Patent Description:
Today, within the food industry, an essential part of a food product is the packaging. Apart from branding of the product and presenting the customers with information the package also has an important role of ensuring the food safety. The packaging materials used in the package can be designed to provide strength and stability, so that the packages are not damaged during transportation. Furthermore, the packaging materials can form a protected environment for the food product so that it is protected from for example bacteria, germs, oxygen and sun light. However, the packaging material is not the only thing that is important in the package. The package needs also to be sealed properly. In a roll-fed system this is usually made by forming a longitudinal sealing along an overlap between two ends of the packaging material such that a tube is formed and thereafter forming packages from the tube by making transversal sealings in a lower end of the tube.

Ensuring the quality of the longitudinal sealing of a food package is not an easy task. Today, a common way of doing this is to evaluate batches of the finished products manually. This means opening finished product to assess the sealing. However this leads to waste of product and to guarantee the quality large quantities of packages must assessed. It is therefore need for an improved method for evaluating the quality of the longitudinal sealing in food packages. Further background art can be found in <CIT>, <CIT>, <CIT>, <CIT>, <CIT> and <CIT>.

It is an object of the invention to at least partly overcome one or more of the above-identified limitations of the prior art. In particular, it is an object to provide a method and apparatus thereof for assessing the quality of a longitudinal sealing in a food package.

It has been realized that by analysing image data of the longitudinal sealing in the processing line, the sealing can be continuously monitored and actions can be taken at an early stage. This leads to a reduction of wasted product and the quality of each package can be assured as opposed to today's methods.

According to a first aspect it is provided a method for assessing quality of a longitudinal sealing in a roll fed packaging machine comprising.

Image data may be interpreted as either still images or a sequence of still images or a video sequence.

An advantage of the proposed method may be that the quality check can be made in-line as a part of the packaging machine. The transmitted status may give indication of whether the process needs to be interrupted or adjusted due to a low quality sealing, thereby reducing the risk of wasted product.

Optionally, the method may further comprise,.

The first longitudinal side section of the protective strip may be applied on the first longitudinal side section of the web, such that the second longitudinal section of the protective strip extends outside the web.

Optionally, the roll fed packaging machine may further comprise,.

A longitudinal sealing should be understood as a general term that may refer to either a longitudinal strip sealing, a longitudinal tube sealing or both. Similarly, a sealing status may refer to either a strip application status, a tube forming status or both.

The second longitudinal side section of the protective strip may be applied on the second longitudinal side section of the web, such that the protective strip covers the intermediate layer of the packaging material that are exposed at the first longitudinal side section of the web.

The strip application image data and/or the tube forming image data may be captured through a polarized filter. The polarized filter(s) may be advantageous in that reflections in the surface the camera is capturing may be reduced. Furthermore, a heat pattern may be more clearly visible.

The transmitted status may be any one of the statuses underheating, normal or overheating. The status underheating may indicate that not enough heat has been provided when forming the longitudinal sealing. On the contrary, the status overheating may indicate that too much heat has been provided. The status normal may indicate that the longitudinal sealing is within acceptable quality.

The status may be transmitted to a control unit of the strip applicator and/or the tube forming device, and adjusting the heating power based on the status. This may be advantageous in that the roll fed packaging machine may adjust the heating automatically.

The status may be determined by providing the extracted features as input to an artificial intelligence model. The status may refer to the strip application status and/or the tube forming status. Artificial intelligence model should be understood as comprising e.g. machine learning models and neural networks.

Optionally, the step of extracting features from the strip application area may further comprise,
identifying an overlapping area, a heat affected protective strip area and a heat affected web area of the strip application area and including these as the features from the strip application image data.

It should be understood that other features that may be useful for defining the quality of a strip may also be used.

The effects of the heating may comprise a number of cracks in the longitudinal sealing, a size of an overlapping area and reflective properties of the longitudinal sealing.

According to a second aspect it is provided a server for assessing quality of a longitudinal sealing in a roll fed packaging machine, said server may comprise a transceiver, a memory and a control unit,.

The strip application status module may determine the strip application status by providing the extracted features to an artificial intelligence model.

According to a third aspect it is provided a system for assessing quality of a longitudinal sealing in a roll fed packaging machine, said system may comprise,.

Having a server communicatively connected to multiple roll fed packaging machines may be advantageous in that an artificial intelligence model used for determining the statuses may be provided with more data so that it may continuously improve. Put differently, the artificial intelligence model may learn from the image data provided by multiple roll fed packaging machines.

The same features and advantages described with respect to one aspect are applicable to the other aspects unless explicitly stated otherwise.

