Patent Application
20190193881
The present invention relates to a packaging process using a gas extraction station and a packaging apparatus comprising a gas extraction station. The packaging process includes extraction of gas from a package or from a semi-sealed package in a gas extraction station having a single vacuum chamber.
A packaging apparatus can be used to package a food product. The product can be a naked 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 naked product is fed through an infeed belt. A tube is created around the product by sealing opposite longitudinal edges of the film. Alternatively, the product is placed in the tube and a leading edge of the packaging 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.
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 a gas extraction station and sealing station. Further, some embodiments can facilitate gas extraction from two or more packages at the same time in the same process step. The latter can be realized, for example, by processing two or more bags at the same gas extraction station or by feeding, in parallel, two or more tubes of film into a packaging apparatus, where the tubes are processed in parallel.
Sealing bars can be used to seal the package, wherein a lower bar and an upper bar are moved with respect to one another in order to contact each other, squeezing the packaging material in between and providing one or more seals. The sealing bars typically also form an adjacent seal, which comprises the opposite end of the next following package, thereby providing one semi-sealed (e.g. having an open end) and one sealed package during a single packaging process step.
The seals are typically transversally extending regions of packaging material that have been processed to provide a seal between the inside of the packaging and the environment. In the context of this document, whenever extraction of gas 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, consist of air (i.e. consist of a mixture of gases corresponding to ambient air). In some embodiments, packages can be flushed with a protective gas (sometimes also referred to as “inert” gas). It is noted that any known protective gas or gas mixture can be used here, for example CO2.
Gas can be injected into the package in the space between the product and the film at a loading station with or without a first seal closing the pack at the first end thereof (i.e. at a trailing edge). Any remaining gas inside the package after gas or air has been extracted therefrom and after the package has been sealed assures a very low residual level of O2 inside the package (e.g., a residual level of O2 of 1% or lower). This is particularly beneficial with respect to protection of perishable products (e.g. cheese with low gassing level during maturation).
A packaging apparatus is typically used for numerous different products with respect to the type of product, size, weight, composition, etc. A range of vacuum chamber machines for an application called “soft vacuum” exists, in which a product (e.g. soft or medium hard cheese with holes) is vacuumized in machines based on a two-chamber apparatus. The two chambers are provided with different air pressures and are separated by a dividing wall having a gasket. The first chamber is a vacuumized chamber provided with a vacuum pressure. The second chamber is a vacuumized chamber provided with vacuum pressure that is higher than the vacuum pressure provided in the first chamber and contains the product placed in a bag.
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 size of products that can be processed depend upon the size of the second chamber holding the product during packaging. In some applications, it is difficult to provide chambers of sufficient size due to structural limitation of some components (e.g. actuators). 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.
US 2012/0174531 discloses a packaging machine and a method of forming a vacuum package. A first evacuable chamber is used for accommodating therein a product-accommodating section of a package, whereas a second evacuable chamber is used for accommodating therein an opening section of the package. Pressure gauges measure the pressure in both chambers, and a supply air valve serves to supply air into the first chamber. The disclosure is characterized in that the supply air valve is a control valve and is adapted to be controlled in dependence upon the difference between the pressures which prevail in the first and second chambers and which are measured by means of the two pressure gauges. The disclosure also relates to the fact that a gap is provided in a partition between the two chambers and that an adjuster is provided for varying and adjusting the cross-sectional area of said gap.
EP 1564147 describes an apparatus and process for vacuum packaging a product in a bag. The apparatus comprises a cover hinged to a base member, the cover and the base member being provided with upper and lower divider walls cooperatively defining a first vacuum chamber, a second vacuum chamber adjacent to the first chamber, and an aperture connecting the first and second chambers for passing therethrough the neck of the bag. The apparatus further comprises means to evacuate the first and second chambers independently from each other and means to close the receptacle. The apparatus further comprises means to admit air in the first vacuum chamber and the aperture is provided with means to reduce the passage of air from one chamber to the other. The evacuation process includes one or more cycles of alternately removing air from within the first and second vacuum chambers, while in some phases pressure is at least partially restored in the first vacuum chamber.
