초록 ▼

Reinforced composite tubes are formed by rolling a flat reinforcement fabric onto a cylindrical or conical mandrel under tension. By pre-impregnating the fabric with a suitable matrix precursor or by serving the individual threads of the fabric with a thermoplastic, the fabric may be compressed by a

Reinforced composite tubes are formed by rolling a flat reinforcement fabric onto a cylindrical or conical mandrel under tension. By pre-impregnating the fabric with a suitable matrix precursor or by serving the individual threads of the fabric with a thermoplastic, the fabric may be compressed by applying heat and pressure during the rolling process. After rolling, the resulting prepreg is cured in a suitable vacuum bag, also under heat and pressure. The cured prepreg may then be converted by pyrolysis and densified by repeated impregnation and converting steps. The resulting composite tubes are substantially free from mechanical defects which would reduce their strength.

대표청구항 ▼

A method for forming reinforced refractory composite tubes, said method comprising: (a) rolling a continuous reinforcement fabric onto a mandrel under tension while simultaneously applying heat and pressure, said fabric being pre-impregnated with a refractory matrix precursor or served with a thermo

A method for forming reinforced refractory composite tubes, said method comprising: (a) rolling a continuous reinforcement fabric onto a mandrel under tension while simultaneously applying heat and pressure, said fabric being pre-impregnated with a refractory matrix precursor or served with a thermoplastic so that successive plies of the fabric are compressed without the introduction of mechanical defects; (b) curing the refractory matrix precursor or thermoplastic serving on the rolled reinforcement fabric under a vacuum at an elevated temperature; (c) converting the cured refractory matrix precursor or thermoplastic on the rolled reinforcement fabric to the corresponding refractory matrix by pyrolysis while the rolled reinforcement fabric is present on a mandrel having a coefficient of thermal expansion from 1.1 to 10 times greater than that of the refractory matrix; (d) impregnating the rolled reinforcement fabric with additional matrix precursor; (e) converting the additional matrix precursor to matrix; and (f) repeating steps (d) and (e) until a desired matrix density is achieved.