Optical analysis of polymer powder materials for Selective Laser Sintering

2016 ◽  
Vol 56 ◽  
pp. 207-213 ◽  
Author(s):  
T. Laumer ◽  
T. Stichel ◽  
K. Nagulin ◽  
M. Schmidt
Keyword(s):  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Powder Materials ◽  
Optical Analysis ◽  
Polymer Powder

scholarly journals Analysis of Tribo-Charging during Powder Spreading in Selective Laser Sintering: Assessment of Polyamide 12 Powder Ageing Effects on Charging Behavior

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 609 ◽  
Author(s):  
Nicolas Hesse ◽  
Maximilian Dechet ◽  
Juan Bonilla ◽  
Christian Lübbert ◽  
Stephan Roth ◽  
...  
Keyword(s):  
Selective Laser Sintering ◽  
Electrostatic Charge ◽  
Laser Sintering ◽  
Process Stability ◽  
Polyamide 12 ◽  
Part Quality ◽  
Polymer Powder ◽  
Novel Approach ◽  
Powder Flowability ◽  
Model Setup

Powder flowability is key to achieving high process stability and part quality by application of smooth and dense layers in selective laser sintering (SLS). This study sheds light on the rarely investigated effect of tribo-electric charge build-up during powder delivery in the SLS process. This is achieved by a novel approach to quantify electrostatic potentials during doctor blading. The presented model setup is used in combination with charge spectrometry and impedance spectroscopy to investigate the alterations in tribo-electric charging behavior for the most commonly used laser sintering material polyamide 12 in its virgin and aged, c.f. reused, states. We show that the electrostatic charge build-up is significantly enhanced for aged polymer powder material, likely contributing to altered performance in SLS processing.

Mechanics Study on Leveling Process by a Roller during Selective Laser Forming

2013 ◽  
Vol 670 ◽  
pp. 101-105 ◽  
Author(s):  
Jin Hui Liu ◽  
W.J. Xie ◽  
C. Zhao ◽  
L. Zhang ◽  
Z.L. Lu
Keyword(s):  
Process Parameters ◽  
Influence Factor ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Laser Forming ◽  
Powder Materials ◽  
Forming Process ◽  
Forming Quality ◽  
Common Reference ◽  
Model Of Friction

Generally, pressures resulted from roller during leveling process in selective laser sintering has the effect of densification of powder materials. But extra frictions due to them become the forces which always deteriorate the surface of the part and mark it with several lines trace. Sometimes, the manufacturing can even not continue if these forces accumulate to a large extent to move the whole part. Therefore, the whole forming process will be obliged to stop owing to the displacement of part from above mentioned damage. In this work, the emerging reason and related variation factors of these forces were studied mathematically, the mathematical and physical model of friction force was also built to describe the connections between the leveling process parameters and them. How to control the influence factor of friction to abate their damages to surfaces and promote the forming quality were also discussed based on these models. This will provide a common reference for the application of selective laser sintering technology.

Temperature Field Simulation of Wood Powder/PES Composite Powder Material

2015 ◽  
Vol 667 ◽  
pp. 218-223
Author(s):  
Yue Qiang Yu ◽  
Yan Ling Guo ◽  
Kai Yi Jiang
Keyword(s):  
Temperature Field ◽  
Heat Source ◽  
Powder Material ◽  
Laser Power ◽  
Composite Powder ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Powder Materials ◽  
Wood Powder ◽  
Composite Powder Material

In view of the physical process of the wood powder/PES composite powder material selective laser sintering forming ,this article establishes the plane moving Gaussian heat source as the input laser heat source model .Based on selective laser sintering wood powder/PES composite powder sintering theory and combined with thermal conductivity of composite powder, specific heat, density and other related theoretical analytical models .It establishes three dimensional finite element model of selective laser sintering process of wood powder/PES composite powder transient temperature field .The laser sintering simulation experiment of wood powder/PES composite powder under different laser power obtains temperature field distribution law of the wood powder/PES composite powder forming under different laser power distribution, and the influence of the forming parts forming quality of wood powder/PES composite powder materials caused by the temperature field. The simulation results also provide certain theoretical basis for the choice of laser power in the subsequent laser sintering experiment.

