A three-dimensional printing system for preparing a three-dimensional object made at least partially of an expanded polymer includes a printing device configured to prepare an expandable polymer melt and deposit a strand of expandable, expanding or expanded polymer onto a surface and a three-dimensional movement device for to enable depositing of the strand of expandable, expanding or expanded polymer at a predetermined time at a precise position within the three-dimensional matrix. The printing device includes a feed section at an upstream end of the printing device, a heating section, a pressurizing section, a blowing agent supply line, a mixing section, a cooling section and a terminal printing head section at a downstream end of the printing device including a die configured to deposit the strand of the expandable, expanding or expanded polymer onto the surface.

An extruder screw for a multi-screw extruder for plastics extrusion includes: a feeding and metering zone for melting and homogenizing the plastic and an evacuating zone for carrying away gaseous constituents and a compressing and/or discharging zone; a multi-screw section, which has a plurality of planetary screws, which lie open on the outer circumference of the extruder screw, at least over part of their length; and a driving zone, in which the planetary screws engage by way of a toothing in an external toothing on a central shaft or in an internal toothing in a stator ring or in the inner wall of an extruder bore of the multi-screw extruder. The feeding and metering zone extends into the multi-screw section, wherein the respective part of the planetary screws that is lying in the metering zone is at least partially enclosed.

The extrusion installation is configured for manufacturing a complex profiled-element strip, such as a tread, based on elastomer compounds by co-extrusion, and comprises multiple extruders feeding elastomer compounds to an extrusion head. The extrusion head receives a proportion of elastomer compound of between 2 and 25% of the total volumetric throughput of the installation from at least one Archimedean-screw extruder and the rest from positive-displacement extruders.

A method for producing low density polyester foam utilizing low I.V. polyester feedstock includes providing a low intrinsic viscosity raw material. The low intrinsic viscosity raw material includes between 25% to 100% of a post consumer polyester and has an intrinsic viscosity of less than 0.8 dl/g. The intrinsic viscosity of the low intrinsic viscosity raw material is increased via a de-condensation reaction configured to support foaming. The intrinsic viscosity of the low intrinsic viscosity raw material is increased to 1.1 dl/g or greater. A starting formulation is created including the low intrinsic viscosity raw material with the increased intrinsic viscosity. The starting formulation is foamed to create the polyester foam. Wherein, the polyester foam produced has a specific gravity of less than 0.65 g/cc.

A multilayered composite shape memory material includes a coextruded first polymer layer of a first polymer material and a second polymer layer of a second polymer material. The composite shape memory material after thermomechanical programming being capable of undergoing at least one temperature induced shape transition from a temporary shape to a permanent shape. The first polymer layer defines a hard segment of the shape memory material that provides the shape memory material with the permanent shape, and the second polymer layer defines a switching segment of the shape memory material that provides the shape memory material with the temporary shape.

The invention relates an extrusion device (100) for extruding a semi¬finished product made of elastomeric material, comprising an extrusion body (10) extending along a feeding direction (A) and a pump (20) arranged downstream of the extrusion body (10) along said feeding direction (A). The extrusion body (10) comprises a hopper (30) for loading an elastomeric material and an extrusion screw (50) extending along said feeding direction (A) and having an inlet portion (50a) arranged close to the hopper (30) and an exit portion (50b) arranged close to the pump (20). The extrusion body (10) also comprises a motorised roller (40) arranged at the inlet portion (50a) of the extrusion screw (50) and configured to receive the elastomeric material from the hopper (30) and feed it to the extrusion screw (30). The extrusion screw (50) has a length and a diameter such that the ratio between length and diameter is comprised between 4 mm and 8 mm. The invention also relates to an extrusion process carried out through the aforementioned extrusion device (100).

To solve problems of complication and malfunction of the device's structure, an increase in the process time, and malfunction caused by catching of a front end portion of a bead apex rubber. A bead apex rubber forming method comprises a forming step P1, a connecting space opening step P2, a connecting space closing step P3, and a connecting step P4. In a rear closed state R of a molding chamber 11, the forming step P1 injects unvulcanized rubber G while a bead core A is being rotated, and forms a bead apex rubber B having a front end portion Bf. when the front end portion Bf approaches a rear shutter part 9, the connecting space opening step P2 removes a second lateral surface S2 together with the rear shutter part 9, and forms, between the front end portion Bf and a rear end portion Br, a connecting space J whose second side surface S2 side is opened. The connecting space closing step P3 closes the connecting space 3 by disposing a third lateral surface S3 extending between the rear end portion Br and the front end portion Bf. The connecting step P4 injects the unvulcanized rubber into the connecting space J closed, and connects between the rear end portion Br and the front end portion Bf integrally.

Method for producing a thermoplastic molding compound (F) in an extruder, which has at least one screw having an outside diameter (D), wherein a thermoplastic component (TP) containing at least one thermoplastic polymer, a component (C) containing a graft polymer based in particular on butadiene and/or acrylate, and optionally a component (Z) containing additives are heated to a temperature of 200° C. to 280° C., melted and mixed by supplying thermal energy in a melting section (S) and/or in at least one mixing section (M) such that the thermoplastic molding compound (F) is formed, and the thermoplastic molding compound is subsequently degassed in a degassing zone (E) of the extruder, wherein an absolute pressure (P1) of less than 2 bar is set in this zone, and after the degassing the molding compound (F) is conveyed to a melt pump (SP) by screw elements, wherein the total length of the screw elements of a conveying path (FS) from the degassing opening (O) to the melt pump (SP) is less than five times the outside diameter (D) of the at least one screw.

The invention relates an extrusion device (100) for extruding a semi-finished product made of elastomeric material, comprising an extrusion body (10) extending along a feeding direction (A) and a pump (20) arranged downstream of the extrusion body (10) along said feeding direction (A). The extrusion body (10) comprises a hopper (30) for loading an elastomeric material and an extrusion screw (50) extending along said feeding direction (A) and having an inlet portion (50a) arranged close to the hopper (30) and an exit portion (50b) arranged close to the pump (20). The extrusion body (10) also comprises a motorised roller (40) arranged at the inlet portion (50a) of the extrusion screw (50) and configured to receive the elastomeric material from the hopper (30) and feed it to the extrusion screw (30). The extrusion screw (50) has a length and a diameter such that the ratio between length and diameter is comprised between 4 mm and 8 mm. The invention also relates to an extrusion process carried out through the aforementioned extrusion device (100).

An installation for producing a polymer melt for a porous film, in particular for a membrane film, comprises a planetary roller extruder. Said extruder is used to produce a flowable polymer melt from thermoplastics. The planetary roller extruder has a filling opening and a discharge side for delivering the polymer melt. A melt pump is further provided. The discharge side of the planetary roller extruder is connected to a downstream inlet side of the melt pump for further conveying the polymer melt. The connection is in the form of a pressure channel shielded from the ambient atmosphere or a pressure line shielded from the ambient atmosphere. The planetary roller extruder and the melt pump are designed and/or can be driven in such a manner that the polymer melt is applied or can be transferred under pressure at the melt pump on the inlet side.