“Procemex TWIN is a breakthrough result of utilizing our joint competences in web break monitoring and web inspection, and combining this with a real requirement from customers for a more simple, flexible and, above all, more performance containing solutions”
Mika Valkonen, CEO of Procemex
Intuitive user interface with extended desktop for fast and easy root cause analysis for web breaks, paper defects, splice analysis and live images.
Paper Defects & Web Breaks – Common Factors?
Traditionally, paper machines are equipped with defect detection systems that ensure product end quality. Production efficiency is separately achieved by positioning cameras along the process, and by filming events for a better understanding. When a web break occurs the user can backtrack the process in slow motion upstream, and identify the root cause of the web break in the form of video footage. Over recent years these two separate camera based systems have been often connected to also better understand the root cause of paper defects.
However, this combination is often not reaching required performance levels. Web breaks and defects visualization with the most upstream located cameras set a high demand on image processing, which is required to simultaneously read in and copy out video data in RAM memory. Also, visualization of the inter-relationships between defects and their root causes has been divided into two separate systems. The lack of unified visualization, together with inadequate tools, make problem analysis for operators difficult and regrettably time consuming.
The start point of the Procemex TWIN system are machine operators. The system assists operators in handling all production quality, and production efficiency items with the aid of a set of computer supported analysis tools.
Under normal running conditions the left hand monitor is used for displaying live images and a machine efficiency time chart. The right hand display continuously updates a defect map that identifies different defects with respective symbols.
Should a machine disturbance occur e.g. web break or paper defect, the monitors change modus and form a unified user interface that displays a complete story of the event with its original root cause.
For the operator, analysis is easy as the system classifies paper defects and displays its evolution through the process. It is wholly beneficial for the operator, that web breaks, defects and their root causes are analysed and displayed in such a clear way.
Procemex TWIN is constructed with the idea of using different types of cameras within the same system, as with different machine parts requirements for visualization differ. The system understands different camera types. One server supports unlimited number of intelligent digital cameras. The cameras can be web monitoring cameras i.e. positioned alongside the process or web inspection cameras built into a carbon fibre camera frame across the paper web.
Standard server for collecting data and managing database
While the actual hard image processing work is achieved on DSP processor boards inside intelligent cameras, the server computer manages files, performs SQL-database handling and data distribution to clients. The permanent data is is stored on a RAID secured break & defect bank. Intelligent digital Megapixel camera technology – the backbone of high definition web break monitoring and web inspection
At the heart of the Procemex-TWIN System is the Procemex-Flex camera. It is a dedicated camera developed by Procemex engineers over the past 7 years. It combines, for the first time, excellent light sensitivity, fast frame rates and high resolution. It is an excellent solution for both web inspection and web monitoring.
The Flex camera has been specifically designed to meet the demands of fast paper machines running over 2000 m/min (6500ft/min). It can be used in all machine sections from wire/forming section, through dryer hood to the reel. It is ideal for providing compromise free web inspection on super fast coating machines and especially winders reaching up to 3000 m/min (9800 ft/min) speed.
Procemex Flex camera features 3 high power DSP processors, significant on-board RAM memory to keep the last minutes of images in a rotating FIFO buffer, high speed detection, analysing and classification of defects in raw image format, and JPG2000 video processing for web monitoring cameras.
Procemex Flex camera has a pixel rate of 130 MHz and overall processing capacity is 12 GOPS (giga operations per second), which guarantees compromise free quality at high machine speeds.
The camera uniquely processes, analyses and classifies all data itself, and sends only pure end results through a TCP/IP network to the system server. It is unique in that it needs no external unit for data processing. It performs this in its own shell.
Such high resolution, the extended amount of greyscales, coupled with several hundreds of frames per second, offer premium performance for papermakers and printers.
Procemex Flex camera & strobe LED light filming trim squirts on a fine paper machine. 1.3 Megapixel resolution provides never seen before zooming possibilities.
Both web inspection and web monitoring cameras utilize the latest and most powerful LED strobe lighting technology developed by Procemex. Procemex Flex camera fully automatically controls the strobe lighting to match the camera frame rate, with camera shutter speeds automatically controlling each light pulse length. This means the strobe light is illuminated when the camera is filming. This strobe lighting uses just an average of 30 W compared to 400-500 W (standard metal halide light), thus eliminating heat and energy consumption problems. Strobe lighting and new super light sensitive CMOS sensor technology, results in camera exposure times of 5-20 Microseconds freezing paper movement effectively, and producing crystal clear images.
