The reclaimed papers are mechanically disintegrated in water to produce a pulp suspension, after which foreign materials are removed. This type of pulp is characterized by low color, as well as low strength, unless produced from carefully selected long-fibered stock.
De-inked paper stock is used in the manufacture of several grades of paper, including book papers, groundwood specialty papers, newsprint, etc. It may be used either alone or combination with virgin fiber. It is produced from printed and/or unprinted reclaimed papers by means of mechanical disintegration, and treated with chemicals and dispersing agents which make possible the removal of most of the ink, filler, and other undesirable materials during subsequent washing. The cooking and washing operations are usually followed by bleaching. In general, the secondary pulp is of shorter fiber length and is somewhat lower in strength than the original pulp; therefore, it is given a minimum of beating and refining. Use of de-inked paper stock results in paper which possesses good formation, opacity, bulk, dimensional stability, and printability.
Paper shavings and cuttings—e.g., from binderies—are used to produce another grade of reclaimed paper stock, which is used extensively in the manufacture of writing and printing papers, as well as board and board linings. These are converted into pulp by mechanical disintegration in water. Their qualities depend upon the grade of paper from which they are made. In general, their physical strengths are lower and the formation superior to those of the original stock.
Timestamp: Saturday, 19-Nov-2011 13:18:44 PST
Retrieved: Wednesday, 20-Feb-2019 01:50:56 GMT