Health and Safety Considerations with DMLS and SLM 3D Printing and Post-Processing

DMLS and SLM 3D print technologies offer manufacturers the ability to create metal parts with complex geometries that may have been impossible to create with traditional manufacturing methods. With this revolutionary technology comes new health and safety considerations for your additive operation.?

DMLS/SLM Overview

Direct metal laser sintering (DMLS for short) and selective laser melting (SLM for short) are 3D print technologies that fuse metal powder particles. A laser selectively scans and fuses metal powder particles and binds them together. It builds parts layer-by-layer. DMLS involves a laser moving across the surface to sinter powder, so the powder is not melted, while SLM uses a stronger laser that fully melts the metal powder. Because of the nature of the metallic powders, production needs to be placed in a temperature-controlled room, as the powders can oxidize.?

DMLS and SLM are ideal technologies for prototyping in production-grade materials. Both 3D-print technologies are widely used across a multitude of applications, including aerospace and automotive industries, as well as tooling and medical prosthetics.

DMLS/SLM Post-Processing

Post-Processing DMLS/SLM parts involve a few steps. Depowdering in a glove box to remove excess powder manually by a technician with brushes. Parts then may need to be removed from the build platform, and construction scaffolding needs to be removed with sharp pliers or chisels. The first round of surface finishing can also occur, again, processed by hand tools for grinding, drilling, and sanding. Many manufacturers use blasting to reduce the roughness of the surface, along with machining to clean crevices.?

Common Health and Safety Considerations with DMLS/SLM

The health and environmental risks associated with traditional post-processing of DMLS/SLM revolve around the material being used to create products (metal powders) and the manual labor required to post-process the parts.?

Risk 1: Fires and/or Explosions. The metal powders are finely milled and volatile. This means there is an increased risk of fire or explosion.?

Solution: Make sure you train your technicians on the correct fire and safety procedures and have additional training provided to machine operators and maintenance technicians.

Risk 2: Inhalation and Skin Irritation. The fine particles are also easily dispersed and can be inhaled or coat walking surfaces and cause slips or falls. Particles that come in contact with skin can also cause irritation. There is also a risk of anoxia, as technicians are in a confined, controlled environment when printing.?

Solution: Proper PPE is required for all technicians, which can include slip-resistant shoes, gloves, safety glasses or goggles, lab coats, respirators, and ear protection. You should install monitors and light and sound alerts in closed rooms to warn technicians of abnormally high gas levels.

Risk 3: The post-processing steps involved with DMLS/SLM printing involve manual tasks that can become repetitive and mundane. High-frequency repetitive movements can cause musculoskeletal disorders (MSDs) like carpal tunnel syndrome, tendinitis, muscle strains, and more.?

Solution: An automated post-processing solution that allows for reduced hands-on cleaning helps prevent musculoskeletal disorders.?

While these are only a few of the health and safety considerations you should take when adopting a new 3D print technology, there are many other opportunities to improve your facility’s environment. You can learn more about health and safety in 3D printing by downloading the ADDITIVE CONSEIL SECURITE 's report “Health and Safety At Work: 3D Printing Station.” Download your copy HERE.