Abstract: The invention relates to a method for estimating a dead zone at closing of a flap (P1) of a discharge valve (VBV1) of a turbomachine, in which the actual position of the actuator (V1) is measured for a setpoint closing signal of the flap (P1), a static angle is determined from the actual position, a closing dead zone is determined, corresponding to the fact that the joint (J1) is compressed so as to not let the primary flow pass through the orifice (O1) in the secondary flow, by the fact that the dead zone is equal to a reference dead zone, which has been predetermined on a reference turbomachine operating on the ground, to which the measured static angle has been added and from which a reference static angle, which has been predetermined on the reference turbomachine operating in flight, has been subtracted.

Abstract: A method and apparatus for heat treating powders of semi-crystalline or crystallizable polymers. The apparatus includes a heating device for heating the powder to a temperature that is less than the melting temperature of a highest melting crystalline form of the powder, a vessel containing the powder that is exposed to heat produced by the heating device, and a mechanism for moving the vessel to cause the powder within the vessel to move with respect to the vessel.

Abstract: A process for the preparation of a semifinished product including a PAEK-based resin and reinforcing fibers, including the stages of: a. preparation of a dispersion including a PAEK-based resin in the pulverulent form dispersed in an aqueous phase including a surfactant; b. bringing the reinforcing fibers into contact with said aqueous dispersion; c. drying the fibers impregnated with dispersion; and d. heating the impregnated fibers to a temperature sufficient for the melting of the resin, so as to form a semifinished product, wherein the surfactant is a thermally stable surfactant. Also, semifinished products capable of being obtained from the process and their use in the manufacture of composite materials.

Abstract: A method for analyzing semifinished products including reinforcing fibers having an essentially unidirectional orientation and a thermoplastic resin, including a first and a second test for measuring the thickness of a stack of semifinished products over time during the compression thereof and for determining the equivalent homogeneous viscosity of the stack; determining the total thickness reduction of the stack of semifinished products during the first test; determining the ratio of the equivalent homogeneous viscosity of the stack from the second test to the equivalent homogeneous viscosity of the stack from the first test; and determining the ratio of the thickness of the stack from the first test after a reference time starting from the moment of the onset of melting of the stack of semifinished products, to the thickness of the stack from the first test at the moment of the onset of melting of the stack of semifinished products.

Abstract: Provided is a poly(aryl-ether-ketone) (PAEK) powder suitable for use in a method for building objects layer-by-layer by electromagnetic radiation-generated sintering, which is obtained from a thermal pretreatment at a temperature between 260° C. and 290° C. and which has a melting temperature which is stable, at the build temperature, and below or equal to 330° C.

Abstract: The invention is targeted mainly at a process for the preparation of a semifinished product comprising a PAEK-based resin and reinforcing fibers, comprising the stages of: a. preparation of a dispersion comprising a PAEK-based resin in the pulverulent form dispersed in an aqueous phase comprising a surfactant; b. bringing the reinforcing fibers into contact with said aqueous dispersion; c. drying the fibers impregnated with dispersion; and d. heating the impregnated fibers to a temperature sufficient for the melting of the resin, so as to form a semifinished product, characterized in that the surfactant is a thermally stable surfactant. It is furthermore targeted at the dispersion of use in said process. Finally, it is targeted at the semifinished products capable of being obtained and also at their use in the manufacture of composite materials.

Abstract: A composition based on poly(ether ether ketone) (PEEK) including poly(ether ketone ketone) (PEKK), wherein the poly(ether ketone ketone) (PEKK) includes a mixture of terephthalic and isophthalic units, the percentage by weight of terephthalic units, with respect to the sum of the terephthalic and isophthalic units, being between 55 and 85%, limits included, and preferably between 55 and 70%, the composition including between 1 and 40%, limits included, preferably between 5 and 40% and more preferably still between 10 and 30% by weight of PEKK, with respect to the total weight of the composition.

Abstract: A process including: the provision of a semicrystalline or crystallizable composition, having a glass transition temperature Tg, including at least one polyaryletherketone; the provision of a compression forming means including: a mold, the mold having at least one cavity; the preparation of the composition in the molten state in said at least one cavity, the mold having a temperature T0 at the end of the preparation stage; the compression and the cooling of the composition in the molten state, the mold being cooled from the temperature T0 down to a final temperature Tfof less than or equal to (Tg+30)° C., to form a compression-formed article; and the removal of the compression-formed article from the mold; in which the composition has a melting point strictly of less than 340° C.

Abstract: The invention relates to a method for estimating and using a dead zone at closing of a flap (P1) of a discharge valve (VBV1) of a turbomachine, in which the actual position of the actuator (V1) is measured for a setpoint signal for closing the flap (P1), a static angle is determined from the actual position, a closing dead zone is determined from the static angle, corresponding to the fact that the joint (J1) remains compressed and seals the closing of the orifice (O1), the dead zone is recorded and the signal (SC1) for controlling the actuator (V1) is generated by the computer as a function of the dead zone.

