Method for producing film from a total amount of raw materials using a film extrusion machine, and computer program product for carrying out the method

Description

[0001] The invention relates to methods for producing film from a total amount of raw materials using a film extrusion machine and a corresponding computer program product.

[0002] DE 10 2016 112 121 A1 discloses a method for producing a plastic film using a film extrusion machine. This method provides for at least one production parameter of the film extrusion machine to be calculated based on a film production model using a control device and semi-automatically suggested by the control device for adjusting production.

[0003] It is well known that in order to produce film with desired properties, film extrusion lines must be adjusted with regard to their production parameters. A multitude of production parameters must be taken into account. Temperatures, pressures, or other physical variables that directly affect the raw materials, intermediate products, and / or the finished film must be adjusted at many points. This applies particularly to the adjustment, i.e., the control and / or regulation of the film extrusion line.

[0004] The resulting film can then be characterized with regard to its properties, particularly in the laboratory, but also during production. In particular, the actual performance of the film's function is examined, as well as measurable film parameters such as tear strength or stretchability.

[0005] Known solutions for controlling and / or regulating film extrusion systems are largely based on the experience and knowledge of the operating personnel.

[0006] The same applies to the selection of raw materials. Here, too, the raw materials are selected based on experience, testing, and the manufacturers' information on the raw materials.

[0007] Overall, the production of a film with the desired properties can require lengthy preparatory work, which can also be expensive.

[0008] The object of the present invention is to at least partially remedy the disadvantages described above. In particular, the object of the present invention is to produce a film with desired properties more cost-effectively and simply.

[0009] The above object is achieved by a method having the features of claim 1 and a computer program product having the features of claim 6. Further features and details of the invention emerge from the subclaims, the description, and the drawings. Features and details described in connection with the method according to the invention naturally also apply in connection with the computer program product according to the invention, and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reference is always made to each other.

[0010] The process according to the invention relates to the production of plastic film from a total amount of raw materials using a film extrusion machine. The process comprises the following steps: Recording film parameters for desired properties of the plastic film Recording raw material parameters for properties of the raw materials Grouping the raw material parameters into at least two raw material parameter groups Forming correlations between raw material parameter groups Forming correlations between the film parameters and the raw material parameter groups on the basis of a film production model Recording a selection of at least one raw material from at least one raw material parameter group Calculating at least one production parameter of the film extrusion machine on the basis of the film production model Output of the production parameter of the film extrusion machine.

[0011] The core idea of ​​the invention is therefore not to simply select from the available total quantity of different raw materials for the production of a desired film, but to first divide the raw materials into groups based on their parameters, i.e., their properties. The grouping can be multidimensional and can include as many groups as desired by the user of the film extrusion machine. For example, a grouping of a raw material can relate to the temperature range at which this raw material is to be processed in the film extrusion machine. In general, there can be several groups that relate to the processing properties of the raw material.

[0012] Another aspect of a grouping can relate to the resulting properties of the raw material in the film. For example, raw materials can be grouped together to represent a permeability range for a specific gas. The quality of adhesion of the molecules of one raw material to molecules of another raw material can also be divided into groups. Furthermore, economic aspects can also play a role and be used to group raw materials. For example, each raw material can be divided into a group based on its price, with each group representing a price range. Further groupings can relate to the length of time the raw material is available. Furthermore, the approval of certain raw materials for specific applications can also be a basis for groupings. For example, not every raw material is approved for food packaging.Raw materials can also be grouped according to their environmental compatibility. Many other grouping options are conceivable.

[0013] The recording of properties forms the basis for grouping raw materials. These properties can be fundamental properties of the raw materials, such as their chemical composition, but also, for example, their manufacturing parameters, such as the operating parameters of the manufacturing plant. Another parameter can be a manufacturing date. Such raw material parameters can be made available to the user of the film extrusion plant, i.e., the manufacturer of the plastic film, at least in part by the raw material manufacturer. The results of tests, such as chemical analysis, can also be included. It is advisable to store the raw material parameters in a database. This can, for example, be stored in an internet data storage on an external server operated by a data provider.

[0014] It is advantageous if a raw material manufacturer only releases selected raw material properties (information) to a user for or within the database. This makes it possible, for example, for the raw material manufacturer to make the information available to the user for a fee, depending on the quantity and importance of the information.

