Selective Laser Sintering (SLS)

One of the most accurate additive manufacturing processes is Selective Laser Sintering (SLS). SLS is a well developed additive manufacturing process that can be successfully used for both prototyping and small batch production applications.

The process uses a CO2 laser, which traces the required shape direct from a 3D CAD model via an STL file across a compacted powder bed of material. As the laser interacts with the first layer of powder it is fused - or sintered - to form the prerequisite shape, and as each layer is completed the powder bed drops down fractionally so the next layer of powder is introduced to the laser and can be sintered and bonded to the previous layer. The powder bed provides any necessary support for the parts that are being built, negating the requirement for any additional supports to be built into the design - a favorable difference from stereolithography and FDM. Once the part is complete, it is raised out of the powder bed and any excess powder can simply be removed by brushing it away.

Advantages:

  • A distinct advantage of the SLS process is that because it is fully self-supporting, it allows for parts to be built within other parts in a process called nesting - with highly complex geometry that simply could not be constructed any other way
  • Parts possess high strength and stiffness
  • Good chemical resistance
  • Various finishing possibilities (e.g. metallization, stove enameling, vibratory grinding, tub coloring, bonding, powder, coating, flocking)
  • Bio compatible according to EN ISO 10993-1 and USP/level VI/121 °C
  • Complex parts with interior components, channels, can be built without trapping the material inside and altering the surface from support removal.
  • Fastest additive manufacturing process for printing functional, durable, prototypes or end user parts.
  • Vast variety of materials and characteristics of Strength, durability, and functionality, SLS offers Nylon based materials as a solution depending on the application.
  • Due to the excellent mechanical properties the material is often used to substitute typical injection molding plastics.

Disadvantages:

  • SLS printed parts have surface porosity. Such porosity can be sealed by applying sealant such as cyanacrylate.