Abstract: A process of obtaining a thermoplastic composition formed from a polyolefin matrix is disclosed. The polyoelfin matrix comprises a polypropylene The process comprises (a) the formation of a viscoelastic mixture of the polypropylene and the lamellar mineral by heating and kneading the composition at a temperature at least equal to the working temperature of the polypropylene, (b) submitting the viscoelastic mixture to thermo-mechanical work, (c) eliminating volatile components from the viscoelastic mixture, and (d) transforming the viscoelastic mixture resulting from step (c) into a granulated material. The viscoelastic mixture is subjected during steps (a) and (b) to a weak and controlled rate of shearing of no more than 200 s?1 and the viscoelastic mixture is subjected in step (b) to at least one cycle of extension and relaxation in a dedicated zone which is at least 25% of the total length of at least one screw of a compounding extruder.

Abstract: A partly cross-linked thermoplastic elastomer polyolefin composition intended to be converted by any plastics processing technique into a molded part, such as a cover for housing a vehicle's safety airbag, comprises an olefin polymer of polypropylene type, at least one copolymer of ethylene-alpha-olefin type, at least one cross-linking agent and a free radicals formation agent characterized in that a) the olefin polymer of polypropylene type is chosen from the group of polypropylene/ethylene or polypropylene/?-olefin copolymers and selected from those having an impact resistance of at least 40 kJ/m2 when measured using the notched Izod impact resistance test at 23° C. in accordance with ISO standard 180. b) at least one copolymer of the ethylene-?-olefin type is selected from the group formed by those having a density at least equal to 0.870 g/cm3 in accordance with ISO standard 1183. c) at least one thermoplastic elastomer is introduced into the composition.

Abstract: A process is disclosed of obtaining a thermoplastic composition formed from a polyolefin matrix comprising a polypropylene with a fluidity index of from 2 to 100 g/10 minutes when measured at 230° C. under 2.

Abstract: The invention concerns a partly cross-linked thermoplastic elastomer polyolefin composition intended to be converted by any plastics processing technique, but by injection in particular, into a moulded part, such as, for example, a cover for housing a vehicle's safety airbag, comprising an olefin polymer of polypropylene type, at least one copolymer of ethylene-?-olefin type, at least one cross-linking agent and a free radicals formation agent characterised in that a) the olefin polymer of polypropylene type is chosen from the group of polypropylene/ethylene or polypropylene/?-olefin copolymers and selected from those having an impact resistance of at least 40 kJ/m2 when measured using the notched Izod impact resistance test at 23° C. in accordance with ISO standard 180. b) at least one copolymer of the ethylene-?-olefin type is selected from the group formed by those having a density at least equal to 0.870 g/cm3 in accordance with ISO standard 1183.