Method for manufacturing sized carbon fibers for composite applications

Various embodiments directed towards methods of applying sizing to fibers are disclosed herein. In some embodiments, solvent can be used to dissolve a sizing material into a solution, which can then be used to coat the fibers. In some embodiments, a water bath is used to coagulate a sizing on the fiber surface and to remove the remove solvent after coating the fibers, so that water vapor can be created during a subsequent drying step as opposed to solvent vapors. In some embodiments, strong acids or strong bases can be used as the solvent.

PROCESS FOR GAS PHASE SURFACE TREATMENT

A gas phase surface treatment for treating carbon fiber including (a) exposing a carbon fiber to a gaseous oxidizing atmosphere to form a modified carbon fiber with an oxidized fiber surface; followed by (b) exposing the oxidized fiber surface to a gaseous nitrogen-containing atmosphere to form a modified carbon fiber with a nitrogen-enriched surface, wherein the nitrogen-enriched surface exhibits an increase in surface nitrogen to surface carbon (N/C) ratio as compared to the surface of the carbon fiber prior to exposure at (a). Steps (a) and (b) are carried out continuously without any additional intervening surface treatment. 1. A gas phase surface treatment for treating carbon fiber , comprising:a) exposing a carbon fiber to a gaseous oxidizing atmosphere to form a modified carbon fiber with an oxidized fiber surface; followed byb) exposing the oxidized fiber surface to a gaseous nitrogen-containing atmosphere to form a modified carbon fiber with a nitrogen-enriched surface, wherein the nitrogen-enriched surface exhibits an increase in surface nitrogen to surface carbon (N/C) ratio as compared to the surface of the carbon fiber prior to exposure at (a),wherein steps (a) and (b) are carried out continuously without any additional intervening surface treatment.2. The gas phase surface treatment of wherein claim 1 , the increase in N/C ratio is at least 30% as measured by X-ray photoelectron spectroscopy (XPS).3. The gas phase surface treatment of wherein claim 1 , the N/C ratio of the nitrogen-enriched surface is in the range of 0.05-0.07 as measured by X-ray photoelectron spectroscopy (XPS).4. The gas phase surface treatment according to claim 1 , wherein steps (a) and (b) are performed immediately claim 1 , without any intervening step claim 1 , after carbonization of a stabilized polyacrylonitrile (PAN) fiber precursor to produce said carbon fiber.5. The gas phase surface treatment according to claim 1 , wherein the gaseous oxidizing atmosphere comprises ozone ...

CARBON FIBERS AND HIGH PERFORMANCE FIBERS FOR COMPOSITE APPLICATIONS

Various embodiments directed towards methods of applying sizing to fibers are disclosed herein. In some embodiments, solvent can be used to dissolve a sizing material into a solution, which can then be used to coat the fibers. In some embodiments, a water bath is used to coagulate a sizing on the fiber surface and to remove the remove solvent after coating the fibers, so that water vapor can be created during a subsequent drying step as opposed to solvent vapors. In some embodiments, strong acids or strong bases can be used as the solvent. 1. A method of applying a sizing onto an organic or inorganic fiber comprising the steps of:providing a quantity of fibers;contacting the quantity of fibers with a composition, wherein the composition comprises a polymer dissolved in a water-miscible solvent, thereby forming a solvent/polymer coating on the quantity of fibers;coagulating the polymer onto the quantity of fibers;removing the water-miscible solvent by washing the quantity of fibers having the solvent/polymer coating with water; andat least partially drying the resultant quantity of polymer-coated fibers to produce a quantity of sized fibers.2. The method of claim 1 , wherein the quantity of fibers is chosen from carbon fibers claim 1 , glass fibers claim 1 , ceramic fibers claim 1 , aramid fibers claim 1 , polyolefin fibers claim 1 , polyester fibers claim 1 , acrylic fibers and combinations thereof3. The method of claim 1 , wherein the quantity of fibers is a fabric.4. The method of claim 1 , wherein the water-miscible solvent is chosen from dimethyl sulfoxide (DMSO) claim 1 , N-methyl-2-pyrrolidone (NMP) claim 1 , dimethylformamide (DMF) claim 1 , hexamethylphosphoramide (HMPA) claim 1 , acetone claim 1 , methylethyl ketone claim 1 , butanone claim 1 , methyl alcohol claim 1 , ethyl alcohol claim 1 , isopropyl alcohol claim 1 , butyl alcohol claim 1 , di-chloro methane claim 1 , chloroform claim 1 , sodium thiocyanate and zinc chloride.5. The method of claim 1 , ...

