3D printed jewelry - The future begins today

What if you could have anything you want printed by a company for you?

It is possible.

Nowadays, there are more and more companies which are offering that solution for you. Not only you can print miniatures, accessories, but also jewelry and art. 

Shapeways is a company producing such objects. How does it work? Just after you enter their website, you need to click a big button ''3D print your models" and then upload your 3D model. That's it. They offer hiring a designer or watching tutorials helping to start your adventure with 3D printing. Why am I writing about it? Lately, 3D printing gained more interest. Last year during Milan Design Week MƎTHESIS exhibited on metal 3D printed products. High quality and good design- these are the main features of products we all want to have. Designers who were participating this event created 10 tableware items. Furthermore, Dough Bucci, a famous designer, created with the help of 3d printing a necklace inspired in his own diabetes-related medical data. It was exhibited in the Cooper Hewitt Smithsonian Design Museum.

The most common materials for jewelry designers are metals like: brass, silver, gold and bronze. Besides metals, jewelry designers also use other 3D printing materials such as polyamide, alumide, rubber-like and even ceramics. 

3D printing is typically used to create jewelry via 2 methods- investment casting and direct printing.
Investment casting produces parts through an 8 step process:

1. Pattern formation

Traditionally this was done by pouring a special casting wax into a metal mold. 3D printing now allows the pattern to directly be printed from wax or a castable resin.

2. Mold assembly

The molded or printed pattern is then assembled onto a “casting tree”. This allows multiple parts to be cast at once. Some 3D printing methods disrupt this step by printing the part patterns and the tree in a single step.

3. Shell building

After completion of the pattern assembly, the entire assembly is submerged multiple times in slurry. The slurry coating is then left to dry and solidify forming a ceramic outer layer over the pattern.

4. Burnout

The structure is then placed inside a furnace and the original wax/resin structure is melted/burnout resulting in a hollow negative mold (cavity).

5. Pouring

Once all the original pattern material has been removed from the ceramic negative the final casting material is poured into the mold and left to cool and solidify. Parts are often cast in brass and then electroplated in precious metals during the finishing stage.

6. Knock off

The outer ceramic mold must then be removed. This is typically done by vibrating the mold to knock off the outer shell.

7. Cut off

After the ceramic shell is completely removed the individual cast items are cut off the mold tree.

8. Finishing

The cast parts then go through traditional jeweler finishing techniques.

The two most suitable technologies for producing 3D printed patterns for investment casting are:

SLA/DLP

SLA and DLP are both vat photopolymerization techniques that photocure a UV sensitive resin one layer at a time to produce a solid part. SLA and DLP are capable of producing smooth, high detail parts from castable resins that have a very low remaining ash percentage after burnout. Both SLA and DLP require support to accurately print parts. Support material generally has a detrimental impact on the surface of a print it is in contact with and must be removed once the print has been completed.

DOD

Drop-on-demand printing is a material jetting technique that uses 2 print jets; one to deposit a wax-like material over a build surface and another to deposit dissolvable support. The wax is deposited one layer at a time and a solid part is built up. 

A much less popular method of producing jewellery via 3D printing is directly printing parts from metal powder. Parts are able to be printed via gold, silver or platinum alloys and then require a significant amount of post-processed to an appropriate finish. Direct printing of jewellery is more expensive than investment casting, even for one-off pieces, and requires a very high level of precious powder management.

DMLS/SLM

Direct metal laser sintering (DMLS) or selective laser melting (SLM) are powder bed fusion techniques used for the production of metal parts. To accurately produce parts DMLS/SLM require a significant amount of support to be included on the part during printing. High temperatures result in high levels of stress meaning parts are often susceptible to warping or deformation. This leads to significant post processing being needed to remove the support and finish the surface where it was attached.

For creating jewelry i.materialise.com uses Lost-Wax Printing and Casting. This technology builds upon modern 3D printing technology as well as traditional metal casting.

It all starts with 3D printing your 3D model in wax. The 3D printer uses a wax-like resin as printing material. Next, one or more wax sprues will be attached to your model. Then your model will be attached by the sprue to a wax ‘tree’, together with several other models. The tree is then placed in a flask and covered in a fine plaster. When the plaster solidifies, it forms the mold for casting the metal. The plaster mold is then put in an oven and heated for several hours to the point where the wax is completely burned out.

What are the advantages of 3D printing? For sure, the biggest benefit for jewelry designers is no longer worrying about production. Moreover, 3D files can be easily edited and such manufacturing method allows to produce an incredible amount of details. According to i.materialise.com it is also cheap to print jewelry. They are presenting a concrete example- a ring printed in PU-coated bronze which costs 33 EUR. In brass the price would be 30 EUR, in gloss silver 57 EUR. In 14k yellow gold the ring would cost 802 EUR.

Metal 3D printing is no doubt a new interesting manufacturing method which will influence the industry and create better solutions. 

Kasia

Useful links:
https://www.shapeways.com/
https://3dprint.com/130335/metal-3d-printing-methesis/
https://i.materialise.com/blog/3d-printed-jewelry/
https://www.3dhubs.com/knowledge-base/jewelry-3d-printing-applications