A complete overview and more even grammage. These are the results of a new method for measurement analysis during paper production. An infrared camera can be used to gather large quantities of data from the whole of the paper web – throughout the process.
The technology already exists for gathering measurement data using an IR camera. The idea was first studied in 2010 at Innventia, and several smaller-scale studies have since been carried out.
There is a big difference compared to today’s method, in which a measuring head on a measuring frame zigzags across the paper web. This only gives individual measurement values, since the paper reels can be up to 8 metres wide and production can take place at a speed of 1,700 metres per minute. Furthermore, data cannot be gathered from the entire surface. The opportunities for adjusting settings in more detail during production are therefore limited, and this can result in uneven grammage.
Innventia’s Catherine Östlund works with online measurement analysis for paper machines. She explains more about Innventia’s ideas for improving papermaking:
“We want to add an infrared camera to the measurement process, mounted at the end of the web where the paper is rolled up. This position will give the camera an overview of the entire paper web, and it can film continuously. This will give us many more measurement values than the current method.”
What is measured is the temperature, and we know how to convert these values into grammage. Having so many more measurement values will allow us to control the machine, giving the paper a more even grammage. The values are shown in high resolution, in real time and online, and can also be correlated to material variations and variations in dryness.
The aim is to develop the IR technology into a system to position permanently on paper webs. Such a system will not be expensive, as it does not require any rebuilding in plants. All that is needed is to mount the camera on the ceiling. The aim is also that the values should be integrated with other data collected during paper production.
“The measurement values can be fed directly into the plant’s quality control system,” says Catherine. “When coordinated with the other data, this can lead to smarter paper production. Following test studies at various different mills, we know that the technology works. We also know that it can be linked to grammage.”
The next challenge is to test the method on an industrial scale over a longer period of time, and to combine the information with other data from the process. We need to deal with and analyse the large quantity of IR data effectively, and we also need to present it to operators in a suitable manner. More measurement values are not necessarily better. They also need to provide useful information for the people who work with them.
What will the future results be? A quality system in which large quantities of data can be integrated will result in paper with a more even grammage. More even quality will lead to fewer returns, and thus also to improved customer satisfaction. We have now come one step closer to our vision of a more sustainable society, in which efficient processes make optimal use of raw materials.
» Find out more about Innventia’s work with IR technology