Abstract: The invention concerns an adhesive composition consisting of at least one ethylene polymer or copolymer, said composition comprising at least one unsaturated carboxylic acid ester comonomer, and at least one functional comonomer, useful in an extrusion-coating process for application on a support or in an extrusion-lamination process for bonding together several supports of different type or not, in a wide temperature range. The invention is characterized in that said composition has an unsaturated carboxylic acid ester content higher than 5 wt % and in that the functional comonomer consists of at least one reactive function in the form of an acid group, anhydride or epoxy, whereof the proportion is less than 1 wt % of the composition.

Abstract: The invention relates to a method for estimating and using a dead zone at closing of a flap (P1) of a discharge valve (VBV1) of a turbomachine, in which the actual position of the actuator (V1) is measured for a setpoint signal for closing the flap (P1), a static angle is determined from the actual position, a closing dead zone is determined from the static angle, corresponding to the fact that the joint (J1) remains compressed and seals the closing of the orifice (O1), the dead zone is recorded and the signal (SC1) for controlling the actuator (V1) is generated by the computer as a function of the dead zone.

Abstract: The invention relates to a method for estimating a dead zone at closing of a flap (P1) of a discharge valve (VBV1) of a turbomachine, in which the actual position of the actuator (V1) is measured for a setpoint closing signal of the flap (P1), a static angle is determined from the actual position, a closing dead zone is determined, corresponding to the fact that the joint (J1) is compressed so as to not let the primary flow pass through the orifice (01) in the secondary flow, by the fact that the dead zone is equal to a reference dead zone, which has been predetermined on a reference turbomachine operating on the ground, to which the measured static angle has been added and from which a reference static angle, which has been predetermined on the reference turbomachine operating in flight, has been subtracted.

Abstract: A method and apparatus for heat treating powders of semi-crystalline or crystallizable polymers. The apparatus includes a heating device for heating the powder to a temperature that is less than the melting temperature of a highest melting crystalline form of the powder, a vessel containing the powder that is exposed to heat produced by the heating device, and a mechanism for moving the vessel to cause the powder within the vessel to move with respect to the vessel.

Abstract: The invention relates to a poly(aryl-ether-ketone) (PAEK) powder, for use in a method for building objects layer-by-layer by electromagnetic radiation-generated sintering, said powder being characterized in that it is obtained from a thermal pretreatment at a temperature comprised between 260° C. and 290° C., preferably between 280° C. and 290° C., and in that it has a melting temperature which is stable, at the build temperature, and below or equal to 330° C., preferably below or equal to 320° C., and more preferably below or equal to 310° C.

Abstract: The invention is targeted mainly at a process for the preparation of a semifinished product comprising a PAEK-based resin and reinforcing fibers, comprising the stages of: a. preparation of a dispersion comprising a PAEK-based resin in the pulverulent form dispersed in an aqueous phase comprising a surfactant; b. bringing the reinforcing fibers into contact with said aqueous dispersion; c. drying the fibers impregnated with dispersion; and d. heating the impregnated fibers to a temperature sufficient for the melting of the resin, so as to form a semifinished product, characterized in that the surfactant is a thermally stable surfactant. It is furthermore targeted at the dispersion of use in said process. Finally, it is targeted at the semifinished products capable of being obtained and also at their use in the manufacture of composite materials.

Abstract: Process for densification of a poly(arylene ether ketone) (PAEK) powder or of a mixture of poly(arylene ether ketone) (PAEK) powders, the process being mixing the powder or the mixture of powders, in a mixer equipped with a rotary stirrer including at least one blade, for a period of between 30 minutes and 120 minutes, preferably of between 30 and 60 minutes, at a blade-tip speed of between 30 m/s and 70 m/s, preferably of between 40 and 50 m/s.

Abstract: A composition based on poly(ether ether ketone) (PEEK) including poly(ether ketone ketone) (PEKK), wherein the poly(ether ketone ketone) (PEKK) includes a mixture of terephthalic and isophthalic units, the percentage by weight of terephthalic units, with respect to the sum of the terephthalic and isophthalic units, being between 55 and 85%, limits included, and preferably between 55 and 70%, the composition including between 1 and 40%, limits included, preferably between 5 and 40% and more preferably still between 10 and 30% by weight of PEKK, with respect to the total weight of the composition.

Abstract: Provided is a poly(aryl-ether-ketone) (PAEK) powder suitable for use in a method for building objects layer-by-layer by electromagnetic radiation-generated sintering, which is obtained from a thermal pretreatment at a temperature between 260° C. and 290° C. and which has a melting temperature which is stable, at the build temperature, and below or equal to 330° C.

Abstract: A composition based on poly(ether ether ketone) (PEEK) including poly(ether ketone ketone) (PEKK), characterized in that the poly(ether ketone ketone) (PEKK) includes a mixture of terephthalic and isophthalic units, the percentage by weight of terephthalic units, with respect to the sum of the terephthalic and isophthalic units, being between 55 and 85%, limits included, and preferably between 55 and 70%, the composition including between 1 and 40%, limits included, preferably between 5 and 40% and more preferably still between 10 and 30% by weight of PEKK, with respect to the total weight of the composition.

Abstract: The invention relates to a process for the heat treatment of poly(arylene ether ketone ketone) powder suitable for laser sintering, and also to the powders resulting from this process.