Technicians Discuss the Challenges of Working with Plastics and Foams

Jeremy Crowell, central fabrication manager at Hosmer Dorrance
Corporation, laughed as he recalled wasting two or three sheets of plastic
while creating AFOs as a first year O&P technician. The plastics would
overheat and eventually bubble, rendering them useless. He laughs now, but
Crowell also recollected his boss being none too pleased. They were being paid
for one AFO, not three or four, Crowell was reminded. He cost his company time
and more importantly, money.


Jim Pankow, CPO, owner of Pankow Fabrication, understands that he must
run an efficient company in order for his business to survive. Still, Pankow
knows the business he is in requires trial and error.

  Jeremy Crowell
  Jeremy Crowell

“Unfortunately, with shrinking dollars, everyone is trying to
fabricate correctly the first time and it does not always work out that
way,” Pankow told O&P Business News. “There is some
trial and error involved. If you are working with a new employee, the best
thing you can do is encourage them to successfully vacuum form.”

Vacuum forming is considered an easier part of the fabrication process
and a great way for a technician to gain confidence.

“There is a little trial and error, but you just become accustomed
to it,” Crowell said. “When the plastic gets ruined or does not
vacuum correctly, you learn how and what to do to make the process more

Many companies throw their employees into the fire right away. Other
times green technicians want to prove to their boss that they have the ability
to handle complex projects, Pankow explained.

“If I throw a technician into a large project and they fail, I
should not be upset at my technician, I should be mad at myself as a
practitioner for not properly showing [him or her] how to perform the job at
hand,” Pankow admitted. “You need that constant communication back
and forth. A technician needs to have the courage to tell their practitioner,
‘I don’t feel confident doing this’ and a practitioner needs to
ask, ‘Do you understand and are you comfortable with the mechanics of this

Pankow recommends that technicians map out the process before they
fabricate. By creating a road map of their fabrication processes, technicians
can communicate to coworkers if and when they need another set of hands for

“Before, we would just take a piece of plastic and ankle-form it to
a model,” Pankow said. “Today, we have ankle joints on there, we have
a piece of carbon on there and we may even have a piece of transfer paper on
there. What one technician may have been able to do before, may [require]
multiple [technicians].”

Lines of demarcation

Communication between technicians will reduce avoidable errors in the
facility. However, constant communication needs to take place between the
technician and the O&P practitioner as well. As the O&P industry
progresses, the practitioner is getting further away from the fabrication side
of the field, according to Pankow. This could lead to differing viewpoints. An
adjustment that may seem simple to a practitioner may not be possible from a
fabricators point of view.

  The challenges of working with foam and plastic vary due to years of practice and equipment condition.
  The challenges of working with
foam and plastic vary due to years of practice and equipment condition.
  Image: Jeremy Crowell

“We have progressed to where we have pretty stable lines of
demarcation,” Pankow said. “If it is a technician’s job it will
go to the tech guys and if it is a clinician’s problem, it will go to the
clinicians. The last thing you need is a headlock between the tech side and the
clinical side.”

In the past, practitioners designed, casted and fitted their own
components. Today, the entire system has changed. Practitioners and technicians
who adapt to the new system, will run a smoother facility, Pankow explained.

“You try to keep the circle smooth so you can move people through
your practice efficiently without getting into headlocks over a project with
your staff,” Pankow said. “If you have poor systems in place, the
patient will suffer.”

Crowell agrees with Pankow that all roads lead to the patient.

“It is the little things that will ultimately determine the quality
of the product,” Crowell said. “If you let any of that lapse, your
customer is going to know.”

Technical challenges: Foam

O&P technicians must find creative ways to work around the
imperfections. Foam acts as an insulator. If a technician is using a soft
interface with an AFO over the foam, such as plastazote, the heat from the
plastic gets trapped between the foam model and the interface foam.

“The heat will completely cook the interface foam,” Rob
Hoskins, RTP, Prosthetic Design Inc, said. “People have tried to do
plaster washes over the foam with only marginal success.”

Another challenge a technician faces on a daily basis is the foam
flexing and bending when they drape-form a piece of sheet plastic onto the
lower leg model of an AFO, Hoskins said.

“There is a chance that if you do not have a built-in strut between
the foot and the shin, the weight of the plastic can cause the toe to rise in a
dorsiflexion motion,” Hoskins said. “The mechanics of your brace will
be incorrect if that occurs.”

Technical challenges: Plastic

It is important to eliminate the unknowns when working with plastic.

“You just never know,” Pankow said. “Plastics can heat at
325·F to 400·F and you never know what that surface is going to
do. You want to take those gambles out of the equation and neutralize things as
much as possible.”

Overheating or not evenly heating the plastics is a common occurrence.
In order to avoid those pitfalls, technicians must balance the preferred
heating instructions of the company with the suggested heating guides of the
plastic manufacturer.

“Usually your plastics provider will send you a chart specifically
designated for the plastic that you are using: your co-polymers, polypropylene
or any other type of plastics,” Crowell said. “They will give you a
recommendation based upon the ovens you have.”

In addition to heating charts from the materials provider, Crowell
recommends technicians make their own charts for company uniformity.
Technicians should constantly check for the plastics to turn clear before they
are ready to be placed under vacuum. The plastics are placed under vacuum to
equal out the temperature and avoid bubbling, Crowell said.

Technicians may find themselves waiting for the plastics to either heat
or cool down. In a busy central fabrication setting, for example, it may be
tempting to speed up the process by raising the temperature of the oven or
taking the plastics out of the oven early.

“It is my opinion that the time you lose heating the plastic, you
pick up in other areas [including] the milling process of the model or the
trimming and cleaning of the piece that you will whittle into an AFO or a
plastic socket,” Hoskins said. “The process is a lot cleaner with
plastics. You have the opportunity to modify the finished product to a greater
degree with heating, which produces a more professional job. By having the
opportunity to modify the plastics, technicians do not have to completely scrap
the job and start over.”

Faulty equipment

If a technician appropriately follows their plastics heating charts and
the plastics are still burnt, the problem may be with the oven.

“You have to change the bulbs in your oven or make sure the door is
shutting properly because the plastic will unevenly heat and it will be too
soft or too hard on the other end,” Crowell said.

An oven door repeatedly opens and closes in a fabrication facility.
Technicians may not notice if weak hinges have left a small gap that will allow
air to get through. This would cause uneven heating.

“You need to maintain your equipment and to do that you need an
updated time schedule,” Crowell said.

Pankow implemented a system at his facility that records adjustments
made to any piece of equipment on a monthly basis.

“It could be as simple as a leak in a vacuum line, where it has
been leaking for months but no one has followed up on it,” Pankow
explained. “It works, but the vacuum is not getting the amount the
clinician wants.”

This could lead to inaccurate readings because the device will be too
large or too small for the patient.

Technicians should also inspect their plastics to insure that they are
of the highest quality.

“Generally speaking, plastics are mostly the same,” Crowell
said. “In our field, they are such an important part [of the process],
that a good relationship between the supplier needs to be there. If the plastic
is damaged, they need to be able to rush you out a replacement.” —
by Anthony Calabro

Leave a Reply

Your email address will not be published.