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Information on Paper Grades
OCI Paper Grades
Waste paper is classified in different ways that is country
and sometimes even regionally dependent. In the USA, ISRI(Institute of scrap Recycling Industries) defines the specifications. In Europe, the governing standards body is BIR(Bureau of International Recycling). China uses the 1996 ISRI standards. Despite these
facts, there are four general classes of waste paper that are recognized:
- Pulp Substitutes -- Substances with similar
characteristics to paper pulp that are used as a replacement
for it fall into this category of waste paper. Substances
of this nature include printing trimmings and lightly
printed waste paper(such as notebook paper and ledger
trimmings). Another substitute is poly-coated board(e.g.
plastic board cartons that are plastic coated, plastic
coated paper plates, and similar substances), which
yields good pulp, but requires more work to make the
pulp, as it needs to be made into pulp again before
use.
- De-Inking Grades
- Brown Kraft Substitutes -- Waste such as
Old Corrugated Containers(OCC) and Kraft
Lined Strawboard(KLS), Kraft sacks, and any other
corrugating plant waste all fall into this category.
KLS is a type of OCC that is comprised of waste and
less than 33% kraft linerboard. This paper grade is
mainly used for test linerboard and fluting and contributes
to recycled product strength because it contains pulp
made of unbleached softwood. The strength is weakened
by the presence of any recycled fiber, starch, and
nonwood pulps and continues to decrease as the concentration
of these increases by a proportionate amount.
For water-proofing, some OCC is waxed and as a consequence,
interfiber bonding is reduced, visible speckling occurs,
and friction is reduced across the paper's surface.
As a result of these factors, waxed OCC has traditionally
been treated as an outthrow(i.e. a paper type deemed
inappropriate for a certain paper grade) or considered
to not be a viable recyclable material. Thermo Black
Clawson and Inland Paperboard have given an estimated
figure of 1 million tons of waxed OCC that plastic
is predicted to supplant, as is presently happening
in the Canada and Europe. In these countries, a method
has been developed to process OCC that has 1% or less
wax content called Xtrax. Most of the unsorted OCC
in North America and Europe, have 0.7% and 0.3% of
wax content, respectively.
It has been estimated by Fortifiber that if all paper
mills in North America were to stop using the wax-based
coatings and to start to use the newly developed water-based,
repulpapble coatings instead, it would allow 13-20%
more OCC to be made recyclable. The reason for this
figure is that 3-5% of OCC are wax coated and 10-15%
of uncoated OCC is mixed with wax-coated OCC, making
recycling efforts difficult or impossible.{Johnson,
M. and Copeland, G. Repulpable barrier coatings to
increase reclamed OCC. Corrugating International,
July 1999, pg. 19}.
- Mixed Waste Paper(MWP) -- This is the lowest
and cheapest quality. This is the grade of paper that
is left over when all other paper grades have been
sorted out, and this includes even hosehold waste
paper. Uses for this grade of paper include gray back
folding boxboard and chipboard.
Household waste, also known as residential mixed
paper is quickly being discovered as another avenue
of rescources. Currently, the United States only recovers
about 20% of its 9 million ton production. The quality
of waste paper is determined by the collection system
employed. In the United States, when collected seperately,
is composed of the following:
- 30% Cartonboard
- 30% White Grades and Mail
- 25% Mechanical Paper(newsprint, magazines,
coated and uncoated paper)
- 15% Brown Kraft(brown bag and OCC)
Residential mixed waste paper is often used as a replacement
for medium quality OCC.{Moore, B. Is RMP set to provide
a cheaper solution to OCC? Pulp and Paper International,
April 1997, pg. 35}.
Waste paper converted to paper grades in Europe in
1993(in millions of tons)*:
From:
To: |
Mixed
Waste |
Corrugated
Containers |
De-inking
Grades |
Other
(With Pulp Substitutes) |
Total |
Newsprint |
0.1 |
- |
3.6 |
- |
3.7 |
Other printing
papers |
0.3 |
0.3 |
0.7 |
0.4 |
1.7 |
Containerboard |
2.7 |
8.2 |
0.2 |
0.3 |
11.4 |
Cartonboard |
0.9 |
0.3 |
0.9 |
0.6 |
2.7 |
Other Packaging |
1.2 |
1.0 |
0.4 |
0.2 |
2.8 |
Others |
0.5 |
0.6 |
1.8 |
0.8 |
3.7 |
Total |
5.7 |
10.4 |
7.6 |
2.3 |
26.0 |
* CEPI
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