Physical characteristics of selective laser sintering of metal—polymer powder composites

1998 ◽  
Vol 28 (5) ◽  
pp. 420-425 ◽  
Author(s):  
A M Ivanova ◽  
S P Kotova ◽  
N L Kupriyanov ◽  
A L Petrov ◽  
E Yu Tarasova ◽  
...  
Keyword(s):  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Physical Characteristics ◽  
Polymer Powder ◽  
Powder Composites ◽  
Metal Polymer

Solid Freeform Fabrication of Ceramics Using Selective Laser Sintering and Selective Area Laser Deposition

1991 ◽  
Vol 249 ◽  
Author(s):  
Uday Lakshminarayan ◽  
Guisheng Zong ◽  
W. Richards Thissell ◽  
Harris L. Marcus
Keyword(s):  
Gas Phase ◽  
Solid Freeform Fabrication ◽  
Laser System ◽  
Selective Laser Sintering ◽  
Three Dimensional ◽  
Laser Sintering ◽  
Laser Deposition ◽  
Powder Materials ◽  
Freeform Fabrication ◽  
Selective Area

ABSTRACTSolid Freeform Fabrication (SFF) is a new computer fabrication technique that does not require any part specific tooling. The starting material can be either solid, liquid or gaseous. The part can be made from metallic, ceramic, polymeric or a composite material. The concept is to use a solid modeling system to define the part of interest and to reduce the model to a set of toggle point data that totally define the geometry. In Selective Laser Sintering the sectioned component is then combined with a rastered laser system that impinges on the precursor powder materials in a layered reconstruction of the three dimensional CAD designed part. The part is then formed in this manner. This approach to producing the part involves a great deal of understanding of the laser materials interactions, the appropriate choice of materials specific to this processing and how the total process integrates. Application to ceramic powders will be described. An alternative approach to SFF is Selective Area Laser Deposition where the three dimensional part is made from the gas phase. The initial gas deposition studies involving deposition of carbon from hydrocarbons will be discussed. For both of the above SFF approaches the laser beam powder and gas phase interactions and the microstructure of the resulting three dimensional forms as a function of system parameters will be described.

3D Modeling of Additive Manufacturing Process: The Case of Polymer Laser Sintering

2020 ◽  
Author(s):  
Lan Zhang ◽  
M'hamed Boutaous ◽  
Shihe Xin ◽  
Dennis A. Siginer
Keyword(s):  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Heat Diffusion ◽  
Laser Scattering ◽  
Transient Phenomena ◽  
Powder Bed ◽  
Process Characteristics ◽  
Polymer Powder ◽  
Volume Method ◽  
Air Diffusion

Abstract This work focusses on studying multiphysical transient phenomena in polymer powders occurring during selective laser sintering in polymers powders. Multiple phenomena stemming from the interaction of the laser with the polymer powder bed and the transfer of the laser power to the powder bed including laser scattering and absorption, polymer heating, melting, coalescence, densification, and the variation of the material parameters with the temperature are simulated via the modified Monte Carlo-ray tracing method coupled with the Mie theory. A finite volume method is adopted for the heat transfer. The model couples heat diffusion, melting, coalescence and densification of the polymer grains, and the crystallization kinetics during the cooling steps. Laser intensity is concentrated on the surface of the material contrary to the predictions of the Beer-Lambert law. Laser acting on thermoplastic material cause the polymer powder melt, coalescence between melted grains, air diffusion versus densification, crystallization and volume shrinkage. All these processes are simulated by a series of multiphysical models. The reliability of the modeling is tested by comparison with experiments in the literature, and a parametric analysis is performed, based on the process characteristics such as laser sweep speed, its intensity and shape, polymeric grain size among others. Several recommendations to optimize the process are proposed.

