Overview of Additive Manufacturing and Potential Occupational Hazards
Gary Roth, MS, PhD NIOSH Health Scientist
DOE Office of Worker Safety and Health Policy, and IH/OS SIG Webinar 8 January 2019
The findings and conclusions in this presentation have not been formally disseminated by the National Institute for Occupational Safety and Health and should not be construed to represent any agency determination or policy. The National Institute for Occupational Safety and Health The U.S. Federal agency responsible for conducting research and making recommendations for the prevention of work-related injury and illness.
Mission: To develop new knowledge in the field of occupational safety and health and to transfer that knowledge into practice. Market Impact of AM
Consumer Electronics Aerospace Automotive Medical
Comparative Advantages
Attribute Traditional Additive Manufacturing Manufacturing Materials Options Vast Small, but growing Quality Control High Varies Throughput High Low Scalability High Low (parallelization) Tool requirements Multiple Single Maximum Complexity Low High Process Modification Difficult Easy Waste material generation High Low Power consumption Low High Labor Pool Existing Training Benefits of AM/3DP
•Computer-Aided Design (CAD) Development •Rapid iteration & prototyping •More innovation space
•Novel geometries •More complex parts Products •Efficiently use high-cost materials •Customization
•Lower material use •Fewer tools Logistics •Just-in-Time fulfillment •Distributed manufacturing PROCESSES The Basics
Computer-Aided Design (CAD)
Feedstock material
Selective x-/y-axis binding
Stepwise vertical (z-axis) build
Post-Processing Materials & Feedstocks
Liquid Resin Solid Plastic Metal Powder
… or any permutation thereof. … or something else entirely. Binding/Joining Mechanisms
Curing Heat/Cooling Cementing Taxonomy
Stereolithography Vat Polymerization Liquid Feedstock Digital Light Processing Material Jetting
Material Extrusion Fused-Filament Fabrication Solid Feedstock Sheet Lamination
Additive Additive Directed Energy Deposition Selective Laser Melting Manufacturing Powdered Feedstock Powder-Bed Fusion Electron Beam Melting
Binder Jetting Selective Heat Sintering Material Extrusion
Build Material
• Thermoplastic
Feedstock Form
• Solid filament
Selector
• Deposition nozzle
Binding Mechanism
• Melting Powder Bed Fusion
Build Material
• Metal/Plastic/Ceramic
Feedstock Form
• Powdered
Selector
• Laser
Binding Mechanism
• Sintering / Melting Vat Polymerization
Build Material
• Photopolymer resin
Feedstock Form
• Liquid
Selector
• UV Laser/Projector
Binding Mechanism
• Curing Binder Jetting
Build Material
• Metal/Plastic/Ceramic
Feedstock Form
• Powdered
Selector
• Printer Head
Binding Mechanism
• Adhesion/cementing Post-Processing
• Wet-chemistry Removing • Powder evacuation material • Manual removal
• Annealing Retreating • Curing
• Sanding/Polishing Finishing • Texturing • Coating POTENTIAL HAZARDS AM requires a Holistic Approach to Risk Management
Materials •Toxicity •Safety •Formulation
Process Environment •Energy/Mechanism •Transport/Storage •Consumables •Contamination •Support Processes •Organization Process, Post-Process, and Support Process Hazards Process Support Processes • UV Light, Lasers, Radiation • Ergonomic concerns • Fire/explosion • Falls & falling objects • Cutting injuries • Crushing injuries • Compressed gases • Burns
Post-Processing Machine • Ergonomic concerns • Electrical shock • Cutting & grinding injuries • Noise generation • Chemical exposures • Heat generation • Burns • Crushing injuries Materials & Hazards
Polymers Acrylonitrile-butadiene-styrene Polylactic acid Particle Emissions Propylene fumarate Poly(vinyl alcohol) Outgassing/VOC Emissions Polystyrene
Solvents Dimethyl fumarate Isopropanol Dermal Toxicity Acetone Methyl Ethyl Ketone Reactivity 2-Butanone
Metals Aluminum
Titanium Flammability
Steel
Superalloys Combustibility
Nanomaterials nFe (steel sintering)
nAg (sintering, conductivity) Specific formulation
