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A Quick, Easy Way to Save Time and Money: Sealing Nylon Vacuum Socks
By Jack Pranzarone CP, LP I would like to share with you a discovery I made a
few months ago.
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Heat Wheel Sealer |
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Having begun my career over 20 years ago as a
technician, I still have a slight bend toward the technical side of
the house. Being extremely picky about quality work and
craftsmanship (they say I'm anal), and wanting the best for my
patients, I still do a lot of my own tech work. With an extremely
busy practice, time is always an issue. Consequently I am always
searching for new techniques that work and save time--both
technical and clinical. It is the little things that we do many
times a day that cumulatively consume so much time, and it is here
that I have found a neat little trick that can save time and
money.
This all started by sealing PVA bags. Many of you can remember
the way we capped the end of a mold with a PVA sheet, then a bag to
seal it before lamination. For several years I did it this way.
Then on a trip to Minneapolis, Minnesota, Steve Rebhuhn of Otto
Bock showed me his PVA bag-sealing trick. It involved the use of a
SealLine ® brand special sealing iron that included
an electrically heated steel wheel that was simply rolled on the
wet PVA bag to seal it. You could conform the PVA bag to any shape
mold by just rolling a different sized arc. We loved this thing.
And it worked for nearly 15 years before we wore it out. But when
it gave up the ghost, we could not find another one like it
anywhere. After looking for nearly two years, I found one at
Heatsealers.net. The company offers a complete line of sealing
devices, many of which may have O&P applications.
PVA Bag Sealer Does the Trick
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12-in. Impulse Sealer |
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Enter Randy Roberts, CPO, of the Pensacola branch
of Hanger Prosthetics & Orthotics. He showed me his version of
a PVA bag sealer. This was a neat little 12-in. impulse sealer that
is an affordable, easy-to-use device that makes watertight seals on
polyethylene bags, PVA bags, or any thin weld-able plastic
material. What is neat is that the element heats only while
sealing. These are available from nearly any of the mail order
hardware outlets, including Harbor Freight; item # 43476-2VGA,
Quill office supplies; item # 901-SPB12, and online at
Heatsealers.net. This thing will seal a wet or dry PVA bag in a
straight line. It is foolproof and quick. Turning the bag at an
angle and clipping the corners with the sealer produces a nice seam
for rounded objects. This tool does a wonderful job on PVA bags,
but just wait until you see what it can do with stockinet and nylon
vacuum hose.
Okay here's my part in this story. We buy our air wick nylon
vacuum socks from SPS. They come without toes. Both sides of the
house use these for vacuum forming both in thermoplastics and in
laminations.
Problem is we always have to deal with the open end of the sock.
We usually tie it off, fold it under, melt it together with a
lighter, or sew it shut. We do whatever is needed to produce the
best seam needed for the specific project at hand.
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Preparing to seal nylon vacuum hose |
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Well, the other day I needed to use one of these
nylons on a BK lamination. I always want as smooth a seam as
possible as it will sometimes show in the finished product.
Normally I would tie it off with a thin thread and cut off the
excess, then drill a hole in the mold and insert the knot in the
hole. When done correctly, this produces a very nice finished
smooth distal end. But it takes some time.
Sealer Great for Other Applications
Then the thought hit me...nylon melts! I put the nylon in the
sealer and lowered the handle. Three seconds later...Voila... a
perfect seam!
This worked so well it was amazing. I did it again and
again--perfect each time.
The sealer works just as well with finish nylon stockinet
too.
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Sealed nylon vacuum hose |
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Then it occurred to me that Nyglass
® should work as well. I put it in the sealer--and
again a perfect seam. Due to the increased thickness it took three
presses in about ten seconds to get it melted all the way through,
but it worked great.
Now in our practice we all are using this technique to seal the
nylons we use everyday. We also seal the Nyglass we use in our
lamination lay-ups. This produces a superior-looking finished
product and saves weight by not having so much fabric at the distal
end to soak up resin.
- Buy the nylons with no toes, and save money.
- Seal the nylons quickly and easily and save time.
- This also works exceptionally well sealing the nylons we use on
our thumb spica molds. It easily makes a thumb and index finger
seam that conforms to the mold much better and prevents the nylon
from bridging the gap.
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Trimmed nylon vacuum hose with seam |
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Seamed PVA bag with clipped corners |
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These impulse sealers range in price from $29 to $129, depending
on where you buy them. I have examined the lowest- and
highest-priced units in the 12-in. size and cannot find any
significant difference other than price, so go for the least
expensive unit. It is my opinion that the 12-in. model will be all
that is needed for a busy O&P facility.
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Seamed Nyglass over mold |
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Mold with seamed nylon and PVA bag |
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We initially bought this sealer to use for sealing our PVA bags
for laminations, but now it is used many more times a day for
seaming the nylons and Nyglass products used in other methods of
fabrication.
I'm sure that you will find other uses for this device as
well.
Good Luck! Jack Pranzarone, CP, is employed at Hanger Prosthetics & Orthotics Inc./Ft. Walton Orthopedic Inc., Fort Walton Beach, Florida. 
Table Of Contents - May 2006
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