An aim of the present invention is to provide a packaging process that facilitates efficient packaging of products of larger sizes irrespective of the size of a vacuum or processing chamber. A further aim of the present invention is to provide a packaging process that facilitate extraction of gas and/or air from a package—similar to vacuumization achieved by known apparatuses and processes—using one chamber only. 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 the steps of providing a semi-sealed package containing a product to be packaged, the semi-sealed package being made from a film and having a first sealed end and a second open end, providing a vacuum chamber including a first member and a second member arranged opposite the first member, the first member and the second member being relatively movable between a first configuration, in which the first and second members are spaced apart from one another, and a second configuration, in which the first and second members are in contact with one another along a perimeter thereof except for at least one opening being formed between the first and second members, adjusting a spacing between the first and second members to bring the first and second members into the first configuration, thereby opening the vacuum chamber, relatively positioning the semi-sealed package and the vacuum chamber such that a terminal portion of the second end is positioned within the vacuum chamber and a non-terminal portion of the second end is positioned outside the vacuum chamber, an intermediate portion of the second end passing through the opening, the intermediate portion extending between the terminal and non-terminal portions of the second end, adjusting the spacing between the first and second members to bring the first and second members into the second configuration, wherein in the second configuration, the first and second members are, except for the opening, substantially sealingly in contact with one another, and the intermediate portion of the second end is received in the opening, creating, within the vacuum chamber, an internal vacuum pressure that is lower than an ambient pressure outside the vacuum chamber, the internal vacuum pressure being selected such as to a) determine a gas flow through the opening causing opposing layers of the film at the second end to maintain a substantially spaced-apart configuration, and b) aspirate both gas from inside the semi-sealed package and gas from an ambient atmosphere through the opening, and creating a second seal on the semi-sealed package at the second end, thereby forming a sealed package containing the product and having first and second sealed ends.
According to the invention, in a 2nd aspect there is provided a packaging process comprising the steps of providing a sealed package containing a product to be packaged, the sealed package being made from a film and having a first sealed end and a second sealed end, providing a vacuum chamber including a first member and a second member arranged opposite the first member, the first member and the second member being relatively movable between a first configuration, in which the first and second members are spaced apart from one another, and a second configuration, in which the first and second members are in contact with one another along a perimeter thereof except for at least one opening being formed between the first and second members, adjusting a spacing between the first and second members to bring the first and second members into the first configuration, thereby opening the vacuum chamber, relatively positioning the sealed package and the vacuum chamber such that a terminal portion of the second end is positioned within the vacuum chamber and a non-terminal portion of the second end is positioned outside the vacuum chamber, an intermediate portion of the second end passing through the opening, the intermediate portion extending between the terminal and non-terminal portions of the second end, adjusting the spacing between the first and second members to bring the first and second members into the second configuration, wherein in the second configuration, the first and second members are, except for the opening, substantially sealingly in contact with one another, and the intermediate portion of the second end is received in the opening, creating an aperture in the film at the terminal portion of the second end, and creating, within the vacuum chamber, an internal vacuum pressure that is lower than an ambient pressure outside the vacuum chamber, the internal vacuum pressure and the size of the aperture being selected such as to a) determine an expansion of the terminal portion causing opposing layers of the film at the second end to maintain a substantially spaced-apart configuration, and b) aspirate gas into the vacuum chamber from inside the semi-sealed package through the opening and through the aperture.
In a 3rd aspect according to aspect 1, the step of providing the semi-sealed 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 semi-sealed package containing the product to be packaged.
In a 4th aspect according to aspect 2, the step of providing the sealed package comprises positioning a tubular film around the product to be packaged, creating, at a sealing station, a first seal on the tubular film, thereby forming a semi-sealed package containing the product, and creating, at the sealing station, a second seal on the tubular film, thereby forming the sealed package containing the product.
In a 5th aspect according to any one of aspects 1 to 4, the process further comprises creating a longitudinal seal along a film in order to obtain the tubular film.
