Methods for producing highly spherical particles that comprise: mixing a mixture comprising: (a) nanoclay-filled-polymer composite comprising a nanoclay dispersed in a thermoplastic polymer, (b) a carrier fluid that is immiscible with the thermoplastic polymer of the nanoclay-filled-polymer composite, optionally (c) a thermoplastic polymer not filled with a nanoclay, and optionally (d) an emulsion stabilizer at a temperature at or greater than a melting point or softening temperature of the thermoplastic polymer of the nanoclay-filled-polymer and the thermoplastic polymer, when included, to disperse the nanoclay-filled-polymer composite in the carrier fluid; cooling the mixture to below the melting point or softening temperature to form nanoclay-filled-polymer particles; and separating the nanoclay-filled-polymer particles from the carrier fluid.

A sealing element (10) for use in a fluid-carrying pipeline (16) comprising a substantially central core (14) surrounded by a coating (12). The outer coating (12) is adapted to perform a partial extrusion through an opening (15) in a pipeline wall (16) to seal the opening (15). The density of the sealing element (10) is substantially the same as the density of the fluid (11) in the pipeline (16). The coating (12) comprises a two-part epoxy putty, and the core (14) is formed from a deformable material. A method of making the sealing element is also disclosed.

An emulsion of a nitrogen atom-containing polymer or salt thereof and a method for producing it are provided. The emulsion has high stability and low dispersity of the particle diameter of emulsified particles. A method for producing particles including a crosslinked nitrogen atom-containing polymer or sat thereof using the emulsion is also provided. The method for producing the emulsion includes a step of mixing a first solution that includes a nitrogen atom-containing polymer or salt thereof and a hydrophilic solvent and has a viscosity of 10 to 2,000 mPa.Math.s, and a second solution that includes a hydrophobic solvent and has a viscosity of 1 to 100 mPa.Math.s, stirring the mixture, and thus obtaining an emulsion of the nitrogen atom-containing polymer or salt thereof, wherein a ratio between the viscosity of the first and second solutions is in a range of 0.1:1 to 300:1.

Methods for producing highly spherical particles that comprise: mixing a mixture comprising: (a) nanoclay-filled-polymer composite comprising a nanoclay dispersed in a thermoplastic polymer, (b) a carrier fluid that is immiscible with the thermoplastic polymer of the nanoclay-filled-polymer composite, optionally (c) a thermoplastic polymer not filled with a nanoclay, and optionally (d) an emulsion stabilizer at a temperature at or greater than a melting point or softening temperature of the thermoplastic polymer of the nanoclay-filled-polymer and the thermoplastic polymer, when included, to disperse the nanoclay-filled-polymer composite in the carrier fluid; cooling the mixture to below the melting point or softening temperature to form nanoclay-filled-polymer particles; and separating the nanoclay-filled-polymer particles from the carrier fluid.

A resin powder may be superior in passability through pipes and silos, and a method may produce such a resin powder. The resin powder contains a vinyl alcohol polymer, an average particle diameter thereof is 100 to 2,000 μm, and an average value PA of a roundness P by formula (1), of 50 particles arbitrarily extracted from the particles of the resin powder having a particle diameter of 100 to 1,000 μm, is 0.1 to 0.8.

P=(Σ.sub.i=1.sup.Nr.sub.i)/NR  (1)

r.sub.i being a radius of curvature of each particle corner of the 50 particles; R being a maximum inscribed circle radius of the particle; and N being a number of particle corners. If the number of particle corners is 9 or more, the radii of curvature of eight corners, in increasing order from a smallest radius of curvature, are adopted, and N is 8.

A process for producing particles of a thermoplastic polymer in spherical form involves providing at least one thermoplastic polymer in a molten state and providing an aqueous solution of at least one surface-active substance. The aqueous solution is in a temperature range from 100 to 300° C. The process also involves dispersing the thermoplastic polymer in the aqueous solution to obtain an aqueous solution containing dispersed thermoplastic polymer, which is cooled down to a temperature below the solidification point of the thermoplastic polymer to obtain a suspension containing an aqueous solution and particles of the thermoplastic polymer suspended in a solid state and in spherical form. The particles can be separated from the suspension and, optionally, dried. The particles obtained from the process have a particle size distribution having a d[4,3] value of more than 10 μm and a d.sub.90.3 value of more than 20 μm.

A method and device for comminuting a thermoplastic polymer, in particular a thermoplastic elastomer, and for producing therefrom pulverulent materials with a predefined grain distribution, includes the following steps: comminuting the thermoplastic polymer, which is provided in lump form, into a starting powder in a comminuting device, and subsequently screening this starting powder at least once until a predefined grain distribution has been attained. A release agent, which reduces the tack and capability for agglomeration formation of the starting powder, is fed into the comminuting device during the comminuting step.

A post-extrusion extruded granular sorbent processing system having a pellet-collecting enclosure that receives pellets of granular sorbent extruded from a starch-containing admixture through a die at a discharge end of an extruder and transports the pellets in air from an air mover flowing from the enclosure through a pellet-conveying duct of a pneumatic conveyor cooling and drying the pellets. The system includes a subsystem configured for processing the pellets after extruding, cooling, and drying using a pellet processing machine configured for reducing a size of each pellet having a size greater than a size reduction setting of the machine. A preferred pellet processing machine has rotating horizontally and circumferentially corrugated rollers with a selectively variable gap between the rollers providing the size reducing setting and configuring the rotating rollers for reducing a size of the pellets passing between the rollers having a size greater than the gap between the rollers.

A process for grinding materials includes grinding a frozen plastic material to form a first-stage plastic material in a first mill. The first-stage plastic material is processed in a second mill to form material having a particle size less than about 100 μm.

A method of making an extruded granular absorbent is provided where the method includes providing an extruder and a starch-containing admixture, and pressurizing the starch containing admixture in the extruder under relatively high extrusion pressures to extrude the pressurized starch-containing admixture from the extruder, and producing a water absorbent and oil absorbent extrudate. The present invention further provides that the extruded granular absorbent may be combined with a non-extruded granular material with relatively high inert or cellulose content where there may be a greater proportion of extruded granular absorbent, and the extruded granular absorbent and non-extruded granular material agglutinate into a clump when wetted with water or urine.