Re: Castable Porous materials

From: Michael Tsenter (
Date: Thu Aug 20 1998 - 19:46:33 EEST

Larry Whitaker wrote:
> I am looking for a castable material that will result in a rigid, porous
> matrix that can be used as a vacuum forming die. My approach is to make RTV > impressions( positives and negatives) from a variety of customer geometry's > and then cast the porous "dies" off of these impressions.

Dear Larry:

Our ESPOR micro-porous air-permeable casting technology may be exactly
what you are looking for. ESPOR material is a combination of aluminum
powder and epoxy. When mixed together, the material resembles wet sand,
and it is then packed against the pattern to create the opposite (ex. if
your pattern is "male", the mold will be "female") The packing is done
with a pneumatic vibrating hammer, so the pattern has to be rigid (RTV
will flex) and strong enough to withstand these forces. The pattern can
be: wood, plastic, epoxy, rigid urethane, RP master (SLA, LOM, FDM, SLS)
backed with epoxy, etc. ESPOR material has "ZERO" shrink, so the
pattern can be 1:1.

The main advathage of ESPOR is to produce vacuum forming molds with very
complex geometry which is dufficult to machine. Complex petterns such
as leather texture, human skin texture, etc. can be duplicated without
any problems. ESPOR technology is also used to produce very large
thermoforming molds such as instrument panels (dash boards) for cars,
molds for refrigirators, molds for truck floors, etc.

ESPOR molds are durable enough for high volume (up to 1,000,000 cycles)
production, and can be supplied with cooling lines installed.

ESPOR Technology is available for licensing (if you plan to make several
molds per week), or as a service from us.

Our air-permeable METAPOR block material is available in plates for

Other applications outside of vacuum forming include:
-tooling for V-process sand casting
-vacuum holding devices
-air bearings
-powder fluidization systems

Feel free to contact me with any other questions.

Best regards,
Michael Tsenter

PORTEC - North America
a division of NEST Technologies
3849 Ridgemoor Drive
Studio City, California 91604

Tel: 818-761-6500 Fax: 818-761-6116 e-mail: web site:

For more information about the rp-ml, see

This archive was generated by hypermail 2.1.2 : Tue Jun 05 2001 - 22:46:31 EEST