In a 6th aspect according to any one of aspects 1 to 5, the step of relatively positioning the package and the vacuum chamber comprises moving the first member of the vacuum chamber and/or moving the second member of the vacuum chamber relative to the other, and moving the package and/or moving the vacuum chamber relative to the other.
In a 7th aspect according to any one of aspects 1 to 6, the step of adjusting the spacing comprises moving the first member of the vacuum chamber and/or moving the second member of the vacuum chamber relative to the other.
In an 8th aspect according to any one of aspects 1 to 7, the step of adjusting the spacing comprises providing the opening with a height of 8 to 20 times a thickness of the film.
In a 9th aspect according to any one of aspects 1 to 8, the step of adjusting the spacing comprises providing the opening with a height of between 0.3 mm and 1.0 mm, optionally providing the opening with a height of 1 mm or less, preferably 0.8 mm or less, most preferably 0.5 mm or less.
In a 10th aspect according to any one of aspects 1 to 9, the step of creating the internal vacuum pressure within the vacuum chamber comprises creating an internal vacuum pressure of between 800 mbar and 500 mbar, preferably between 750 mbar and 525 mbar, most preferably between 700 mbar and 550 mbar.
In an 11th aspect according to any one of aspects 1 to 10, the process further comprises providing the inside of the film and/or the package with a protective gas, optionally the protective gas substantially consisting of CO2.
In a 12th aspect according to any one of aspects 1 to 11, the process further comprises providing a second vacuum chamber and, optionally, operating the second vacuum chamber substantially in parallel to the vacuum chamber.
In a 13th aspect according to aspect 12, the steps of adjusting the spacing between the first and second members of the vacuum chamber to bring the first and second members into the first configuration, thereby opening the vacuum chamber, and adjusting a spacing between first and second members of the second vacuum chamber to bring the first and second members of the second vacuum chamber into a second configuration, in which the first and second members of the second vacuum chamber are, except for an opening of the second vacuum chamber, substantially sealingly in contact with one another, are performed substantially at the same time
According to the invention, in a 14th aspect there is provided a device for extracting gas from a semi-sealed package in a packaging apparatus, the semi-sealed package containing a product and having a first sealed end and a second open end, the second end having a terminal portion, a non-terminal portion, and an intermediate portion located between the terminal and non-terminal portions of the second end, the device comprising a vacuum chamber having a first member and a second member arranged opposite the first member, the first member of the chamber and/or the second member of the chamber being movable relative to the other between a first configuration, in which the first and second members are spaced apart from one another, and a second configuration, in which the first and second members are in contact with one another along a perimeter thereof except for at least one opening being formed between the first and second members, and an evacuation means for providing the chamber with an internal vacuum pressure that is lower than an ambient pressure outside the chamber, and a control unit programmed for a) adjusting a spacing between the first and second members and bringing the first and second members in the second configuration such that the intermediate portion of the second end is received in the opening without creating an air-tight seal between the intermediate portion and the first and second members along the opening, wherein, in the second configuration, the first and second members are, except for the opening, sealingly in contact with one another, b) activating the evacuation means to provide the vacuum chamber with the internal vacuum pressure, and c) controlling the internal vacuum pressure for i) allowing a gas flow through the opening causing opposing layers of film at the second end to maintain a substantially spaced-apart configuration, and ii) allowing aspiration of both gas from inside the semi-sealed package and gas from an ambient atmosphere through the opening.
