Abstract: Flat continuous multifilament nylon apparel yarns suitable for critical dye applications and a process for making such yarns are provided. The process for making the yarns includes spinning nylon polymer with a relative viscosity between about 35 and about 80 and stabilizing to make a feed yarn. The withdrawal speed in spinning is sufficiently high that highly uniform feed yarns are provided. In the process, feed yarn is drawn and subsequently relaxed, preferably in the form of a warp of yarns, so that the resulting drawn yarns have properties suitable for use as flat yarns and have excellent dye uniformity with large molecule acid dyes.

Abstract: Flat continuous multifilament nylon apparel yarns suitable for critical dye applications and a process for making such yarns are provided. The process for making the yarns includes spinning nylon polymer with a relative viscosity between about 35 and about 80 and stabilizing to make a feed yarn. The withdrawal speed in spinning is sufficiently high that highly uniform feed yarns are provided. In the process, feed yarn is drawn and subsequently relaxed, preferably in the form of a warp of yarns, so that the resulting drawn yarns have properties suitable for use as flat yarns and have excellent dye uniformity with large molecule acid dyes.

Abstract: Flat continuous multifilament nylon apparel yarns suitable for critical dye applications and a process for making such yarns. The process for making the yarns includes spinning nylon polymer with a relative viscosity between about 35 and about 80 and stabilizing to make a feed yarn. The withdrawal speed in spinning is sufficiently high that highly uniform feed yarns are provided. In the process, feed yarn is drawn and subsequently relaxed, preferably in the form of a warp of yarns, so that the resulting drawn yarns have properties suitable for use as flat yarns and have excellent dye uniformity with large molecule acid dyes.

Abstract: In processes of the production of thermoplastic polymer yarns, a process for controlling slippage of yarn on rolls across which there is a tension change. The yarn is advanced along pairs of rolls with the yarn contacting the rolls in successive wraps. At least one of the rolls is driven and has a changing diameter as the yarn advances between at least two of the successive wraps. The wraps contact the contact areas on the surface of the driven roll to each define a total wrap angle for the wrap. The number of wraps is selected and the diameter of the driven roll at the contact areas is selected to increase or decrease the tension while preventing a wrap angle in creep for any one of the wraps from being greater than about 90% of the total wrap angle for the wrap.