<FIG> illustrates a simplified view of a roll fed packaging machine <NUM>, enabled for assessing quality of a longitudinal sealing <NUM>, <NUM>. The packaging material <NUM> can be provided on a roll of packaging material <NUM>. A web of packaging material <NUM> can be provided to a strip applicator <NUM>. The strip applicator <NUM> can further be provided with a protective strip <NUM>. The strip applicator <NUM> can apply the protective strip <NUM> on the web <NUM> thereby forming a longitudinal strip sealing <NUM>. The strip applicator <NUM> is described in more detail in connection to <FIG>. A strip application camera <NUM> can be provided to capture strip application image data from a strip application area <NUM>. A polarized filter 116a may be provided in front of the strip application camera <NUM> such that the strip application image data is captured through the polarized filter 116a. The strip application image data can depict the longitudinal strip sealing <NUM> between the protective strip <NUM> and web <NUM>. It can be in the form of a image, a sequence of images or a video sequence. From the strip application image data a status of the longitudinal strip sealing <NUM> can be determined. The status may relate to the quality of the seal.

A tube forming device <NUM> can be provided, configured to receive the web of packaging material <NUM> with the protective strip <NUM> applied. The tube forming device <NUM> can be further configured to form a tube <NUM> of the web <NUM> and attaching the ends of the web together. The tube forming device <NUM> can be further configured form a longitudinal tube sealing <NUM>. The longitudinal tube sealing <NUM> is described in more detail in connection to <FIG>.

A tube forming camera <NUM> can be provided, herein illustrated inside of the tube <NUM>. The tube forming camera <NUM> can capture tube forming image data of the tube forming area <NUM>. A polarized filter 116b may be provided in front of the tube forming camera <NUM> such that the tube forming image data is captured through the polarized filter 116b. The tube forming image data can depict the longitudinal tube sealing <NUM>. The tube <NUM> can be sent to a filling and sealing device <NUM>.

The roll fed packaging machine <NUM> described above is a simplification for illustration purpose. Such a machine may be achieved by installing a strip application camera <NUM> and/or tube forming camera <NUM> into an already existing roll fed packaging machine, such as the Tetra Pak Brick System.

<FIG> is a cross-sectional view of an overlapping area of the packaging material <NUM> that forms the longitudinal sealing. Put differently, it illustrates, in cross-section, by way of example, a part of a rear panel of the package where the two ends of the packaging material <NUM> meet in order to create the tube.

The packaging material <NUM> may comprise of an inner protective layer <NUM>, an outer protective layer <NUM> and an intermediate strengthening layer <NUM>. The intermediate layer <NUM> may comprise of one or more layers of material. As an example, the intermediate layer <NUM> may comprise a paper board layer. The inner protective layer <NUM> and the outer protective layer <NUM> may be plastic layers. A protective strip <NUM> may be provided on the inside of the package, with the purpose of creating a sealing between the overlapping ends of the packaging material <NUM>. The sealing may protect the intermediate layer <NUM> from coming in contact with the food product held in the food package.

<FIG> illustrates, in top view, a section of the protective strip <NUM> and the web of packaging material <NUM>. For reference purpose, the protective strip <NUM> may be divided into a first <NUM> and second <NUM> longitudinal side section. For reference purpose, the web of packaging material <NUM> may have a first <NUM> and a second <NUM> side section. <FIG> illustrates how the protective strip <NUM> is applied to the web of packaging material <NUM> by the strip applicator <NUM>. The first side section <NUM> of the protective strip may be applied to the first side section <NUM> of the web of packaging material <NUM> such that the second side section <NUM> of the protective strip extends outside of the web of packaging material <NUM>. The second side section <NUM> of the protective strip may later be applied to the second side section <NUM> of the web of packaging material <NUM>. Also illustrated in <FIG> is a strip application area <NUM>. The strip application area <NUM> may comprise an overlapping area <NUM>, a heat affected protective strip area <NUM> and a heat affected web area <NUM>. Even though illustrated to cover a part only, the strip application area <NUM> may in other embodiments extend along the longitudinal strip sealing <NUM>.

<FIG> illustrates the longitudinal sealing <NUM>,<NUM> in a tube <NUM> formed by the web of packaging material <NUM>. A longitudinal strip sealing <NUM> of the protective strip <NUM> is illustrated along the first side section <NUM> of the web. A longitudinal tube sealing <NUM> of the protective strip <NUM> is illustrated along the second side section <NUM> of the web. A tube forming area <NUM> is illustrated as covering the longitudinal tube sealing <NUM> as well as a section of the web <NUM> outside the longitudinal tube sealing <NUM>, and a section of the protective strip <NUM> outside the longitudinal tube sealing <NUM>. Even though illustrated as a circular tube, the tube <NUM> may be of other shapes.

