| Tyvek® is not paper – it's 100% non woven
polyethylene fibre. Most styles have been treated to improve ink
adhesion and have been coated with an antistatic agent to facilitate
sheet handling.
Here are a few tips to help you get excellent
results every time you print on Tyvek®:
- Use low solvent content inks:
Tyvek® is unaffected by water, but hydrocarbon solvents found
in most litho inks will swell and distort it. It is important
to use inks containing less than 3% volatile solvent. These inks
are usually made from dry pigment. Most ink suppliers have litho
inks for Tyvek®.
- Inks made from permanent pigments are
recommended for printing on Tyvek®: Alkali Blue, Red
Lake 2C, and Rubine Red 52 are not recommended for use on Tyvek®.
- Add more impression: Tyvek®
will require about 0.08-0.10mm additional impression compared
to a sheet of paper of equivalent thickness.
- Reduce the level of dampening solution:
Tyvek® does not absorb water as readily as paper and, for
this reason, the press should be run with less dampening solution.
If the printing is dull or washed out, reduce the amount of dampening
solution, don't increase the ink volume.
- Print with the minimum ink film thickness:
this will minimize dot distortion, sheet distortion and the appearance
of fibre swirls as well as reducing ink drying time.
- Litho inks dry more slowly on Tyvek®
than on paper. When doing full coverage multicolour printing,
keep the pile height below 50cm. Winding the sheets will also
accelerate drying. Too much dampening solution can cause excessive
ink drying time.
- Tyvek® is unaffected by alcohol and alcohol
substitute dampening solution additives.
- Tyvek® can be printed on both sides.
Generally, the smooth side, with a slight downward curl at the
edges, is preferred. However, for two-side printing with heavy
coverage, print the smooth side first with the least coverage
and back it up on the rough side with the heavier coverage.
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