Re: Castable Porous materials

From: Bill Seil (
Date: Mon Aug 24 1998 - 14:51:52 EEST

We've had a great deal of success at PDSI with the Syntactic foams from Emerson & Cummins (formerly Grace Specialty Polymers, 617-861-6600). They should be able to help you find the material you need. We would be
happy to save you time and money by produceing your dies for you. Please contact us (919-848-0123, if you'd like more details.


Wade Williams
Sales Manager

Michael Tsenter wrote:

> 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
> machining.
> 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

For more information about the rp-ml, see

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