Rapid Product Development – SLA

Design and Development - Comments Off - Posted on January, 30 at 5:36 pm

Stereolithography (SLA) is a Rapid Prototyping process used to develop plastic prototypes from CAD data in a matter of hours. Similar to PolyJet, SLA is an additive manufacturing process and may also be referred to as rapid prototyping, solid-free-form fabrication, or 3D printing. This process is highly accurate producing fine feature detail and is often used to create a small quantity of parts early in the design process. SLA models are typically used as visual aids, to help communicate a vision, to fix design issues, for form and fit studies, or as master patterns for molding techniques.

Like other additive manufacturing technologies, the SLA process begins when CAD data is “sliced” into thin cross-sections or layers (as small as .004”) and transferred to a SLA machine containing a vat of UV-curable photopolymer resin.

The machine begins to build the part one layer at a time. Each layer is constructed from a UV laser that traces a cross-section of the design on the surface of the resin material. As the laser traces the pattern on the resin, the material is hardened/ solidified on contact. Once the layer is constructed, the build platform is lowered slightly to make room for the next layer. A recoating blade moves across the surface ensuring a thin coat of fresh liquid resin is evenly spread over the object. This allows the next layer to be accurately built on the preceding layer. The laser continues to trace and form each layer upon the previous layer, building from the bottom up until all cross-sections are built.

The completed part is then carefully removed from the liquid and separated from the platform. A chemical bath removes excess resin and the part is cured in a UV oven. Next, support structures are removed from the part. These structures are created during the build to strengthen weak areas such as overhanging (down-facing) features. They prevent gravity and the pressure of the moving arm from damaging the part. Raw SLA parts have small stair-steps or ridges due to the layer additive process. The larger the layer, the more stepping or “tree barking” the part will have. Hand sanding can be used to remove any stepping on the product if so desired. Solid Concepts provides hand sanding and both cosmetic and non-cosmetic paint options through its Finishing Department that can give prototypes the look and feel of production quality parts.

source: www.solidconcepts.com

Posted in Design and Development | Comments Off

Comments are closed.