According to the invention, in a 15th aspect there is provided a device for extracting gas from a sealed package in a packaging apparatus, the sealed package containing a product and having a first sealed end and a second sealed end, the second end having a terminal portion, a non-terminal portion, and an intermediate portion located between the terminal and non-terminal portions of the second end, the device comprising a vacuum chamber having a first member and a second member arranged opposite the first member, the first member of the chamber and/or the second member of the chamber being movable relative to the other between a first configuration, in which the first and second members are spaced apart from one another, and a second configuration, in which the first and second members are in contact with one another along a perimeter thereof except for at least one opening being formed between the first and second members, a puncturing means, an evacuation means for providing the chamber with an internal vacuum pressure that is lower than an ambient pressure outside the chamber, and a control unit programmed for a) adjusting a spacing between the first and second members and bringing the first and second members in the second configuration such that the intermediate portion of the second end is received in the opening without creating an air-tight seal between the intermediate portion and the first and second members along the opening, wherein, in the second configuration, the first and second members are, except for the opening, sealingly in contact with one another, b) controlling the puncturing means to create an aperture in the terminal portion of the second end, c) activating the evacuation means to provide the vacuum chamber with the internal vacuum pressure, and d) controlling the internal vacuum pressure for i) allowing an expansion of the terminal portion causing opposing layers of film at the second end to maintain a substantially spaced-apart configuration, and ii) allowing aspiration of gas into the vacuum chamber from inside the sealed package through the opening and through the aperture.
In a 16th aspect according to aspects 15, the device further comprises sealing and cutting means, wherein the control unit is further programmed for controlling the sealing and cutting means to provide the package with a seal at the second end between the first end and the aperture.
In a 17th aspect according to aspect 14, the device further comprises sealing and cutting means, wherein the control unit is further programmed for controlling the sealing and cutting means to provide the package with a seal at the second end.
In an 18th aspect according to any one of aspects 15 or 16, the puncturing means comprise one of a punch and a heat wire.
In a 19th aspect according to any one of aspects 15 or 16, the control unit is further programmed for controlling the sealing and cutting means to cut excess film material outside the seal from the second end.
In a 20th aspect according to any one of aspects 13 to 19, the opening has a width of 1000 mm or less, preferably 500 mm or less.
In a 21st aspect according to any one of aspects 13 to 20, the control unit is programmed for adjusting the spacing such that the opening has a height of 8 to 20 times a thickness of the film, the control unit optionally being programmed for adjusting the spacing such that the opening has a height of 10 times a thickness of the film or less.
In a 22nd aspect according to any one of aspects 13 to 20, the control unit is programmed for adjusting the spacing such that the opening has a height of between 0.3 mm and 1.0 mm, optionally the opening having a height of 1 mm or less, preferably 0.8 mm or less, most preferably 0.5 mm or less.
In a 23rd aspect according to any one of aspects 13 to 22, the opening has a depth of 50 mm or less, preferably 20 mm or less, and more preferably 12 mm or less.
In a 24th aspect according to any one of aspects 13 to 23, the control unit is programmed for controlling the evacuation means to create an internal vacuum pressure of between 800 mbar and 500 mbar, preferably between 750 mbar and 525 mbar, most preferably between 700 mbar and 550 mbar.
In a 25th aspect according to any one of aspects 13 to 24, the device further comprises a second vacuum chamber having a respective first member and a respective second member arranged opposite the first member, the first member of the second vacuum chamber and/or the second member of the second vacuum chamber being movable relative to the other between a first configuration, in which the first and second members of the second vacuum chamber are spaced apart from one another, and a second configuration, in which the first and second members of the second vacuum chamber are substantially in contact with one another along a perimeter thereof except for at least one opening of the second vacuum chamber being formed between the first and second members of the second vacuum chamber
According to the invention, in a 26th aspect there is provided a packaging apparatus comprising a control unit; a gas extraction station coupled to the control unit; an output station; a means for moving coupled to the control unit, the control unit being configured to control the means for moving to move one or more packages, each containing a product to be packaged, towards and through the gas extraction station, and towards the output station; wherein the gas extraction station comprises a device for extracting gas according to any one of aspects 13 to 25.
According to the invention, in a 27th aspect there is provided a packaging apparatus comprising a control unit, a gas extraction station coupled to the control unit, an output station, means for moving coupled to the control unit, the control unit being configured to control the means for moving to move one or more packages, each containing a product to be packaged, towards and through the gas extraction station, and towards the output station. The gas extraction station comprises a device for extracting gas according to aspect 25, optionally the control unit being configured to control the means for moving to move one or more packages to alternately supply the vacuum chamber and the second vacuum chamber.
