Friday, 11 October 2013

What is so shameful about plaster?

In the last few days Asda (Walmart in UK) started advertising a service to 3D scan and 3D print figurines. The press release for this seems to include the description of the process as "The shape is then recreated in 3D form by spraying ceramic fluid in thin layers to build up a solid object." - see both Guardian and Daily Mail.


I need to buy this machine!

Or do I?

It turns out a UK 3D Systems reseller is boldly stating today (11th October 2013) that it is selling Projet Colour Ceramic 3D Printers.

Now I am pretty sure that ceramic is a sexier material than plaster but is this in any way factual?

The 3D Systems MSDS for the powder that they now call VisiJet PXL Core (formerly zp151) states that between 80 and 90% of the material is Calcium Sulphate Hemihydrate. CaSO4·~0.5H2O is more normally known as Plaster of Paris.

I do not know know if the Asda press release and the UK 3D Systems reseller are connected (although the UK reseller sells both the 3D printer and the 3D scanner shown on the Asda 3D printing promotional video) but something is clearly going on here. ZPrinters now known as ProJet x60 are to my knowledge plaster based 3D printers - our ZPrinter 650, by contrast to the Asda machine, sprays water based binding fluid from printheads on to plaster based powder bed.

So what is ceramic? 

A ceramic is, according to the fount of all knowledge Wikipedia, an "inorganic, nonmetallic solid prepared by the action of heat and subsequent cooling."

The last part of this definition is important. Ceramics are formed by the transformational action of heat and subsequent cooling. I can find no connection to ceramics and plaster except that plaster moulds are used for ceramic slip casting.

The ZPrinter works by spraying a water based liquid (mostly it is water) onto a plaster based substrate (mostly it is plaster of Paris) and the part is created by in the first instance as a result of the water + plaster reaction.

As a final note the 3D Systems website Cubify is selling parts made in ceramic as Ceramix. These do look like real ceramic parts and 3D Systems do not make any claim to sell a ceramic based 3D printer to produce these parts. It is possible, though I have no specific knowledge that Cubify's Ceramix parts are printed on a legacy ZPrinter using something like ViriClay from Viridis.

And as an even more final note. Axiatec developed a cold ceramic finish to spray onto ZCorp parts. The notion of a cold ceramic precipitated heated debate among ceramicists and the general consensus was that a ceramic is not the physical characteristics of the material but the a product of a transformational process that includes heating and cooling. The Axiatec product looked and felt cold and heavy like a ceramic - Plaster parts feel like plaster parts.

Below is an image of a colour 3D print made at Lee 3D using 3D Systems plaster based powder in a ZPrinter 650 colour 3D printer. Part of a series of work on show at the Design Museum and on show until January 12 2014.

Plaster and proud of it.

(As of March 2016 - the UK 3D Systems reseller continues to sell the Projet x60 range of plaster based 3D printers as ceramic.)

To find out more about Quality Colour Plaster based 3D Printing visit

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