LISTENING
STUDY Question 53:
Is there an optimal mix of tree free fibers with tree
fibers in a paper?
When
it comes to the molecular levels of fibers, there is
no distinction between the wood fibers and nonwood fibers.
Fiber lengths and widths are the only concern and more
on the fiber length. - James S Han, Research
Chemist, USDA Forest Service Forest Products Laboratory
It depends on the fiber properties. If the fiber
characteristics are inappropriate for papermaking, the
optimal mix may be less than 10% nonwood. If the fiber
resembles wood fiber, such as kenaf, the optimal mix
is 100% nonwood. - Tom Rymsza, President, Vision
Paper
A
50/50 blend would be ideal, starting with 25% ag fiber
would be a great first step. - Jeff Lindenthal,
President, Green Field Paper Company
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. Most practicalists now
advocating for the use of non-woods in paper want to
see a blend of minimum 30% ag-residues, minimum 35%
post-consumer recycled and the remaining from a dedicated
fiber, whether FSC wood or non-wood, or both.
- Jeanne Trombly, Fiber Futures
Yes,
but it varies from fiber to fiber and type of tree fiber
whether you are using softwood or hardwood and what
species of tree. - Living Tree Paper Company
All sorts of blends of woods with non-woods and
non-woods with other non-woods have produced viable
paper. The ideal mix would depend on the bioregional
availability of particular fibers and what type of paper
is desired.
It would be interesting
to issue a protocol for 33/33/33, calling for 33% ag-residues,
33% post-consumer recycled and 33% ecologic certified
"fresh" fiber as it is called in Germany. This could
mean virgin wood or a dedicated non-wood crop, such
as hemp or kenaf or bamboo or Arundo. All paper would
meet this protocol; variations would be issued depending
on where one is located, what type of paper is needed
and other local conditions. - Jeanne Trombly,
Fiber Futures
Depending
on the grade of paper desired. The spectrum of agri-fiber
is very broad; thus, the range of paper products that
could be made is also large.
See, for example,
my presentations, "Experience in the Technical and Market
Development of Agri-Pulp Printing Papers in North America,"
"Selected Physical Properties of Blends of Wood Pulp
and Alkaline Sulphite Flax Straw Pulp," "Alkaline Sulphite
Pulping of Hesperaloe, An Arid-Zone Native Fiber Plant
from Northern Mexico," "Alkaline Sulphite Pulping of
Red Fescue(Festuca rubra L. var. Boreal) Straw," and
"Alkaline Sulphite Pulping of Spartina Grass (Spartina
alterniflora Loisel)." - Al Wong, Founder, Arbokem
Different paper grades require different combinations
of fiber types and other additives. Depending on the
type of paper being produced, there may be no combination
of agricultural fibers that produces the desired finished
product. - International Paper
What
is important in making paper is not the specific source
of the fiber so much as its particular attributes. Even
papers made entirely of forest fibers generally incorporate
several different tree species because each brings different
important qualities. So also with nonwood fibers, it
is important to mix long fibers (for strength) and short
fibers (for flexibility), with the specific proportions
dependant on the particular type of paper being produced
and the performance requirements it must meet. As we've
seen in many of the tables in the Listening Study, nonwood
fibers cover a whole range of fiber lengths. Therefore,
it is feasible (and actually already occurring) that
some papers could include only different types of nonwood
fibers, while others might incorporate some forest fibers
for different properties. Ultimately, we hope that long
nonwood fibers will replace most of the forest fibers
in paper (with the shorter fibers being supplied by
recycled content) so that the demand for trees is significantly
reduced and reoriented towards products in which wood
truly is the only and/or best material. (Even the most
ecologically acceptable product uses for trees, however,
are likely to produce sawdust, which currently is an
important source of virgin forest fiber in papers and
may be of acceptable environmental value in paper even
in a predominantly nonwood fiber future.) - Susan
Kinsella, Conservatree
The
appropriate mix depends entirely on the end-use application,
and the performance properties each fiber brings to
the sheet. - Peter Hopkins, Environmental Papers
Consultant for Crane Paper Company, Gargan Communications
The optimal mix would depend on the specific paper
grade, as partly discussed above. - Michael
Jackson, Consultant, Tolovana Park, OR
It depends on the paper product, the region, etc.,
as described above. - Peter A. Nelson, President,
AgroTech Communications, Inc.
You
can mix Arundo donax just like softwoods and hardwoods,
where one has short fibers and the other long. Arundo
donax, on the other hand has both short and long fibers.
- Ernett Altherimer, Founder and Chairman, Nile Fiber
The
producers of the range of specialty papers being manufactured
today from nonwood fibers may attest to the levels of
quality which are possible and when we consider the
blending of nonwoods with recycled fibers, wood and
other nonwood species. - Hurter 1998
Table
12. Fiber Dimensions of Nonwood Plant Fibers |
Nonwood
fiber |
Average
length (mm) |
Average
diameter (microns) |
Abaca
(Manila hemp) |
6 |
24 |
Bagasse
(depithed) |
1.0-1.5 |
20 |
Bamboo |
2.7-4 |
15 |
Com
stalk and sorghum (depithed) |
1.0-1.5 |
20 |
Cotton
fiber |
25 |
20 |
Cotton
stalks |
0.6-0.8 |
20-30 |
Crotalaria
sp. (sun hemp) |
3.7 |
25 |
Esparto |
1.5 |
12 |
Flax
straw |
30 |
20 |
Hemp |
20 |
22 |
Jute |
2.5 |
20 |
Kenaf
bast fiber |
2.6 |
20 |
Kenaf
core fiber |
0.6 |
30 |
Rags |
25 |
20 |
Reeds |
1.0-1.8 |
10-20 |
Rice
straw |
0.5-1.0 |
8-10 |
Sisal |
3 |
20 |
Wheat
straw |
1.5 |
15 |
Wood
fibers |
|
|
Temperate
zone coniferous woods |
2.7-4.6 |
32-43 |
Temperate
zone hardwoods |
0.7-1.6 |
20-40 |
Mixed
tropical hardwoods |
0.7-3.0 |
20-40 |
Eucalyptus
sp. |
0.7-1.3 |
20-30 |
Source:
Pande 1998, citing
Original
Source: Atchison and McGovern (1993)
|
|