You say you want a revolution
by Graeme Rodden, Editor
At some conferences I have attended recently as well in some articles I have read, there has been talk of a malaise within the industry: no, not the economic one we are well aware of, but a technical malaise. People decry the lack of revolutionary new technology. It has been said that long-retired papermakers could run today's paper machines, that a 19th century papermaker would recognize today's mill. At best, I feel that is an oversimplification, at worst, a gross misrepresentation of the level of technology in modern mills.
I started to write about this industry in 1980 and yes, on the surface, a paper mill looks much the same now as it did then: incoming raw material, pulping, bleaching, stock prep, paper machine, drying (and perhaps coating), finishing. A recovery island for chemical pulping and effluent treatment round out the process flow. But, let us take a closer look. On the furnish side, wood species that were previously considered no more valuable than weeds are now being pulped with excellent results. The harvest of the "urban forest" is now a given, not a novelty.
For many mills, the large woodpiles are a thing of the past, as residual chips from sawmills make up the main part of the furnish. Whole logs can have much more value as lumber so why waste them on pulp? Mills have the technology to pulp chips
of an increasingly smaller size as sawmill technology improves to make more use
of the log.
In pulping, the alphabet soup of mechanical pulps - RMP, TMP, CTMP, BCTMP - are now used for virtually all paper grades, not just the low end of the scale. In bleaching, chlorine is practically a dirty word for many mills. Chlorine dioxide, hydrogen peroxide, oxygen and ozone dominate the bleaching scene.
In stock preparation, fiber fractionation allows a mill to impart specific properties to its pulp to meet the specific needs of the paper grade being produced. Freeness can be lowered without reducing strength.
Faster, faster
Paper machines can be said to follow the Olympic ideals: faster, higher, stronger. Yes, the basic look of a paper machine has not changed much, but the machine has changed, greatly. In 1980, a newsprint machine running at 1,200 m/min was considered fast. Now, the new generation of newsprint machines will run at 2,000 m/min. Manufacturers are also pushing the envelope when it comes to width with wire widths of more than 11 m now possible. Open draws are a thing of the past with the new high speed machines. What used to be produced by two or three machines can now be made by one machine, cheaper and with better quality.
No one is going to take a paper machine, which can be more than a kilometer long if supercalendering and roll finishing is all done on line and suddenly turn it on its end, at least not in our lifetimes.
Process control is another area in which change has been constant. From the old pneumatic controls to analog to digital, mills run by wire. But even the distributed control system (DCS) that became a routine part of a mill's equipment in the 1980s is on its way out, according to information in our mill-wide automation focus (see Control room revolution). As Executive Editor Jonathan Roberts writes, the DCS should be "consigned to history" by Fieldbus.
To give one specific example in another area of the industry: Metso Paper recently introduced a new coating process that operates much like spray painting, an idea borrowed from the automotive industry. Will it change the way a mill looks? Probably not by much. But, it is another in a continuing line of change that can be seen in mills.
These are but a few of the advances that have changed the pulp and paper industry over the last 20 years. All of this to say that change in this industry does occur all the time, but evolutionary, not revolutionary. Perhaps change is not coming as fast as some people would like, but then for some it seldom does.
Work still to be done
It is also not to say that all is perfect within the industry. It's not and probably never will be. Sometimes change was forced upon the industry from outside instead of coming from within. And perhaps the industry has been slow to adapt to new technology. Closing more loops within mill processes or zero effluent mills are goals to strive for. There are pitfalls at present, corrosion problems being one. Reducing water and energy consumption are also current areas of study. Improvements will come and they will be
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incorporated into mill processes and soon become part of a routine that no one will think twice about.
Yes, an old time papermaker would recognize most of what he sees in a present day mill, but delving deeply into the process, he would be amazed at what has transpired.
You cannot tell a book by its cover. That's especially true of the pulp and paper industry. It is what goes on inside the covers that has changed, dramatically.
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