Abstract
The additive manufacturing process of the laser sintering of polymers (LS) allows the production of complex parts right from CAD data. However, the manufactured parts often show dimensional inaccuracies. In order to fundamentally determine the influencing parameters on the accuracy of LS parts, a hatching specimen, a layer-specimen and defined part geometries are manufactured and subsequently measured. These, combined with a theoretical observation of the layer wise geometry buildup, are used to determine the fundamental portions of the development of dimensions in building direction (z-direction). The results indicated a defined powder adhesion height at the top and the bottom of a melted layer, along with the dependency of melt depth and the hatch number for small structures. Depending on the nominal heights of an LS part, either an oversize or undersize was detected.
- List of abbreviations
- LS
Laser Sintering of Polymers
- PA12
Polyamide 12
- CAD
Computer-aided Design
- DSC
Differential Scanning Calorimetry
- pvT
Pressure-Volume-Temperature Test
- FTIR
Fourier-Transform Infrared Spectroscopy
- DRIFT
Diffuse Reflectance Infrared Fourier Transform Spectroscopy
- FDM
Fused Deposition Modeling
- SLM
Selective Laser Melting (Metals)
- SLA
Stereolithography Apparatus
- EBM
Electron Beam Melting
Acknowledgements
We wish to say thank you to the project partner, EOS GmbH, for providing the full spectrum machine system for the LS process and the new powder material. Furthermore, we would like to thank Sintermask GmbH, which provided intensive support on the application. The authors would also like to thank the BMW Group for their support. Moreover, the authors would like to express their sincere thanks to the Freistaat Bayern for funding the project “Green Factory Bavaria” in the framework of the future initiative “Aufbruch Bayern.”
Conflict of interest statement: The authors declare to have no conflict of interests regarding this article.
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Articles in the same Issue
- Frontmatter
- Material properties
- Thermo-oxidative and thermal degradation kinetics of silica/polymethyl methacrylate composites with electrostatic interaction phase interfaces
- Study of the rheology and foaming processes of poly(vinyl chloride) plastisols with different foaming agents
- The non-isothermal crystallization behavior of polyamide 6 and polyamide 6/HDPE/MAH/L-101 composites
- Preparation and assembly
- Preparation and properties of biodegradable polymer/nano-hydroxyapatite bioceramic scaffold for spongy bone regeneration
- Properties of EPDM/PP thermoplastic vulcanizates produced by an intermeshing-type internal mixer comparing with a co-rotating twin-screw extruder
- Applications and characterization of silicalite-1/polydimethylsiloxane composite membranes for the pervaporation of a model solution and fermentation broth
- Electroless plate of polyaniline-silver composite layer on polyester fibers
- Surface modification of polymeric flat sheet membranes by adding oligomeric fluoroalcohol
- Engineering and processing
- Processing polymer nanocomposites with natural additives for medical applications
- Dissolution improvement of an active pharmaceutical ingredient in a polymer melt by hot melt extrusion
- Determination of the fundamental dimension development in building direction for laser-sintered parts