The WEBFREX NV system is used with film making machines to perform accurate online measurement of film and sheet thickness. It produces graphs (profiles) that give a quick grasp of the distribution; these can be used to control thickness and ensure that all films and sheets coming off the production line have a uniform thickness.
Complete Line of Sensors
We have a complete line of sensors available: Beta-ray, X-ray, and Infrared sensors. The Beta-ray sensor can be applied to various materials. The X-ray sensor is highly sensitive to metallic elements. The Infrared sensor uses no radiation. You can select the sensor most suitable for your application.
Please feel free to contact us if you have a request for the sample test.
Well-Proven Control Functions
The control functions perform control calculation to the sheet in machine and cross-machine directions based on measurement data. They are well-proven in various processes. We will provide suggestions for the control function most suitable for your production lines.
Please feel free to contact us if you considering the introduction of these functions.
WEBFREX NV can integrate the management of data from several production lines, for improved production efficiency. WEBFREX NV uses open and highly versatile Ethernet technology to facilitate connections with user systems at the information management, quality/production management, and control levels.
Partial upgrade of your WEBFREX3 system allows you to obtain the latest WEBFREX NV system for continued use. Contact us when your system is WEBFREXⅡ or older. Details on the system upgrade depend on your system version. For more information, please contact us through the following:
A frame is a driving unit that has sensors mounted on it for scanning films and sheets. To get full performance from the sensors, the frame must be very rigid and have a high performance driving mechanism.
Highly Rigid and Durable Design
The frame is either built with rigid steel I-beams or has a monocoque design. The resulting structure is very strong, allowing the mounted sensors to measure film and sheet thickness with high accuracy even in harsh environments.
For these frames, Yokogawa has developed a dedicated CPU with high performance and reliability.
Complete Frame Lineup
Frames are available in a variety of shapes for different measured objects and installation spaces. For installation spaces that require other frame shapes, Yokogawa can provide consultation.
Suitable for all applications. More than one sensor can be mounted.
Best suited for applications that require a small device footprint and have a narrow measurement width. Examples of the latter include ceramic and sheet edge measurement. More than one sensor can be mounted.
Measurement operator stations run under Windows®, allowing you to easily connect to printers and other peripheral devices.
Intuitive Design, Easy to Use
WEBFREX NV has a variety of easy to use operation and monitoring screens. Operation screens display an easy to comprehend profile showing the frame / sensor status and the thickness measurement data. Operation management screens facilitate the management of various film and sheet grades as well as reporting. With a single mouse click, online guidance screens can be displayed from each of these screens.
Combination of Quality and Production Management Functions
The profile stack server, which has previously run on a user PC, can also be installed on the measurement operator station.
User PCs can be continuously introduced for large-scale systems.
Introduction of Specifically Designed PC That Can be Maintained for a Long Period
A PC introduced as the measurement operator station is a computer designed specifically under an agreement with YOKOGAWA and a manufacturer. Its supply period is about two times longer than that of commercially available models with the same functions, assuring you of long-term maintenance.
Highly accurate Beta-ray, X-ray, and Infrared sensors are available for a variety of measurement applications. These are non-contact sensors that can measure objects without damaging them.
- Beta-ray sensor (0 to 5,000 g/m2 with aluminum)
- X-ray sensor (0 to 1,200 g/m2 with aluminum)
- Infrared sensor (0 to 2,000 μm with PP)
Beta-ray sensors irradiate objects to measure their thickness (basis weight), calculating this based on the attenuation of the radiation as it passes through the object. Beta-ray sensors can measure any object provided the thickness is within the specified measuring range.
Beta ray sources for measuring objects:
147Pm (promethium), 85Kr (krypton), and 90Sr (strontium) sources are available and are selected depending on the object that is to be measured.
High measurement accuracy
Beta-ray sensors measure both the object and the surrounding air layer. The sensor compensates for this by using an air purge mechanism to keep the air layer at a constant temperature and density, thereby minimizing its impact on measurement accuracy. It also contains an automatic compensation function for the decay of the radiation source and a calculation function to reduce radiation noise. These and other functions ensure stable and highly accurate measurement.
