Ceramic 3D printing tests 06 - and more...

19.06.13

My penultimate day here at KHIO in Oslo and a morning of ups and downs. I mentioned yesterday that we were asked to use a kiln with extraction that has the benefit of being able to control the cooling cycle.

As you can see, the new test cubes, with thicker walls, have suffered in the firing. one has broken in two, one has cracked and the third is OK.

 

The larger version of my architectural piece has also suffered. It has deformed due to the weight of the upper part and the shell has come away from the core. There are a number of possible causes:

1. The speed of firing was too fast.
2. The speed of cooling was too fast.
3. The structure of the piece was not strong enough.
4. The binder settings were wrong. 
5. The ceramic powder formulation.

My feeling is that the cause was primarily either 1 or 2. Previous firings have been successful and the deformation of the pieces has happened in the printer, not in the kiln. 

The structure could be stronger to support the upper part.

We obviously need to conduct more tests, especially as the red earthenware seems to behave itself very well.

I have just found out that the Potclays powder will withstand 1300°C, so I plan to take some of the tests back to Manchester with me and try a selection of high temperature glazes.

So far today, the good news has been my Prtlnd Vase. It appears to have come through the printing unscathed, I'm very pleased with the detail of the surface decoration. There's litle loss of definition. The photograph shows the piece just after it was cleaned up in the depowdering unit, but it is still full of powder at this point. At this moment in time it is sat in a warm kiln, my next job, when I have finished writing this, is to remove the powder from the interior and put it back into the kiln on a warming cycle. And then programme the kiln to start firing at about 10pm this evening.

If it goes well, I will be able to take it home with me to decorate and glaze fire.

Here's what the Prtlnd Vase looked like on the Zprint software.

Before packing up for the day I glazed a selection of tests with the clear glaze and set them to fire overnight.

Tomorrow afternoon's kiln opening will be very interesting, hopefully there will be some posiitve results.