<FIG> illustrates, in top view, a strip applicator <NUM> configured to form a longitudinal strip sealing <NUM> between a protective strip <NUM> and a web of packaging material <NUM>. The web of packaging material <NUM> and the protective strip <NUM> may be fed into the strip applicator <NUM>. The strip applicator <NUM> may heat the protective strip <NUM> and the web <NUM>. Further, the strip applicator <NUM> may press the heated protective strip <NUM> and the heated web of packaging material <NUM> together, thereby forming a seal between them, also referred to as a weld. In <FIG>, the strip applicator <NUM> is illustrated in side-view. The strip applicator <NUM> may comprise a heating element <NUM> for heating the protective strip <NUM> and the web of packaging material <NUM>. The strip applicator <NUM> may further comprise means for applying pressure to the protective strip <NUM> and web of packaging material <NUM>, herein illustrated as two rolls 506a, 506b being pressed together.

<FIG> are images of longitudinal strip sealings of different quality. <FIG> are examples of underheated longitudinal strip sealings. <FIG> are examples of normal longitudinal strip sealings. <FIG> are examples of overheated longitudinal strip sealings. Cracks <NUM> in the longitudinal strip sealings are visible, for instance in <FIG>.

<FIG> is a flow chart illustrating the steps of a method <NUM> for assessing quality of a longitudinal sealing <NUM>, <NUM>.

In a first step <NUM>, strip application image data of the strip application area <NUM> may be received.

In a second step <NUM>, features from the strip application image data may be extracted, wherein the features are related to effects of the heating provided by the strip applicator <NUM>.

In a third step <NUM>, a strip application status may be determined by evaluating the features, wherein the strip application status relates to the quality of the longitudinal strip sealing <NUM>.

In a fourth step <NUM>, the strip application status may be transmitted, thereby providing a quality assessment of the longitudinal strip sealing <NUM>.

Optionally, in a fifth step <NUM>, the web of packaging material <NUM> may be received by the packaging material receiver.

Optionally, in a sixth step <NUM>, the protective strip <NUM> may be received by the strip receiver.

Optionally, in a seventh step <NUM>, the longitudinal strip sealing <NUM> may be formed by the strip applicator <NUM>.

Optionally, in an eight step <NUM>, the strip application image data may be captured from the strip application area <NUM> by the strip application camera <NUM>.

Optionally, in a ninth step <NUM>, tube forming image data of the tube forming area <NUM> may be received.

Optionally, in a tenth step <NUM>, features from the tube forming image data may be extracted, wherein the features are related to effects of the heating provided by the tube forming device <NUM>.

Optionally, in an eleventh step <NUM>, the tube forming status of the longitudinal tube sealing <NUM> may be determined by evaluating the features, wherein the tube forming status is related to the quality of the longitudinal tube sealing <NUM>.

Optionally, in a twelfth step <NUM>, the tube forming status may be transmitted, thereby acquiring a quality assessment of the longitudinal tube sealing <NUM>.

Optionally, in a thirteenth step <NUM>, the tube <NUM> of the web of packaging material <NUM> may be formed by the tube forming device <NUM>.

Optionally, in a fourteenth step <NUM>, the first <NUM> and second <NUM> longitudinal side sections of the web may be attached by the tube forming device <NUM>.

Optionally, in a fifteenth step <NUM>, the longitudinal tube sealing <NUM> may be formed by the tube forming device <NUM>.

Optionally, in a sixteenth step <NUM>, the tube forming image data may be captured from the tube forming area <NUM> by the tube forming camera <NUM>.

Even though described in a certain order, the different steps may also be performed in other orders.

<FIG> illustrates a schematic view of a server <NUM>. The server <NUM> may be configured for assessing quality of a longitudinal sealing <NUM>, <NUM>. The server <NUM> may comprise a transceiver <NUM>, a control unit <NUM> and a memory <NUM>.

The transceiver <NUM> may be configured to enable the server <NUM> to communicate with other devices. The transceiver <NUM> may execute a strip application image data receiver <NUM> arranged to receive strip application image data of the strip application area <NUM>. It may further comprise a strip application status transmitter <NUM> arranged to transmit the strip application status, thereby providing a quality assessment of the longitudinal strip sealing <NUM>. The status may be transmitted to the roll fed packaging machine <NUM>.

