A vulcanizing agent is added during the processing of a polymer, and can form a crosslinking structure network in the polymer, thereby improving the mechanical properties of the material. Furthermore, the crosslinking agent can also de-crosslink the polymer material at a high temperature, and after being cooled, same can be crosslinked again to produce a network structure, thus endowing the polymer material with thermoplasticity for repeated processing.

The devices and systems described herein generally relate to magnetic field chambers and reversibly hardenable ferrofluids. The reversibly hardenable ferrofluid can include a magnetically responsive fluid and a reversible hardening agent. The reversibly hardenable ferrofluid can achieve a first shape using one or more magnetic fields, such as delivered from a magnetic field chamber. Once the first shape is achieved, the reversibly hardenable ferrofluid can be cured or otherwise hardened. The hardened reversibly hardenable ferrofluid can be used for the intended purpose and then returned to a liquid state once the task is completed, allowing for reuse. The steps of hardening and liquifying can be mediated by the magnetic field chamber, as described in embodiments herein.

Disclosed is a recycling apparatus for a cross-linked polyethylene resin using a twin screw extruder. The recycling apparatus for a cross-linked polyethylene resin using a twin screw extruder according to an embodiment of the present disclosure includes: a raw material supply unit configured to supply a raw material that is a cross-linked polyethylene resin; and a twin screw extruder configured to receive the raw material from the raw material supply unit, the twin screw extruder including a cylinder and a twin screw installed inside the cylinder to rotate in the same direction, the twin screw extruder being configured to de-crosslink and recycle the raw material under a de-crosslinking reaction temperature and reaction pressure atmosphere while continuously transporting the raw material along the twin screw by the rotation of the twin screw.

This disclosure describes hydrogel three-dimensional printing kits, methods of three-dimensional printing hydrogels, and hydrogel three-dimensional printing systems. In one example, a hydrogel three-dimensional printing kit can include a particulate build material, a crosslinking agent, a whitening agent, and a coloring agent. The particulate build material can include a polyhydroxylated swellable polymer. The crosslinking agent can include water and a crosslinker that is reactive with hydroxyl groups of the polyhydroxylated swellable polymer to crosslink the polyhydroxylated swellable polymer. The whitening agent can include water and a dispersed white pigment. The coloring agent can include water and a colorant.

A fiber-reinforced composite material and a method of manufacturing the fiber-reinforced composite material are disclosed. The fiber-reinforced composite material includes a fabric manufactured by weaving a weft including a synthetic fiber and a warp including a synthetic fiber, a carbon fiber, or a combination thereof, and a resin with which the fabric is impregnated and/or coated, wherein the resin includes urethane, urethane acrylate, urea, epoxy, acryl, polycarbonate, polymethyl methacrylate, polypropylene, polyvinyl chloride, polyvinyl butyral, or any combination thereof.

Provided herein is a method of recycling reactive prepolymers from additively manufactured articles or recovered coating material that comprises a crosslinked polymer formed from a single-cure resin comprising a reactive blocked prepolymer and a crosslinker, by forming and recovering a regenerated reactive prepolymer. Light-polymerizable resins, methods of making recyclable objects from such resins, and methods for sustainable manufacturing are also provided.

A functional polymeric cutting edge structure and methods for manufacturing cutting edge structures using polymeric materials are provided. A razor blade for use in a razor cartridge or a blade box for assembly in a razor cartridge frame may be formed using the present invention.

An integrally-formed three-dimensional (3D) bio-printing system capable of alternate feeding of multiple materials, comprising: an optical imaging unit and a light path conversion unit, wherein the optical imaging unit comprises an image processing unit and a projection unit, the image processing unit segmenting a 3D modeling graphic of a printed subject to form image information, the projection unit converting the image information into one or more optical images, and the light path conversion unit projects the imaged light paths into bio-ink that can be cured by light, so that the projected image can cure the bio-ink by means of the focus of light.

The present disclosure is directed to a physically crosslinked, closed cell continuous multilayer foam structure comprising at least one foam polypropylene/polyethylene layer with a TPU cap layer. The multilayer foam structure can be obtained by coextruding a multilayer structure comprising at least one foam composition layer with at least one cap composition layer, irradiating the coextruded structure with ionizing radiation, and continuously foaming the irradiated structure.

There is provided a die for extrusion in which an undesired reaction is suppressed in an inside thereof and with which variation in thickness of a resin sheet to be obtained can be reduced. A die for extrusion of the present invention includes: a cylindrical inflow port into which a molten resin flows; a manifold connected to the inflow port; a first slit connected to the manifold; a second slit connected to the first slit; and a lip land connected to the second slit. In the die for extrusion, the shape of a flow path is optimized based on a relationship among a position in the die, an operation time, and a vulcanization degree.