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.

Systems and methods are provided for ultrasonic imaging of composite parts. One embodiment is a method that includes providing an object having multiple layers of fibers and resin, inducing ultrasonic waves at locations along the object, and attenuating the ultrasonic waves at the regions due to regions interspersed among the layers that each exhibit an elastic modulus distinct from an elastic modulus of the fibers and distinct from an elastic modulus of the matrix. The method further includes receiving the attenuated ultrasonic waves, and analyzing the attenuated ultrasonic waves to determine depths of the regions.

The invention relates to a workpiece having a shape produced by thermoforming from at least one sheet (3) of plastic material, such as polycarbonate, and at least one applied element (6, 8; 7, 9) that is applied to the at least one sheet and secured there, characterised in that the securing of the at least one applied element to the at least one sheet takes place at least partially by means of crimping.

A plastic molded lip structure may extend along a perimeter of a planar element and may include an outer wall, an inner wall, structural portions, and protruded features. The outer wall may extend in a normal direction from the planar element. The inner wall may be disposed in an inward direction relative to the outer wall. The structural portions may be disposed along structural sections of the perimeter and may include first portions of the inner wall and of the outer wall. The first portions may be disposed parallel to the inner wall and separated from the first portions by a first distance along the structural sections. The protruded features may be interposed between two structural portions and an inner wall may be separated from second portions of the outer wall by a second distance that is greater than the first distance.

A hitch step assembly comprises a first shot component injection molded from a first polymer compound with a high flexural modulus and a second shot component injection molded from a second polymer compound having a lower flexural modulus relative to the first shot compound. A post and a step body core are molded from the first polymer compound. A shell of the step body is molded from the second polymer compound and is overmolded onto the step body core. The shell forms a compression zone that attenuates rear impact forces the hitch step encounters, thus offering some protection against rear impacts. The hitch step assembly exhibits satisfactory resistance to deflection and torsional bending about a hitch receiver axis when a force is applied on the top surface of the hitch step near its lateral ends.

A process for producing expanded pellets from a thermoplastic elastomer having an elongation at break of more than 100% measured to DIN EN ISO 527-2, comprising: (a) pressing a polymer melt comprising a blowing agent through a perforated disk (18) controlled to a temperature between 150 C. and 280 C. and into a pelletizing chamber (26), (b) using a cutting device (20) to comminute the polymer melt pressed through the perforated disk (18) into individual expanding pellets, (c) discharging the pellets from the pelletizing chamber (26) using a liquid stream (36),
wherein the blowing agent comprises CO.sub.2 and/or N.sub.2 and the amount of blowing agent in the polymer melt is from 0.5 to 2.5 wt %, the pelletizing chamber (26) is traversed by a stream of liquid at a temperature between 5 C. and 90 C. and the pressure of 0.1 bar to 20 bar above ambient pressure such that the pellets are expanded in the pressurized liquid by the blowing agent, producing expanded pellets having an uninterrupted skin.

One aspect of the present invention is concerned with a method of manufacture of a hair brush. The method has the steps of providing a base member having connection means at circumferential region thereof, providing a sheet material having a plurality of spikes extending from outwardly facing surface of the sheet material, the sheet material and the spikes are integrally formed by injection molding of a plastic(s) material selected from the group consisting of thermoplastics polyester elastomer (TPE-E), polyether block amide copolymer (TPE-A), thermoplastic polyurethane (TPU) and polyurethane (PU), with a hardness from substantially Shore D50 to D65, and with a flexural modulus from 30,000 PSI to 40,000 PSI, assembling the sheet material by fitting perimeter thereof to the circumferential region of the base member, the base member and the connection means are configured to allow the sheet material to secure to the base member. The outwardly facing surface assumes a convex curvature. In an assembled configuration, a cavity is defined between the sheet material and the base member. In use, when the spikes are under pressure the spikes are movable in response to the pressure, causing corresponding movement to the sheet material, the movement creating a cushioning effect.

Method of manufacturing a three-dimensional object of a building material by an additive layer-wise building method, wherein based on material parameters of the building material and predetermined characteristics of the object to be manufactured, an internal structure of the object having a grid structure calculated, and the three-dimensional object is manufactured with this internal structure by the additive layer-wise building method, so that it comprises the predetermined characteristics.

Various embodiments are directed to apparatuses and methods involving an elastomer material comprising a flexible polymer backbone with a particular ratio of at least first moieties and second moieties. The first moieties provide a first number of dynamic bonds resulting from interactions between the first moieties and the second moieties provide a second number of dynamic bonds resulting from interactions between the second moieties, the second number of dynamic bonds having a weaker bonding strength than the first number of dynamic bonds. The elastomer material, based on the ratio of the first moieties and second moieties, exhibits autonomous self-healing, a particular toughness, and is stretchable.

A molded article of a fiber-reinforced resin contains at least a bundled aggregate [A] of discontinuous reinforcing fibers and a matrix resin [M], wherein the average layer thickness h in the molded article of the fiber-reinforced resin is 100 ?m or less and the CV value of the average layer thickness h is 40% or less; and a compression molding method therefor. It is possible to reliably and greatly reduce the occurrence of stress concentration in the molded article and to thereby achieve higher mechanical properties and further reduce variation in the mechanical properties.