High tech at low speed
Hydration Technology's web guiding, tension control makeover fine-tunes its water-filtration membrane product for applications in new markets.
By Editor in Chief Mark Spaulding -- Converting Magazine, 2/1/2010 2:00:00 AM
Imagine you're the victim of a natural disaster-an
earthquake, a hurricane, a flood. Now list the things you'll need to
survive until help arrives. Besides medical care, a source of safe,
drinkable water likely tops your checklist of priorities. Fortunately,
you and thousands of other survivors of natural disasters have turned
to the water-filtration products of Hydration Technology Innovations
LLC (HTI). And those products are, in turn, made possible by the
Albany, OR-based converter's newly rebuilt and upgraded casting and
drying lines.
See more photos of Hydration Technology Innovations' membrane-converting operation at the end of this article.
At the core of all HTI water filters is an unusual forward-osmosis (FO), cellulosic membrane capable of filtering water molecules out of any liquid (see "Anywater, Anywhere" sidebar below). The membrane, manufactured through a custom-engineered high-tech coating system, works similarly to how a tree draws water from damp soil. All contaminants are removed, even down to viruses and bacteria.
"We just made an artificial tree root; basically it's the same
process," explains Jack Herron, HTI project engineer. "We just make it
in sheet form, instead of tiny fibers."
From the ground up
At the casting-line unwind are a Fife Kamberoller® steering guide, a Fife SE-22 infrared sensor (above) and a MAGPOWR “C” Series magnetic-particle clutch.
At
the casting-line unwind are a Fife Kamberoller® steering guide, a Fife
SE-22 infrared sensor (above) and a MAGPOWR "C" Series
magnetic-particle clutch.The brief history of Hydration
Technology's membrane production was punctuated by a devastating fire
that destroyed the manufacturing lines in March 2007. HTI immediately
began to build a new plant, which presented the opportunity to not only
solve several web handling problems that had troubled the original
lines but also to fine-tune the finished product for applications to
serve new end-use markets. All components were delivered in late 2007,
and approved membrane was once again being regularly produced in
September 2008.
Today, a 5,000-sq-ft plant houses the separate membrane-casting and
drying lines as well as R&D facilities to investigate new membrane
materials. Conversion of membrane into finished products (shown at top),
including new spiral-wound filters in several configurations, is
handled in a larger 24,000-sq-ft plant. Other operations include
raw-material slitting/rewinding, bagforming, RF-welding of pouches,
manual filling/sealing and final product quality control.
Overseeing the casting-line web handling components are a MAGPOWR Cygnus® web-tension control and a Fife D-MAX Series web guiding system.
Overseeing
the casting-line web handling components are a MAGPOWR Cygnus®
web-tension control and a Fife D-MAX Series web guiding system.In
its production, the membrane begins as a cellulose polymer dissolved in
a proprietary collection of solvents. Using a standard coating method,
this solution is applied to a back web, which may be either a woven or
wet-laid nonwoven fiber. The ultra-thin, asymmetrical coating is partly
infused into the back web. Finished rolls are transferred to the drying
line, where a non-volatile coating is applied to the web. Lastly, the
treated material is run through a convection dryer and rewound.
Slow and steady wins the race
"It's a very slow process and a very high-value
product," says Herron. So, as elsewhere in converting, the challenge is
to get your tension control and edge guiding to act really fast to
handle a super-fast process, here it's to get it to back off enough and
yet be very precise. We needed stability at slow speeds, especially
with a long length of very thin material between unwind and rewind."
Key to the smooth operation and improved efficiency of the new lines
are several web-handling components supplied by Fife, MAGPOWR and
Tidland (all companies of Maxcess Intl. [www.maxcessintl.com]).
The drying line now uses a MAGPOWR VERSATEC™ tension control, C-Series clutch and a Fife D-MAX web guiding system.
The drying line now uses a MAGPOWR VERSATECTM tension control, C-Series clutch and a Fife D-MAX web guiding system."We're
so slow that you could do a pretty good job with manual web control,
but you'd have to constantly tweak it to make it work," explains Steven
W. Peterson, HTI senior project engineer. Manual guiding was good
enough to make rolls later converted in-house, but HTI is now seeking
to do high-speed, form-fill-seal product manufacturing and contract
packaging. "If we were going to make more of our spiral-wound product,
we needed better web guiding," he adds. "We had one very skilled
operator, but we couldn't clone him to do all manual guiding."
