A technique for stable, high-speed treatment of reinforcement fiber. In a state where a unidirectional fiber bundle is held between a supporting surface of a support and a pressing surface of a resonator ultrasonically vibrating in a pressing direction perpendicular to the supporting surface, a pressed part of the unidirectional fiber bundle pressed by the pressing surface is moved in a longitudinal direction of the unidirectional fiber bundle. By doing so, the unidirectional fiber bundle can be stably treated at high speed when the unidirectional fiber bundle is opened or impregnated with a resin.

A method of processing a carbon fiber tow includes the steps of providing a carbon fiber tow made of a plurality of carbon filaments, depositing a sizing composition at spaced-apart sizing sites along a length of the tow, leaving unsized interstitial regions of the tow, and cross-cutting the tow into a plurality of segments. Each segment includes at least a portion of one of the sizing sites and at least a portion of at least one of the unsized regions of the tow, the unsized region including and end portion of the segment.

Methods and systems for separating fiber tows (e.g., carbon tows) are disclosed. The system may include a chamber defining first and second openings and a hollow interior therebetween. The first opening may be configured to receive a fiber tow and the second opening may be wider than the first opening. A vacuum source communicating with the chamber may be configured to reduce an air pressure in the hollow interior and expand the fiber tow. The method may include pulling a fiber tow having an initial width into a first chamber opening, through a hollow chamber interior, and out of a second chamber opening. Air pressure within the hollow chamber interior may be reduced to separate the fiber tow residing in the hollow chamber interior into an expanded fiber tow having a width greater than the initial width. The disclosed methods may separate the tow more gently than mechanical methods.

Methods and systems for separating fiber tows (e.g., carbon tows) are disclosed. The system may include a chamber defining first and second openings and a hollow interior therebetween. The first opening may be configured to receive a fiber tow and the second opening may be wider than the first opening. A vacuum source communicating with the chamber may be configured to reduce an air pressure in the hollow interior and expand the fiber tow. The method may include pulling a fiber tow having an initial width into a first chamber opening, through a hollow chamber interior, and out of a second chamber opening. Air pressure within the hollow chamber interior may be reduced to separate the fiber tow residing in the hollow chamber interior into an expanded fiber tow having a width greater than the initial width. The disclosed methods may separate the tow more gently than mechanical methods.

A method of producing an opened fiber bundle is in a space-saving manner. The method of continuously producing an opened fiber bundle for a cleaning member, includes the steps of (a.sub.1) providing (i) first nip rolls, (ii) second nip rolls, (iii) third nip rolls, and (iv) an air feeder; (a.sub.2) conveying a fiber bundle using the first nip rolls and the second nip rolls to apply a tensile force to the fiber bundle; (a.sub.3) conveying the fiber bundle using the second nip rolls and the third nip rolls to relax the fiber bundle, thereby forming a belt-shaped fiber bundle; and (a.sub.4) blowing air from the air feeder in a direction intersecting with the conveying direction of the first belt-shaped fiber bundle.

A method of producing an opened fiber bundle is in a space-saving manner. The method of continuously producing an opened fiber bundle for a cleaning member, includes the steps of (a.sub.1) providing (i) first nip rolls, (ii) second nip rolls, (iii) third nip rolls, and (iv) an air feeder; (a.sub.2) conveying a fiber bundle using the first nip rolls and the second nip rolls to apply a tensile force to the fiber bundle; (a.sub.3) conveying the fiber bundle using the second nip rolls and the third nip rolls to relax the fiber bundle, thereby forming a belt-shaped fiber bundle; and (a.sub.4) blowing air from the air feeder in a direction intersecting with the conveying direction of the first belt-shaped fiber bundle.

A transport of carbon fiber bundles, in as fabricated carbon fiber tow form, with in-line manipulation of the fiber bundles (spreading or spreading and volumization with manipulators) during fiber bundle transport is described herein. A method including positively transporting and placing a fiber bundle via a moveable fiber bundle delivery mechanism interposed between a fiber bundle supply and a fiber bundle delivery location, manipulating at least one of a fiber volume and an areal weight of the fiber bundle via an air jet device coupled between the fiber bundle delivery location and the fiber bundle supply, and controlling delivery of the fiber bundle tension from the fiber supply through an electronic unwinder is also described.

A transport of carbon fiber bundles, in as fabricated carbon fiber tow form, with in-line manipulation of the fiber bundles (spreading or spreading and volumization with manipulators) during fiber bundle transport is described herein. A method including positively transporting and placing a fiber bundle via a moveable fiber bundle delivery mechanism interposed between a fiber bundle supply and a fiber bundle delivery location, manipulating at least one of a fiber volume and an areal weight of the fiber bundle via an air jet device coupled between the fiber bundle delivery location and the fiber bundle supply, and controlling delivery of the fiber bundle tension from the fiber supply through an electronic unwinder is also described.

A production method for a separated fiber bundle includes at least: [A] a partial separation step for obtaining a partially separated fiber bundle in which separation-processed parts, each separated into a plurality of bundles, and not-separation-processed parts are alternately formed along the lengthwise direction of a fiber bundle comprising a plurality of single fibers; and [B] a cutting step for cutting the not-separation-processed parts of the partially separated fiber bundle formed in the step [A] along the lengthwise direction of the fiber bundle. A separated fiber bundle produced by the method, a fiber-reinforced resin molding material that uses the separated fiber bundle, and a production method for the fiber-reinforced resin molding material.

A production method for a separated fiber bundle includes at least: [A] a partial separation step for obtaining a partially separated fiber bundle in which separation-processed parts, each separated into a plurality of bundles, and not-separation-processed parts are alternately formed along the lengthwise direction of a fiber bundle comprising a plurality of single fibers; and [B] a cutting step for cutting the not-separation-processed parts of the partially separated fiber bundle formed in the step [A] along the lengthwise direction of the fiber bundle. A separated fiber bundle produced by the method, a fiber-reinforced resin molding material that uses the separated fiber bundle, and a production method for the fiber-reinforced resin molding material.