A three-dimensional printing kit can include a polymeric build material and a fusing agent. The polymeric build material can include polymer particles having a D50 particle size from about 2 μm to about 150 μm. The fusing agent can include an aqueous liquid vehicle including water and an organic co-solvent, a radiation absorber to generate heat from absorbed electromagnetic radiation, and from about 2 wt % to about 15 wt % of a carbamide-containing compound.

A three-dimensional printing kit can include a polymeric build material and a fusing agent. The polymeric build material can include polymer particles having a D50 particle size from about 2 .Math.m to about 150 .Math.m. The fusing agent can include an aqueous liquid vehicle including water and an organic co-solvent, a radiation absorber to generate heat from absorbed electromagnetic radiation, and from about 5 wt% to about 20 wt% flame retardant including dicyandiamide.

The invention relates to a polyamide molding composition with good weathering resistance containing or preferably consisting of the following components: 85 to 99.85% by weight of a component A, where component A consists of polyamide A1 or of a mixture of the polyamides A1 and A2, where A1 is at least one amorphous or microcrystalline polyamide having more than 60 mol % of monomers having exclusively aliphatic structural units, based on the total amount of monomers, and A2 is at least one acyclic aliphatic polyamide, and where the sum of components A1 and A2 gives 100% by weight of component A; 0.05 to 2.0% by weight of at least one colorant B; 0.10 to 3.0% by weight of at least one stabilizer C; 0 to 10% by weight of additives D, other than A, B and C; the proportions by weight of components A to D summing to 100% by weight, wherein the polyamide molding composition comprises neither carbon black nor nigrosine, the color lightness L*, determined according to DIN EN ISO 11664-4:2020 in the CIELAB color space on a plate of the dimension 60×60×2 mm, being at most 32, and the polyamides A1 having a transparency of at least 88% and a haze of at most 5%, in each case determined according to ASTM- D1003-21 on a plate of the dimension 60×60×2 mm.

The present disclosure is drawn to material sets and 3-dimensional printing systems that include a fusing agent. One example of a material set can include a fusing agent and a detailing agent. The fusing agent can include water, a carbon black pigment, and a water-soluble co-solvent in an amount from 20 wt % to 60 wt %. The detailing agent can include water and a black dye. In another example, a material set can include a fusing agent and a thermoplastic polymer powder.

The present invention provides a method of producing the composite comprising: a) melt blending the matrix with the fibers to produce a melted composite, b) injecting the melted composite into a mold and allowing the melted composite to solidify and, c) removing at least a portion of the outermost layer of a composite such that the fibers protrude from the surface of the composite. Also provided is composite produced by the methods of the invention comprising soft and hard fibers embedded in a soft rubber-like matrix, wherein the fibers protrude from the composite's surface. In specific embodiments, the composite comprises carbon fibers and poly(p-phenylene-2,6-benzobisoxazole) (PBO) fibers in a thermoplastic polyurethane (TPU) matrix, wherein the fibers protrude from the composite's surface. Slip-resistant product comprising the composite are also provided.

A composite structure includes a foam core formed from a first polymer and between about 0.5 wt. % and about 2.5 wt. % graphene. The foam core has an average pore size between about 25 μm and about 75 μm, and a cell density between about 4×10.sup.6 cells/mm.sup.2 and about 6×10.sup.6 cells/mm.sup.2. Also, an overmolded skin formed from a second polymer and between about 0.25 wt. % and about 5.0 wt. % graphene is disposed on the foam core. A method of manufacturing a composite structure includes injection molding a foam core from a first polymer containing between about 0.25 wt. % and about 5.0 wt. % graphene, and injection molding an overmolded skin from a second polymer containing graphene between about 0.25 wt. % and about 5.0 wt. % graphene.

A process for producing a three-dimensional (3D) object by a fused filament fabrication process employing at least one filament and a three-dimensional (3D) extrusion printer. Within said process, the filament is first fed to a cooling device, where the filament is cooled down to a temperature of 20° C. or colder. Afterwards, the cooled-down filament is transported to a heating device located inside the printing head of the 3D extrusion printer, where the cooled-down filament is heated to a temperature, which is high enough to at least partially melt the filament. The heated filament is extruded through the nozzle of the printing head of the 3D extrusion printer in order to obtain an extruded strand, which in turn is used to form the respective 3D object in a layer by layer way. Further an apparatus is disclosed, to be used within such a fused filament fabrication process or 3D printing technology, respectively.

Techniques are disclosed for fabricating multi-part assemblies. In particular, by forming release layers between features such as bearings or gear teeth, complex mechanical assemblies can be fabricated in a single additive manufacturing process.

The present invention provides a method for preparing an ultra high molecular weight polyethylene (UHMWPE) composite material including the following steps: providing a substrate material having medical grade ultra high molecular weight polyethylene powders, drying the substrate material to obtain fully dried UHMWPE powders, and pressing the fully dried UHMWPE powders to form a UHMWPE board; immersing the UHMWPE board into a graphene oxide solution and performing an ultrasonic induction by an ultrasonic processor such that the graphene oxide solution infiltrates into the UHMWPE substrate to obtain an ultra high molecular weight polyethylene composite material with excellent biocompatibility and tribological properties. The graphene oxide can be adsorbed and evenly spread on the surface of UHMWPE substrate by ultrasonic induction to form a lubricating film which can effectively reduce wear.

A graphene reinforced polyethylene terephthalate composition is provided for forming graphene-PET containers. The graphene reinforced polyethylene terephthalate composition includes a continuous matrix comprising polyethylene terephthalate and a dispersed reinforcement phase comprising graphene nanoplatelets. The graphene nanoplatelets range in diameter between 5 μm and 10 μm with surface areas ranging from about 15 m.sup.2/g to about 150 m.sup.2/g. In some embodiments, the graphene reinforced polyethylene terephthalate comprises a concentration of graphene nanoplatelets being substantially 3% weight fraction of the graphene reinforced polyethylene terephthalate. The graphene reinforced polyethylene terephthalate is configured to be injection molded into a graphene-PET preform suitable for forming a container. The graphene-PET preform is configured to be reheated above its glass transition temperature and blown into a mold so as to shape the graphene-PET preform into the container.