Nipson Varypress 200, Бумажное руководство

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2-
2
Paper guide
VARYPRESS 200
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2.2 PHYSICAL CHARACTERISTICS
These characteristics affect directly the print quality and paper passage in the printer.
Paper weight
Is a basic characteristic which has an influence on mechanical behavior. It is given in terms of
either the mass per square meter of paper (g/m
2
), or the weight in pounds of 500 sheets of
paper cut to 17" x 22".
1 lb. basis weight -> about 3.759 g/m
2
(ex.: 20 lb. paper -> 75 g/m
2
)
Moisture content
Affects directly the electrical resistivity of the paper. It is expressed as the weight percentage
of water contained in the paper.
Electrical resistivity
Affects the electrostatic transfer of the toner to the paper, thus affecting printing density.
Relative humidity in the paper stack
Is an easily-measurable parameter related to moisture content.
Roughness (or smoothness)
Defines the surface aspect of the paper. A paper which is too rough will give poor image
quality.
Opacity
Describes the paper's ability to block transmitted light. Sufficient opacity is required to allow
detection by optical sensors, and to prevent print show-through.
Stiffness
Affects paper folding ability as well as paper passage through transfer.
Fiber orientation
Affects paper mechanical properties; the dominant fiber direction must be parallel to the
machine direction (orientation = 0º) to prevent fold orthogonality defects which can cause
paper stack lean for fanfold paper.
Tensile strength
Indicates resistance to tearing at perforations.
Tearing resistance
Indicates resistance to tearing at tractor feed pins.