Re: Copying Model
Leow Eng Lye
Description
Collection
Title:
Re: Copying Model
Creator:
Leow Eng Lye
Date:
2/7/1999
Text:
Hi Harold
I'm an upper limb prosthetist specialising in silicone hand and finger
prosthetics. An intergral part of my work involves taking impressions of the
hand and duplicating models.
I have some suggestions as regards your post on duplication of hand models.
If it's important to you that the fine details of the hand is well
duplicated, you may want to use epoxy resin (Chemi, H77N, Ciba Geigy,
Switzerland) as the casting material instead of plaster. I assure you that
this would give a near-exact duplication result that is difficult to achieve
with plaster. Whichever material you eventually use , you might just want
to consider destroying the aliginate impression. All would not be lost as
the model would have been duplicated. Therefrom, I would recommend that you
use a 2-component RTV silicone elastomer (KE1300T, Shin-Etsu Chemical Co.
Ltd, Japan or Otto Bock 617H43 silicone gel) to make a master negative
mould of the duplicated hand model. From this master negative, you would
proceed to make as many duplicate models as you wish. The advantage with
using silicone is that there wouldn't be a problem with model withdrawal as
would with alginate. Since silicones are elastic, the hand model can be
removed without having to destroy it - you could have used a 2-component RTV
silicone to make the impression to begin with. A word of caution when using
RTV-2 addition-curing silicones...... do not use latex gloves or contaminate
casting surfaces with rubbery/ latex materials as this would poison the
silicone and cause it not to cure fully.
I hope these information would provide you with some leads. If you need
further information on the manufacturers'/ suppliers' contacts, please feel
free to e-mail me. Good luck!
Regards!
----------------------------------------------------------------------------
--------------------
Michael EL Leow, M.Sc., Cert.Prosthetics (Northwestern)
Research Fellow
Dept of Orthopaedic Surgery
National University of Singapore
&
Prosthetist & Medical Illustrator
Dept of Hand & Reconstructive Microsurgery
National University Hospital
5 Lower Kent Ridge Rd
Singapore 119074
E-mail: <Email Address Redacted>
Tel: 65-7725549; Fax: 65-7732558
> ----------
> From: Anderson Harold R.[SMTP: <Email Address Redacted> ]
> Reply To: Anderson Harold R.
> Sent: Saturday, February 06, 1999 1:05 AM
> To: <Email Address Redacted>
> Subject: Copying Model
>
> I was asked to take an impression of a dying man's hand for his family
> which
> I did using Alginate. I got a good impression and now need to make 9
> copies
> for members of the family. The plaster model will not come out of
> alginate
> without destroying it. Any ideas of a material and procedure to use to
> clone this hand 9 times?
>
> Harold Anderson C.O.
>
I'm an upper limb prosthetist specialising in silicone hand and finger
prosthetics. An intergral part of my work involves taking impressions of the
hand and duplicating models.
I have some suggestions as regards your post on duplication of hand models.
If it's important to you that the fine details of the hand is well
duplicated, you may want to use epoxy resin (Chemi, H77N, Ciba Geigy,
Switzerland) as the casting material instead of plaster. I assure you that
this would give a near-exact duplication result that is difficult to achieve
with plaster. Whichever material you eventually use , you might just want
to consider destroying the aliginate impression. All would not be lost as
the model would have been duplicated. Therefrom, I would recommend that you
use a 2-component RTV silicone elastomer (KE1300T, Shin-Etsu Chemical Co.
Ltd, Japan or Otto Bock 617H43 silicone gel) to make a master negative
mould of the duplicated hand model. From this master negative, you would
proceed to make as many duplicate models as you wish. The advantage with
using silicone is that there wouldn't be a problem with model withdrawal as
would with alginate. Since silicones are elastic, the hand model can be
removed without having to destroy it - you could have used a 2-component RTV
silicone to make the impression to begin with. A word of caution when using
RTV-2 addition-curing silicones...... do not use latex gloves or contaminate
casting surfaces with rubbery/ latex materials as this would poison the
silicone and cause it not to cure fully.
I hope these information would provide you with some leads. If you need
further information on the manufacturers'/ suppliers' contacts, please feel
free to e-mail me. Good luck!
Regards!
----------------------------------------------------------------------------
--------------------
Michael EL Leow, M.Sc., Cert.Prosthetics (Northwestern)
Research Fellow
Dept of Orthopaedic Surgery
National University of Singapore
&
Prosthetist & Medical Illustrator
Dept of Hand & Reconstructive Microsurgery
National University Hospital
5 Lower Kent Ridge Rd
Singapore 119074
E-mail: <Email Address Redacted>
Tel: 65-7725549; Fax: 65-7732558
> ----------
> From: Anderson Harold R.[SMTP: <Email Address Redacted> ]
> Reply To: Anderson Harold R.
> Sent: Saturday, February 06, 1999 1:05 AM
> To: <Email Address Redacted>
> Subject: Copying Model
>
> I was asked to take an impression of a dying man's hand for his family
> which
> I did using Alginate. I got a good impression and now need to make 9
> copies
> for members of the family. The plaster model will not come out of
> alginate
> without destroying it. Any ideas of a material and procedure to use to
> clone this hand 9 times?
>
> Harold Anderson C.O.
>
Citation
Leow Eng Lye, “Re: Copying Model,” Digital Resource Foundation for Orthotics and Prosthetics, accessed November 6, 2024, https://library.drfop.org/items/show/211234.
