paper&tree - lowres
TRANSCRIPT
How MucH PaPer can Be Made froMa Tree?
A lthough it seems simple, the answer to this question is really quite complicated.Manufactured paper is most likely made of wood fiber. But where did the fiber come from? A whole tree? Wood chips from a saw mill? Old copy paper? Maybe a combination of all three? If the paper was made from a whole tree, how old and how big was the tree? What kind of tree was it? Finally, a lot depends on the type of paper. What is its end use? And how was it manufactured?
So as you can see, there are so many influencing factors involved, it is impossible to arrive at any one figure.
From fiber to pulp to paperUnit measurements of pulpwood for paper and packaging are in “cords”. A pulpwood cord is a stack of logs 1.2 meter high, 1.2 meter deep and 2.4 meter wide (approximately 3.5 cubic meters). All measurements of how much wood fiber is used to produce paper products are in cords or tons.
The amount of fiber in a cubic meter of wood varies greatly from species to species. Hardwoods (broadleafed species) tend to have greater wood densities
than softwoods (conifers), meaning they have more fiber per cubic meter of wood.When trees are harvested for papermaking, the limbs are removed and the trunk is transported to a pulp mill. At the mill, the bark is removed and burned for fuel or processed to use as garden mulch. The wood is often chipped into small pieces about the size of a coin, and then broken down further into individual fibers in a process called pulping. The pulping method influences the amount of fiber the wood yields.Mechanical pulping (pressing and grinding the wood to separate the fibers) is very efficient, converting 95 percent of the dry weight of the wood into pulp. Chemical pulping is another method in which a chemical solution dissolves the lignin (lignin is a natural wood chemical that holds fibers together) to help separate the fibers. Paper made from chemical pulp is stronger and less prone to discoloration. But the pulp yield from chemical pulping is much lower, though, since the lignin has been removed. Most papermakers combine mechanical, chemical and recycled pulp in varying amounts to produce the highest quality paper required from the least possible amount of fiber.
But in general…
Now you know how difficult it is to find out exactly how much paper can be made from one tree. But let’s assume that most paper products have been produced using 100 percent hardwood. We know that a cord of wood is approximately 1.2 meter high, 1.2 meter deep and 2.4 meter wide. A cord of airdried, dense hardwood weighs roughly 2 tons (2,000 kg), about 15 – 20 percent of which is water.So, it has been estimated that one cord of this wood will yield approximately 454 kg – 908 kg of paper (depending on the process), or nearly 90,000 sheets (180 rims) of bondquality paper (letterhead paper).
InterestIng Facts
Here is a list of yields from a “generic” cord of wood:
• 454 kg – 908 kg of paper (depending on the process / the grade)
• 90,000 sheets or 180 rims of letterhead bondquality paper
• 1,200 copies of magazine (the size of U.S. edition National Geographic magazine)
• 2,700 copies of an average (36 page) daily newspaper• 61,370 standard (#10) envelopes• 4,384,000 postage stamps• 12 dining room table sets (seating eight)• 30 rocking chairs• 7,500,000 toothpicks
One other interesting rule of thumb is that an acre of forested land may yield an average of 10 – 15 cords of wood when harvested at maturity — depending not only on the size of the trees, but also on how productively the land has been managed.
SourceS1. American Forest & Paper Association2. http://www.wipapercouncil.org/fun3.htm
For more inFormAtion, pleASe contAct:
JAtnA SupriAtnA, phD
regional Vice president
Conservation International Indonesia
Jl. Pejaten Barat No. 16 A
Jakarta 12550
Indonesia
T 62 21 7883 8626
chriS mArguleS
leader, indonesia-pacific
Field Division
Conservation International
PO Box 1023
Atherton Q 4883 Australia
T 61 7 4091 8800
www.conservation.org | www.conservation.or.id