A new stickies test method : statistically sound and user friendly

There is no standardized global method for measuring stickies content in recycled market pulp. This paper proposes a test method that is statistically rigorous and easy to use. Statistical requirements for choosing the correct sample size are explained, and the test procedure is discussed in detail. The use of a specially designed coated paper is an essential aspect of the proposed method. Design specifications for this specialty coated paper are described. The concept of stickies area density is introduced as a useful means of quantifying stickies content. Graphing the stickies area density over the stickies size classes provides an excellent tool for fine-tuning operations to improve stickies removal efficiency across the recycle process. Application : a proposed test method for measuring stickies content in recycled pulps ensures that only tacky contaminants exposed to temperature and/or pressure are measured within statistically sound confidence intervals.