In a 28th aspect according to any one of aspects 26 or 27, the packaging 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 29th aspect according to any one of aspects 26 to 28, the packaging apparatus further comprises a protective gas supply means coupled to the control unit, wherein the control unit is configured to provide the inside of the tubular film with a protective gas, optionally the protective gas substantially consisting of CO2.
Advantages of the packaging process and the packaging apparatus include that the packaging process can be performed using a single vacuum chamber only. This may also entail a decrease in processing times and/or processing costs.
Advantages of the packaging process and the packaging apparatus include that the evacuation station allows for scaling the evacuation procedure in order to optimize the duration of evacuation with respect to an operating rate and/or throughput of remaining operative stations or steps included in the packaging apparatus or process.
Advantages of the packaging process and the packaging apparatus further include that products of larger sizes can be efficiently packaged irrespective of the size of the 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 extraction of gas or air.
The packaging process may also facilitate full integration and automation with a horizontal form, fill, and seal (HFFS) apparatus.
Typically, products 20 are loaded onto a continuously supplied film, for example supplied from a roll of film (not shown), the film being subsequently longitudinally sealed in order to create a sequence of products 20 placed in tubular film 21. Optionally, a flusher 34 may be provided in order to flush the inside of tubular film 21 with a protective gas or mixture of gases. The gas or gases may substantially comprise or consist of CO2.
Products 20 to be packaged assume different states (e.g. 20a, 20b, 20c, 20d) of packaging. States 20a, 20b, 20c, and 20d denote a product 20 being in different packaging stages. For example, state 20a denotes product 20 placed inside tubular film 21, state 20b denotes product 20 being contained in a semi-sealed package (i.e. a package having a sealed end and an open end), and states 20c and 20d denotes product 20 being contained in a sealed package (i.e. a package having two sealed ends, wherein gas in the package being has or has not been extracted).
In state 20a, film 21 is positioned around product 20 or product 20 is positioned in a tubular film 21. Alternatively, in state 20a product 20 is positioned on film 21, which is subsequently folded over and sealed at its longitudinal edges in order to form a tubular film 21. This step can be carried out at the loading station and/or at a (separate) longitudinal sealing station.
Sealing station 3 comprises an upper sealing and cutting member 31 and a lower sealing and cutting member 32 configured to seal and cut film 21. Sealing and cutting members 31 and 32 are configured to create a first seal on film 21, thereby creating a semi-sealed package 23 containing product 20 in state 20b and separating semi-sealed package 23 from the continuously supplied film 21 that is sealed at the downstream end of the film. Product 20 in state 20b is situated inside film 21 and semi-sealed package 23 comprises a sealed end and an opposite open end.
The gas extraction station 35 is configured to create a second seal on film 21 at the second open end of the semi-sealed package, thereby creating a sealed package 24. In state 20d, product 20 is situated inside film 21 and sealed package 24 comprises a first sealed end and an opposite second sealed end. The first and second sealed ends can also be situated not directly opposite each other, for example in cases where one of the seals is created at an angle to a longitudinal extension of the package and/or to a lateral extension of the other seal. In another embodiment, the gas extraction station 35 take over the function of sealing station 3 in that while gas is extracted from a semi-sealed package, gas extraction station 35 performs sealing and cutting as described above with respect to sealing station 3. This concept can be visualized based on the embodiment shown in
Gas extraction station 35 comprises a first (or upper) member 351 and a second (or lower) member 352, which can be brought from a first configuration, in which the members 351 and 352 are spaced apart from one another (see
With respect to
Control unit 50 may further be connected to additional components, such as a hot air or shrink tunnel 33, where the film material around packaged products 20 in state 20d can be additionally shrinked after having been sealed. It is noted that the gas extraction station 35 can comprise any means for gas extraction known in the art.
