Open Collections

Mahdavi Hezaveh, Hooman

University of British Columbia

The measurement of moisture content (MC) distribution in the paper is important as it affects the overall quality of the paper. It is common practice to measure the moisture content distribution at the end of the forming section of the paper machine, in order to control the papermachine headbox slice gap distribution. However, there exists no equivalent measurement technique to measure the moisture distribution downstream of the press section in real-time. This thesis presents a novel non-contact method for measuring moisture content. The method is based on the high light absorptivity of liquid water in the 1400-1500 nm wavelength range. By using a short-wave infrared (SWIR) camera and an infrared LED to illuminate the paper, the relationship between moisture content and relative intensity RI was investigated for four different samples (Whatman paper, NBSK, NBHK, tissue paper), where RI corresponds to the measured light intensity due to wet paper normalized by the intensity due to dry paper. The results show that for all samples, RI decreases as moisture content increases, and it is possible to measure the spatial moisture content distribution using this relationship. The value of this measurement technique was demonstrated by using it to measure the moisture distribution in the paper during a simulated pressing operation.

Text

2023-03-23

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/83993

Mechanical Engineering

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/