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Fwd: Re: UV coatings on magazine covers



Forwarded from Printech.
-Wayne

From: GaryJGATF@aol.com
Date: Tue, 10 Jul 2001 17:20:07 EDT
Subject: Re: UV coatings on magazine covers
To: printech@great-lakes.net

Wayne:

There are some misconceptions regarding the recycling of printed matter that
has either been printed with UV cured inks or coated with UV cured coatings.
These types of printed products have always been recyclable if a lower grade
paper such as board for folding paper boxes, corrugated containers, or tissue
paper was to be made. I classify this type of recycling as "downcycling".  
The problem with UV cured printed matter lies in the manufacturing of paper
that is equal or better in grade than the paper being recycled or "upcycled".

In recent years, there has been a dramatic improvement in "upcycling" paper
printed with UV cured inks or coatings. This is due to the progress made by
paper companies in adopting new technology for recycling paper.  Back in the
early 1990's, the most common recycling technology used was washing and
screening. UV cured materials were not easily "upcycled" with this approach.
With the introduction of floatation cells into the recycling process, UV
cured materials could be "upcycled" more easily.

As paper companies have upgraded existing plants and built new ones in
response to the demand for recycled paper, floatation has become more popular
and the problem with UV cured printed matter has diminished quite
dramatically.

Essentially, floatation cells are used to bubble air through the repulped and
screened fiber. Large particles such as formed from repulping UV cured
materials adhering to the fiber are carried to the surface of the pulp and
are removed. While it does take more energy to repulp UV cured printed or
coated materials, this does not prohibit their ability to be recycled.
Economic factors also play a role in recycling paper as uncoated paper tends
to be more in demand than coated paper since there is more harvestable fiber
per ton of paper, but in order for the floatation cells to be effective, they
require a certain amount of clay or other inert to work properly. The clay
content can either be added or it can be supplied through using coated paper,
which has increased the demand for coated papers.  

It is interesting that this was never an issue in Europe where flotation was
adopted before it became popular in the US. Conversely, paper printed via
water-based flexography is not readily recyclable with floatation technology.
The paper companies are working to improve this, but to the best of my
knowledge, it has not been resolved. 

Gary Jones
Graphic Arts Technical Foundation
200 Deer Run Road
Sewickley, PA 15143
412/741-6860 x608 - Phone
412/741-2311 - Fax

MARK YOUR CALENDAR!
March 17-19, 2002
National Environmental, Health and Safety Conference
for the Graphic Communications Industries, Sheraton Imperial Hotel, RTP, NC




Wayne P. Pferdehirt
Director, MEPP, http://epdweb.engr.wisc.edu/mepp/
Co-Director, PNEAC  http://www.pneac.org
Specialist, SHWEC, http://www.uwex.edu/shwec/
tel 608.265.2361
fax 608.262.6250