Stereolithography (SLA)

Stereolithography is the original additive manufacturing process. Developed in the early 1980s this is the most established of all the additive manufacturing processes. It rapidly produces parts which are both tough and accurate.

Like all additive manufacturing processes, the starting point is a 3D CAD model which has been developed on a suitable 3D CAD software package.

The process uses an ultraviolet light laser which is carefully guided over the surface of a bath which contains the photo polymer epoxy resin from which the parts are made. The original CAD model is oriented in space and then sliced into layers not 0.1 mm thick. This “slice file” is then used to create the SLA physical model.

Aben manufactures stereolithography models to high tolerance and excellent surface finishes in a variety of Somos stereolithography resins supplied by DSM. Commonly available is the water-clear “11122 Watershed” resin and the new “Next Generation LV Grey” resin. To find out more about these resins please visit our data sheets page. The stereolithography process can also be used to manufacture casting patterns, using the Quickcast process.

The Quickcast Process – tool free investment casting

By making the model hollow and introducing a lattice structure into the hollow space to maintain surface rigidity it is possible to significantly reduce the mass of resin in the part. Such a part can then so be sent to an investment casting foundry where it can be used in place of a normal wax in the lost wax process. Consequently it is possible to manufacture a metal casting without the requirement of expensive and time consuming wax tooling. Almost any metal can be used in the investment casting process and so this process is a quick and simple method of producing metal castings in very small timescales. To find out more please contact our sales staff.

File formats

Aben can accept all the common 3D CAD formats including STL, IGES, STEP, Parasolid and CATIA, as well as several others. If you have any doubt about the format of your CAD model please contact us.

SLA Surface finishing

Aben uses a specific method of defining the surface finishes which can be achieved on our additive manufactured models. The two digit alphanumeric code is used to define the surface finishes which can be achieved. The first digit controls the finish of the ’A’ surface of the part and the second digit controls the finish on the ‘B’ surface. The table below summarises the method.

Finishing Definitions

Model 'A' Surface Model 'B' Surface Finish Definition
C 3 As built with a light sand blast finish. Layer lines are still likely to be visible, but he dimensions of the part are as close to the CAD model as the SLA process can produce.
B 2 The part is finished using 600 grade wet and dry paper. Layer lines will be removed and the part is effectively ready to paint.
A 1 The part is finished using 1000 grade paper. The part will effectively be in a semi-polished state. This finish is required for the part is to be finished with a gloss paint.

Paint Finishes

Aben offers a range of paint finishes including matt, satin and a gloss. A standard range of colours are available by particular RAL numbers can be obtained upon request. Please contact our sales staff for more information.

Other Finishes

Aben can offer additional finishes including plating, the use of conductive paint and aqua-film finishes. Again if you have a special finish requirement, please contact our sales staff.