Bioelastic Responses

John Brinkmann, CPO, FAAOP

Description

Title:

Bioelastic Responses

Creator:

John Brinkmann, CPO, FAAOP

Date:

1/2/2002

Text:

Dear List Members: Here are the responses to the question I posed about
use of Bioelastic. Happy New Year to all.

John Brinkmann, CPO

To: < <Email Address Redacted> >
Sent: Thursday, December 20, 2001 7:31 AM
Subject: [OANDP-L] Bioelastic

Dear List Members: I'm planning on doing some fabrication with
Bioelastic for the first time. I'd appreciate any hints on fabricating
a flexible AK liner - should I pull directly against the mold, sealed or
unsealed; can the plastic be draped (bond to itself with a seam) or does
it have to be drooped; best temp for heating; do you heat the mold prior
to pulling; etc?
John Brinkmann, CPO


Pretty much as you'd expect. It will bond to itself and you can finish
the seam to be all but invisible, but bubble forming is easier and
prettier. Assure the seal at the valve by tying the bioelastic into the
valve housing groove - I prefer a wire tie, but string works - just
don't tie it so tight that you thin the plastic out too much. Unlike
polypro, you can put your hands on the bioelastic - gently! - as you
pull it, so you can manually move the plastic to avoid webbing or
relocate webs to areas which will be trimmed out.
Daniel Watkins MS CPO


…use a frame that is big enough, pull against the model (no nylons), it
will bond to itself if you would rather seam it and I believe the best
temp is 350.
Andy Steele


John, Bioelastic is actually Northvane. Northvane is supplied by
Endolite and is less expensive as well.
It is 24% EVA & 76% low density polyethelene material that is press
moulded, so there is no shrinkage.
You can seam it if you wish, but blister forming will get you a good
result if you correctly heat the material. Approx 3mins per mm
thickness, I would still rotate it halfway thru it's cycle. Unless you
are using an infra-red oven. Temperature is 150C or 302F.
Call me at Endolite if you need any more assistance.
Alan


Hi there..I have worked extensivley with bio elastic for the last 10
years.heres some hints...300 degrees is the best temp to cook it. Buble
forming works best you can drape it it does easily adhere to itself when
heated,however it is extremely soft and droopy when heated, difficult to
lift off a tray... do not seal the cast any thing on the surface of the
cast will adhere to the bio elastic so the cast must be clean plaster
period..i
have never preheated the mold and have never had a problem with
shrinkage,once its formed it holds that shape very well..you can also
weld to it by heating both pieces till clear and then applying the new
piece
wherever you need it and squeezing the two together..should the patient
loose our gain volume after you fit the socket keep the cast you made it
off of and simply remodify then heat the bio till floppy and put it
over the modified cast and throw a heavy plastic trash bag over it and
aplly vacum it will reshape to the new mold either shrinking our
stretching..if i can be of more help e mail me at
<Email Address Redacted> will be glad to help..its wonderfull stuff to
work with and the patients love it..Steve
Wilson..L.P..L.O.A


Bioelastic can be draped over a non heated cast without any problems.
By the way you would have bought a different thickness if you wanded to
blister mold it. Even heating is essential.


Hi John.
We use Bioelastic a lot in this lab. We find the following: For 1/2
thickness, 325°F works best, for 16 min. +/- 2 min. There is no need to
seal the cast, but it should be free of any imperfections, as the
Bioelastic will suck into everything. It can be draped or drooped. It
is not necessary to heat the mold. For drooping, you should let it
stretch 50% of mold length.

Brett Barnts, CPO

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Citation

John Brinkmann, CPO, FAAOP, “Bioelastic Responses,” Digital Resource Foundation for Orthotics and Prosthetics, accessed November 22, 2024, https://library.drfop.org/items/show/218224.