[vc_row][vc_column][vc_column_text][/vc_column_text][vc_tour][vc_tab title=”Material description” tab_id=”1409798254-1-64″][vc_column_text]Ceramic objects are printed from alumina silica ceramic powder and sealed with porcelain and silica. Objects are glazed a lead free, non toxic gloss white glaze. This material is food safe* and heat resistant.
NB: Pricing for Glazed Ceramic is based on surface area of your object. Pricing listed in the sidebar is in cm2 for the surface area of your object not cm3.
[/vc_column_text][/vc_tab][vc_tab title=”Technology description” tab_id=”1409798254-2-72″][vc_column_text]Ceramic objects are made on a ZCorp 3D printing machine. These machines form the part layer by layer, using an inkjet head to deposit binder onto a bed of compacted powder. Powder is layered and cured in succession until a part is formed.
The powder bed containing the printed part is removed from the 3D printer and placed in a drying oven. Drying increases the strength of the part but it is still very fragile at this point. The part is extracted from the powder bed and excess powder is removed. The part is then fired in a kiln and this is where it gains it’s strength.
After the first firing a pre-glaze coating is applied. The coating is dried and then fired for a second time. Next the objects are glazed and fired for the final time. Now the shiny smooth glaze coating is evident.[/vc_column_text][/vc_tab][vc_tab title=”Design tips” tab_id=”1409798479055-3-1″][vc_column_text]
- **MINIMUM BOUNDING BOX SIZE: Must add up to at least 120mm.
- **MAXIMUM BOUNDING BOX SIZE: Must not be greater than 400mm.
Your object needs a density (object volume/bounding box volume) percentage of 5% or higher. Generally objects with a lower density are not structurally strong enough to print. If your object does not meet these criteria, this material will not be available to make from.
- Minimum wall thickness
- 3.0mm for bounding box size 120 mm < X+Y+Z < 200 mm
- 4.0mm for bounding box size 201mm < X+Y+Z < 300 mm
- 6.0mm for bounding box size 301 mm < X+Y+Z < 400 mm
- Maximum wall thickness – 15mm
- Minimum positive detail size – 2mm
- Minimum negative detail size – 3mm
Objects need enough strength to be self-supporting especially when in the green state before firing. For example, appendages for characters should be designed with care, with sufficient structure to avoid them breaking during handling.
Objects are subjected to extreme heat during manufacture and this may mean that your object will warp. If your geometry changes from big to small, thick to thin too abruptly, or is generally not supportive of itself (eg: the complexity image above) this warping will be more prominent. Objects can also shrink up to 3% after firing.
Large, bulky geometries connected with thin structures (like a character with a big head on a skinny neck) are likely to break during handling (especially during shipping) and should be designed to avoid this. If you have features that extend and converge to a point (eg a cone) they should be at an angle greater than 10 degrees. Unsupported struts should be less than 20mm long.
Nested objects (objects floating within another object), hinged objects, and interlinking objects like chains are not possible for this material.
Objects are dipped for glazing. Your design must have an obvious base/bottom for this process to work the best. The base will remain unglazed as the object needs to rest on the base while in the kiln.
The glazing can add 1mm of material to the surface of your product. This will simplify/smooth over any fine details in your design. 3mm separation is recommended to retain definition of details on the surface. Glaze will be thinner on hard edges and will pool in valleys.
It’s hard to get a perfectly uniform object using this technique and the glossiness of the glaze accentuates these imperfections. It may be better to intentionally design facetted objects to disguise the imperfection rather than to aim for a perfectly smooth geometry.
*Glazing is key to making this material food safe. If your object cannot be glazed (eg. inside a tight container with a small opening) it will not be food safe.
For more tips on how to get the best result from glazing see this post.
Objects shouldn’t have any sharp corners where one face transitions into another. These should have a radius of 2mm so that they can be glazed well.
Holes should be a minimum of 4mm in diameter. Anything smaller and will get closed by the glaze. It is difficult to glaze internal areas of objects so these areas might not be glazed depending on the geometry.
Hollow geometry requires a hole to clean out the unbound powder from the inside. Drain holes in your object need to be 10-15mm or larger.
If objects are designed to fit together, like a pot with a lid, 4mm tolerance is recommended. The glaze can add ~1mm extra material to the walls of an object so this, as well as shrinkage, needs to be allowed for.
The original post from http://www.ponoko.com/make-and-sell/show-material/357-3d-printed-glazed-ceramic-white#main-image