Details:
Summary:
Over the last 20 years and more, great progress has been made in the reduction of linting and picking of newsprint and other uncoated papers. But changing printing technology and customer demands for ever-increasing quality mean that our quest for the perfectly clean sheet surface is a moving target. Despite many improvements, we have yet to find the ideal lint test for the finished product: precise, representative, and fast. Improving mechanical pulp quality remains a priority in lint reduction, in terms of reducing the content of unbonded ray cells. The evolution of low freeness, low coarseness, thin-walled fibres is continuing, through improved refining and processing, although much remains to be done. Recent work on relating colloidal properties of fines to their specific surface area and so to linting propensity is of value in controlling pulp quality, while on-line fibre classifiers also show great promise. New techniques of surface consolidation are of interest in reducing linting, although excess consolidation can make linting worse. Even low amounts of surface size can produce a very large reduction in lint.