic system as described above with respect to channels 74. In some embodiments, sealing means (e.g. sealing rollers 24) may be arranged differently, such that sealing may be performed while packages 50 are still being evacuated. In such embodiments the sealing means may be arranged at the end of, or within, the evacuation station 300. Such an arrangement of the sealing means may entail the advantage that evacuation is optimized and air/gas is prevented from entering the packages 50 after evacuation has been concluded, but before sealing has been performed.
The belts 80 and 82 preferably have substantially flat outer surfaces configured to contact film 21 at the neck of packages 50 in order to stretch the film material and in order to substantially reduce or eliminate any wrinkles present in the film material before sealing. This can be achieved by substantially flat outer surfaces and a higher operating speed of the belts 80 and 82 with respect to an operating speed of the belts 70 and 72. The outlet section 300 can further include knives or blades (not shown in
Generally, the adjacent portions of the belts 70 and 72 should exert little or no pressure on layers of film 21 positioned between the belts 70 and 72. However, in some applications and/or some stages of evacuation, it can be beneficial to enhance the sealing contact between the adjacent portions of the belts 70 and 72, for example during flushing, in order to minimize loss of inert gas. In order to enhance the sealing contact, pressurized air can be introduced through channels 74, thereby forcing the adjacent portions of the belts 70 and 72 against one another, depending upon the pressure of the air provided. As each channel 74 has a rather local effect on a respective section of one of the belts 70 and 72 (e.g. being effective along a section of 5 to 10 cm), the individual pressure and/or duration can be set and/or modulated as desired.
A control unit (see above) can be configured to control a source of pressurized air and corresponding valves in fluid communication with channels 74 to provide a predetermined pressurized air flow such that a desired pressure is exerted upon the adjacent portions of the belts 70 and 72. Different channels 74 (e.g. each extending vertically and perpendicular to the movement direction 40, arranged in series along the length of vacuum chamber 10 in support 101 and/or support 101′) can be supplied with the same or different pressure in order to adjust and/or modulate the pressure exerted upon adjacent portions of the belts 70 and/or 72.
The outlets 120i-10 may be provided in form of a plurality of discrete openings arranged along an elongated integrated nozzle 120i extending substantially parallel to the opening 14. Each of the plurality of openings is spaced apart from adjacent openings in a manner allowing for a flow of gas being provided along substantially the length of the corresponding elongated integrated nozzle 120i. In other embodiments, a single outlet 120i-10 is provided in form of an elongated opening extending along an elongated integrated nozzle 120i, which in turn extends substantially parallel to the opening 14. The elongated opening allows for a flow of gas being provided along substantially the length of the corresponding elongated integrated nozzle 120i. A flusher chamber 10-xf may be provided with one or more (elongated) integrated nozzles 120i of either type (e.g. including a plurality of discrete opening or a single elongated opening) in order to provide a flow of gas along substantially the entire length of the flusher chamber 10-xf.
As discussed above with respect to
The packaging can comprise a multi-layer film 21. The film 21 can comprise PET, PA, or polyolefin (PP, PE). The film 21 can be a fully coextruded shrinkable film 21. The package provides a barrier to gas passing between the interior of the package to the exterior of the package. Accordingly, the environment inside the package is isolated from the environment outside the package. This helps to preserve food products 56 and to avoid contamination. This can be advantageous with respect to food hygiene. The package 50 can provide a barrier to aromas or to gasses. This can be particularly useful when the product 56 is a food product. The package can be abuse-resistant.
The packaging can be transparent or translucent. This allows a customer to see the product 56 through the packaging. For example, the packaging may comprise a transparent film 21. The packaging film can have anti-fog properties. This ensures high consumer appeal. The packaging film can be printable. This allows labels to be printed directly onto the packaging.
The packaging may be formed from a roll of film 21. The tubular film 21 can be made by forming a tube from the roll of film 21. The packaging apparatus can comprise a forming station configured to form the roll of film 21 into a tube. The forming station can form the tube by forming a longitudinal seal along the longitudinal edges of the roll of film 21. The tube may be formed from two webs of film 21. In this case, the forming station forms two longitudinal seals along the opposing edges of the two rolls of film 21.
The packaging apparatus can comprise a flusher. The flusher is configured to flush gas through the tube of film 21 that forms the packaging. The gas flush may prevent the tube from collapsing. The gas flush helps to maintain a distance between a product 56 in a tray and the film 21. This helps to improve the hygienic appearance of the film 21 because the film 21 remains untarnished by the product. The flusher flushes gas longitudinally through the tube. The gas used for flushing can comprise about 70% oxygen and about 30% carbon dioxide or other suitably modified atmosphere.
Additionally, the flush gas allows the product 56 to be packaged in a modified atmosphere. The gas may help to preserve the product 56, prolonging its shelf life. The desired amount of gas inside each sealed package depends on the type of product 56 and the length of shelf life needed.
The packaging apparatus can comprise a shrink station configured to shrink the film 21. The shrink station may be a water- or air-based shrink tunnel, for example a hot air tunnel. After sealing, packages 50 undergo heat-shrinking in the shrink station. The shrinking process may involve heating the packages 50. The packages 50 may be heated to a temperature within the range of from about 130° C. to about 150° C.
The product 56 can be a food product. For example, the product 56 may comprise meat, cheese, pizza, ready meals, poultry and fish. The product 56 may be substantially dry, as in the case of cheese. For some products, such as cheese, there is no need for a tray to support the cheese. Alternatively, the product 56 may be wet. In this case, it is particularly desirable for the product 56 to be disposed in a tray. Further, the product 56 can also be a non-food product, for example including clothes, sheets, textile material or other compliant material. In such applications, the volume of packaged products can be reduced significantly, thereby providing substantial advantages regarding shipping and/or storage space requirements. The products 56 can further include soft or rigid products, bulk goods, or other items. In packaging applications for medical goods, the storage life of the packaged products can be significantly increased, for example by keeping the products 56 sealed and isolated from the outside atmosphere and/or in an inert and/or sterile internal environment.
Desirably, the packaging apparatus comprises a horizontal form fill and seal machine. However, the packaging apparatus may comprise other types of form fill and seal machines, such as a vertical form fill and seal (VFFS) machine. In a vertical form fill and seal machine, the packages 50 move through the packaging apparatus in a vertical direction during the packaging process. In a VFFS machine, the packaging may be sealed once to form the lower end of a sealed package. The product 56 is then fed into the open-ended package. The top end of the package 50 is then sealed to form a sealed package.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and the scope of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 15193959.2 | Nov 2015 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2016/077182 | 11/9/2016 | WO | 00 |