Control unit 50 can be configured for controlling the transport of products 20 along a predefined path, for example by controlling a motor comprised in means for moving 30 according to a step-by-step motion or according to a continuous motion. The control unit can also control actuators of different components as described below, for example, in order to create transverse seals on the tubular film or in order to actuate members 31, 32, 351, and/or 352.
Control unit 50 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.
Control unit 50 is connected to a means for evacuating (not shown) and is configured to send and/or receive control signals to/from the means for evacuating. Control unit 50 can further be configured to control the means for evacuating to provide an internal vacuum pressure to vacuum chamber 353. To this aim, control unit 50 can be configured to control a power driving a vacuum pump connected to vacuum chamber 353.
Control unit 50 can be configured to control the means for moving 30. For example, control unit 50 can be configured to increase or decrease an operating speed of means for moving 30. Control unit 50 can further be configured to control the operating speed of means for moving 30 depending on a position of products 20 with respect different components of the packaging apparatus 1 (e.g., with respect to sealing station 3 or gas extraction station 35).
Control unit 50 can additionally or alternatively be configured for controlling the sealing and cutting members 31 and 32. The control unit 50 can further be configured to control the sealing and cutting members 31 and 32 depending on a position of products 20 with respect to the means for evacuating and/or the sealing and cutting members 31 and 32. For example, the control unit 50 can be configured to activate the sealing and cutting members 31 and 32 depending on a position of products 20 and/or tubular film 21 with respect to the outlet and/or sealing and cutting members 31 and 32.
In particular, the control unit 50 can be configured to control one or more components depending on signals sent to and/or received from other components. For example, the control unit 50 can be configured to control an activation of one or more components depending on the position of products 20 and/or tubular film 21 with respect to other components of packaging apparatus 1. This way, the control unit 50 can activate, for example, the sealing and cutting members 31 and 32 when two subsequent products 20 are in state 20a, such that between the two products 20 the first seal is created on the film 21 and the film is cut accordingly.
After the creation of the first seal and the cutting of film 21, semi-sealed packages 23 are moved along movement direction 30a through the packaging machine, towards and through gas extraction station 35. In
Members 351 and 352 are now brought into their second configuration, in which members 351 and 352 are substantially in sealed contact to one another, thereby defining closed vacuum chamber 353. The contact between members 351 and 352 is substantially sealed (e.g. air-tight), except for an elongated opening at which members 351 and 352 engage the intermediate portion of the second open end of semi-sealed package 23 without creating an air-tight seal along the opening.
This configuration facilitates at least the following effects upon extraction of gas from vacuum chamber 353. On one hand, a gas flow through the opening towards the inside of vacuum chamber 353 is created between opposing surfaces of members 351 and 352 and corresponding surfaces of the intermediate portion of the second open end interposed between members 351 and 352. This gas flow causes adjacent layers of film at the second end of the semi-sealed package 23 to assume and/or maintain a substantially spaced-apart configuration (i.e. opposite layers of film are pulled apart from one another). On the other hand, gas is not only aspirated from outside vacuum chamber 353 and semi-sealed package 23, but also from inside semi-sealed package 23, thereby extracting air from semi-sealed package 23. Typically, the gas aspirated from the outside is air and the gas aspirated from inside the semi-sealed package is a protective gas or gas mixture, such as CO2. This process is described in more detail below.