X-ray sensors irradiate objects to measure their thickness (basis weight), calculating this based on the attenuation of the X-ray as it passes through the object. The sensitivity of the X-ray sensor varies according to the atomic weight of the object that is measured. Being particularly sensitive to metallic elements, the X-ray sensor is often used to measure IT-related materials such as ceramic sheets (like MLCC) and battery electrodes.
Unique X-ray tube with stability and higher output
The X-ray sensor uses a unique tube with a reflective triode structure that achieves outstanding stability and high output.
As with the Beta-ray sensor, the X-ray sensor has a compensation function that maintains the air layer at a constant temperature to minimize its impact on measurement accuracy.
Infrared sensors irradiate objects to measure their thickness (basis weight), calculating this based on the attenuation of the infrared light as it passes through the object. They are sensitive to CH groups and can be used with many different types of films and sheets.
No replacement necessary
The light source uses a long-life heating wire that rarely, if ever, will require replacement. Highly sensitive wavelength filters are available for measuring objects of varying thicknesses.
By using various kinds of wavelength filters and filters that are sensitive to thickness, changes in haze levels, color, and ambient temperature can be minimized to achieve stable and highly accurate measurements.
Machine direction (MD) thickness and cross-machine direction (CD) thickness are controlled by the control unit. Based on the type of film making machine (such as cast and bi-axially oriented) and response time, the appropriate control method can be selected from the following options:
Other control methods are available: CD adaptive control continually monitors the process status during CD control to automatically recognize and adjust mappings between actuators and measurement points on profiles. By formulating rules based on the customers' control know-how, peaks can be aligned to achieve a flat roll shape ( roll shape control).
This method utilizes MD to control the thickness of films and sheets. Either sampled data PI control or finite time settling response control can be selected. Up to four loops can be implemented for each measurement operator station.
Virtual zone profile control has already achieved satisfactory results in many processes. It generates profiles at the midpoint between real bolts as well as on these bolts to perform control calculation. This prevents the occurrence of profile peaks and troughs between the bolts, which often become a problem in conventional profile controls only intended for profiles on the bolts. (Yokogawa patents)
Virtual Zone Profile Control
Expert fuzzy control based on fuzzy logic incorporates the manual bolt operation expertise of experienced machinery operators. This control method is effective with machines (mainly bi-axially oriented machines) where there is low repeatability of profile response to bolt manipulations, realizing more stable control than conventional control methods. Expert fuzzy control employs the concept of the virtual zone.
Expert Fuzzy Rule
Finite settling model predictive control applies the finite time settling response method to profile control. This predictive control employs a dead time internal model and a first-order lag system so that even machines with long lag times can settle down to target values within the shortest possible time. The control has a dramatic effect on machines with long lag times.
Finite Time Settling Response
Mapping is the most important parameter of CD control; however, it varies depending on operational conditions such as stretch ratio and machine speed. For this reason, setting parameters for each grade and re-tuning have been required to maintain optimum control.
Always monitoring the process status during CD control, CD adaptive control automatically recognizes and adjusts mappings between actuators (such as heat bolts) and measurement points on profiles using a proprietary Yokogawa algorithm that combines the steepest descent method with a neural network.
Automatic Mapping Control
Roll shape control incorporates rules that have been formulated based on the customers' know-how and applies it to CD control. By means of CD control, it improves roll shape by eliminating outstanding peaks.
Roll Shape Control
Optional software packages are available that provide profile stack server and a real time 3D profile view and analysis function. These packages can store, display, and analyze profile data for extended periods, and can be used to judge film production quality at a single glance.
Profile Stack Server
The profile stack server runs on a user PC or measurement operator station.
- Stores profile data of manufactured film and sheet automatically in real time
- Stores up to several lines of profiles on a roll-by-roll basis
- Saves long-term profile data
- Open database structure allows users to easily access data via a PC
- The integration of this package with a quality rating cutting system helps ensure the efficient and stable production of high quality products
Real Time 3D Profile View and Analysis Function
- Invokes and displays profile data collected by the profile stack server in three dimensions on a roll-by-roll basis
- Displays profiles and machine directional trends at the position indicated by a cursor
- Specifies and zooms in on a range for analysis
¿En busca de información adicional sobre Yokogawa Iberia, tecnología y soluciones?Contáctenos