Innventia is set to carry out case studies using thermography at paper and board mills with the goal to integrate it into the quality control system (QCS). This is expected to bring significantly better possibilities to detect process variations compared with the current point-based technology.
Ongoing studies within the Innventia Research Programme have shown great advantages of using thermography to analyse process variations in paper and board manufacturing. One of the most significant advantages is that the entire paper web can be measured continuously, compared with today's traversing point measurement method. By integrating thermography into the QCS, 100 % of the produced product can be analysed compared with the current method that measures less than one percent.
Identifying and minimising process variations is of the utmost importance in papermaking. Process variations lead to less uniform product properties. Larger process variations - for example in grammage or moisture content - can lead to web breaks. However, many variations cannot be detected using today's traversing point measurement due to the limitations of the existing measuring systems in the form of low resolution and a low proportion of total measured surface.
Thanks to financial support from Ångpanneföreningen's Research Foundation, Innventia will now carry out case studies at two Swedish paper mills in order to evaluate integrating thermography measurement results into existing QCSs. The project is a continuation of a research project within the current Innventia Research Programme, which will conclude in autumn 2014.
"Thermography will provide much more possibilities compared with today's measurements of product properties," says Hannes Vomhoff, research manager within paper technology at Innventia.
"For example, we can analyse time-dependent variations in the stock fed into the headbox and separate these variations from variations caused by the paper machine," adds Catherine Östlund, an image analysis specialist at Innventia.