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Methods for manufacturing containers
The invention relates to a method for manufacturing a container comprising a substantially rigid outer container and a deformable inner bag, wherein the outer container and the inner bag are made of a first thermoplastic material and a second thermoplastic material. The preform is positioned between the open mold halves of a blow mold. When
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A method for preparing polyurethane foam
The invention develops a preparation method of polyurethane sponge, which abandons traditional foaming processes. Instead, one-component moisture-curable polyurethane resin, water-soluble inorganic salt, starch, silicone microspheres, nonionic surfactants with an HLB value of 4‑15 and solvents are internally mixed, extruded through a die by an extruder, and then immersed in clean water to dissolve out calcium
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An extruder including screw elements with particularly high pitch in the degassing port area and its application
A multi-shaft extruder with screw shafts capable of co-rotating at the same speed is provided, which is equipped with at least one degassing port. In the inlet area of the degassing port, the extruder is fitted with screw elements having an extra-large pitch, or screw elements with asymmetric profiles or eccentrically mounted on the rotating
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Methods for 3D printers and 3D printer equipment
A method for a 3D printer is provided. The 3D printer includes a print head defining a filament channel with a first end and an opposite second end for filament melting, and the filament channel is formed by joints of multiple print head components with seams; an extruder for feeding filament into the channel from
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A mandrel material for rocket engine propellant grain molding and its preparation method
The invention relates to the field of conductive plastics, especially to a core mold material for grain column molding of rocket engines and its preparation method. The core mold material is composed of the following raw materials in parts by weight: 100 parts of plastic particles, 10‑25 parts of high-conductivity filler, 5‑15 parts of reinforcing
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Apparatus and method for preventing extruder vacuum backflow
The invention provides a device and a method for preventing material backflow in the vacuum section of an extruder. The device includes an extruder barrel, a vacuum cavity assembly, a vacuum pumping assembly and a safety valve. The safety valve consists of a valve sleeve assembly, a valve core assembly and a thermal induction actuator.