The memory <NUM> may be configured to store program code or modules. The memory <NUM> may comprise a strip application image data processing module <NUM> arranged to extract features from the strip application image data, wherein the features are related to effects of the heating provided by the strip applicator <NUM>. It may further comprise a strip application status module <NUM> arranged to determine a strip application status by evaluating the features, wherein the strip application status relates to the quality of the longitudinal strip sealing <NUM>.

The control unit <NUM> may be configured to perform the control of the functions and operations of the server <NUM>. The control unit <NUM> may include a processor <NUM>, such as a central processing unit (CPU). The processor <NUM> may be configured to execute program code or modules stored in the memory <NUM>.

The transceiver <NUM> may be further configured to execute a tube forming image data receiver <NUM> arranged to receive tube forming image data of the tube forming area <NUM>. It may further execute a tube forming status transmitter <NUM> arranged to transmit the tube forming status, thereby providing a quality assessment of the longitudinal tube sealing <NUM>. The status may be transmitted to the roll fed packaging machine <NUM>.

The memory <NUM> may further comprise a tube forming image data processing module <NUM> arranged to extract features from the tube forming image data, wherein the features are related to effects of the heating provided by the tube forming device <NUM>. It may further comprise a tube forming status module <NUM> arranged to determine a tube forming status of the longitudinal tube sealing <NUM> by evaluating the features, wherein the tube forming status is related to the quality of the longitudinal tube sealing <NUM>.

<FIG> illustrates a schematic view of a system <NUM> for assessing quality of a longitudinal sealing <NUM>, <NUM>. The system <NUM> may comprise of a server <NUM>. The server <NUM> may be a server <NUM> as described in connection to <FIG>. An artificial intelligence model <NUM> may be provided to the server <NUM> for determining a sealing status.

The system <NUM> may further comprise of one or more roll fed packaging machines 904a-c communicatively connected to the server <NUM>. The server <NUM> may receive image data from the one or more roll fed packaging machines <NUM>. As described in connection to <FIG>, the server <NUM> may determine a status based on the image data and transmit the status to the roll fed packaging machine 904a-c corresponding to the image data. In addition, the server <NUM> may use the image data received by multiple roll fed packaging machines 904a-c to improve the artificial intelligence model <NUM>. Put differently, the artificial intelligence model <NUM> may continuously learn from image data provided by the roll fed packaging machine(s) 904a-c. The server <NUM> may be a central server connected to a processing plant. In this case, the one or more roll fed packaging machines 904a-c may comprise the roll fed packaging machines of that processing plant. The server <NUM> may also be a central server connected to multiple processing plants. In this case, the one or more roll fed packaging machines 904a-c may comprise roll fed packaging machines of multiple processing plants.

The artificial intelligence model <NUM> may be a model designed to output a status of a longitudinal sealing <NUM>, <NUM> based on extracted features from image data. The artificial intelligence model <NUM> may also take the image data as input and extract the features itself.

As a non-limiting example, the artificial intelligence model <NUM> may be an image classification neural network such as the ResNet <NUM> convolutional neural network. The artificial intelligence model <NUM> may be trained on images of longitudinal sealings labelled with statuses. For example, images such as those in <FIG> may be used to train the artificial intelligence model <NUM>.

Claim 1:
A method (<NUM>) for assessing quality of a longitudinal sealing (<NUM>, <NUM>) in a roll fed packaging machine comprising
a packaging material receiver arranged to receive a web (<NUM>) of packaging material (<NUM>), wherein the packaging material (<NUM>) comprises an outer protective layer (<NUM>), an inner protective layer (<NUM>) and an intermediate strengthening layer (<NUM>), and wherein the web (<NUM>) has a first (<NUM>) and second (<NUM>) longitudinal side section,
a strip receiver arranged to receive a protective strip (<NUM>), wherein the protective strip (<NUM>) has a first (<NUM>) and a second (<NUM>) longitudinal side section,
a strip applicator (<NUM>) arranged to form a longitudinal strip sealing (<NUM>) by applying the protective strip (<NUM>) on the web (<NUM>) by heating the web (<NUM>) and the protective strip (<NUM>) and pressing the web (<NUM>) and protective strip (<NUM>) together,
a strip application camera (<NUM>) arranged to capture strip application image data from a strip application area (<NUM>),
said method (<NUM>) comprising,
receiving (<NUM>) strip application image data of the strip application area (<NUM>),
extracting (<NUM>) features from the strip application image data, wherein the features are related to effects of the heating provided by the strip applicator (<NUM>),
determining (<NUM>) a strip application status by evaluating the features, wherein the strip application status relates to the quality of the longitudinal strip sealing (<NUM>),
transmitting (<NUM>) the strip application status, thereby providing a quality assessment of the longitudinal strip sealing (<NUM>).