Optical Properties, Stickies, and Strength Tutorial

摘要

Recycling mills set quality targets for dirt count, brightness, and strength. Some mills also quantify stickies. In our time of lean manufacturing, often control room operators are required to test samples in addition to their other duties. While these tests are relatively simple, a better understanding of the principles behind the methods will allow mill staff to better interpret the results and identify the limitations of the methods. Furthermore, better understanding these test methods will also help the engineering staff to troubleshoot mill processes. This tutorial will be an overview of optical properties, brightness, opacity, gloss, color, dirt counting, stickies quantification, and ERIC. After a general description of light scattering from paper, each method will be discussed. Important points about instrumentation and interpretation will be presented. For each method, particular attention will be given to the reproducibility and typical standard errors. In the second part of this tutorial, physical testing will be discussed. In particular, the impact of recycling on physical morphology of the fibers will connected to the observed changes in tensile and tear. This information will allow mill operators to understand the impact of their unit operations on their final product quality.