When gas has been extracted from semi-sealed package 23, a sealing assembly, typically integrated into gas extraction station 35, creates a second seal at the second open end, thereby sealingly closing the package and transforming the semi-sealed package 23 into a sealed package 24, which contains product 20 in state 20d (see far left of
With respect to
As shown in
The width of opening 354 may vary according to the application and, preferably is designed to meet the product size with respect to the width of the product or a multiple thereof, in addition to a certain margin. This means that vacuum chamber 353 can be sized to meet the width of the product in the sense that opening 354 largely corresponds to the width of film 21 at the second open end (when brought into a flattened configuration, as shown in
The different effects facilitating extraction of gas from the packages are explained in more detail with respect to
One way to separate opposite layers of film or to prevent opposite layers from adhering to one another is to create a transition from a relatively high pressure, low velocity, area (shown as HP/LV on the left at the top of
The gradient of pressure/velocity changes in transition between HP/LV and LP/HV areas can be modified by providing edges D, F, D′, and/or F′ with corresponding profiles. Modification of the shape of edges D, D′, F, and F′ impacts gas flow in the associated areas and can, for example, facilitate or prevent delamination of gas flow or facilitate or prevent turbulences. The individual effect can be a result of the effects of corresponding shapes on the gas flow (e.g. pressure, velocity, direction, etc.). Edges D and D′ denote entry edges in the figures, while edges F and F′ denote exit edges, with reference to gas flow upon extraction of gas from vacuum chamber 353. As shown in
Another effect that predominantly occurs with members 351 and 352 having profiles as described above and with reference to
The individual parameters for achieving the above effects vary depending on the individual application. For example, thicker film material may require a different pressure differential gradient than thinner film material. Further, the values of the different pressures and gas flow velocities are also decisive factors. The following table 1 of examples illustrates different parameter combinations that have proven to be effective with respect to the first embodiment described above. In these examples, an opening of the processed semi-sealed packages was ensured and efficient extraction of gas from the packages was achieved.
In general, the described process and apparatus can be used in combination with a large number of known film materials. In some examples, the film materials used have the properties listed in the following table 2 (LD denotes longitudinal direction, TD denotes transversal direction). It is noted that these films are merely examples showing the applicability of the described process and apparatus.
Sealing and cutting members 31 and 32 are, in the second embodiment, configured to create not only a first seal on tubular film 21 but also a second seal. In this manner, products 20 placed within tubular film 21 exit the sealing station 3 in state 20c, namely in a sealed package 24′ (instead of state 20b and in a semi-sealed package 23). A sealed package 24′ differs from a sealed package 24 in that gas present in package 24′ has not yet been extracted. As shown, means for moving 30 move packages 24′ towards and through gas extraction station 35. Gas extraction station 35 operates essentially similar as described above, although it is adapted to handle sealed packages in the manner described below. After extraction of gas from package 24′, thereby transforming package 24′ into sealed (and gas-extracted) package 24, movement means 30 move packages 24 away from gas extraction station 35.
As can be seen in
A puncturing means 359 is engaged in order to provide the terminal portion with an aperture 241, thereby providing a potential passage of gas from inside package 24′ into vacuum chamber 353. In general, any puncturing means suitable for puncturing the terminal portion of the second end can be employed here, for example, a punch (e.g. creating a substantially round hole by punching or stamping) or a suitably shaped heat wire (e.g. a horseshoe-shaped heat wire creating a corresponding substantially round hole by thermally cutting the film). The puncturing means are preferably configured to provide the terminal portion of the second end with a hole that prevents (further) rupture of the film material, which can happen, for example, when creating a simple (linear) cut or an opening having sharp corners. Upon extraction of gas from vacuum chamber 353, the terminal portion expands (see outward pointing double arrows in
The vacuum chamber 353′ structurally and functionally corresponds to vacuum chambers 353 as described above. Thus the vacuum chambers 353′ may include members 351′ and 352′ and may be configured to open and close (not shown in
Substantially upon introduction (e.g. at the same time or shortly before/after) of the upstream end of the package 24′ into the opening (see state 20c in
Pinch station 360 can include pinch rollers having protrusions 360′, on a peripheral surface of a roller, configured to, in combination with recesses 360″ present on a counter surface, perforate a film 21 being supplied to the pinch station 360. As shown, pinch station 360 can be implemented as a set of oppositely arranged rollers carrying, for example, protrusions 360′ and recesses 360″ (alternatively also any combination of protrusions and/or recesses configured to create one or more apertures; see also above). It is noted that other means for perforating the film 21 can be employed (e.g. heat wires as mentioned above or knife rollers configured to cut along an upstream edge of the package) as long as it is ensured that a seal established by film 21 at the upstream end of the package 24′ has been compromised in order to facilitate gas extraction as described in detail above.
