Provided is a molded resin strand configured so that interlayer fusion of a shaped object can be improved and mechanical aptitude (specifically, stiffness) in a 3D printer can be more improved even in a case where an inorganic filler such as carbon fibers is mixed. The molded resin strand contains thermoplastic resin, an inorganic filler, and α-olefin elastomer. The thermoplastic resin is polypropylene, for example. The inorganic filler is carbon fibers, for example. The α-olefin elastomer is ethylene-α-olefin copolymer, for example. The molded resin strand of the present invention is used for a 3D printer employing a fused deposition modeling method.

Provided is a molded resin strand configured so that interlayer fusion of a shaped object can be improved and mechanical aptitude (specifically, stiffness) in a 3D printer can be more improved even in a case where an inorganic filler such as carbon fibers is mixed. The molded resin strand contains thermoplastic resin, an inorganic filler, and α-olefin elastomer. The thermoplastic resin is polypropylene, for example. The inorganic filler is carbon fibers, for example. The α-olefin elastomer is ethylene-α-olefin copolymer, for example. The molded resin strand of the present invention is used for a 3D printer employing a fused deposition modeling method.

A formulation for producing a polymeric material including high-density polyethylene, a chemical blowing agent, and other optional components is described.

The invention relates an extrusion device (100) for extruding a semi-finished product made of elastomeric material, comprising an extrusion body (10) extending along a feeding direction (A) and a pump (20) arranged downstream of the extrusion body (10) along said feeding direction (A). The extrusion body (10) comprises a hopper (30) for loading an elastomeric material and an extrusion screw (50) extending along said feeding direction (A) and having an inlet portion (50a) arranged close to the hopper (30) and an exit portion (50b) arranged close to the pump (20). The extrusion body (10) also comprises a motorised roller (40) arranged at the inlet portion (50a) of the extrusion screw (50) and configured to receive the elastomeric material from the hopper (30) and feed it to the extrusion screw (30). The extrusion screw (50) has a length and a diameter such that the ratio between length and diameter is comprised between 4 mm and 8 mm. The invention also relates to an extrusion process carried out through the aforementioned extrusion device (100).

The invention relates an extrusion device (100) for extruding a semi-finished product made of elastomeric material, comprising an extrusion body (10) extending along a feeding direction (A) and a pump (20) arranged downstream of the extrusion body (10) along said feeding direction (A). The extrusion body (10) comprises a hopper (30) for loading an elastomeric material and an extrusion screw (50) extending along said feeding direction (A) and having an inlet portion (50a) arranged close to the hopper (30) and an exit portion (50b) arranged close to the pump (20). The extrusion body (10) also comprises a motorised roller (40) arranged at the inlet portion (50a) of the extrusion screw (50) and configured to receive the elastomeric material from the hopper (30) and feed it to the extrusion screw (30). The extrusion screw (50) has a length and a diameter such that the ratio between length and diameter is comprised between 4 mm and 8 mm. The invention also relates to an extrusion process carried out through the aforementioned extrusion device (100).

Porous and microporous parts prepared by additive manufacturing as disclosed herein are useful in medical and non-medical applications. The parts are prepared from a composition containing both a solvent soluble component and a solvent insoluble component. After a part is printed by an additive manufacturing process it is exposed to solvent to extract solvent soluble component away from the printed part, resulting in a part having surface cavities.

Porous and microporous parts prepared by additive manufacturing as disclosed herein are useful in medical and non-medical applications. The parts are prepared from a composition containing both a solvent soluble component and a solvent insoluble component. After a part is printed by an additive manufacturing process it is exposed to solvent to extract solvent soluble component away from the printed part, resulting in a part having surface cavities.

Polymer composites containing carbon nanotubes often exhibit high glass transition temperatures, which can complicate their use in additive manufacturing processes. Extruded filaments containing carbon nanotubes and residual solvent can have desirably lowered glass transition temperatures. Extruded filaments can contain a polymer as a continuous phase, a nanomaterial such as carbon nanotubes homogeneously mixed throughout the continuous phase, and above 0% to about 15% solvent by weight. Methods for making extruded filaments can include producing a solvated composite by dissolving a polymer and a nanomaterial in a solvent, producing a partially desolvated composite by reducing a solvent content of the solvated composite to a range of about 10% to about 30% by weight, forming particles of the partially desolvated composite, supplying the particles to an extruder, and extruding a filament having the polymer as a continuous phase and the nanomaterial homogeneously mixed throughout the continuous phase, which also contains residual solvent.

Polymer composites containing carbon nanotubes often exhibit high glass transition temperatures, which can complicate their use in additive manufacturing processes. Extruded filaments containing carbon nanotubes and residual solvent can have desirably lowered glass transition temperatures. Extruded filaments can contain a polymer as a continuous phase, a nanomaterial such as carbon nanotubes homogeneously mixed throughout the continuous phase, and above 0% to about 15% solvent by weight. Methods for making extruded filaments can include producing a solvated composite by dissolving a polymer and a nanomaterial in a solvent, producing a partially desolvated composite by reducing a solvent content of the solvated composite to a range of about 10% to about 30% by weight, forming particles of the partially desolvated composite, supplying the particles to an extruder, and extruding a filament having the polymer as a continuous phase and the nanomaterial homogeneously mixed throughout the continuous phase, which also contains residual solvent.

A method of making a medical implant is provided by electrospinning a polymer solution to form a preform around a mandrel. The formed preform distinguishes an inner surface and an outer surface. The formed preform is removed from the mandrel and flipped inside-out resulting in the inner surface of the formed preform becoming the outer surface of the inside-out flipped preform, and the outer surface of the formed preform becoming the inner surface of the inside-out flipped preform. At least part of the inside-out flipped preform forms the medical implant such as e.g. an artificial heart valve, an artificial leaflet, an artificial graft, or an artificial vessel. The products made according to the method of this invention greatly improve the performance and durability of the medical implant.