Additive manufacturing of PA12 carbon nanotube composites with a novel laser polymer deposition process

Abstract

The facile manufacture of PA12 MWCNT/silica (50/50 by weight) nanocomposite powders through a high energy mixing process is presented, which are useful to generate 3D objects by a novel Laser Polymer Deposition (LPD) process. The mixing as well as the LPD process led to no discernible changes in the material properties (DSC, SEM, LD) of the core‐shell nanocomposites, enabling the recycling of unconverted powder. The built parts yield ultimate tensile stresses and Young's modulus at 10%–20% of the bulk material. Partially unmolten particles and voids were identified as the main mechanical failure mechanism in the built parts. The mechanical properties are better with low additive content (Young's modulus: 89.8 ± 5.4 MPa; UTS: 12.9 ± 5.3 MPa with 0.25 wt% additives). Electronic conductivity up to the region of moderate conductivity could be achieved by multiwalled carbon nanotube (MWCNT) network formation (8 × 10−4 S cm−1 at 1.25 wt% of additives). A variant of the processing strategy revealed that a higher mechanical strength can be achieved by a laser induced remelting of the traces following their initial construction.

Development and Optimization of Medical-Grade Multi-Functional Polyamide 12-Cuprous Oxide Nanocomposites with Superior Mechanical and Antibacterial Properties for Cost-Effective 3D Printing

“…A new era in manufacturing processes is met through the utilization of additive manufacturing (AM), which is currently considered as the most prominent manufacturing method in a wide range of industrial and research applications [ 1 , 2 , 3 , 4 , 5 , 6 ]. Developments and new implementation methods are presented at a geometrically increasing rate in automotive/aerospace industries [ 2 , 7 ], building and constructions [ 8 , 9 ], electronic devices [ 10 , 11 ], medical devices [ 7 , 12 ], and many others. The high interest for AM in academia and industry is attributed to the capabilities given to users from this manufacturing method [ 8 , 13 ].…”

“…To overcome these issues and improve the performance of the parts produced by the FFF technology, composite materials are developed using well-established polymers in engineering applications (usually called engineering-grade polymers) as the matrix. Such composites are fabricated using fillers in micro/nano or fiber form to achieve improved mechanical [ 12 , 35 , 36 ], thermal [ 37 , 38 , 39 ], or electrical performance [ 11 , 40 , 41 ], compared to the matrix alone. Many additives hinder the flow of the material, so several studies on the flowability of composites exist in this field [ 12 , 42 ].…”

“…Still, it was studied in literature and used as a pure material and as a matrix material in composites in several important MEX 3D printing applications [ 31 , 35 , 45 , 46 , 47 , 48 , 49 , 50 ] and as a matrix material with metals and oxides as fillers in AM applications requiring antibacterial properties from the materials [ 51 , 52 , 53 , 54 ]. Its enhanced toughness properties and its ability to widely extend before it breaks are some of its merits for utilization in 3D printing [ 11 , 13 , 29 , 38 ], while its flow behavior is trouble-free for both the extrusion and the 3D printing process [ 37 ]. Additionally, it has very good behavior when mixed with additives for the improvement of its properties [ 38 , 55 ].…”

Medical-Grade Polyamide 12 Nanocomposite Materials for Enhanced Mechanical and Antibacterial Performance in 3D Printing Applications

“…PA12 has a semi-crystalline internal structure [ 29 ]. While it is mainly used in conventional manufacturing methods, SLS, and similar AM techniques [ 30 ], it has also demonstrated great potential in FFF implementations [ 17 , 30 , 31 , 32 , 33 ]. Its semi-crystalline form and rather stable thermal performance suggest that PA12 does not require any special setup for 3D printing (i.e., closed-heated printing chamber) [ 33 , 34 ].…”

Trilateral Multi-Functional Polyamide 12 Nanocomposites with Binary Inclusions for Medical Grade Material Extrusion 3D Printing: The Effect of Titanium Nitride in Mechanical Reinforcement and Copper/Cuprous Oxide as Antibacterial Agents

“…This specific grade has been investigated and applied in different additive manufacturing (AM) processes, such as binder jetting [ 9 ], powder bed fusion [ 10 , 11 ], and material extrusion (MEX) as pure material, or as the matrix material in composites [ 5 , 8 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. PA12 is a material suitable for the 3D printing (3DP) process, due to its rheological characteristics [ 22 ], its toughness, and high strain values before its failure [ 10 , 23 , 24 , 25 ]. 3D printing orientation is also a critical parameter affecting the mechanical properties of the built parts [ 26 ], and this applies to the PA12 polymer as well [ 27 ].…”