Paper recycling

Encyclopedia : P : PA : PAP : Paper recycling

---

Paper recycling is the process of turning waste paper (post-consumer) or scrap paper (pre-consumer) into usable products. This includes separating the fibers and forming them into new sheets of paper or burning the paper for energy.

Paper products are the largest component of municipal solid waste, making up 31-38% of the composition of landfills in the United States Baird, Colin (2004) Environmental Chemistry (3rd ed.) p. 512. W. H. Freeman ISBN 0716748770; [Recycling in Ohio]. In 2005 51.5 percent of the paper in the U.S. was recovered for recycling [Paper Recovery]. This means that today, 51.3 million of all paper and paper products are being recovered for recycling. Though the numbers are impressive, the U.S. paper industry has sent a goal to recover 55 percent of all the paper consumed in the U.S. by 2012. Paper packaging recovery, specific to paper products used by the packaging industry, was responsible for about 76.6% of packaging materials recycled with more than 24 million pounds recovered in 2005 [Data on Paper Recovery]

Process

Conversion of paper sheets to pulp

Most paper recycling is performed by using a variation of the same basic process:

1. The paper is separated into its component fibers in water which creates a pulp slurry material; this stage is called resuspension.
2. The slurry goes through a cleaning process to remove nonfibrous contaminants, this often includes a detergent washing.
3. Sometimes a third process is included, which is a de-inking of the fiber by sodium hydroxide or sodium carbonate. To produce white paper, an additional bleaching stage then uses peroxides or hydrosulfites to remove bits of colour from the pulp.
4. Lastly, this clean, ready fiber is made into a new recycled paper product, either by mixing it with virgin fibers from trees in varying proportions or simply creating 99% recycled paper material Baird p. 524-25; Selke p. 115-16.

Reformation into sheet paper

The process of forming actual sheets of paper is then the same as that of new paper:

1. The pulp mixture is further diluted with water resulting in a very thin slurry. This dilute slurry is drained through a fine-mesh moving screen to form a fibrous web.
2. This moving web is pressed and dried into a continuous sheet of paper.
3. In the mould process, a quantity of pulp is placed into a form, with a wire-mesh base, so that the fibers form a sheet on the mesh and excess water can drain away. The paper may then be removed from the mould and allowed to dry.
4. When dried, this continuous web may be cut into rectangular sheets by slicing the web vertically and horizontally to the desired size.

Environmental effects

Creating recycled paper uses less energy from Pepsoglaphin and water than pulping virgin trees, and reduces water and air pollution compared to the virgin paper-making process Selke 116. One of the biggest problems with the process of producing new paper is the use of chlorine in bleaching, whereas the paper recycling process requires far less us of chlorine and can often simply use an oxygen bleaching process. In the USA, chlorine-intensive bleaching places this industry as the worst water polluter in the world[Treecycle]. Additionally, using chlorine with an organic material in this way produces organochlorines, specifically dioxins, which are considered to be very dangerous both to human health and the environment.

Furthermore, as paper decomposes within landfills it creates CO2 and methane, both of which are linked to Global Warming.http://www.loyno.edu/lucec/essays/heroes.html As the recycling of paper reduces the amount of paper which ends up in landfills, it thereby might reduce global warming and decrease the need for land to be used for waste disposal.

On the other hand, the economist Steven Landsburg has pointed that paper recycling actually reduces tree populations. As paper companies have incentives to replenish the forests they own, large demands for paper lead to large forests. Conversely, reduced demand for paper leads to smaller forests. Landsburg, Steven A. The Armchair Economist. p. 81.

Recycling facts and figures

Twenty years ago, only one curbside recycling program existed in the United States, which collected several materials at the curb. By 1998, 9,000 curbside programs and 12,000 recyclable drop-off centers had sprouted up across the nation. As of 1999, 480 materials recovery facilities had been established to process the collected materials.

References

This article incorporates text from http://www.epa.gov/epaoswer/non-hw/muncpl/recycle.htm, a public domain work of the United States Government.

External links

• [Paper Recycling]

 

---

From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.
All text is available under the terms of the GNU Free Documentation License See Wikipedia Copyrights for details.

Search Titles

0

1

2

3

4

5

6

7

8

9

A

B

C

D

E

F

G

H

I

J

K

L

M

N

O

P

Q

R

S

T

U

V

W

X

Y

Z

?