MAKING YOUR VISION REALITY
stereo lithography 3d printing
SLA Stereolithography is a process by which a 3D printing machine, called a Stereo Lithograph Apparatus (SLA), converts liquid plastic into solid objects.
The drawing of the product is received in the form of data which is converted to an STL file. This is used to design and control the build. At this point it is processed through other software and a support structure is applied.
In order to complete your 3D print the initial model is sliced. These slices are then built using an SLA machine until the final layer is printed, completing your model. SLA Machines use UV setting resin which is then cured by using UV lasers.
Fused Deposit Material (FDM) or Fused Filament Fabrication (FFF) is probably the most popular printing process, due to the number of printers available on the market (from the 3D Printer Kit versions to the Professional 3D printer).
FDM is an additive manufacturing process that is great for rapid prototyping concept parts, functional models, manufacturing tooling, moulding, and even end use parts. This process works by the material being melted and extruded through a nozzle ,this is in order to 3D print a cross section of an object each layer at a time. The bed lowers for each new layer and repeats until the object is completed. Layer height determines the quality of the 3D print.
Some FDM 3D printers can have two or more print heads that can print in multiple different colours ,and use support for overhanging areas of a complex 3D print. Many different materials exist for this type of printing process. It varies between the industrial versus the consumer version. The most common however are ABS, PLA and polycarbonate. Unlike ABS, PLA is biodegradable and is popular due to it being non-toxic. There are also dissolvable materials such as PVA which is often used for support.
Objects which are printed with Selective Laser Sintering (SLS), are created with powder based materials, most commonly plastics, such as nylon, which are dispersed in a thin layer on top of the build platform inside an SLS machine.
A computer controlled laser pulses down on the platform, tracing a cross-section of the object onto the powder. The laser heats the powder either to just below its boiling point (sintering) or, above its boiling point (melting), this fuses the particles in the powder together into a solid form.
As each layer is formed, the SLS machine platform lowers, usually by less than 0.1mm, and a new layer of powder is laid down for the laser to trace and fuse together. This process continues until the entire object has been printed.
The many advantages of SLS are : SLS requires very little additional tooling once an object is printed, meaning that objects don't usually have to be sanded or otherwise altered once they come out of the SLS machine.
SLS doesn't require the use of additional supports to hold an object together while it is being printed. Such supports are often necessary with other 3D printing methods, such as SLA or FDM, making these methods more time-consuming than SLS.
SELECTIVE LASER SINTERING
Digital Light Projection (DLP) uses a similar printing process to SLA. The initial set up is the same, requiring an STL file as the initial model. The sliced model is then projected onto the surface of the resin, hardening the area exposed to the light. This forms a layer and as each layer is formed the bed is lowered building the 3D form.
DLP has the advantage that each slice, regardless of area, is exposed at the same speed. A scanning technique slows as the volume increases. DLP is one of the finer machines when regarding organic forms. Our machines can capture a resolution of 25 microns. Minimal post print clean up is also a benefit of using this form of printing.