Stripes in web in 1st dryer can be traced back to the head box at 1300 m/min
Today web break reasons can be backtracked with standard cameras only to the press section of a paper machine. The wire/forming section, where web content is almost pure water, is today too difficult to be analysed with standard cameras due to small contrast differences and low camera resolutions.
Thanks to high light sensitivity, 10 Bit digital gray scaling and very high 2.1 million pixel resolution, Procemex Flex camera technology has opened a new door to improve efficiency on paper machines – with the aid of wire/forming section disturbance analysis. Procemex Flex camera visualizes the wire section across the full machine width. Web breaks or paper defects detected by web inspection cameras at the reel can be synchronized and analysed backwards to the head box of the PM.
There has existed, from the first paper machine, a need to identify and understand visual sheet defects, which must be detected and identified in real-time and presented to the papermaker in an easily understandable way.
To achieve detection of relevant defects a number of digital Procemex Flex cameras are installed to a multiple camera beam or beams, when detection is required at multiple locations or on both sides of the sheet.
Web inspection camera has detected a hole in the paper at the reel (upper left hand image). The hole is backtracked through the dryer and press sections to the cameras installed on top of the head box. The above right hand image and bottom zoomed image reveal the root cause of the defect which existed straight after the head box of the paper machine.
This specially constructed carbon fibre beam absorbs machine vibration, and is sturdy enough for the widest machines in the world. Sheet widths well in excess of 12 meters can easily be reached.
Some defects may be in different layers inside the web which requires different illumination for detection. Procemex Flex camera controls up to 3 separate strobe light sources simultaneously. The flashing of each light source takes place in individual sequences at the same point of the web, so the actual point is being inspected 3 times, each under different light conditions. The results of these three images are combined for reliable conclusions on the defect type and location (bottom, middle, top layer). This type of triple defect inspection requires 3 times higher data processing capacity over a single light source use.
Stainless steel strobe LED light for web monitoring
Procemex Target Control System (TCS) enables the operators to remove or repair off-quality production on a re-winder or on a slitter winder. The encoded machine directional position is marked on the edge of sheet on the paper machine. The TCS decodes the length marks and synchronises the winder automatically to the selected defects.
Fine paper on-line formation measurement
Procemex and Papiertechnische Stiftung (PTS) have implemented in co-operation an on-line formation measurement to help paper makers make fast decisions and to understand fluctuations in short circulation of the paper machine.
Paper formation measurement takes place in real-time inside the Procemex Flex camera indicating paper contrast, cloudiness and fiber orientation. The operator can view CD formation profile in full width and also view MD videos constructed from single formation images. The formation values calculated with the PTS method are comparable between different grades and different paper machines thus giving the paper maker real tools to tune the formation of the various products.
Pinhole camera filming trim squirts on a fine paper machine.
Pinhole camera on a liner machine. The viewing hole in the middle of the camera housing is fully open and provides 100% visibility
Web monitoring cameras are kept clean under harsh wet end conditions with the aid of instrument air flow. The air is blown through a 5 mm hole in front of the camera housing. As the air flow speeds up when passing the pinhole it forms a strong protection against dirt and prevents water and dirt from entering the camera housing. The housing has no protection window that could get dirty or wear out. The camera is equipped with a dedicated pinhole zoom lens capable of viewing through the hole.
The benefits of pinhole cleaning are trouble-free operation, low air consumption, 100% continuous visibility and the simplicity of the concept. There are no moving and wearing parts: wipers, electronics or controlling components. Continuous air flow enables Pinhole cameras to film undisturbed 100% of the time without washing cycles or wiper movements causing blind times during the cleaning process.
Cameras are cooled by using the same instrument air as for pinhole cleaning. Temperature insulation inside the camera housing reduces to some extent the need for cooling. In some positions warmer than 60 C/ 140 F it is necessary to use a Vortex cooler to guarantee a suitable ambient temperature for the camera. In extremely hot positions like in modern impingement dryers reaching 200 - 250 C/390-480 F ambient temperatures, it is necessary to use water to cool the cameras.
To meet health and safety and fire safety demands the web monitoring and inspection lights use strobe lighting, with low energy consumption and remain cool even in hot positions.
This makes them a perfect choice for positions with potential fire risks for e.g. in dryer sections. The web monitoring strobe LED lights are in stainless steel housings along the paper making process. They have been designed to take ambient temperatures up to 250C/480 F and have an indirect cooling system for hot positions.
LED-lights are cleaned with a thinwater film over the protection window in demanding wet end positions.
The web inspection cameras and LED illumination modules in carbon fibre frame are cooled by blowing air through the camera and light frames.
Stainless steel strobe LED lights feature indirect air cooling.