A dental appliance for positioning a patient's teeth includes a removable orthodontic tooth positioning appliance having teeth receiving cavities shaped to directly receive at least some of the patient's teeth and apply a resilient positioning force to the patient's teeth. The appliance includes a hard polymer layer having a hard polymer layer elastic modulus disposed between a first soft polymer layer having a first soft polymer layer elastic modulus and a second soft polymer layer having a second soft polymer layer elastic modulus. The hard polymer layer elastic modulus is greater than each of the first soft polymer layer elastic modulus and the second soft polymer layer elastic modulus. At least one of the first soft polymer layer and the second soft polymer layer has a flexural modulus of greater than about 35,000 psi.

Polytetrafluoroethylene (PTFE) composite articles that have a macro textured surface. The composite articles include at least two different PTFE membranes in a layered or stacked configuration. The composite article has a macro textured surface characterized by a plurality of strands raised from the surface of the PTFE membrane. The strands may be formed of either interconnected nodes of PTFE or of at least one nodal mass of PTFE and have a length equal to or greater than about 1.5 mm. The macro textured surface provides a topography to the first PTFE membrane. The composite articles have a bubble point from about 3.0 psi to about 200 psi, a thickness from about 0.01 to about 3.0 mm, and a bulk density from about 0.01 g/cm.sup.3 to about 1.0 g/cm.sup.3.

An epoxy dual cure resin useful for additive manufacturing of three-dimensional objects includes: (i) a photoinitiator; (ii) monomers and/or prepolymers that are polymerizable by exposure to actinic radiation or light; (iii) optionally, a light absorbing pigment or dye; (iv) an epoxy resin; (v) optionally, but in some embodiments preferably, an organic hardener co-polymerizable with the epoxy resin; (vi) optionally but preferably a dual reactive compound having substituted thereon a first reactive group reactive with said monomers and/or prepolymers that are polymerizable by exposure to actinic radiation or light, and a second reactive group reactive with said epoxy resin (e.g., an epoxy acrylate); (vii) optionally a diluent; (viii) optionally a filler; and (ix) optionally, a co-monomer and/or a co-prepolymer. Methods of using the same in additive manufacturing are also described.

Disclosed herein are plastic-metal hybrid materials that are formed by injection molding a plastic composition comprising a polyketone onto a surface of a metal part, the surface having nanometer-sized pores, micron-sized pores, or both, the pores having been formed by chemical etching or by electrical oxidation and surface coating. Also provided are methods for forming the plastic-metal hybrids, components for electronic devices comprising the hybrid materials, and electronic devices that include a component comprising a plastic-metal hybrid material as disclosed.

Principles and embodiments of the present invention relate generally to thermoplastic polyurethane materials having controlled and improved stiffness and/or flexibility, and methods to prepare them. The thermoplastic polyurethanes described herein having superior stiffness and softening properties may be fabricated into film, tubing, and other forms of medical devices. The thermoplastic polyurethanes comprise: an aromatic diisocyanate excluding non-aromatic diisocyanates; at least one polyglycol; and a chain extender comprising at least one side-chain branching diol and excluding linear diols.

A three-dimensional shaping apparatus includes an ejection portion, a base stage, a movement portion, and a controller. The ejection portion configured to eject a fused thermoplastic resin. The movement portion configured to change relative positions of the ejection portion and the base stage. The controller configured to control the movement portion and the ejection portion such that a wall is formed by ejecting a fused thermoplastic resin from the ejection portion while relatively moving the ejection portion with respect to the base stage to provide a space surrounded by the wall in a horizontal direction and open in an upward direction, and such that a filling portion is formed by injecting a fused thermoplastic resin into the space from above.

Methods of layerwise fabrication of a three-dimensional object, and objected obtained thereby are provided. The methods are effected by dispensing at least a first modeling formulation and a second modeling formulation to form a core region using both said first and said second modeling formulations, an inner envelope region at least partially surrounding said core region using said first modeling formulation but not said second modeling formulation, and an outer envelope region at least partially surrounding said inner envelope region using said second modeling formulations but not said first modeling formulation; and exposing said layer to curing energy, thereby fabricating the object, The first and second modeling formulations are selected such they differ from one another, when hardened, by at least one of Heat Deflection Temperature (HDT), Izod Impact resistance, Tg and elastic modulus.

Nano-composite films and methods for their fabrication. The nano-composite films include a polymer matrix (e.g., polyethylene, polypropylene, or the like) and a filler capable of exfoliation such as graphene or hexagonal boron nitride (e.g., TrGO). The filler provides reinforcement, increasing tensile strength, Young's modulus, or both for the resulting nano-composite film, as compared to what it would be without the filler. The nano-composite film may have a specific tensile strength that is greater than 1 GPa/g/cm.sup.3, a specific Young's modulus that is greater than 100 GPa/g/ccm.sup.3, or both. Tensile strength and modulus values of up to 3.7 GPa/g/cm.sup.3 and 125 GPa/g/cm.sup.3, respectively, have been demonstrated. The film maybe formed by combining powdered filler and polymer matrix powder in a solvent (e.g.,decalin), high-shear extruding the resulting solution to disentangle the polymer chains and exfoliate the filler, freezing the solution to form a solid film, and then drawing the film.

The present invention is to provide a bound stopper, which has high mechanical strength, is excellent in durability against fatigue breaking, settling or the like when a heavy load is repeatedly received, and is easy to be produced, in which the bound stopper comprises a polyurethane foam obtained from a polyurethane foam composition containing an isocyanate component and a blowing agent, and the isocyanate component contains a urethane prepolymer having an isocyanate group, the urethane prepolymer being obtained from a polyol component, a polyrotaxane containing a cyclic molecule having an active hydrogen group as a constituent, and an isocyanate.

A method for forming a multilayer plastic sheet material (1) for floor and/or wall panels, wherein a first polymer mass comprising a rigid PVC is melted under pressure and is passed through an extruder head at a specified discharge rate in the form of a plastic strand in sheet form that is provided with one or more layers so that a multilayer plastic strand is formed, which is passed to two or more rolls of a finishing stand, which processes the multilayer plastic strand into a sheet of defined thickness, which is then led away via a transport device to a sawing device to be cut to the desired length, wherein, after the plastic strand in sheet form leaves the extruder head, it is first passed between a top roll and a bottom roll of a roughing stand, wherein the speed of the rolls of the finishing stand and the rolls of the roughing stand is synchronized with the discharge rate of the plastic strand in sheet form from the extruder head, so that said plastic strand is processed without stress.