Yarns and process for production thereof

A process for producing a yarn which comprises drawing an undrawn yarn comprising multifilaments of a thermoplastic synthetic polymer and having substantially the same break elongation, in a twisted state at an elevated temperature thereby to remarkably flatten portions of the individual filaments which appear on the outer layer of the yarn, and immediately detwisting the yarn to break at least a part of those portions of said filaments which are flattened to a lesser degree, followed by taking up the yarn.

A yarn comprising thermoplastic synthetic staple fibers and continuous filaments in which the individual fibers constituting the yarn contain twisted crimps and have cross-sectional surfaces with a markedly flattened portion, in which the staple fibers contained therein have broken ends comprising mainly portions flattened to a lesser degree, a plurality of fibers having this structure uniformly and alternately forming the surface and inner layers of the yarn and being intertwined at fluffs formed of the broken ends of the individual fibers.

A process for producing a yarn which comprises breaking at least a part of an undrawn yarn of multifilaments of a thermoplastic synthetic polymer which have substantially the same break elongation by means of heating, drawing and false-twisting the yarn at the same time to form a yarn containing staple fibers, and applying to the yarn a means for improving its heat stability, followed by taking up the yarn.

A process for producing a yarn which comprises breaking at least a part of an undrawn yarn of multifilaments of a thermoplastic synthetic polymer which have substantially the same break elongation by means of heating, drawing and false-twisting the yarn at the same time to form a yarn containing crimped staple fibers, and applying to the yarn a means for improving its coherency, followed by taking up the yarn.

A process for producing a yarn which comprises breaking at least a part of an undrawn yarn of multifilaments of a thermoplastic synthetic polymer which have substantially the same break elongation by means of heating, drawing and false-twisting the yarn at the same time to form a yarn containing crimped staple fibers, and false-twisting the yarn to improve its coherency, followed by taking up the yarn.

A process for producing a yarn which comprises breaking at least a part of an undrawn yarn of multifilaments of a thermoplastic synthetic polymer which have substantially the same break elongation by means of heating, drawing and false-twisting the yarn at the same time to form a yarn containing crimped staple fibers, and true-twisting the yarn to improve its coherency, followed by taking up the yarn.

A process for producing a yarn which comprises breaking at least a part of an undrawn yarn of multifilaments of a thermoplastic synthetic polymer which have substantially the same break elongation by means of heating, drawing and false-twisting the yarn at the same time to form a yarn containing crimped staple fibers, and subjecting the yarn to a fluid jet to improve its coherency, followed by taking up the yarn.

A process for producing a yarn which comprises breaking at least a part of an undrawn yarn of multifilaments of a thermoplastic synthetic polymer which have substantially the same break elongation by means of a heating, drawing and false-twisting the yarn at the same time to form a yarn containing crimped staple fibers, and applying a bundling agent to the yarn to improve its coherency, followed by taking up the yarn.