Patent Application
20220024710
The invention relates to a method for winding up a film web according to the preamble of claim 1 as well as a corresponding device according to the preamble of claim 6 as well as a system according to claim 8.
After the production of plastic film webs, these are usually wound up on at least one winding reel in order to transport them in a format as compact as possible and to make them available again later for further processing in a simple manner.
For further processing in particular, it is often important that the winding reel meets certain quality requirements. In order to be able to assess whether these quality requirements are met, quality features of the winding reel are determined. More generally speaking, properties of the winding reel can be determined. These properties can then also include quality features.
The object of the present invention is therefore to propose a method, a device and a system for determining quality features or properties of the winding reel. In particular, the object is to detect, evaluate and/or improve the quality of the winding reel.
According to the invention, this object is achieved by all the features of claim 1. Possible embodiments of the invention are specified in the dependent claims.
According to the present invention, it is provided that at least the following steps are carried out for determining quality features of the winding reel:
Thus, measurements are first carried out on the winding reel. These may be measurements taken only once, for example on the finished reel, multiple times, continuously and/or periodically. The measurements can first be carried out on a tarred winding sleeve, which later carries the film web in order to determine, for example, the concentricity of the winding sleeve or the arrangement of the sleeves on the winding shaft (detection of sleeve misalignment) as a quality feature. In particular, the measurements can be carried out on a winding reel in the process of being created, i.e., on the winding reel during the winding. Measurements can also be made after the winding reel has been completed.
The production of a winding reel generally refers to the production of web shaped materials. By web shaped materials are meant primarily elastic webs, in special cases also plastic film webs. These webs can be wound, for example, in extrusion processes, especially in a cast and blown film extrusion, but also in coating, printing, laminating and metallizing processes. The present invention can also be used in rewinding and slittering processes.
In this context, it may be the case that several winding reels are created simultaneously on one axis during production. The described process can be used with only one winding reel, but also with several, in particular with all winding reels.
Quality features or properties can be understood, for example, as geometric or optical deviations of an ideal winding reel. An ideal winding reel is in particular cylindrically shaped and optically homogeneous. Deviations from this shape that occur during the winding process are usually referred to as winding defects. Winding defects can occur on the shell surface, but also on the end face of the ideal cylinder.
Quality features can also be defined as the optical properties of the winding reel. Gloss, haze and shadowing of a winding reel can be important quality features or properties.
Various measuring methods are available with which the measurements can be carried out. Measuring methods include, for example, contacting measuring methods and non-contacting measuring methods. Contacting measuring methods are, for example, weight measurements or force measurements on a machine component that is in contact with the winding reel. Geometric measurements, which can be carried out with simple measuring means such as measuring tapes, are also conceivable for taking out measurements. Alternatively or additionally, optical, acoustic and/or electrical measuring methods are conceivable as measuring methods. Even measurement methods that use particle beams are conceivable. All of these measurement methods provide measurement values for the measurements performed, which are provided. In particular, both laser triangulation and optical detection using camera systems are suitable measurement methods. In this context, the measurement methods can be point-based, linear or two-dimensional measurements on the shell and/or end face. In particular, measurement with a linear triangulation sensor is suitable for detection. Other optical measurement methods may use, for example, white light or infrared radiation. A sensor can detect, for example, a shadow cast when using an electromagnetic radiation. In particular, it can be provided to use at least two measuring methods that differ in principle in order to be able to conclude further parameters, in particular parameters that are not directly measured, by combining the respective measurement values.
The information and data flow are described in the figure description using the diagram shown in
From the provided measurement values of the sensor, at least one item of characteristic data can then be filtered out in the diagnostic unit. This means that information is obtained from measurement values and/or from parts thereof which can be used for a statement with regard to quality features. Quality features or properties are thus derived from the characteristic data according to the invention. The quality features can also relate to the film web as such, because certain measuring methods measure properties of the film, so that their measurement results relate to the film web. Nevertheless, properties of the film web also have an influence on the winding reel. Alternatively, or additionally, the quality features can refer to the way in which the film web is or was wound up. It should be emphasized that the film web which is wound up has been created on a film production system and is wound up without intermediate storage, i.e., inline Such a film production system is in particular a flat film line or a blown film line.