MANUFACTURE OF INTERMEDIATE MODULUS CARBON FIBER

The present disclosure relates generally to carbon fibers having high tensile strength and modulus of elasticity, as well as a process for the manufacture of such carbon fiber. The process comprises spinning a polymer/solvent solution into a solvent/water bath in the range of 78%-85% solvent, thereby producing a dense fiber structure, and subsequently carbonizing the polymer precursor fiber at a lower than typical carbonization temperature to form carbon fibers. 1. A process for producing carbon fibers comprising:spinning a polymer solution having a concentration of about 19% to about 24% polymer in a coagulation bath at a coagulation bath concentration of about 70% to about 85% solvent and about 15% to about 30% water, thereby forming carbon fiber precursor fibers;drawing the carbon fiber precursor fibers through one or more draw and wash baths, wherein the carbon fiber precursor fibers are substantially free of solvent after the step of drawing the carbon fiber precursor fibers; andstabilizing and carbonizing the carbon fiber precursor fibers;wherein the carbon fiber precursor fibers are carbonized at a temperature of from about 1100° C. to about 1500° C.2. The process of claim 1 , wherein the bath temperature of the coagulation bath is from about 0° C. to about 10° C.3. The process of claim 1 , wherein the solvent in the coagulation bath is dimethyl sulfoxide.4. The process of claim 1 , wherein the polymer solution is a polyacrylonitrile polymer solution.5. The process of claim 1 , wherein the polymer has a weight averaged molecular weight (M) of about 120 claim 1 ,000 to about 180 claim 1 ,000.6. The process of claim 1 , wherein the polymer solution is spun by air-gap spinning.7. The process of claim 6 , wherein the air-gap spacing from a face of a spinneret to a surface of the coagulation bath is about 2.0 to about 10.0 mm.8. The process of claim 1 , wherein the carbon fiber precursor fibers from the coagulation bath have an average pore diameter of about 0.01 ...

PROCESS FOR GAS PHASE SURFACE TREATMENT

A gas phase surface treatment for treating carbon fiber including (a) exposing a carbon fiber to a gaseous oxidizing atmosphere to form a modified carbon fiber with an oxidized fiber surface; followed by (b) exposing the oxidized fiber surface to a gaseous nitrogen-containing atmosphere to form a modified carbon fiber with a nitrogen-enriched surface, wherein the nitrogen-enriched surface exhibits an increase in surface nitrogen to surface carbon (N/C) ratio as compared to the surface of the carbon fiber prior to exposure at (a). Steps (a) and (b) are carried out continuously without any additional intervening surface treatment. 111-. (canceled)12. A continuous process for manufacturing carbon fiber comprising:i. passing a continuous polyacrylonitrile (PAN) fiber through an oxidation zone to form a stabilized PAN fiber;ii. passing the stabilized PAN fiber through a carbonization zone to form a continuous carbon fiber;iii. exposing the continuous carbon fiber to a gaseous oxidizing atmosphere to form a modified carbon fiber with an oxidized fiber surface; andiv. exposing the oxidized fiber surface to a gaseous nitrogen-containing atmosphere comprising at least 50% by volume of ammonia gas to form a modified carbon fiber with a nitrogen-enriched surface, wherein the nitrogen-enriched surface exhibits an increase in surface nitrogen to surface carbon (N/C) ratio as compared to the surface of the carbon fiber prior to exposure at (iii),v. wherein steps (i) to (iv) or steps (ii) to (iv) are carried out continuously.13. The continuous process of claim 12 , wherein N/C ratio of the nitrogen-enriched surface is in the range of 0.05-0.07 as measured by X-ray photoelectron spectroscopy (XPS).14. The continuous process of claim 12 , wherein the increase in N/C ratio is at least 30%.15. The continuous process according to claim 12 , wherein the gaseous oxidizing atmosphere comprises ozone and at least one gaseous component selected from: air claim 12 , oxygen claim 12 , ...

