THE COMPLEAT FIBRE ORIENTATION CONTROL AND EFFECTS ON DIVERSE PAPER PROPERTIES

摘要

This paper gives a review of the factors affecting fibre orientation on both macro and micro scales. A brief overview of the advantages and disadvantages of the most commonly used fibre orientation measuring methods is given. The influence of fibre orientation on paper quality for various paper grades and on machine runnability is discussed to show that efficient manufacture and good product quality are dependent on control of fibre orientation to a considerable extent. The main emphasis of this paper is to explain the processes by which fibre orientation is influenced and by what means it can be controlled. In addition to theoretical explanation, this paper includes six mill scale troubleshooting case histories. These demonstrate the lateral thinking logic often needed to solve fibre orientation related problems. The causes and cures for "edge roll defects" are also discussed as a separate special case topic.rnMost of the material in this paper is devoted to "macro" scale fibre orientation issues (full width or large scale faults) as these are the most common problems a mill must deal with on a routine basis. In addition there is a section on "micro" scale faults which explains how the underlying causes of curl, cockle and structural streakiness are related to fibre orientation and what can be done to control them.rnGenerally this paper summarizes measurement of fibre orientation, its influence on paper properties and machine operation and gives practical troubleshooting examples as a guide for mill scale orientation control.