An Apparatus for Research on Processes of Selective Laser Sintering of Powder Materials with High Spatial Resolution

2020 ◽  
Vol 63 (2) ◽  
pp. 288-290 ◽  
Author(s):  
N. V. Minaev ◽  
A. V. Mironov ◽  
S. A. Minaeva ◽  
O. A. Mironova ◽  
M. A. Syachina ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Powder Materials

An Inverse-Free Disturbance Observer for Adaptive Narrow-Band Disturbance Rejection With Application to Selective Laser Sintering

2017 ◽  
Author(s):  
Tianyu Jiang ◽  
Hui Xiao ◽  
Xu Chen
Keyword(s):  
Disturbance Observer ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Servo Control ◽  
Powder Materials ◽  
Adaptation Algorithm ◽  
Research Attention ◽  
3 Dimensional ◽  
Part Quality ◽  
Online Simulation

Selective laser sintering (SLS) is an additive manufacturing (AM) process that builds 3-dimensional (3D) parts by scanning a laser beam over powder materials in a layerwise fashion. Due to its capability of processing a broad range of materials, the rapidly developing SLS has attracted wide research attention. The increasing demands on part quality and repeatability are urging the applications of customized controls in SLS. In this work, a Youla-Kucera parameterization based forward-model selective disturbance observer (FMSDOB) is proposed for flexible servo control with application to SLS. The proposed method employs the advantages of a conventional disturbance observer but avoids the need of an explicit inversion of the plant, which is not always feasible in practice. Advanced filter designs are proposed to control the waterbed effect. In addition, parameter adaptation algorithm is constructed to identify the disturbance frequencies online. Simulation and experimentation are conducted on a galvo scanner in SLS system.

Structure and Mechanical Properties of PCL/PG Devices Prepared by Selective Laser Sintering for Drug Delivery Applications

2013 ◽  
Author(s):  
Gean V. Salmoria ◽  
Priscila Klauss ◽  
Carlos R. M. Roesler ◽  
Luiz Alberto Kanis
Keyword(s):  
Drug Delivery ◽  
Selective Laser Sintering ◽  
Rapid Prototype ◽  
Laser Sintering ◽  
Laser Beams ◽  
Powder Materials ◽  
Layer By Layer ◽  
Medical Field ◽  
Rapid Prototype Process ◽  
Drug Delivery Devices

Selective laser sintering (SLS) is a rapid prototype process that creates objects, layer by layer, using infrared laser beams to process powder materials [1–8]. In recent years, the SLS process has shown great prominence in the medical field, and several researchers have conducted studies showing a wide diversity of materials and applications, such as the manufacture of porous drug delivery devices (DDDs) [9–12].

Study on Sucrose Powder in Selective Laser Sintering Mechanism

2014 ◽  
Vol 541-542 ◽  
pp. 209-213 ◽  
Author(s):  
Lai Xia Yang ◽  
Xu Sheng Yao ◽  
Ying Bao Xue
Keyword(s):  
Weight Loss ◽  
Melting Point ◽  
Heating Temperature ◽  
Selective Laser Sintering ◽  
Thermo Gravimetric Analysis ◽  
Decomposition Temperature ◽  
Laser Sintering ◽  
Powder Materials ◽  
Gravimetric Analysis ◽  
Sintering Mechanism

In this paper, the selective laser sintering mechanism of sucrose powder materials were studied. This paper uses DSC/TG technology to sucrose by thermo gravimetric analysis. The results show that, the melting point of sucrose at 187 °C, its decomposition temperature at 220°C, 300°C after weight loss in more than 50%, sucrose and reasonable final heating temperature was between 187°C~220°C. The results show that, the melting point of sucrose at 187°C, its decomposition temperature at 220°C, 300°C after weight loss in more than 50%, sucrose and reasonable final heating temperature was between 187°C~220°C.

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