In some embodiments, several subsequently processed packages are directed into the vacuum chambers 353′ in an alternating fashion such that each vacuum chamber 353′ receives, for example, every second package in a series of packages (alternatively, any number of subsequent packages 24′—e.g. 3—can be directed to one of the vacuum chambers 353′ for evacuation). Each vacuum chamber 353′ can be sized and configured to be able to process several packages simultaneously, for example between 2 and 5 packages, preferably at least 3 packages as shown in
The packaging apparatus 1 can comprise an HFFS machine. The HFFS machine may comprise a conveyor belt 30 for supporting and transporting the packages 22, in a horizontal direction. The product 20 may be disposed on a surface. The surface may extend substantially in the horizontal direction. The surface may comprise the upper surface of a conveyor belt 30. The conveyor belt 30 may be a continuous conveyor belt 30. For example, the conveyor belt 30 may be suspended between at least two rollers. The conveyor belt 30 may transport the product 20 in a horizontal direction.
The product 20 can be disposed in a tray. The tray supports the product 20. The tray can comprise walls that extend substantially vertically from the base of the tray to a height greater than the vertical dimension of the product 20. Alternatively, the tray height may be less than or equal to the height of the product 20. The packaging extends around the tray. The tray can comprise a material selected from a list consisting of polystyrene, Aluminium, or other thermoplastic material such as PET, or cardboard. The tray can be rigid, solid or foamed, and have any color and shape.
The packaging can comprise a multi-layer film 21. The film 21 can comprise a polyolefin. 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 20 and avoid contamination. This can be advantageous with respect to food hygiene. The package can provide a barrier to aromas or to gasses. This can be particularly useful when the product 20 is a food product 20. The package can be abuse-resistant.
The packaging can be transparent or translucent. This allows a customer to see the product 20 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 formed by forming a tube from the roll of film 21. The packaging apparatus 1 can comprise a former configured to form the roll of film 21 into a tube. The former 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 former forms two longitudinal seals along the opposing edges of the two rolls of film 21.
The packaging apparatus 1 can comprise a flusher 34. The flusher 34 is configured to flush gas through the tube of film 21 that forms the packaging. The gas flush prevents the tube from collapsing. The gas flush helps to maintain a distance between a product 20 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 20. The flusher 34 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 20 to be packaged in a modified atmosphere. The gas may help to preserve the product 20, prolonging its shelf life. The desired amount of gas inside each sealed package depends on the type of product 20 and the length of shelf life needed.
The packaging apparatus 1 can comprise a shrinking machine configured to shrink the film 21. The shrinking machine may be a water- or air-based shrink tunnel, for example a hot air tunnel 33. The sealed package 24 is shrunk in the shrinking machine. The shrinking process may involve heating the sealed package. The package 24 may be heated to a temperature within the range of from about 130° C. to about 150° C.
Before the sealed package 24 is shrunk, there may be undesirable gas trapped in the sealed package along with the product 20. Additionally, the sealed package 24 may comprise undesirable “dog ears”, where a dog ear is a portion of the packaging that extends away from the product 20 (for example due to the product 20 not being a regular rectangular prism). After the shrinking process the dog ears and the gas content are reduced. This gives the sealed package 24 a more aesthetic appearance. In the case of cheese, the cheese may consume any residual gas that remains in the sealed package 24 following the shrinking step.
The product 20 can be a food product 20. For example, the product 20 may comprise meat, cheese, pizza, ready meals, poultry and fish. The product 20 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 20 may be wet. In this case, it is particularly desirable for the product 20 to be disposed in a tray.
The packaging process of the invention may be employed to package food products 20 that are to have a shelf life in the region of from about six days to about 14 days, for example.
Desirably, the packaging apparatus 1 comprises a horizontal form fill and seal machine. However, the packaging apparatus 1 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 22 move through the packaging apparatus 1 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 20 is then fed into the open-ended package. The top end of the package 22 is then sealed to form a sealed package 24′.
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 |
|---|---|---|---|
| 14191956.3 | Nov 2014 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2015/074878 | 10/27/2015 | WO | 00 |
