Nipson Varypress 200, Paper Manual

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2-
1
Paper guide
VARYPRESS 200
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2. Paper characteristics
2.1 COMPOSITION
2.1.1. Paper pulps
Mechanical pulps
Made from mechanically-separated wood fibers. Their medium whiteness, limited mechanical
strength, and tendency to yellow with time restrict their range of applications.
Chemical pulps
Contain cellulose fibers which have been chemically separated from other wood constituents.
These are used in all high-quality writing and printing papers.
Recycled pulps
Give paper with a greyish color which tends to restrict their use.
Kraft pulps
Give brown-colored paper or cardboard having high mechanical strength.
NOTA : NIPSON recommends using a 100% chemical-pulp paper. Paper using mechanical or
recycled pulp may, however, give good results for certain applications.
2.1.2. Paper additives
Blueing agent
Fluorescent substance which increases paper whiteness. Very high levels tend to decrease
printing density.
Filler
Substances such as clay, chalk, or marble used to increase opacity and uniformity.
Internal sizing
Increases strength and binds additives to the paper fibers (reducing dusting).
Surface sizing
Starch applied to the paper surface to reduce absorbancy.
Surface coatings
Clay or chalk applied to paper to give a smoother surface.