A process for preparing an olefin polymer, including the steps of forming a particulate olefin polymer in a gas-phase polymerization reactor in the presence of a C.sub.3-C.sub.5 alkane as polymerization diluent, separating discharged polyolefin particles from concomitantly discharged gas at a pressure from 1 to 2.2 MPa, degassing the polyolefin particles at a pressure from 0.1 to 0.4 MPa with a gas made from or containing a C.sub.3-C.sub.5 alkane; and transferring the separated gas and the gas from the degassing to a work-up unit operated at a pressure from 0.001 to 0.2 MPa below the pressure of the separation, wherein the gas for degassing is continuously received from the work-up unit.

A powder with a volume-weighted particle size distribution, with a median diameter D50 ranging from 40 to 120 micrometers, including at least one polyaryl ether ketone and at least one filler, in which: said at least one polyaryl ether ketone forms a matrix incorporating, at least partly, said at least one filler, and said filler has a Stokes equivalent spherical diameter distribution with a median diameter d′50 of less than or equal to 5 micrometers. Also a powder manufacturing process and the use thereof in a process for the layer-by-layer construction of objects by electromagnetic radiation-mediated sintering.

A powder with a volume-weighted particle size distribution, with a median diameter D50 ranging from 40 to 120 micrometers, including at least one polyaryl ether ketone and at least one filler, in which: said at least one polyaryl ether ketone forms a matrix incorporating, at least partly, said at least one filler, and said filler has a Stokes equivalent spherical diameter distribution with a median diameter d′50 of less than or equal to 5 micrometers. Also a powder manufacturing process and the use thereof in a process for the layer-by-layer construction of objects by electromagnetic radiation-mediated sintering.

A drying hopper for drying granular material includes a hopper casing defining a plenum chamber for granular material, and an upper part and a bottom part. The hopper also includes a material inlet for the granular material arranged in the upper part; a material outlet port at the bottom part; a component for introducing hot drying gas into the hopper casing; and a gas outlet arranged in the upper part. The component for introducing hot drying gas includes gas pipes arranged to extend substantially vertically in the upper part, each gas pipe having a gas outlet port at its lower end and being connected at its upper end to an annular gas duct having a gas inlet for receiving a flow of drying gas, the gas pipes being distributed on the annular gas duct.

Preparing hybrid-treated plastic particles from waste plastic includes combining waste plastic particles with bio-oil to yield a mixture, irradiating the mixture with microwave radiation to yield oil-treated plastic particles, and contacting the oil-treated plastic particles with carbon-containing nanoparticles to yield hybrid-treated plastic particles. The hybrid-treated plastic particles have a bio-oil modified surface and a coating comprising carbon-containing nanoparticles on the bio-oil modified surface of the plastic particle. In some examples, a diameter of the plastic particle is in a range between 250 m and 750 m, and a thickness of the coating is in a range of 1 nm to 20 nm. A modified binder includes an asphalt binder or a concrete binder and a multiplicity of the treated plastic particles. The modified binder typically includes 5 wt % to 25 wt % of the hybrid-treated plastic particles.

Preparing hybrid-treated plastic particles from waste plastic includes combining waste plastic particles with bio-oil to yield a mixture, irradiating the mixture with microwave radiation to yield oil-treated plastic particles, and contacting the oil-treated plastic particles with carbon-containing nanoparticles to yield hybrid-treated plastic particles. The hybrid-treated plastic particles have a bio-oil modified surface and a coating comprising carbon-containing nanoparticles on the bio-oil modified surface of the plastic particle. In some examples, a diameter of the plastic particle is in a range between 250 m and 750 m, and a thickness of the coating is in a range of 1 nm to 20 nm. A modified binder includes an asphalt binder or a concrete binder and a multiplicity of the treated plastic particles. The modified binder typically includes 5 wt % to 25 wt % of the hybrid-treated plastic particles.

An extruder includes a cylinder, a screw built in the cylinder, a dehydration cylinder block provided in the middle of the cylinder and discharging moisture that is separated from a resin material supplied into the cylinder. The dehydration cylinder block has a structure in which plate-shaped members each having an opening are arranged in a long-axis direction of the cylinder, a screw passing through the opening. Surface roughness of mutually opposing surfaces of the plurality of plate-shaped members is rougher than surface roughness of an inner wall of the cylinder.

An extruder includes a cylinder, a screw built in the cylinder, a dehydration cylinder block provided in the middle of the cylinder and discharging moisture that is separated from a resin material supplied into the cylinder. The dehydration cylinder block has a structure in which plate-shaped members each having an opening are arranged in a long-axis direction of the cylinder, a screw passing through the opening. Surface roughness of mutually opposing surfaces of the plurality of plate-shaped members is rougher than surface roughness of an inner wall of the cylinder.

Polymer particles that comprise a thermoplastic polymer and a nucleating agent may be useful in additive manufacturing methods where warping may be mitigated. For example, a method of producing sais polymer particles may comprise: a thermoplastic polymer, a nucleating agent, a carrier fluid, and optionally an emulsion stabilizer at a temperature at or greater than a melting point or softening temperature of the thermoplastic polymer to emulsify a thermoplastic polymer melt in the carrier fluid; cooling the mixture to form polymer particles; and separating the polymer particles from the carrier fluid, wherein the polymer particles comprise the thermoplastic polymer, the nucleating agent, the emulsion stabilizer, if included, and wherein the polymer particles have a crystallization temperature that is substantially the same as a crystallization temperature of the thermoplastic polymer prior to mixing.

An ethylene-vinyl alcohol copolymer composition contains: (A) an ethylene-vinyl alcohol copolymer including two or more types of ethylene-vinyl alcohol copolymers having different ethylene structural unit contents; and (B) an iron compound; wherein the iron compound (B) is present in an amount of 0.01 to 5 ppm on a metal basis based on the weight of the ethylene-vinyl alcohol copolymer composition. The ethylene-vinyl alcohol copolymer composition is substantially free from coloration and excellent in heat stability.