materials | 3D printing
such as mechanical properties or electrical conductiv- ity. The association says processing parameters are important in the filament extrusion process as well as during the printing process. AIMPLAS has created a working group comprised of
Figure 1: PLA printed by AIMPLAS at 210°C showing poor interlayer fusion
Figure 2: Processing at 230°C results in a more homogenous structure
SEM morphological studies carried out at AIMPLAS
reveal the effect of printing parameters. Figure 1 shows the morphology of a PLA product printed at 210°C while Figure 2 shows the morphology when the melt tem- perature used was 230°C. It can be seen that with a filament melting temperature of 210°C there are distinct holes between the deposited layers that will enhance the fragility of the final product (each will act as a stress concentration factor). Appropriate selection of the material and processing conditions results in better flow, which improves the wetting and adhesion between adjacent layers. This reduces the number of holes between layers, improves product density and reduces fragility.
Below: Internal view of the 3D print research lab at the AIMPLAS technical centre in Spain
Processing influences One of the major areas of interest for AIMPLAS researchers is to develop an understanding of the key material properties that have an effect on processability and also on the final product properties. For example, the most suitable melt flow index range for 3D printing. Another important area of study is the influence of processing parameters on the final material properties,
polymer researchers and 3D printing specialists in order to combine material expertise with process optimisation. Two internal projects are underway to optimise electrical conductivity and mechanical properties of 3D printing products. Compounding facilities, a filament extrusion line and different 3D printing machines have been employed for 3D printing developments. The association participated in the European
Nanomaster research programme in which compounds and filaments based on graphene and expanded graphite were developed for 3D printing. The material developed has a high electrical conductivity (in the semiconductor range 10-2
S/cm) and a good surface
finish. These results are being achieved at high printing speeds (90mm/s or 3.6mm³) compared with current commercial electrically conductive materials that are printed at low speeds (50mm/s or 3.2mm³).
Increased functionality Netherlands-based Helian Polymers established ColorFabb as its brand for 3D printing filaments in 2013. The company collaborates with Eastman Chemi- cal Company as a primary material partner and Witcom, a speciality compounder of metal-filled material and copolyesters. According to chief executive officer Ruud Rouleaux, ColorFabb is seeing steady growth in demand for advanced materials with function- ality in fused filament fabrication (FFF) printing. “All trends are dictated by market needs. Currently these needs are more functionality, temperature resistance, stiffness, electrical conductivity, dissolvable support materials and improved mechanical properties in order to service industrial applications. There is also a need for materials that have specific aesthetic qualities. One particular technical area of interest at present is functional prototyping in the automotive industry, for example. This requires materials such as ColorFabb’s XT-CF20, which is made from Eastman Chemical Company’s AM1800 with 20% carbon fibre and compounded by Witcom,” he says. “In the past five months we have released two new
materials, made with Eastman’s Amphora copolymers - nGen and ColorFabb_HT. nGen is available in 17 colours and is an easy to use material for a wide range of purposes. More functionality can be achieved with colorFabb_HT, an engineering grade material for FFF 3D printing with a glass temperature of greater than
18 COMPOUNDING WORLD | May 2016
www.compoundingworld.com
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94