An apparatus is intended to produce a multi-layer extrudate comprising an intermediate material interposed between at least two layers of outer material. The apparatus comprises an arrangement of ducts which includes a first duct and a second duct through which respective lateral flows of outer material can flow. The arrangement of ducts also includes a further duct through which a central flow comprising at least the intermediate material can flow. The apparatus further comprises at least one obstructing element for interacting at least with the central flow while the central flow is advancing in an advancement direction. The at least one obstructing element is movable with a movement having a component directed transversally to the advancement direction, so as to obstruct the central flow in the advancement direction at preset intervals.

Provided is a three-dimensional modeling material used for a fused deposition modeling three-dimensional printer. The three-dimensional modeling material has a multilayer structure and contains, in respective different layers, a thermoplastic resin (A) having a shear storage elastic modulus (G′) of 1.00×10.sup.7 Pa or less as measured at 100° C. and 1 Hz and a thermoplastic resin (B) having a shear storage elastic modulus (G′) of more than 1.00×10.sup.7 Pa as measured at 100° C. and 1 Hz.

A system is disclosed for additively manufacturing a composite structure. The system may include a support, and a print head operatively connected to and moveable by the support. The print head may include an outlet configured to discharge a material in a trajectory along a central axis of the outlet, and a compactor disposed downstream of the outlet relative to the trajectory and configured to press the material transversely against an adjacent surface. The outlet may be configured to translate relative to the compacting module.

The present invention relates to a method for continuously manufacturing UHMWPE products comprising:—providing a counter-rotating twin-screw extruder;—feeding UHMWPE powder into a hopper of said counter-rotating twin-screw extruder;—transporting said UHMWPE powder from said hopper through said counter-rotating twin-screw extruder to an outlet of said counter-rotating twin-screw extruder;—further transporting said UHMWPE powder from said outlet of said counter-rotating twin-screw extruder to an entrance of a heat-controlled tooling system for defining the shape of UHMWPE products;—withdrawing said UHMWPE products from an outlet of said heat-controlled tooling system.

A composite porous membrane contains at least one porous base layer and at least one uniaxially stretched coating layer located on at least one side surface of the porous base layer. For example, the composite porous membrane comprises at least one porous base layer and at least one nanofiber-like non-polyolefin polymer porous layer oriented along the transverse stretching direction of the composite porous membrane and located on one or two side surfaces of the porous base layer, or the composite porous membrane comprises a biaxially stretched polypropylene porous base layer and a uniaxially stretched coating layer located on at least one side surface of the porous base layer. The composite porous membrane is coated with a coating solution prior to transversely stretching. The nanofiber-like non-polyolefin polymer porous layer may reduce cracking of the composite porous membrane in the machine direction.

A method enabling the selection, modification and/or creation of polymer materials which can provide improved response to the application of local shear and/or extensional deformation inside the polymer melt in manufacturing technologies including injection molding, injection stretch blow molding, direct injection, extrusion blow molding, sheet extrusion, thermoforming, etc., is provided. A method for manufacturing a polymer article includes injecting or extruding molten polypropylene, polyethylene or polyester based polymer for converting it into semi-final shape while applying shear and/or extensional deformation on the polymer melt. Applying shear and/or extensional deformation on the polymer melt includes selectively modifying the flow path of the molten semi-crystallizable polymer as a function of local pressure profile over at least part of the flow path. Local pressure profile is a function of optimized response of the polymer melt to the applied local shear and/or extensional deformation over at least the part of the flow path.

A method of recycling a mixed plastic waste comprising plastics having different melting temperatures includes conveying the mixed plastic waste through an extruder such that at least some of the higher melting point plastic is passes through the extruder without melting and is present in the extrudate as solid material.

A system is disclosed for additively manufacturing a composite structure. The system may include a support, and a print head operatively connected to and moveable by the support. The print head may include a first supply configured to hold a liquid matrix, a second supply configured to hold a continuous reinforcement, and a wetting module configured to separately receive the liquid matrix and the continuous reinforcement from the first and second supplies, respectively, and to discharge a composite material including the continuous reinforcement wetted with the liquid matrix. The wetting module may include a body forming an internal chamber having an upstream open end and a downstream open end, an entrant nozzle disposed within the upstream open end and configured to receive the continuous reinforcement, and an exit nozzle disposed within the downstream closed end and configured to discharge the composite material.

A blow molding assembly includes a die, a mandrel, and a die holder. The die defines an inner wall. The mandrel is disposed at least partially inside the inner wall of the die and defines, with the inner wall of the die, an annular gap that shapes a molten resin passed therethrough, forming a parison. The die holder includes a body and three or more spring-loaded fasteners positioned around an inner perimeter of the body. The spring-loaded fasteners apply pressure to respective positions on an outer surface of the die while permitting movement of the die within a plane that is substantially orthogonal to a longitudinal axis of the mandrel in response to pressure variations of the molten resin, keeping a thickness of the parison substantially even. Each of the spring-loaded fasteners includes a spring-loaded plunger engaging the respective position on the outer surface of the die.

Improvements in the extrusion of thermohardenable materials are achieved by cooling the material in the initial zone of the extruder and reducing residence time by use of a prescribed length to diameter ratio and screw speed, particularly useful for intermittent application during robotically controlled mass production.