Changing Paper Grades and Product Mix Using Advanced Instrumentation, PaperCon2017

Papermakers on swing machines have long faced the dilemma of changing set-ups for grade type changes, and sheet weight changes. The time taken to make these changes, the bad paper produced, and quality issues related to using the same set-ups for different grades, create issues that put production needs at odds with sheet properties and standardization.  Similarly, in today’s markets, it frequently occurs that machines must switch from one paper market segment to another, negating all relevant history of process parameters.  

In the first case study a microwave consistency instrument was installed between the secondary headbox and the BelBond, and another after the vacuum box between the two units. These microwave instruments have a 4-20 ma output which enabled the unit to control vacuum, ie, consistency, at the box before the BelBond by means of an adjustable valve. Both medium and liner were examined in weights ranging from 30-90 gsm. The objective of this study was to document the best settings for each weight of the grades being produced. 

A curve was then generated that plotted the microwave unit’s calculation of l/min. (from which, of course, consistency can be calculated) coming into the top wire vs. good tons produced for each grade and weight combination. During these trials, it was sometimes necessary to adjust slice opening to get the required properties. 

TAPPI conference proceedings and presentations, technical papers, and publication articles provide technical and management data and solutions on topics covering the Pulp, Paper, Tissue, Corrugated Packaging, Flexible Packaging, Nanotechnology and Converting Industries.

Simply select the quantity, add to your cart and your conference paper, presentation or article will be available for immediate download.