Overview of
Additive Manufacturing and
Potential Occupational Hazards
Gary Roth, MS, PhDNIOSH Health Scientist
DOE Office of Worker Safety and Health Policy, and IH/OS SIG Webinar8 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 Manufacturing
Additive 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)
•Rapid iteration & prototyping
•More innovation spaceDevelopment
•Novel geometries
•More complex parts
•Efficiently use high-cost materials
•Customization
Products
•Lower material use
•Fewer tools
• Just-in-Time fulfillment
•Distributed manufacturing
Logistics
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
TaxonomyA
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Liquid Feedstock
Vat Polymerization
Stereolithography
Digital Light Processing
Material Jetting
Solid Feedstock
Material Extrusion Fused-Filament Fabrication
Sheet Lamination
Powdered Feedstock
Directed Energy Deposition
Powder-Bed Fusion
Selective Laser Melting
Electron Beam Melting
Selective Heat SinteringBinder Jetting
Material Extrusion
• Thermoplastic
Build Material
• Solid filament
Feedstock Form
• Deposition nozzle
Selector
• Melting
Binding Mechanism
Powder Bed Fusion
• Metal/Plastic/Ceramic
Build Material
• Powdered
Feedstock Form
• Laser
Selector
• Sintering / Melting
Binding Mechanism
Vat Polymerization
• Photopolymer resin
Build Material
• Liquid
Feedstock Form
• UV Laser/Projector
Selector
• Curing
Binding Mechanism
Binder Jetting
• Metal/Plastic/Ceramic
Build Material
• Powdered
Feedstock Form
• Printer Head
Selector
• Adhesion/cementing
Binding Mechanism
Post-Processing
Removing material
• Wet-chemistry
• Powder evacuation
• Manual removal
Retreating• Annealing
• Curing
Finishing
• Sanding/Polishing
• Texturing
• Coating
POTENTIAL HAZARDS
AM requires a Holistic Approach to Risk Management
Materials
•Toxicity
•Safety
•Formulation
Environment
•Transport/Storage
•Contamination
•Organization
Process
•Energy/Mechanism
•Consumables
•Support Processes
Process, Post-Process, and Support Process Hazards
Process
• UV Light, Lasers, Radiation
• Fire/explosion
• Cutting injuries
• Compressed gases
Support Processes
• Ergonomic concerns
• Falls & falling objects
• Crushing injuries
• Burns
Post-Processing
• Ergonomic concerns
• Cutting & grinding injuries
• Chemical exposures
• Burns
Machine
• Electrical shock
• Noise generation
• Heat generation
• Crushing injuries
Materials & HazardsPolymers Acrylonitrile-butadiene-styrene
Polylactic acid
Propylene fumarate
Poly(vinyl alcohol)
Polystyrene
Solvents Dimethyl fumarate
Isopropanol
Acetone
Methyl Ethyl Ketone
2-Butanone
Metals Aluminum
Titanium
Steel
Superalloys
Nanomaterials nFe (steel sintering)
nAg (sintering, conductivity)
nCB, CNT (conductivity, stiffness, tensile strength)
nSiOx (polymer strength)
Particle Emissions
Outgassing/VOC Emissions
Dermal Toxicity
Reactivity
Flammability
Combustibility
Specific formulation
Process-induced changes
Environment
Transport & Storage
Waste Management
Workspace Ventilation & Airflow
Area Contamination
Robotics & Automated Systems
Scheduling
Psychosocial Stresses
Example Hazards
Thermoplastic Extrusion
• Burns
• Particulate emissions
• VOC emissions
• Post-process chemical use
Stereolithography
• Chemical dermal contact
• VOC emissions
• Post-process exposure
• Ergonomic hazards
Aluminum Laser Sintering
• Fire/explosion
• Powder inhalation
• Powder dermal contact
• Ergonomic hazards
Plastic Binder Jetting
• Fire/explosion
• Powder inhalation
• VOC Emissions
• Post-processing
AM users and knowledge will vary
Large Enterprises Small-to-Medium Enterprise
Service Locations
Hospitals Schools Libraries
• Budget for OSH activities (controls)
• Expertise (in both OSH and additive manufacturing)
• Synergistic exposures
• Demographics
• Communication preferences
• Decision-making structure
• Safety culture
Users may differ in terms of …
Safe AM requires Communication
Safety Officers
• Hazard identification
• Risk assessment
• Safety controls
Operators
• Build operations
• Support operations
• Practicalities
Designers
• Product application
• Material properties
• Process principles
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