In particular, it is provided to compare the properties of a winding reel with those of an older winding reel in order to detect long-term changes. This purpose may also be served by comparing data measured at different times but on the same winding reel.
In a further embodiment of the invention, it is provided in particular in the diagnostic unit that one or more characteristic data items are assigned to a winding defect. The characteristic data can thereby originate from measurement values of one or more measurements, which are obtained with one or more measuring devices. In particular, several measurements can be combined to obtain characteristic data. In this way, characteristic data can preferably be assigned to a winding defect. A winding defect can be caused by the formation of the winding reel, by the process steps preceding the winding, such as the setting or holding of parameters when guiding the film web, and/or by the properties of the film web itself. Of course, a winding defect, in particular its type, its frequency and/or its intensity, is a quality characteristic in the sense of the present invention.
The process information, for example set values, measurement values, adjustment values, can also be present in the diagnostic unit and, in particular, evaluated and/or processed together with the sensor data. Likewise, operator instructions can be used to condense the information obtained. At the same time, information from the evaluation unit can be given to the operator, so that the operator is enabled to change the process in such a way that the desired defect or the characteristic property of the winding reel is changed. In a further application, it is also possible to provide the quality features of the winding reel(s) obtained here in the form of a (digital) log, so that subsequent processes can use this information.
In order to be able to define quality features, it is preferably provided that these comprise at least partial quality indicators. In particular, these quality features can indicate whether and to what extent a parameter of the winding reel deviates from an ideal value and/or a set point value. An ideal value can be a theoretically predetermined value. A target value can be any predeterminable value or also an average value from previous measurements. In particular, these key figures and target values are generated, controlled and displayed to the operator via the evaluation unit.
In a preferred embodiment of the invention, it is provided that a winding defect is associated with one or more machine components, product parameters and/or process parameters. In this way, the quality features can be influenced with the aim of producing a qualitatively improved winding reel. Once such an assignment has been made, target-oriented changes can be made to the product or process parameters and/or, for example, machine components can be changed if they are defective. The reconfiguration unit in particular is provided for this purpose. For example, the diagnostic unit can detect when edge trimming blades that trim the edges of the film web are worn. The worn blades result in a larger diameter on the winding reel at the edges than on the rest of the shell surface. In this case, the present invention serves to detect the geometric change on the winding reel already during the winding process and to provide the operator with instructions to replace the worn blades. In a further case, for example, longitudinal grooves on the shell surface of the shell reel can be detected and identified. These grooves, often referred to as tin canning, can also be selected and avoided or even completely eliminated via changes to the process parameters by the reconfiguration unit.
Furthermore, properties of the elastic web can also be determined, for example by drawing conclusions about an uneven thickness distribution of the elastic web from detected elevations on the winding reel—so-called thick spots. The reconfiguration unit can then be used to homogenize the thickness distribution by adjusting the process parameters.
The above-mentioned object can also be achieved by a device for winding up a film web, which can be created in particular on a film production system, on at least one winding reel, having a diagnostic unit which is provided and set up for determining quality features of the winding reel,
The same advantages are thus achieved as they have already been described in connection with the method according to the invention.
The above-mentioned object can furthermore be achieved by a system for producing and winding up a film web comprising a film production system, with which the film web can be created, a winding device, with which the film web can be wound on at least one winding reel, with a diagnostic unit, which is provided and set up to determine quality features of the winding reel,
The same advantages are thus achievable as they have already been described in connection with the method according to the invention.
The features mentioned in the claims and in the description can be essential to the invention individually or in any combination of the features mentioned. Within the scope of the entire disclosure, features and details described in connection with the method according to the invention naturally also apply in connection with the device according to the invention and/or the system according to the invention and vice versa in each case, so that reference is or can always be made mutually to the individual aspects of the invention with respect to the disclosure. The attached figures are described in more detail below. Both the figures and the following description disclose further features of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2018 222 374.2 | Dec 2018 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2019/085541 | 12/17/2019 | WO | 00 |
