Filament for additive manufacturing and process for making the same
OwnerAdam Chaplin, Connor Dallas +3inventors
InventorsAdam Chaplin, Connor Dallas, Charlotte Ridout, Martin Riley, Adrian Thorpe
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Abstract
A fused filament fabrication filament, method and process, for layer-wise formation of a component, wherein the filament, method and process comprise feedstock material comprising a polyaryletherketone, PAEK and optionally, one or more filler means.
Claims15
A fused filament fabrication (FFF) filament, for use in layer-wise formation of a component, wherein the filament comprises feedstock material comprising a polyaryletherketone, PAEK and one or more filler means, wherein the PAEK is a copolymer comprising repeat units of formula
- and
- repeat units of formula
- wherein at least 95 mol % of the copolymer repeat units are repeat units of formula I and of formula II;
- wherein the repeat units I and II have a molar ratio 1:11 from 60:40 to 80:20;
- and
- wherein the PAEK has a shear viscosity, SV, from 100 to 400 Pa·s as measured using capillary rheometry at 400° C. at a shear rate of 1000 s−1 by extrusion through a tungsten carbide capillary die of 0.5 mm diameter and 8.0 mm length;
- and
- wherein the one of more fillers comprises at least 5 wt. % and up to 38 wt. % of the composition.
A filament according to any preceding claim, wherein the one of more fillers is selected from a fibrous filler and a non-fibrous filler.
A filament according to any preceding claim, wherein the fibrous filler is a continuous fibrous filler or a discontinuous fibrous filler.
A filament according to any preceding claim, wherein the one or more fillers is selected from glass fibre, carbon fibre, asbestos fibre, silica fibre, alumina fibre, zirconia fibre, boron nitride fibre, silicon nitride fibre, boron fibre, fluorocarbon resin fibre and potassium titanate fibre, mica, silica, talc, HydroxyApatite (or Hydroxyl Apatite), alumina, kaolin, calcium sulfate, calcium carbonate, titanium oxide, titanium dioxide, zinc sulphide, ferrite, clay, glass powder, zinc oxide, nickel carbonate, iron oxide, quartz powder, magnesium carbonate, fluorocarbon resin, graphite, graphene, carbon powder, nanotubes, nanofibres and/or barium sulphate.
A filament according to any preceding claim, wherein the one or more fillers is discontinuous carbon fibre having a nominal length between 50 microns and 300 microns, and more preferably between 100 and 300 micros and even more preferably between 125 microns and 175 microns.
A filament according to any preceding claim, wherein the feedstock material further includes a viscosity modifier selected from ethylene-octene copolymer such as Paraloid 3815, buytyl acrylate/PMMA core-shell such as Paraloid 3361, silicone such as Kaneka Kane-Ace MR02, or polyoctohedralsilsesquioxane compounds.
A filament according to any preceding claim, wherein the ratio of the copolymer shear viscosity measured at a shear rate of 100 s−1 to the copolymer shear viscosity measured at a shear rate of 10,000 s−1 is from 2.0 to 6.0, with the shear viscosity at each shear rate measured using capillary rheometry at 400° C. by extrusion through a tungsten carbide capillary die of 0.5 mm diameter and 8.0 mm length, and more preferably, the ratio of the copolymer shear viscosity measured at a shear rate of 100 s−1 to the copolymer shear viscosity measured at a shear rate of 10,000 s−1 is from 3.0 to 5.5, or even more preferably, 3.5 to 5.0, with the shear viscosity at each shear rate measured using capillary rheometry at 400° C. by extrusion through a tungsten carbide capillary die of 0.5 mm diameter and 8.0 mm length.
The use of a filament according to any preceding claim, in a process for formation of a component in a layer-wise fashion by sequentially depositing layers of the feedstock material in layers, each layer defining a cross-section of the component.
A process for improving the printability of a fused filament fabrication filament, the process comprising:
- extruding feedstock material through a die to form a filament wherein the feedstock material comprises a polyaryletherketone, PAEK and optionally, one or more filler means;
- annealing the filament at a temperature between a glass transition temperature Tg of the feedstock material and a melt temperature Tm of the feedstock material, for a period of time sufficient to increase the temperature of the filament to above the glass transition temperature of the feedstock material.
Dependencies are inferred from the claim text.