Abstract: An acrylic multifilamentary material possessing an internal structure which is particularly suited for thermal conversion to high strength carbon fibers is formed via a specifically defined combination of processing conditions. The acrylic polymer while in substantially homogeneous admixture with appropriate concentrations (as defined) of acetonitrile and water is melt extruded and is drawn at a relatively low draw ratio which is substantially less than the maximum draw ratio achievable. This fibrous material which is capable of readily undergoing drawing is passed through a heat treatment zone wherein the evolution of residual acetonitrile and water takes place. The resulting fibrous material following such heat treatment is subjected to additional drawing to accomplish further orientation and internal structure modification and to produce a fibrous material of the appropriate denier for carbon fiber production.

Abstract: An acrylic multifilamentary material possessing an internal structure which is well suited for thermal conversion to high strength carbon fibers is formed via a specifically defined combination of processing conditions. The acrylic polymer while in substantially homogeneous admixture with appropriate concentrations (as defined) of C.sub.1 to C.sub.2 nitroalkane and water is melt extruded and is drawn at a relatively low draw ratio which is substantially less than the maximum draw ratio achievable. During the melt extrusion a C.sub.1 to C.sub.4 monohydroxy alkanol preferably also is present in the substantially homogenous admixture. The fibrous material which is capable of readily undergoing drawing next is passed through a heat treatment zone wherein the evolution of residual nitroalkane, monohydroxy alkanol and water takes place.

Abstract: An acrylic multifilamentary material possessing an internal structure which is particularly suited for thermal conversion to high strength carbon fibers is formed via a specifically defined combination of processing conditions. The acrylic polymer while in substantially homogeneous admixture with appropriate concentrations (as defined) of acetonitrile, C.sub.1 to C.sub.4 monohydroxy alkanol, and water is melt extruded and is drawn at a relatively low draw ratio which is substantially less than the maximum draw ratio achievable. This fibrous material which is capable of readily undergoing drawing is passed through a heat treatment zone wherein the evolution of residual acetonitrile, the monohydroxy alkanol and water takes place. The resulting fibrous material following such heat treatment is subjected to additional drawing to accomplish further orientation and internal structure modification and to produce a fibrous material of the appropriate denier for carbon fiber production.

Abstract: An acrylic multifilamentary material possessing an internal structure which is particularly suited for thermal conversion to high strength carbon fibers is formed via a specifically defined combination of processing conditions. The acrylic polymer while in substantially homogeneous admixture with appropriate concentrations (as defined) of acetonitrile and water is melt extruded and is drawn at a relatively low draw ratio which is substantially less than the maximum draw ratio achievable. This fibrous material which is capable of readily undergoing drawing is passed through a heat treatment zone wherein the evolution of residual acetonitrile and water takes place. The resulting fibrous material following such heat treatment is subjected to additional drawing to accomplish further orientation and internal structure modification and to produce a fibrous material of the appropriate denier for carbon fiber production.

Abstract: An acrylic multifilamentary material possessing an internal structure which is well suited for thermal conversion to high strength carbon fibers is formed via a specifically defined combination of processing conditions. The acrylic polymer while in substantially homogeneous admixture with appropriate concentrations (as defined) of C.sub.1 to C.sub.2 nitroalkane and water is melt extruded and is drawn at a relatively low draw ratio which is substantially less than the maximum draw ratio achievable. During the melt extrusion a C.sub.1 to C.sub.4 monohydroxy alkanol preferably also is present in the substantially homogenous admixture. The fibrous material which is capable of readily undergoing drawing next is passed through a heat treatment zone wherein the evolution of residual nitroalkane, monohydroxy alkanol and water takes place.

Abstract: An acrylic multifilamentary material possessing an internal structure which is particularly suited for thermal conversion to high strength carbon fibers is formed via a specifically defined combination of processing conditions. The acrylic polymer while in substantially homogeneous admixture with appropriate concentrations (as defined) of acetonitrile, C.sub.1 to C.sub.4 monohydroxy alkanol, and water is melt extruded and is drawn at a relatively low draw ratio which is substantially less than the maximum draw ratio achievable. This fibrous material which is capable of readily undergoing drawing is passed through a heat treatment zone wherein the evolution of residual acetonitrile, the monohydroxy alkanol and water takes place. The resulting fibrous material following such heat treatment is subjected to additional drawing to accomplish further orientation and internal structure modification and to produce a fibrous material of the appropriate denier for carbon fiber production.

Abstract: An improved multifilamentary tow of carbon fibers is provided which possesses a novel physical configuration that better enables it to undergo impregnation with a matrix-forming resin to form quality composite articles. The individual filaments of the tow are randomly decollimated and commingled with numerous filament cross-over points throughout the length of the multifilamentary tow in order to create a multitude of interstices between adjacent filaments which are well adapted to receive and retain a matrix-forming resin as evidenced by the ability of the filaments when subjected to the flaring test described herein to resist lateral expansion to a width that is as much as three times the original width. The tow commonly comprises approximately 1,000 to 50,000 filaments. Also, the filaments of the tow are substantially continuous and contain at least 70 percent carbon by weight (preferably at least 90 percent carbon by weight).

Abstract: An improved multifilamentary tow of carbon fibers is provided which possesses a novel physical configuration that better enables it to undergo impregnation with a matrix-forming resin to form quality composite articles. The individual filaments of the tow are randomly decollimated and commingled with numerous filament cross-over points throughout the length of the multifilamentary tow in order to create a multitude of interstices between adjacent filaments which are well adapted to receive and retain a matrix-forming resin as evidenced by the ability of the filaments when subjected to the flaring test described herein to resist lateral expansion to a width that is as much as three times the original width. The tow commonly comprises approximately 1,000 to 50,000 filaments. Also, the filaments of the tow are substantially continuous and contain at least 70 percent carbon by weight (preferably at least 90 percent carbon by weight).

Abstract: An improved process is provided for the thermal conversion of a multifilamentary tow of an acrylic fibrous material wherein the filaments are disposed in a substantially parallel relationship in a multifilamentary tow of carbonaceous fibrous material which contains at least 70 percent (preferably at least 90 percent) carbon by weight. During at least one stage of the process the multifilamentary tow is subjected to the impingement of at least one stream of a liquid whereby the parallel relationship of the filaments is disrupted in the substantial absence of filament damage with the filaments becoming decolumnized to a degree sufficient to enable the resulting carbonaceous fibrous material to be more readily impregnated by and dispersed within a matrix-forming resin. In a preferred embodiment such impingement is carried out following a thermal stabilization step and prior to a carbonization step while the multifilamentary tow is simultaneously completely submerged within a liquid.

Abstract: The present invention is directed to carbon fibers which are coated on the surface with a sizing agent of either a polyisocyanate, such as polymethylene polyphenyl polyisocyanate, or a sorbitol polyglycidyl ether having a specifically defined total chlorine content and epoxide equivalent weight. The coated carbon fibers are employed to prepare carbon fiber composites wherein the matrix resin is a thermoplastic polyester such as poly(1,4-butylene terephthalate). The matrix resin of the composite exhibits improved bonding with the coated carbon fibers thereby imparting improved interlaminar shear strength to the composite.

Abstract: Yarns of balanced low tensile characteristics, especially low tensile factor (TE.sup.1/2) are produced in high speed spinning (e.g. greater than 10000 fpm) operations including an annealing stage by process control, particularly inverse spinning temperatures for given yarn. Polyethylene terephthalate yarns of balanced tensile characteristics and tensile factor of as little as 15-17 are prepared directly from a spin draw line at maximum productivity.