How does 3D Printing work?
In our series about 3D Printing, I briefly introduced what is 3D Printing and the three processes I use at OHLINA – these were: FDM (Fused Deposition Modelling), SLS (Selective Laser Sintering) and SLA (Wax Stereolithography Printing) & Casting.
Before we dive into the details of how each of these processes work — as a general thread about 3D Printing — it is an additive manufacturing process that takes your 3D digital file and transforms its DNA (data) by printing layer upon layer of material in sequence to create the outcome of an object.
FDM (Fused Deposition Modelling) — Direct 3D Printing
I will begin with the most conventional way of printing and this is FDM (Fused Deposition Modelling).
In our studio, we use FDM to thoroughly test out designs and forms — it is perfect for prototyping because it is inexpensive to run and you can achieve fast output within minutes to hours. This makes it a perfect option during our prototyping stage, where we refine our designs until it is perfect in form and size using FDM before we send it to the high-resolution large industrial printers.
It begins by importing the digital file into the slicing software, where it slices across the XY plane of the model from the bottom up for the build process. Each slice generated is a “layer” of material — each layer is produced by extruding molten filament material (PLA or ABS plastic) through the nozzle. The movement of the nozzle is generated by the tool paths created through the slicing software — with the print being built from the bottom up, one layer at time. Support structure and a raft (base) maybe generated, if necessary.
SLS (Selective Laser Sintering) — Direct 3D Printing
For our nylon-based jewellery, we use SLS (Selective Laser Sintering) as the final manufacturing process after prototyping with FDM. It works similar to the workflow of FDM – using a slicing software to generate the layers for it to be built. But, instead of “extruding molten material”, thin lines of the laser are drawn through the nylon powder. The laser melts and bonds the powder together to form a thin layer of the model before a roller is rolled across to apply a fresh layer of nylon powder ready for a new layer to be fused. This process is repeated from bottom up – resulting in a large block of powder with the printed models contained inside, which would need to be brushed away to reveal the final object. Post-production is necessary, such as cleaning, polishing and dyeing the print.
SLA (Wax Stereolithography) Printing & Casting — Indirect 3D Printing
For our precious metal jewellery, we use a hybrid indirect printing process called SLA Printing (Wax Stereolithography), where a wax-like resin print is made through a curing process – a type of stereolithography. Wax sprues are attached to the print ready to be covered in plaster to make a mould. The mould is formed and heated to melt away the wax print - leaving a void for the molten metal to be poured into the cavity left by the wax. Once the metal has been cooled and solidified, the mould is broken and the metal cast is removed to be polished by hand. Combining digital and the traditional hand, this process shows us the time and effort in craftsmanship that goes into a precious metal piece by OHLINA. We continue to strive to achieve the highest quality of beauty in design and its material to respect and honour the artistic value of complex craftsmanship.
I hope you have enjoyed the How in 3D Printing and have gained an insight of why we are passionate with what we do at OHLINA!
Stay up to date with our OHLINA blog and sign up to our mailing list at the bottom of the page or in our pop up window!
— Selina Yau, Founder & Creative Director of OHLINA
All copyrights and rights reserved to OHLINA. All images, descriptions and all related assets are the sole property of OHLINA and cannot be duplicated, reproduced or used without attribution (the acknowledgement and credit to the copyright holder).