Microporous breathable films include a polyolefin and an inorganic filler dispersed in the polyolefin.

The production of a biaxially oriented tube from thermoplastic material, wherein a tube in preform condition is extruded from thermoplastic material using an extruder having an extruder die head with an inner die member that forms a lumen in the tube in preform condition. The tube in preform condition is subjected to a temperature conditioning. Use is made of a expansion device comprising a non-deformable expansion part having a gradually increasing diameter to a maximum diameter, which expansion part is contacted by the tube and exerts an expanding force so as to bring about expansion of the tempered tube in circumferential direction. The method comprises drawing the tempered tube over the expansion device using a drawing device, in such a manner that said tube is transformed from a tube in preform condition into a biaxially oriented tube with thermoplastic material which is oriented in axial direction and in circumferential direction of the tube.

A pressure chamber is provided for a blown film extrusion apparatus having (i) a die head for extruding a tubular polymer bubble, and (ii) a cooling assembly down-stream of the die head for receiving the bubble and applying a cooling fluid to the bubble. The pressure chamber includes an upstream end wall sealed around the die head outlet, and extending outward from the seal; a side wall movable between a closed position for controlling air flow from a chamber volume surrounding the bubble to the atmosphere, and an open position for permitting air flow from the chamber volume to the atmosphere. The upstream end wall has an inlet for receiving air from an air supply, and an outlet in fluid communication with the inlet and configured to direct the air into the chamber volume to pressurize the chamber volume when the side wall is in the closed position.

A thermoregulation system of rotating metal cylinders in plants for the extrusion and conversion/transformation of plastic films includes heating elements applied to each rotating cylinder, wherein the heating elements are infrared heating elements, and wherein the rotating cylinder includes a metal tube rotating around a fixed shaft, which is rigidly connected to two side plates.

An object of the present invention is to improve spinnability, productivity, and tensile strength of a polyester fiber containing poly(3-hydroxybutyrate-co-3-hydroxyhexanoate). By spinning the polyester resin containing the poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) at a high spinning velocity, the spinnability, productivity, and tensile strength of the polyester fiber can be improved.

A method for manufacturing a dull polyamide 56 fiber includes steps as follows. Bright polyamide 56 chips are provided. A viscosity adjusting step is provided, wherein a relative viscosity in sulfuric acid of the bright polyamide 56 chips is adjusted to a range of 2.90 to 3.00. A moisture adjusting step is provided, wherein a moisture content of the bright polyamide 56 chips is adjusted to a range of 350 to 550 ppm. A spinning step is provided, which includes providing dull polyamide 6 chips and a blending step. The dull polyamide 6 chips include TiO.sub.2. In the blending step, the dull polyamide 6 chips and the bright polyamide 56 chips dealt with the viscosity adjusting step and the moisture adjusting step are melted and blended, and then spun at a temperature ranging from 275° C. to 285° C., thus the dull polyamide 56 fiber is obtained.

A method of fabricating a gas separation membrane includes providing a coextruded multilayer film that includes a first polymer layer formed of a first polymer material and a second polymer layer formed of a second polymer material, the first polymer material having a first gas permeability. The coextruded multilayer film is axially oriented such that the second polymer layer has a second gas permeability that is greater than the first gas permeability.

An exemplary method of, for instance, forming a baffle or reinforcer includes extruding an expandable material to have a particular cross-sectional profile, inserting the expandable material into a molding tool, cutting the expandable material to a predetermined length within the molding tool, and overmolding a carrier material onto a portion of the expandable material within the molding tool.

The present disclosure provides a print head apparatus and method for printing a multi-coloured three-dimensional object. The apparatus separately receives at least two filaments in a cold section, separately feeds the at least two filaments in a transition section, and heats the at least two filaments in a hot section. The hot section includes a combiner tube to combine the at least two filaments, which are then mixed together in a mixing chamber by a mixing shaft. The molten filament mixture is then extruded out of a nozzle. The print head apparatus further includes lifter discs that can lift the mixing shaft out of the chamber, creating a negative pressure in the chamber and sucking the remaining molten filament from the nozzle upwardly and back into the apparatus to reduce oozing and stringing.

Described herein are extrusion processes to produce hollow pellets. Also disclosed are pelletizer devices that can be used to produce the hollow pellets. The processes and devices make use of an extrusion die having a die orifice and an insert that is placed in the die orifice to produce the hollow pellets.