A Comparative Study of Thermomechanical and Chemomechanical Texturing of Nylon 6 Multifilament Yarns

Abstract

Nylon 6 multifilament yarn is textured by both the conventional false-twist method and a new method of solventtexturing with aqueous phenol. The physical, mechanical, and structural properties of the textured yarns are compared.It is observed that the solvent-textured yarn has a considerably higher dye uptake than the conventionally-textured yarn. SEM studies reveal interesting differences in the surface characteristics of fibers textured by the two processes. ' ' ' ~ --Introduction 'The texturing process involves mechanical deformation of a filament or a bundle of filaments and dissipation of internal strain~nduced by mechanical stressing to obtain a permanent or quasipermanent, stress-free, distorted configuration. The dissipation of the elastic strain imposed on the matrix by the mechanical field is brought about by providing a thermal environment in the case of texturing of thermoplastic yarns. , The °g eneral mechanism of thermostabilization involves breaking of intermolecular bonds, chain-relaxation, and subsequent bond-reformation in energetically more favorable sites. The strain-dissipative environment need not, necessarily, be thermal in nature. It may be a suitable solvent, the suitability being dependent on the solubility parameters of the polymer and the solvent. Jacobs ~1~, from his study of nylon/phenol interactions, proposed a general mechanism involving three elementary-rate processes: intermolecular bondbreaking, chain-relaxation, and bond-reformation. It may be observed that the mechanism involved is, in principle, similar to the principle of thermosetting. ()ne of the present authors, in a previous paper ~6~, reported successfully texturing of polyester, nylon 66, and acetates -With the aid of suitable solvents. Texturing with solvents becomes all the more appealing when one realizes that setting through a re-arrangement of morphological order need no longer be confined to thermoplastic fibers. Work on nonthermoplastic fibers, carried out in our laboratory, has yielded interesting results, which have been reported elsewhere ~7, 8).. ' The present paper deals with torque-texturing of nylon 6 with aqueous phenol and compares the properties of solvent-textured yarn with the conventional false-twist yarn. ' Experimental Methods , . MATERIAL. A 3% concentration (v/v) of phenol in water was used as the solvent for texturing semi-dull nylon 6 multifilament yarn of 11.6 mg/m comprising . 24 filaments. --SOLVENT TEXTURING. A bath containing a pair of hositively-driven aluminum rollers running at. the same surface speed of the front rollers of a ring frame, was attached to the back of the frame. The rollers were completely immersed in aqueous phenol. The filament yarn from a bobbin was wrapped round the rollers by several turns to give an effective immersion time in solvent for 2 min, passed through the nip of the front pair of rollers of a draftin assembly via suitable guide, and twisted and wound o a ring bobbin. The yarn was twisted to 23.6 ~turns/cm. The twisted yarn was then transferred. onto a per...

New Methods of Texturing Polyester/Viscose Blended Yarns by Simultaneous Setting of the Components

“…In a recent publication we showed that cotton yarns can also be textured through a decrystallization-recrystalliia.tion cycle following a chemomechanical route [8]. We also reported that thermoplastic yarns can be textured by setting through solvent-induced crystallization [9,10].…”

Solvent Texturing of Polyester Yarn

“…Two reasons that solvent texturing is of interest are its potential for energy savings [ 2 ] and a considerably higher dye uptake [ 4,5].…”