The Light Green Machine Institute
Check out Nip Impressions weekly
Nip Impressions� is Paperitalo Publications' flagship publication.  Published every Thursday afternoon (US Eastern Time), Nip Impressions� is eagerly read by pulp and paper professionals around the world.

26 Aug 15: Why is the wet end still exposed to the atmosphere?
Crescent formers and the like are the most nearly closed forming sections ever designed for paper machines. However, even they (don't even need to mention Fourdriniers) are still subject to the vagaries of the atmosphere. Why? Why can't we build a pressurized Fourdrinier? We think we are doing something with fancy foils, vacuum boxes and so forth, but all the air we suck through the wire comes to the wire from anywhere scientific principles say it can.

Put a tight hood over the whole thing, condition the air that is introduced into the hood and design a distribution system for putting that conditioned air exactly where it is needed. If nothing else, such a system will stop the ceiling from corroding and falling in every few years!

But I think we can make better paper, particularly if we seal right at the edge of the wire and slightly pressurize the top side. In fact, then we may be able to precisely control how much water is removed from each vacuum box or flat box.

If you look around the wet end, the forming section, and watch the vapor in the air, be if from the wire, the couch pit or wherever, it is easy to deduce that this is a process out of control. If you observe the condensation on equipment and building elements, you know for sure this is a process out of control.

So why is all of this open to the atmosphere? Because we have always done it this way? Because we think we have to be able to personally approach the process and observe it from a very close distance? It is time to re-examine our thinking on these matters.

Here at the Light Green Machine Institute, it is our stated objective to reduce the installed weight of the pulp and paper mill. That is good in and of itself, but it should make mills more economical to build. That savings can either be returned to improve ROI or, if in the questions we are postulating here, it makes sense to do some of these things and improve the process, we should. I would much rather spend money on equipment that makes the process better than on more inert concrete and structural steel just because we are too lazy to design better systems.
Jim Thompson
We would like to hear from you. Please send an email to [email protected] 
with "LGMI Frontiers" in the subject line. 

As always, your comments will be appreciated.
Think light!


Brian Brogdon, Ph.D.
Executive Director




Jim Thompson

Send us your comments by emailing Brian Brogdon
or Jim Thompson!




LGMI Weekly Ideas are presented for your consideration and inspiration only.  It is solely your responsibility to check for engineering correctness, applicability, standards, insurance policy and local, national or any other legal compliance required before implementing.  Neither The Light Green Machine (TM) Institute, Paperitalo Publications, Talo Analytic International, Inc., nor any individual associated with these entities accepts any responsibility for your application or compliance issues.


The Light Green Machine Institute is a stand-alone non-profit Delaware Corporation.  

Copyright 2015 LGMI All Rights Reserved