[0015] Furthermore, the invention provides a step in which a correlation is established between the film parameters and the raw material parameter groups. This assignment is based on a film production model in which the influence of raw materials from raw material parameter groups on the properties of the film is mapped. This makes it possible to output a selection of raw materials for the desired properties, preferably one or more raw materials for each property of the film.

[0016] However, in order to avoid, for example, incompatible raw materials being available for selection, the invention provides for correlations to be formed between individual raw material parameter groups.

[0017] After determining possible raw material combinations to be considered for the production of the film, a selection of raw materials is made, which is recorded in a step according to the invention. It is advantageous if the recorded selection is verified. In particular, it is determined whether the selection leads to the desired film. "Recording at least one raw material from at least one raw material parameter group" can also mean that a selection of raw materials is calculated directly from the raw material parameter groups.

[0018] Finally, to ensure that the desired film is extruded within the film extrusion machine, at least one film production parameter for the film extrusion machine is calculated and output based on the film production model and recorded data. This makes it possible to leave the setting of the film extrusion machine parameters to more than just the machine operator, ensuring that the desired film, especially a film with the desired quality, is produced.

[0019] Film extrusion machines can refer to all extrusion machines, but also downstream components, with which raw materials can be converted into film, as well as downstream machine components such as stretching devices, all the way up to winding devices in which the film is first wound for transport. An extrusion machine can operate according to the principle of a blown film line or a flat film line.

[0020] In the context of the present invention, "capturing" can refer to various types of data collection. This data may, for example, already be available in the form of data, particularly in digital form. Various databases are conceivable for this purpose. Data collection can also be carried out through direct input by the user or through measurement using measuring instruments. In particular, upstream machines in the production process, such as a raw material manufacturing machine, can transmit data, particularly measurement data, to a machine in a downstream production process via data connections.

[0021] The term "output" is to be understood in the same way. The production parameters can be displayed on a screen or made accessible to the film extrusion machine operator in another way. It is also conceivable that the computer system performing the aforementioned calculations transmits them directly to the film extrusion machine, particularly to its control system, via data connections.

[0022] In an advantageous development of the invention, a level of detail for the raw material parameter groups is recorded. This allows, for example, the definition of how small or large the parameter ranges of the raw material parameters are. For example, if the parameter range is selected too narrowly, no raw material that meets one of the requirements is available. In this case, the parameter range can be adjusted to enable an expanded raw material selection.

[0023] In a further advantageous embodiment of the invention, an output of selection suggestions for a selection of raw materials is provided. In other words, for at least one raw material parameter group, at least two raw materials are output, from which a raw material is to be selected. In particular, in this embodiment, an evaluation can be output for each of the raw materials in the selection suggestion. Based on this evaluation, the influences of the raw materials on the plastic film can be estimated. For example, a plastic film can be produced that does not fully meet the quality requirements compared to the desired film, but is significantly less expensive.

[0024] It is also advantageous to weight raw material parameter groups. In this case, the individual raw material parameter groups can be assigned an importance, which is then taken into account in the correlation between the individual raw material parameter groups. In other words, the film production model can be adapted using these weightings.

[0025] The invention can be further improved if production parameter ranges of at least one film production machine are recorded. These production parameter ranges can be used to expand the number of possible raw materials and make an optimal selection from them. Conversely, the selection of raw materials can be adapted, for example, to optimal operating parameter points of the film production machine.

[0026] "Capturing" encompasses various types of data capture. For example, immutable parameters for a film production machine can be captured once in a database. This is the case, for example, when they concern geometric properties of the film extrusion machine. Other parameters can be changed at intervals, such as information about the available raw materials. Still other parameters can be captured on a job-specific basis, such as the desired film properties. Accordingly, capture can also be based on different characteristics. For example, the parameters can be made available via databases, which are stored, for example, in the memory of the film extrusion machines or decentrally in internet portals. In this case, capture would be referred to as "reading data." For example, job-specific parameters can be captured via input devices, such as a keyboard.

[0027] Within the scope of the method according to the invention, it can be advantageous to record machine parameters and / or settings for at least one film extrusion machine. The recording of machine parameters can take place in particular during commissioning, during which, for example, geometric data of the film extrusion machine is stored in a database. This geometric data includes, in particular, the maximum number of layers of the film, the maximum number of individual raw materials that can be used for a single layer, the design of extruder screws for melting the raw materials, the width or circumference of the die lip, and the thickness of the die lip. This list is not exhaustive and therefore does not limit the invention.