MANUFACTURE OF INTERMEDIATE MODULUS CARBON FIBER

The present disclosure relates generally to carbon fibers having high tensile strength and modulus of elasticity, as well as a process for the manufacture of such carbon fiber. The process comprises spinning a polymer/solvent solution into a solvent/water bath in the range of 78%-85% solvent, thereby producing a dense fiber structure, and subsequently carbonizing the polymer precursor fiber at a lower than typical carbonization temperature to form carbon fibers. 1. A process for producing carbon fibers comprising:spinning a polymer solution having a concentration of about 19% to about 24% polymer in a coagulation bath at a coagulation bath concentration of about 70% to about 85% solvent and about 15% to about 30% water, thereby forming carbon fiber precursor fibers;drawing the carbon fiber precursor fibers through one or more draw and wash baths, wherein the carbon fiber precursor fibers are substantially free of solvent after the step of drawing the carbon fiber precursor fibers; andstabilizing and carbonizing the carbon fiber precursor fibers;wherein the carbon fiber precursor fibers are carbonized at a temperature of from about 1100° C. to about 1500° C.2. The process of claim 1 , wherein the bath temperature of the coagulation bath is from about 0° C. to about 10° C.3. The process of claim 1 , wherein the solvent in the coagulation bath is dimethyl sulfoxide.4. The process of claim 1 , wherein the polymer solution is a polyacrylonitrile polymer solution.5. The process of claim 1 , wherein the polymer has a weight averaged molecular weight (M) of about 120 claim 1 ,000 to about 180 claim 1 ,000.6. The process of claim 1 , wherein the polymer solution is spun by air-gap spinning.7. The process of claim 6 , wherein the air-gap spacing from a face of a spinneret to a surface of the coagulation bath is about 2.0 to about 10.0 mm.8. The process of claim 1 , wherein the carbon fiber precursor fibers from the coagulation bath have an average pore diameter of about 0.01 ...

Process for gas phase surface treatment

A gas phase surface treatment for treating carbon fiber including (a) exposing a carbon fiber to a gaseous oxidizing atmosphere to form a modified carbon fiber with an oxidized fiber surface; followed by (b) exposing the oxidized fiber surface to a gaseous nitrogen-containing atmosphere to form a modified carbon fiber with a nitrogen-enriched surface, wherein the nitrogen-enriched surface exhibits an increase in surface nitrogen to surface carbon (N/C) ratio as compared to the surface of the carbon fiber prior to exposure at (a). Steps (a) and (b) are carried out continuously without any additional intervening surface treatment.

gas phase surface treatment to treat carbon fiber, and continuous process to manufacture carbon fiber.

um tratamento de superfície da fase gasosa para tratar fibra de carbono incluindo (a) expor uma fibra de carbono a uma atmosfera de oxidação gasosa para formar uma fibra de carbono modificada com uma superfície da fibra oxidada; seguido por (b) expor a superfície da fibra oxidada a uma atmosfera contendo nitrogênio gasoso para formar uma fibra de carbono modificada com uma superfície enriquecida com nitrogênio, em que a superfície enriquecida com nitrogênio apresenta um aumento na razão de nitrogênio da superfície para carbono da superfície (n/c) comparado à superfície da fibra de carbono antes da exposição a (a). etapas (a) e (b) são realizadas continuamente sem nenhum tratamento de superfície intermediário adicional. a gas phase surface treatment for treating carbon fiber including (a) exposing a carbon fiber to a gaseous oxidation atmosphere to form a modified carbon fiber with an oxidized fiber surface; followed by (b) exposing the surface of the oxidized fiber to a gaseous nitrogen-containing atmosphere to form a modified carbon fiber with a nitrogen-enriched surface, wherein the nitrogen-enriched surface exhibits an increase in the surface-to-carbon nitrogen ratio of the surface. surface (n / c) compared to the carbon fiber surface prior to exposure to (a). Steps (a) and (b) are performed continuously without any additional intermediate surface treatment.

Manufacture of intermediate modulus carbon fiber