Process control of chemicals in fibre furnishes

[摘要] ENGLISH SUMMARY: In a competitive and environmentally concerned business atmosphere,the role of wet end chemistry has become extremely important to a papermill's profitability and long term viability. In the past decade,understanding of the papermaking chemistry has improved and sensorsfor measurement of the various variables on-line have been developed.Some of these variables are reviewed as well as the instruments whichhave been evaluated or developed for on-line measurement during thisinvestigation. Process control loops to maintain control over the wet endchemistry during stock preparation are presented as well as an overallstrategy to combine all the control variables. The primary thrust behindthe control of the chemicals added is to minimise process variability andimprove product uniformity as illustrated in this investigation. Areduction in chemical cost and paper losses coupled with improvedcustomer satisfaction are some of the benefits obtained. More work isstill required to fully master the multiple interactions and changing states ofwet end chemistry and this will be attained with the improvement ofexisting or development of new on-line sensors.

[发布机构] Stellenbosch University