nCB, CNT (conductivity, stiffness, tensile strength) Process-induced changes nSiOx (polymer strength) Environment
Transport & Storage
Waste Management
Workspace Ventilation & Airflow
Area Contamination
Robotics & Automated Systems
Scheduling
Psychosocial Stresses Example Hazards
Thermoplastic Extrusion Stereolithography • Burns • Chemical dermal contact • Particulate emissions • VOC emissions • VOC emissions • Post-process exposure • Post-process chemical use • Ergonomic hazards
Aluminum Laser Sintering Plastic Binder Jetting • Fire/explosion • Fire/explosion • Powder inhalation • Powder inhalation • Powder dermal contact • VOC Emissions • Ergonomic hazards • Post-processing AM users and knowledge will vary
Users may differ in terms of …
• Budget for OSH activities (controls) Large Enterprises Small-to-Medium Service Locations • Expertise (in both OSH and additive Enterprise manufacturing) • Synergistic exposures • Demographics • Communication preferences • Decision-making structure Hospitals Schools Libraries • Safety culture Safe AM requires Communication
Safety Officers • Hazard identification • Risk assessment • Safety controls
Designers Operators • Product application • Build operations • Material properties • Support operations • Process principles • Practicalities SUMMARY Additive Manufacturing …
Is substantially impacting multiple market sectors
Includes many materials and processes
Hazards will vary significantly based on particulars
Requires rapid and responsible development NIOSH Performs On-Site Research
• Over 100 visits (65 sites)
• Uses existing methods
• Evaluate processes & personal exposures
• Provide Guidance and recommendations
• Seeking more partnerships and collaborations! References & Image Sources
• Bloomington Public Schools (2014) Poplar Bridge Elementary to incorporate 3D printing. URL: https://www.bloomington.k12.mn.us/node/3121478 (accessed 20-Nov-2017). • Florida Public Library (2017) Our 3D Printer. http://www.floridapubliclibrary.org/news/our-3d-printer/ (accessed 20-Nov-2017). • GE Additive (2017a) GE Additive takes bold moves in aerospace industry. https://www.ge.com/additive/press- releases/ge-additive-takes-bold-moves-aerospace-industry (accessed 20-Nov-2017). • GE Additive (2017b) GE Additive to certify new production partners. https://www.ge.com/additive/press- releases/ge-additive-certify-new-production-partners (accessed 20-Nov-2017). • Hewitt, Cooper (2014). Design Dictionary: Powder Bed 3D Printing. Youtube. URL: https://youtu.be/kBHsfNDsbCs (accessed 8-Feb-2017). • McCue, TJ (2018). Wohlers Report 2018: 3D Printer Industry Rises 21 Percent To Over $7 Billion. Forbes. URL: https://www.forbes.com/sites/tjmccue/2018/06/04/wohlers-report-2018-3d-printer-industry-rises-21-percent-to- over-7-billion/#4875d8092d1a (accessed 14-Jun-2018) • O’Conner, Daniel (2013). Formlabs launch new Resin and win CES award. TCT Magazine. URL: https://www.tctmagazine.com/tct-events/formlabs-launch-new-resin-and-win-ces-award/ (accessed 13 Feb 2017). • Open Biomedical Initiative (2016) Japanese medical insurance to cover cost of 3D printed organ models. URL: http://www.openbiomedical.org/japanese-medical-insurance-to-cover-cost-of-3d-printed-organ-models/ (accessed 20-Nov-2017). • Pesce, Mauizio (2015). 3D Printing Materials. Wikimedia Commons. URL: https://commons.wikimedia.org/wiki/File:3D_Printing_Materials_(16837486456).jpg (accessed 13 Feb 2017). • Sęk, Matylda (2011). Crosslinker, UV Stratalinker 2400. Wikimedia Commons. URL: https://commons.wikimedia.org/wiki/File:Crosslinker_UV_Stratalinker_2400-1.jpg (accessed 13 Feb 2017). • Sols Systems (2016) Mapp3D. http://www.sols.com/mapp3d/ (accessed 20-Nov-2017). • Vít, Tomáš (2017). Selective Laser Sintering (or LaserCUSING) cycle. Youtube. URL: https://youtu.be/5-y8iep7jTk (accessed 8-Feb-2017). Acknowledgments
• Charles Geraci • Laura Hodson • Kevin L. Dunn • Eric Glassford • Kevin H. Dunn • Duane Hammond • Aleksandr Stefaniak [email protected]