At the casting-line unwind now are a Fife Kamberoller® steering
guide (provides immediate lateral correction), a Fife SE-22 infrared
sensor (capable of sensing the porous back web) and a MAGPOWR "C"
Series magnetic-particle clutch (driven the opposite way to achieve the
right amount of differential speed with the motor). Overseeing these
components are a MAGPOWR Cygnus® web-tension control (allows
adjustments using multifunction "smart keys" and a large backlit
display) and a Fife D-MAX Series web guiding system (pre-wired and
pre-integrated for fast setup). The D-MAX is said to provide even
higher dynamic response than previous controllers and displays text,
guiding nomenclature and web-guide graphics on a 122 x 92 mm LCD.
Wrinkling had been a big issue with the
membrane-casting process because the web is typically only 3.5-mils
thick, Peterson says. The real struggle was with tension control along
the full length from unwind to rewind. "There's a lot of festooning of
the material in the casting tanks, so you get some stretching, and the
unwind and rewind can start fighting with each other," he explains.
"Maxcess worked with us on stabilizing those tension fluctuations that
gave us the wrinkling. It all works well now. It's pretty boring, but
that's a good thing."
Unusual core-shaft combo
Uncoated substrate moves past HTI senior project engineer Steven Peterson in the casting-line area.
Uncoated substrate moves past HTI senior project engineer Steven Peterson in the casting-line area.In
HTI's original plant, changing rolls was a slow, complicated process
that Peterson and Herron sought to remedy with the new lines. The
converter now uses Tidland Series 800 GX ultra-lightweight aluminum
shafts and Boschert safety chucks throughout the two facilities'
unwinds and rewinds. An older Arrow slitter/rewinder used to trim
out-of-spec raw-material rolls prior to coating has also been
retrofitted with these components. "They are very nice, inflatable
bladder-type shafts, and we found them to be very convenient," Peterson
says.
Because part of HTI's membrane-casting process takes
place underwater, and the finished web must be kept moist, the
company's roll cores are actually PVC piping. "Tidland specified a
shaft that could handle the loads we had and still get good traction on
wet PVC pipe," Herron says.
Prior to full-production startup in September 2008, HTI experienced
some tension control problems on its drying line. MAGPOWR assisted with
the VERSATECTM tension control (with an ultrasonic sensor to
measure distance and roll diameter) and retrofitting to a larger
C-Series clutch. "These changes got the line running smoothly,"
Peterson says.
In early 2009, the D-MAX Series web guiding system and controller
was added as well. HTI operators prefer the new components because of
their intuitive ease-of-use. "It's been a real clean retrofit after our
startup," Peterson says.
Experienced extrapolation
Process operator Mike Flores checks the new web handling controls on the casting line.
Process operator Mike Flores checks the new web handling controls on the casting line.Both
he and Herron have high praise for all the Maxcess Intl. engineers they
worked with during the casting and drying line rebuilds. Because web
handling had been totally manual in the past, using only MAGPOWR
clutches, very little information was available (mainly web widths and
roll diameters) to help specify the proper components and controls.
"We had been inventing the whole [membrane-casting] process as we
went along," Peterson says, but the end result has been thoroughly
successful.
What's ahead for Hydration Technology Innovations? With its purchase
in March 2009 by Scottsdale, AZ-based holding company Innovations
Management, plans for a major boost in production capacity include
designing a new membrane line to be sited nearby or in the existing
casting-line building.
| MORE INFO: | ||
| CONVERTER: | ||
| HYDRATION TECHNOLOGY INNOVATIONS LLC, 541/917-3335, www.htiwater.com | ||
| SUPPLIERS: | ||
| FIFE CORP., 800/639-3433, www.fife.com/hti | ||
| MAGPOWR, 800/639-3433, www.magpowr.com/hti | ||
| TIDLAND CORP., 800/426-1000, www.tidland.com/hti | ||
Close-up of Hydration Technology Innovations' water-filtration membrane web.
Editor's Note: At presstime, HTI was shipping its HydroPack and HydroWell Village products to Haiti as part of international earthquake relief efforts. The donated supplies will provide at least 6,000 people with one liter of clean drinking water each day.
Winding station on the coating line at Hydration Technology Innonvations.
High tech at low speed
02/04/2010"AnyWater, Anywhere"
11/22/2009Of retrofits and recovery
01/31/2010
