Tissue360 - Fall/Winter 2016 - 20
Parent rolls are wrapped with clear film at the
dry end of the machine.
Finished rolls are stored in a 12,000 sq. ft. roll storage area.
out. "Through my years of experience, I know
how to treat one. With the Nalco EWCD early
wear detection system on our unit, we haven't
developed any chatter problems. I guess the
biggest reason for buying a cast unit is heat
transfer. If you know what you are doing with
the coating chemistry, you don't really have
to put anything on top of that cast to make it
work. The coating chemistry we use is a Nalco
polymer type-Nalco 6450 Tulip. It doesn't
build molecular weight over time, temperature,
and pH. So you don't have to worry about those
things like a PAE coating does," James says.
During the March 31 startup this year, a
sheet was on the reel the first try. The machine
produced 27 tons of sellable tissue the first
day. "The folks at Valmet were excited to
see that happen. I think that Nalco also was
pleasantly surprised with the startup. At Nalco,
Gary had been involved with some of the other
NTT startups in Chile and elsewhere, and that
helped a lot. For a startup like this, you need
experienced, knowledgeable people who know
what they are doing to do it right. You can't
learn to run until you run, and we've learned
a lot of things since then. Valmet has made
some continuing corrections and things are
proceeding very well," Pankratz points out.
"Once you have the sheet on the reel and
are winding it up, then you just have control
issues," he explains. "There was automation
that had to be tuned in, and we had the usual
infant mortality failures of level sensors and
pressure sensors, etc. Sometimes it would take
two hours or more to figure out some of these
little issues, and sometimes we might have
to wait for another piece to come in. Valmet
made changes throughout the startup-refiner
work and similar things that sometimes held
us back. But we were always able to run, only
at a reduced speed. And because we were able
to keep running, everybody was progressing
and we never lost ground. It's been like that
ever since. Every once in a while we have a
mechanical issue that crops up, and we occasionally have to run a few things on manual to
work them out."
The Natchez mill is now past its startup
curve and things are looking very good.
Valmet, Pankratz and James say, still owes the
mill a couple of things to get up to speed-a
couple of water handling issues that they are
working through, for example. The mill has
run 6,000 fpm, and has met production goals
already. But to sustain that over time, there are
a few more mechanical pieces that need to be
added to the machine, they point out.
Pankratz and James are both very happy so
far with the NTT machine. They say they are
seeing what was expected with the structure
and uniformity of the sheet. "It is just amazing
compared with our other machines. We have to
make a lot of lightweight tissue and towel, and
have to make a lot of different grades. Some of
the other technologies were sort of like a Swiss
army knife-they could do a lot of different
things, but don't seem to really do any of them
well. This machine was simpler than most of
the others," Pankratz notes.
"When it's time to take that belt off and put
it on, it's simple and fast," James adds. "-a
couple of hours at the most rather than a full
day. Wire and felt changes also are easy. It's a
Tissue360º FALL/ WINTER 2016
The Natchez operations that von Drehle
acquired in early 2013 originally started out
as Diamond Co., making egg carton and other
products from newsprint. It was acquired
by MRP in 1995 and became a full-fledged
deinked pulp plant. Pankratz noted that he
was at the mill in October 2012 and it wasn't
running then, adding that he thought it had
shut down about three months earlier, which
would have been about mid-2012.
"MRP's wetlap sales had dropped off considerably about 2010 as demand in the area
decreased, Pankratz explains. "MRP was
struggling to find a place to send its wet lap.
High moisture content affected the economics
of shipping far. They mainly used mixed office
wastepaper, the same grades we generally use
today. We took out a lot of old equipment-their
stock washers, side hill screens, etc., and put in a
couple of Kadant/Black Clawson DNT washers.
We replaced the high consistency pulper with
a Voith Drum Pulper and Flotation Deinking
System. Those were the biggest changes," he says.
Currently, the mill's pulp plant is capable
of producing some 160 tpd, and the paper
machine is designed for about 120 tpd. "But
we have some surge capacity, Pankratz says.
"Some of the grades we produce are heavier
and require more tons per day. We still have
the wet lap line, so when we're not using all of
our pulp capacity when the paper machine is
running tissue grades, we make wet lap and
build inventory. Then we put it back in the
system for the heavier grade production runs."
As noted, the tissue machine produces about
30,000 tpy with a current blend of two-ply bath