Abstract
Foam formed paper was compared to water formed paper made
with same process parameters. The variables in base
papers were wet pressing line load, water/foam density
and the amount of cellulose microfibrils. Test sheets
were coated with a metered size press, with a pre-coating
formulation containing CaCO3. Coating layer was analysed
with microscopy and burn out tests.
The results will be discussed in details. The main
results are that the penetration of the coating colour
clearly depends mostly on the used line load in wet
pressing of the paper machine. With the highest line
load, the penetration of the liquid phase is smaller and
the coating colour stays more on the surface, while the
base papers produced with the lowest line load in wet
pressing had more bulky structure and more surface voids.
With foam forming, the coating layer coverage is slightly
poorer than with water forming. The addition of cellulose
microfibrils to the base paper structure can improve the
uniformity of the coating layer. In general, the surface
of the base paper for coated products should be
engineered to be dense.
Original language | English |
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Pages (from-to) | 20 - 27 |
Journal | International Paperworld IPW |
Issue number | 2-3 |
Publication status | Published - 2016 |
MoE publication type | D1 Article in a trade journal |
Event | 27th PTS Coating Symposium 2015 - München, Germany Duration: 16 Sept 2015 → 17 Sept 2015 |
Keywords
- foam forming
- porous
- structure
- coating
- metered size press
- hold-out