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3D FOR JEWELLERY

For decades, making Jewellery patterns out wax for direct casting was a dominant method. The skilled Jewellers need to skilfully craft hand-drawn designs . This method requires a lot of skills and time.
By entering into a digital era, Jewellers could design their ideas by 3D design software like AutoCad 3D or Rhino 3D. Also some years later CNC milling machines have been introduced to manufacture wax patterns automatically. Digital 3D design and CNC milling saves a lot of time and labour. However, there were still some limits on complexity of designs and speed of manufacturing.
3D printing and 3D wax materials have opened new opportunities for designers and Jewellers. Through the use of Liquid Crystal 3D printers this enables manufacturing of highly customized, geometrical complex and more cost effective jewellery models. Another unique feature of the Liquid Crystal 3D printers is the time to print multiple models. Multiple models can be produced in the same time as one single model, saving you time and money

PROCESSING PRINTED PARTS

After printing, wash parts thoroughly with warm, soapy water. Ensure there is no remaining, uncured resin on the parts after washing them. If the parts are very delicate it is easier to clean them in an ultrasonic cleaner using warm soapy water.
For Daylight resin: Post expose parts under water in a clear container (glass or plastic) for 10 minutes in strong light (UV lamp) or 30 mins under a table light or in sunshine. Turn the object half way through to give it even exposure to light.
For DLP and Laser UV resin: Post expose parts for 10 minutes in a UV lightbox under water. Turn the object half way through to give it even exposure to light

DIRECT CASTING (LOST WAX CASTING)

Final Steps prior to casting for Daylight and UV resins

If you have cleaned and post exposed parts thoroughly they will have dry surface finish. If they are still a little sticky after post exposure, wipe them with IPA until dry. Coating samples with a PTFE coating prior to casting is recommended to prevent the investment sticking and leaving a rough surface over the cast parts. We recommend Plasticast investment (preferably Plasticast with BANDUST) by Ransom & Randolph.

Casting Process:

Note: Dwell time is highly dependent on flask casting size. The following times are recommended for tree-like assembly in casting flasks less than Ø100 x 200mm.

Quick Burnout: If you are not pre-placing any precious stones in the casting flask, you can also use a quick casting cycle as follows:

Heat your kiln to 730 °C
Place the flask in preheated kiln (730 °C), and hold for 4 hours.
Allow to cool naturally with furnace door ajar, to casting temperature.
Hold at casting temperature for 30 minutes, then pour molten metal into the cast.

Moulding

Rubber moulds can be made from the master design pattern. Liquid wax is then injected to the mould cavity and multiple wax parts will be manufactured one after each other resembling the detail of the master design. The master design pattern can be built out of wax either crafted, machined or printed as a 3D object. 3D printed objects are the more cost effective and time efficient in comparison to any previous techniques.

Printing and post processing

A ring model has been printed with the Liquid Crystal HR using daylight high tensile at 100 um. The ring is then washed with warm soapy water and left in ultra sonic bath filled with fresh soapy water for 10 minutes. Followed by 30 minutes post exposure under a UV lamp in water.

Creating the mould

A regular silicon rubber mould has been made from the ring. The ring can be packed between multiple sheets of silicon rubber and then the whole pack is placed under a hot press. Through this method the rubber softens, while the pressing rubber sheets weld together.

The welded rubber pack is then cooled down to room tempreture. It has been cut skillfully into two halves, in order to release the ring and leave a cavity to make multiple wax rings. Cleaning the ring throughly is extremly important to achieve perfect mould with smooth cavity surface. Ensure enough post curing has occurred and make sure the surface of ring is not sticky.

Making Multiple Wax Models

After making the mould the 2 parts are put together and hot liquid wax is injected into the ring cavity. The mould is left to cool down and the outcome is a wax ring the same of the 3D printer ring. These steps can be repeated to produce multiple rings from the same mould