Jump to content
Sign in to follow this  
vinoodd

Help Needed On Ceramic Moulding

Recommended Posts

Hi Everyone,

 

I am a newbie and would like to learn how do we make ceramic pots or tiles.

 

Currently, I am stuck in an application where i need to make a ceramic top for an instrument which can withstand temperature upto 500 C.

The instrument is similar to a Hot Plate.

 

Any knowhow on how to make such ceramic tops will be a great help for completing my project on time.

 

Thanks in advance.,

 

Vinod

Share this post


Link to post
Share on other sites

Dear All,

 

Thank you all for the replies.

 

The dimension of the top plate I am looking for is around 25 X 25 cms.

We have successfully tested the temperature by winding a spring type nichrome coil on bottom part of an SS block where the path for the same is grinded of.

We have done it with an SS top sheet and due to the non uniform heating and as some chemicals tends to react on SS, we are planning to move to ceramic.

The max temperature, i.e 500 C is reached within 10 minutes on the SS sheet, almost uniformly is 25 X 25 cms. The time required to achieve desired temperature is not a big issue.

I am not an expertise in ceramic pottery or clay pottery and that is the main reason why i posted my requirement here., among the group of experts.

 

Pardon me, I am a newbie in this field and I need information from tip to toe., ie. starting from which ingredients are used/preferred to how much temperature is required in firing.

The requirement is a single use., maybe for 2 equipments. So I am not looking for any costlier investments on machines for this. 
There are such equipments already been in market and can be bought off the shelf, but my requirement needs some customization and no vendors will entertain such customizations for low volume orders unless they sees some business potential in it.

 

An example of a standard equipment is in the web link given below. 

http://www.laboratory-equipment.com/laboratory-equipment/ceramic-hot-plates-cimarec.php

 

Kindly have a look. 

Awaiting your valuable replies.. 
Thanks in advance,

 

VinoD

Share this post


Link to post
Share on other sites

The simplest thing to do might be to just buy a kiln shelf and try that. They can be cut to size with a with a masonry blade on a circular saw. If you can slow down the 10 minutes to 500C heating time it would lessen the chance of it cracking.

 

I don't know where you are but something like this: http://www.axner.com/cordierite-shelf-13x14x58-rectangle.aspx 

Share this post


Link to post
Share on other sites

Hi Vinod:

Very unusual and unique request: then again the kind of problem I like. You are dealing with a thermal expansion issue: 500C in 8 minutes. Will have to work on some formula, but can already say high alumina and pyrophyllite will be the basis of the clay body. You will have to fire it to 1280C in order to get adequate mullite formation: in lieu of the usual glassy matrix of a standard clay body. How much chemical resistance will be needed? You have no means to press mold this piece, so the clay formula will have to include some ball clay simply to allow you to form the piece.

Nerd

Share this post


Link to post
Share on other sites

Vinod:

Came up with a modification of a burner plate body I did a couple of years back. It is lightweight (as clay goes) and has fairly high thermal shock resistance. After I fired it, I put it in my test kiln and heated it up to 600F. Took it out of the kiln and dropped it in a bucket of cold water, and then back into the kiln again: not one crack! The piece I made was an 8" circle, with a 2" hole in the center for the flame to pass through. The plate on the burner you showed looks like it has a profile that was pressed into shape. For that reason I am going to increase the ball clay to give you enough plasticity to form it.

Test Batch 1:

Alumina Hydrate 35.0%

Stoneware Clay  20.0%    (A ball clay with larger particle size, and higher plasticity.)High iron content okay.

Pyrophllite          17.0%

Silica  200m         8.0%

Nep Sy.               20.0%  ( Nepheline Syenite)  Might try some Colemanite, but let's see how this works first.

>>> 0.52¢ a lb.

Make a 200 gram test batch:  enough for 4 x 4 tile by 1/2" thick. Slow fire to 1280C in gas kiln if available: electric is okay too.)

Torture Test: After firing to maturity: reheat to 400C, pull if from the kiln (protective gloves) and toss it into cold water.

Was also trying to create a body that would absorb/transfer heat without much interference.

If chemical resistance is imperative: can trick it up a bit and make it self glaze.

Nerd

Share this post


Link to post
Share on other sites

Prophillite what ll help you a lot in this application as Nerd says

The kiln shelve will be cheaper by far the make your own clay body for a beginner will have its own learning curve.

Good luck with the tests

Share this post


Link to post
Share on other sites

I approve of glazenerd's recipe (but haven't tried it). In general, alumina will be the key ingredient for ceramics that need a high thermal conductivity and low electrical conductivity.

 

I wouldn't be surprised if Tempco can solve your problem.

Share this post


Link to post
Share on other sites

Dear All,

 

Thanks everyone for the suggestions. 

 

I think i will try the glazenerd's method. I think i can get all the chemicals listed from a lab store but not sure from where to obtain the Stoneware Clay.

I dont have press mould but can make one in lathe in SS if i really needs it. 

The ceramic top should have enough chemical resistance to wipe off the chemicals which might fall on it.
Most chemicals we use with are oxides. I still dont know whether it will stain the ceramic surface or not. But it might not be an issue if we make the top in black color.

Regards,

 

VinoD

 

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.