Basf Corporation

Honeywell International Inc.

Theodore G Karageorgiou

Dean R Gadoury

Harry Y Hu

Carl R Holzer, Jr

Ulrike Breiner

Gary W Hanwell

David L Caldwell

Otto M Ilg

Natacha Berthelon

Richard T Phelps, Iii

Eugene Carnes

Charles E Eatmon

Freddie L Banks

James A Hucks

Jewell D Purvis

Philip T Earley

Richard Arnold

Larry D Blackston

Jerry M Walker

Billy K Osborne

Dennis W Pomeroy

John M Temples

Thomas M Toney

David M Pendley

John E Emery, Ii

James F Coker

A modified polyamide polymer having a high amino end group content, with more than 30 percent of the amino end groups being secondary or tertiary amine, dramatically improves the dye bleed performance. The modified polyamide may be prepared by polymerization of polyamide-forming monomers in the presence of a carboxylic acid and a hindered piperidine derivative in amounts sufficient to achieve the high amino end group content.

Process for preparing wetfast polyamide fibers

Wetfast polyamide fiber with high amino end group content

Polyamide-6 articles exhibit dramatically improved dye bleed and perspiration performance characteristics, as well as reduced color change of fluorescent dyed polyamide-6. These improvements are achieved according to the present invention by modifying conventional dyeing and aftertreatment conditions. That is, conventional temperatures used for dyeing and the aftertreatment of polyamide-6 yarns are typically about 100&deg; C. and 77&deg; C., respectively. In contrast, the dyeing and aftertreatment procedures of this invention are carried out at about 80&deg; C. or lower, and about 5&deg; C. or lower, respectively. Bath ratios of between about 15:1 to about 20:1 are employed with the polyamide-6 article being retained in the bath sufficient to achieve about 75% dye uptake.

Dyed polyamide-6 articles having improved wetfastness properties and methods of making same

Processes whereby sheath/core bicomponent fibers are melt-spun at relatively high spinning rates. In particularly preferred forms, polyamide sheath/core bicomponent fibers are made at melt-spinning speeds of about 4000 meters per minute or greater, and more preferably about 4500 meters per minute or greater. Most preferably, the sheath is formed of nylon 6,12 while the core is formed of nylon 6.

High speed spinning of sheath/core bicomponent fibers

Materials are off-wound from a package by magnetically levitating the package about a centerline, such that the package remains relatively free from rotation; and removing the material from the package in a direction that is approximately parallel to the centerline.

Off-winding yarn by magnetic levitation

A generally cylindrical yarn package having multiple yarn ends is formed by converging the multiple yarn ends to form a substantially planar yarn end ribbon having the multiple yarn ends in a side-by-side untwisted contacting relationship with one another. The yarn end ribbon formed of the converged yarn ends is then wound about a continuously rotating yarn package core by reciprocally traversing the yarn end ribbon parallel to the longitudinal axis of the yarn package core while maintaining the side-by-side untwisted contacting relationship between the multiple yarn ends of the yarn end ribbon. In such a manner, a generally cylindrical yarn package is formed having multiple yarn ends which may later be separated into individual yarn ends for downstream processing by tangentially unwinding and separating the individual yarn ends from the yarn package. As a result, the present invention allows an increase in spinning capacity to be achieved (i.e., since a greater number of yarn ends may be produced) without the need for additional substantial capital investment for new individual winders.

Method of making spun yarn packages multiple individually separable yarn

A yarn twister mechanically twists a filamentary yarn prior to take-up so as to improve filament-to-filament cohesion. The yarn twister most preferably includes an annular housing defining an annular race in which a follower element is orbitally movable. Pressurized fluid (e.g., air) is introduced substantially tangentially into the race so as to propel the follower in an orbital path along the race. The follower includes a yarn guide element which radially extends through an annular slot in the housing into the housing's cylindrical interior region. The pressurized fluid is discharged through the slot into the cylindrical interior region of the housing so as to provide a fluid bearing for the follower. In use, the traveling yarn will thereby be guided through the yarn guide so that orbital movement of the follower will responsively impart a desirable twist to the yarn so as to increase the filament-to-filament cohesion of the yarn.

High speed yarn twister with fluid propelled yarn guide

A polyamide filament having improved properties such as increased tenacity and dyeability. The filament has a birefringence of at least 0.040 and an .alpha.-crystal content of at least 30%. The filament is prepared by contacting the filament with water after the filament has been cooled to a temperature below its stick point but above its glass transition temperature. The water can be applied intermittently to the filament to produce a resulting filament having variable dyeing characteristics.

Polyamide filaments having improved properties and method of preparation

Growing community of inventors

Arden, NC, United States of America

Theodore G Karageorgiou