Laser sintering, selective

Since the SLS technique involves high processing temperatures, it is limited to the processing of thermally stable polymers. Up to now the production of prototypes and functional parts has been dominated by polyamide, a semi-crystalline polymer. 

This thermoplastic material covers a wide range of applications but requirements concerning a high temperature resistance above 200 °C and tensile strengths above 50 N mm are not fulfilled despite glass fillings. Further materials which are investigated include other thermoplastic materials, PC, PS [121], PEEK [122], 

PE [123]. In particular, SLS of biocompatible polymers such as PEEK, polyvinyl alcohol (PVA), polycaprolactone, poly(L-lactic acid) [124—127] is an area of active research for manufacturing scaffolds for tissue engineering. 

Laser machining and laser-based processing are well established techniques for polymer processing. They provide flexibility and obvious advantages in terms of rapid manufacturing and customization of devices. Laser processes will very likely become more prevalent as lasers offer more cost-effective solutions. 

Generative laser-based techniques for 3D microfabrication are widely used and their importance is likely to grow as the need for rapid prototyping and manufacturing as well as customization of a variety of products is increasing. 

---

Selective laser sintering Fused deposition modeling... 

Fischer, P., Blatter, A., Romano, V. and Weber, H.P. (2004) Highly precise pulsed selective laser sintering of metal powders. Laser Physics Letters, 620-628. 

Figure 7.32 Selective laser sintering process. A laser is bounced off a mirror, which is controlled by a scanner to selectively trace the outline of a cross section of a part on a powder bed. When one layer has been traced, the part is lowered and fresh powder is rolled into place. After finishing, the part is removed from the loose, unfused powder.

SFF encompasses many different approaches to additive fabrication, including Stereolithography (SLA), Selective Laser Sintering (SLS), Electron Beam Melting (EBM), Laminated Object Manufacturing (LOM), Fused Deposition Modeling (FDM), and 3D Printing. 

Despite the fact that Selective Laser Sintering (SLS) is not an Inkjet 3D printing process, due to its industrial importance, a brief description of this method is included here. 

SDM standard deviation measurement SLS selective laser sintering... 

Bourell D et al (2002) Powder densification maps in selective laser sintering. Adv Eng Mater 4(9) S.663-S.669... 

Kroh M (2008) Development of a modified processing technique for selective laser sintering of high temperature resistant polymers with a Nd YAG-laser. Conference of the polymer... 

Rietzel D et al (2008) Enhanced range of plastics for selective laser sintering serving different user profiles and also consumer and industry requests. Euro-uRapid2008, Berlin, pp. S.209-S.216... 

Schmidt M, Pohle D, Rechtenwald T (2007) Selective laser sintering of PEEK. Annals of the CRIP - Manufacturing Technology 56(1) S.205-S.208... 

H. Liang, M.M. Savalani, Y. Zhang, K.E. Tanner, R.A. Harris, Selective laser sintering of hydroxyapatite reinforced polyethylene composites for bioactive implants and tissue scaffold development. Proc. Inst. Mech. Eng. [H] 220, 521-531 (2006)... 

D printing Layered manufacturing Selective laser sintering Stereolithography... 

Williams, J.M., A. Adewunmi, R.M. Schek, C.L. Flanagan, P.H. Krebsbach, S.E. Feinberg, S.J. Hollister, and S. Das. 2005. Bone tissue engineering using polycaprolactone scaffolds fabricated via selective laser sintering. Biomaterials 26 4817. 

Stereolithography Selective Laser Sintering X-ray Lithography Mechanical Prepolymer Deposition Conventional Chemical Vapor Eteposition Laser Assisted Chemical Vapor Deposition... 

K. Bartels, R. Crawford, S. Das, S. Gudur, A. Bovik, K. Diller and S. Aggarwal, Fabrication of macroscopic solid models of 3-dimensional microscopic data by selective laser sintering, Journal of Microscopy, Oxford, 196,383-389(1993). 

---