[0028] It can be further advantageous to provide a recommendation as to which film extrusion machine should be selected to produce the desired film if several film extrusion machines, in particular different film extrusion machines, are available for producing the film. Often, a manufacturing plant has several film extrusion lines available that differ from one another in their designs with regard to geometric data as well as their physical parameters. In such a situation, it is possible to select one of these lines based on the film production model. For example, if the desired film has a five-layer structure, it may be advantageous if the product is produced on a film extrusion line for films with a maximum of seven layers.

[0029] The present invention also provides a computer program product comprising instructions that, when executed on a computer, cause the computer to perform the steps of a method according to the invention. Thus, a computer program product according to the invention provides the same advantages as those explained in detail with reference to a method according to the invention. Fig. 1Schematic representation of a film extrusion machine, Fig. 2Schematic representation of another film extrusion machine Fig. 3Schematic representation of the sequence of the method according to the invention

[0030] In the Figures 1 and 2Illustrated are exemplary film extrusion machines 10. These film extrusion machines have in common that they are equipped with extruders 20. Each individual extruder supplies the film extrusion machines with molten plastic material for one layer of the subsequent film, which is a plastic film. For this purpose, one or more raw materials R1,... are fed to a first extruder via metering devices 60, and one or more raw materials Rx,... are fed to a second extruder in this manner. The raw materials are generally in the form of plastic granules. The type and / or quantity of the raw materials fed in are predetermined by the method according to the invention.

[0031] The process according to the invention can be carried out using a flat film or blown film extrusion line according to Figure 2 be carried out. The Figure 1shows a blown film line with the previously described extruders 20. A film web, or film for short 40, is discharged from the nozzle 30. The nozzle 30 is designed as an annular blowing nozzle. The film web is initially formed as a bubble, but is later flattened. This film, which now comprises two individual films lying on top of one another, is wound onto a winding roll 50 via various intermediate elements or, after cutting them apart, onto two winding rolls to the left.

[0032] In the Figure 2 The film extrusion machine is a flat film extrusion machine, which is also equipped here, as an example, with two extruders 20 for different formulations. A film web 40 is output from the nozzle 30, which cools on a cooling roller and is then wound onto a winding roll 50.

[0033] The Figure 3shows a schematic of the process according to the invention. A storage and processing unit 100 is provided with film parameters FP relating to the desired properties of the film, and raw material parameters RP n relating to the properties of the raw materials. The index n of the raw material parameters RP indicates that this is a set of raw materials from which one or more raw materials can be selected. Within the storage and processing unit, the raw material parameters are first grouped into at least two raw material parameter groups, which is indicated by the reference numeral 200.In two subsequent steps, which can be performed in any order or simultaneously, correlations are formed between raw material parameter groups 300 and correlations are formed between the film parameters and the raw material parameter groups 400 based on a film production model that is stored and / or implemented within the storage and processing unit. In the subsequent step 500, a selection of at least one raw material from at least one raw material parameter group is recorded.

[0034] After the control and computing unit 100 has calculated at least one production parameter PP of the film extrusion machine on the basis of the film production model, the production parameter of the film extrusion machine is output. List of reference symbols 10 Film extrusion machine 20 Extruder 30 nozzle 40 film web 50 winding roll 60 Dosing device 100 Storage and computing device FPM Film production model

Claims

1. Method for producing a plastic film from a total quantity of raw materials with a film extrusion machine, comprising the following steps: - detecting film parameters relating to desired properties of the plastic film - detecting raw material parameters relating to properties of the raw materials - grouping the raw material parameters into at least two raw material parameter groups - forming correlations between raw material parameter groups - forming correlations between the film parameters and the raw material parameter groups based on a film production model - detecting a selection of at least one raw material from at least one raw material parameter group - calculating at least one production parameter of the film extrusion machine based on the film production model - outputting the production parameter of the film extrusion machine.

2. Method according to claim 1, additionally with the following step: detecting a level of detail for the raw material parameter groups.

3. Method according to any one of the preceding claims, additionally with the following step: outputting selection suggestions for a selection of raw materials.

4. Method according to any one of the preceding claims, additionally with the following step: weighting raw material parameter groups.

5. Method according to any one of the preceding claims, additionally with the following step: detecting production parameter ranges of at least one film production machine.

6. Computer program product comprising instructions which, when the program is executed on a computer, cause the computer to perform the steps of a method with the features of any one of claims 1 to 5.