GRAiL

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Additive Manufacturing AM is used to build physical models, prototypes, patterns, andproduction parts in a wide variety of materials (in particular plastic, and metals) for a widerange of markets (AppA). Components in digital format are rendered into thin horizontalsections and using various techniques (e.g. Selective Laser Sintering (SLS), VatPhotopolymerisation, Material Extrusion and Powder Bed Fusion) material is added layer bylayer to build the component. SLS which utilises lasers to melt layers of metal or polymerpowder on to each other (AppA) was developed in 1984 and since the patents expired and theprice and availability of these machines has dropped dramatically, further stimulatingdemand. Initially, polymer SLS systems used amorphous polymers (ABS) with a broadmelting range but today almost all polymer SLS systems use crystalline polymers with a sharpmelting point (typically Nylon PA12) and the powder is melted. Unfortunately SLS polymerproperties are diminished compared to conventional extruded material.Fibrous fillers can improve toughness but the nylon has to be compounded and then cryogroundor milled producing angular surfaces on the powder which restrict its flowcharacteristics. Rapid Powders has a proprietary process whereby precipitated sphericalpowders can be coated with a wide range of filler materials (including nano-fillers) and inparticular Graphene which is a desirable filler for polymer nanocomposites and improves theirmechanical properties. We propose to prove the concept of the production of a range of PA12graphene nanocomposite powders with good flow characteristics that when melted or sinteredin a SLS machine have improved properties comparable to extruded PA12 enabling the SLSproduction of finished components.