Cap wrinkling in a contoured composite hat stringer is reduced by constraining the cap as the hat stringer is being formed from a flat composite charge. The cap is constrained by an inflatable bladder placed in a tool set used to form the composite charge.

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.

Some tissue adhesives include a solid having bio-absorbable fibers and at least one of nano-spheres, micro-spheres, nano-tubules, or micro-tubules. A first layer of the solid has a positive Poisson's ratio and a second layer of the solid has a negative Poisson's ratio. In some cases, the second layer has been transformed from a positive Poisson's ratio material to a negative Poisson's ratio material. In some cases, an entire face of the first layer is in contact with an entire face of the second layer. In some cases, the second layer includes one or more pores, at least a portion of the one or more pores containing a secretion from one or more barnacles. In some cases, the secretion is configured to adhere the tissue adhesive to one or more layers of tissue to at least partially close a wound.

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 method of manufacturing a heart valve, comprising: a step of injection moulding a first part (110) of the heart valve from a first block-copolymer, wherein the injection moulding is performed at a temperature below an order-disorder transition temperature of the block copolymer, such that a phase structure is present in the molten block-copolymer; a step of injection moulding a second part (114) of the heart valve from a second block-copolymer that is different to the first block-copolymer, by over-moulding over the first part (110) to form an over-moulded structure, wherein the injection moulding is performed at a temperature below order-disorder transition temperatures for the first and second block copolymers, such that a phase structure is present in the molten second block-copolymer and remains present in the first block-copolymer; and a step of cooling the over-moulded structure, without heating it above the order-disorder transition temperatures between the step of injection moulding the second part (114) and the step of cooling, so as to preserve an arrangement of the phase structures created during the steps of injection moulding and produce anisotropic physical properties in the second part (114). The invention also relates to the thus manufactured heart valve.

A curved human interface device is manufactured by thermoforming a stack. The stack comprises a front substrate formed of a transparent, first thermoplastic material; an OLED display configured to display an image through the front substrate; and a thermomechanical buffer layer formed of a transparent, second thermoplastic material arranged between the front substrate and the OLED display. Heat is applied to the stack for causing a temperature of the front substrate and buffer layer to increase to a respective processing temperature at which the first and second thermoplastic materials become pliable. The stack is thermoformed while the thermoplastic materials are pliable to form the curved human interface device. The second thermoplastic material has a lower stiffness at the respective processing temperature than the first thermoplastic material.

Methods of making molded polystyrene articles are described. The methods include introducing steam into a mold simultaneous to filling the mold with foam particles, and cooling the mold without the use of cooling water. The method can be performed faster and with a lower temperature differential than conventional molding processes, permitting faster turn-around to the production of subsequent molded articles. The molded articles produced by the method can have thicker side walls, improved foam particle fusion, and improved compression properties as compared to conventional EPS molding processes.

A multilayer sheet comprising first and second layers is provided. The first layer consists of a co-polyester. The second layer consists of a thermoplastic polyurethane elastomer having an elongation at break of greater than 200%, a hardness of 60A to 85D, an ultimate tensile strength of greater than about 5000 psi, and a light transmission between 400 nm and 800 nm of greater than about 75%. A mold is provided and the multilayer sheet is thermoformed over the mold to form a plurality of tooth-receiving cavities configured to receive and reposition a patient's teeth from a first arrangement toward a second arrangement. Excess material is trimmed from the thermoformed multilayer sheet to form a multilayer dental aligner.

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 structure, such as a tabletop, may be constructed from plastic, such as blow-molded. The tabletop may include an upper surface, a lower surface, and a hollow interior portion disposed between the upper surface and the lower surface. A lip may extend downwardly relative to the lower surface of the tabletop, and the lip including an outer surface and an inner surface. A plurality of supports may be disposed in the inner surface of the lip, and a plurality of joints may be disposed in the inner surface of the lip. A joint may be disposed between adjacent supports. A distal portion of the lip may include a compression edge. A lower portion of the supports may contact the compression edge, and/or a lower portion of the joints may contact the compression edge.