To produce standard fluorescence reference paper for calibration of brightness tester

Abstract

In pulp and paper industries, optical properties are extremely important, especially brightness. This is because brightness is used as the reference value in bleaching process and also it is what people see. In order to measure brightness of pulp and paper accurately, the brightness tester must be regularly calibrated. One set of reference papers for calibration of brightness tester consists of four types of paper, which are fluorescence, brightness 90, brightness 70 and brightness 60 to calibrate all parameters in a brightness tester.

In this article, the method of how to produce standard fluorescence reference paper for calibration of brightness tester according to ISO TC 6 (Paper, board and pulps) and OPALs (Optical Properties Authorized Laboratories) is described. The standard fluorescence reference paper for calibration of brightness tester obtained were sent to Technidyne Laboratory Services (TLS), USA, one of the OPALs, to perform quality assurance every month since October 2009 to present. Two values issued, which were C brightness and D65 Whiteness were verified. It was found that the average quality of the standard fluorescence reference paper for calibration of brightness tester obtained was satisfied as the average difference in C brightness measured was less than 0.15 and the average difference in D65 Whiteness measured was less than 0.3. Moreover, the standard fluorescence reference paper for calibration of brightness tester obtained was also distributed to thirteen pulp and paper laboratories in Thailand as free trial every month since February 2010 to present.