STUDY Question 50:
Are there performance problems with certain equipment?
Only if the fibers are too long or too short.
- James S. Han, Research Chemist, USDA Forest Service
Forest Products Laboratory
Performance problems would be expected. Where
such problems arise, equipment modifications or replacements
would be required. Confidence in the size and sustainability
of market demand for such fiber would be necessary to
justify the financial commitment. - International
The performance problems are potentially serious
depending on the type of fiber and the degree to which
the fiber is refined. - Living Tree Paper Company
some runs at the Ecusta Mill, there was too much dirt
in the kenaf and flax mix. However, newer harvesting
and disking methods, similar to corn harvesting, are
used that solve this problem. Once the kenaf is past
the digester, it runs just like wood pulp. - Tom
Rymsza, President, Vision Paper
Again, there is so much variation in the quality
of the non-woods, if a poor quality pulp is produced
than of course there will be performance problems. If
a high quality non-wood pulp is produced, there will
not be performance problems. - Jeanne Trombly,
These have mostly been noted above: Raw material
handling equipment needs to be specially designed for
plant fibers, pulping digesters also need to be specially
designed for plant fibers, all stages where water is
drained from the pulp fibers need to be adjusted to
the slower drainage. The high speed modern paper machines
are probably more difficult to adjust to accept nonwood
fibers. - Michael Jackson, Consultant, Tolovana
fiber that has poor papermaking qualities can affect
everything from drainage to printability and recyclability.
A fiber such as kenaf will have no problems on any equipment.
- Tom Rymsza, President, Vision Paper
donax goes through the machines just like wood. However,
it absorbs the chemicals better and faster than wood
because of the spores in the end. So, the fibers break
down faster, leading to a faster processing time.
- Ernett Altherimer, Founder and Chairman, Nile Fiber
We haven't heard any from the printing side.
- Tyson Miller, Program Director, Recycled Products
whole kenaf stalk has a low lignin content (11-13%)
and is easily pulped by either the Kraft process of
soda, with or without anthraquinone additive. Good reduction
in kappa to bleachable ranges (20-25) was obtained at
high yields (48-49%). - Jackson 1997
[wheat straw and rice straw] have a high silica content,
with that of rice straw being about double that of wheat
straw - and so contributing to nonwood chemical recovery
problems. Thus, in Canadian wheat straw of 6-11% ash
content, at least 60% is silica (distributed in the
stem as small bodies called phytoliths), and 10-20%
is potassium (another undesirable non-process element).
[Watson, P.A. and Bicho, P.A. 1998]
The new Cellpaille
mill, in France, is using a Saica digester and soda
cook, with spent liquor recovery/treatment by the LPS
Process (Granit). The spent black liquor is acidified
to pH 2.5-3 to precipitate the lignin, which is then
processed, washed, dried and sold for uses similar to
those for lignosulfonates (although it is sulfur-free).
The resulting filtrate is treated by wet air oxidation
(SRS Process; sodium recovery system), with oxgyen being
utilized rather than air. Wheat straw has a slower drainage
and higher content of nonfibrous cells, which may slow
down paper machines and necessitate the use of special
washers in the processing lines. Due to high hemicelluloses
(aids in swelling of fibers), may aid in water retention.
- Jacobs 1997