Abstract: An apparatus for extruding a polymeric material, having an extrusion head which includes a male die, a female die coaxially arranged with respect to the male die, a conveying channel, and at least one portion of which is defined between the male die and the female die. The apparatus further includes a device for adjusting a cross-sectional area of the at least one portion of the conveying channel by reciprocally displacing the female die with respect to the male die in response to an extrusion speed variation of the polymeric material.

Abstract: An apparatus for extruding a polymeric material, having an extrusion head which includes a male die, a female die coaxially arranged with respect to the male die, a conveying channel, and at least one portion of which is defined between the male die and the female die. The apparatus further includes a device for adjusting a cross-sectional area of the at least one portion of the conveying channel by reciprocally displacing the female die with respect to the male die in response to an extrusion speed variation of the polymeric material.

Abstract: A multiscrew extruder device for production of elastomeric compounds is intended for manufacturing tires for vehicle wheels. The device includes a holding body; a mandrel inserted in the holding body extending along a longitudinal axis and delimiting an annular chamber with the holding body; and a plurality of extrusion screws disposed in the annular chamber and parallel to the longitudinal axis. A first circuit for a heat-exchange fluid for temperature control is formed in the mandrel and includes a central channel extending in the mandrel along the longitudinal axis and a plurality of parallel peripheral channels extending in a peripheral portion of the mandrel close to the annular chamber and in fluid communication with the central channel.

Abstract: An apparatus for extruding a polymeric material, having an extrusion head which includes a male die, a female die coaxially arranged with respect to the male die, a conveying channel, and at least one portion of which is defined between the male die and the female die. The apparatus further includes a device for adjusting a cross-sectional area of the at least one portion of the conveying channel by reciprocally displacing the female die with respect to the male die in response to an extrusion speed variation of the polymeric material.

Abstract: A method for extruding a polymeric material includes the steps of: a) feeding the polymeric material to an extrusion apparatus including an extrusion head, the extrusion head including: a male die; a female die coaxially arranged with respect to the male die; a conveying channel, at least one portion of which is defined between the male die and the female die; and b) adjusting a cross-sectional area of the at least one portion of the conveying channel by reciprocally displacing the female die with respect to the male die in response to an extrusion speed variation of the polymeric material. An extrusion apparatus and a process for manufacturing a tire which uses the extrusion apparatus, are also disclosed.

Abstract: A multiscrew extruder device for production of elastomeric compounds is intended for manufacturing tyres for vehicle wheels. The device includes a holding body; a mandrel inserted in the holding body extending along a longitudinal axis and delimiting an annular chamber with the holding body; and a plurality of extrusion screws disposed in the annular chamber and parallel to the longitudinal axis. A first circuit for a heat-exchange fluid for temperature control is formed in the mandrel and includes a central channel extending in the mandrel along the longitudinal axis and a plurality of parallel peripheral channels extending in a peripheral portion of the mandrel close to the annular chamber and in fluid communication with the central channel.

Abstract: A utility pole includes a thermoplastic composite material including: (a) at least one olefin polymer; and (b) at least one reinforcing fiber material embedded in the at least one olefin polymer, the thermoplastic composite material having a specific tensile strength higher than or equal to 15 MPa/(gr/cm3), preferably 20 MPa/(gr/cm3) to 200 MPa/(gr/cm3), and more preferably 30 MPa/(gr/cm3) to 150 MPa/(gr/cm3) and a specific tensile modulus higher than or equal to 2000 MPa/(gr/cm3), preferably 2500 MPa/(gr/cm3) to 20000 MPa/(gr/cm3), and more preferably 3000 MPa/(gr/cm3) to 15000 MPa/(gr/cm3).

Abstract: A utility pole includes a thermoplastic composite material including: (a) at least one olefin polymer; and (b) at least one reinforcing fiber material embedded in the at least one olefin polymer, the thermoplastic composite material having a specific tensile strength higher than or equal to 15 MPa/(gr/cm3), preferably 20 MPa/(gr/cm3) to 200 MPa/(gr/cm3), and more preferably 30 MPa/(gr/cm3) to 150 MPa/(gr/cm3) and a specific tensile modulus higher than or equal to 2000 MPa/(gr/cm3), preferably 2500 MPa/(gr/cm3) to 20000 MPa/(gr/cm3), and more preferably 3000 MPa/(gr/cm3) to 15000 MPa/(gr/cm3).

Abstract: A method for extruding a polymeric material includes the steps of: a) feeding the polymeric material to an extrusion apparatus including an extrusion head, the extrusion head including: a male die; a female die coaxially arranged with respect to the male die; a conveying channel, at least one portion of which is defined between the male die and the female die; and b) adjusting a cross-sectional area of the at least one portion of the conveying channel by reciprocally displacing the female die with respect to the male die in response to an extrusion speed variation of the polymeric material. An extrusion apparatus and a process for manufacturing a tyre which uses the extrusion apparatus, are also disclosed.