The Processing of Porous Superfine-Denier Nylon 6 FDY Yarn

Jiang Li1,a, Chaowei Hao1,b*, ,Zheng Wang1,c, Qingfang Ma1,d,

and Jianxiong Jiang1,e 1 Key Lab of Organosilicon Chemistry and Material Technology Ministry of Education, Hangzhou

Normal University, Hangzhou, 310012, P. R. China

a394274657,

bcwhao@hznu.edu.cn,

c447949295@qq.com,

dmaqf_0226@163.com,

efgeorge@126.com

Keywords: Masterbatch; Superfine-denier; Nylon 6; FDY

Abstract. In this paper, the porous superfine-denier Nylon 6 FDY(22dtex/35f) was successfully

manufactured by blending Nylon 6 chips with a compound masterbatch according to a certain

proportion through adjusting the process conditions on high speed spinning machine. The influence of

masterbatch’s content and spinning technologies on the properties of FDY fibers with porous

superfine-denier is also particularly discussed. And finally we find out the best spinning techniques

for Nylon 6 FDY fiber with porous superfine-denier.

Introduction

It is known that Nylon 6 is an important polymer material used in different fields ranging from

textile and carpet production to special technical applications. Nowadays, superfine fibers have

attracted more and more attentions from peoples for its occupying the special properties, and the

research on the superfine fibers is developing quickly [1]. Nylon 6 fibers have well hydrophilcity,

hygroscopicity, permeability and comfortability, etc.

However, the plenty of hydrogen bonding between chains in Nylon 6, quickly crystal capacity,

high crystallinity and chain defects in the crystal lattice restrict the molecular arrangement and

orientation, which hinders the achievement of higher DR during the Nylon 6 spinning and the

processing of the superfine fiber and applications. Extensive investigation has revealed that amide

groups of the polymer possess considerable ability to coordinate to the metal ions in the

polymer–metal ion systems [2-5]. Some approach to disrupt hydrogen bonding in polyamide is to

complex carbonyl groups with Lewis acids. Jenekehe et al. [6–7] investigated Lewis acid complexed

with various polyamides. Xu YZ et al. [8] studied the Lithium salts complexed with polyamides as

well. Yang ZK et al. investigated the on dry spinning and structure of low mole ratio complex of

Calcium Chloride- Nylon 6[9].

We had discussed the processing of porous superfine-denier nylon 6 DTY yarns [10] in details in

2011ICTEM. In this article, the work involved with a low mole ratio (MR) complex system of LaCl3-

Nylon 6. The partially complexed masterbatch were produced by melt blending PA6 chips, anhydrous

lanthanum chloride and other additive reagents through the twin screw. By blending the rare-earth

masterbatch and Nylon 6 chips, the spinning process begins and the superfine-denier Nylon 6 fiber

(22dtex/35f) produces as well.

Figure 1 showed the superfine-denier Nylon 6 fiber spinning process, which can be summarized

as follows. Polymer chips are fed to screw extruders and melted at temperatures of approximately

255~265oC. In the storage vessels, the chips are strictly kept under a flow of nitrogen with a constant

dew point to guarantee constant moisture content and to avoid at the same time Nylon 6 oxidation.

The polymer melt is then conveyed to a heated manifold, which is composed of several pipes

departing to the single spinning positions. One gear pump, placed just before the spin packs, extrudes

the melt through the spin packs into open air, transforming one single melt stream into many thin

filaments. Filaments are finally cooled in the open air and wound in bobbins.

Advanced Materials Research Vol. 627 (2013) pp 357-360Online available since 2012/Dec/27 at www.scientific.net© (2013) Trans Tech Publications, Switzerlanddoi:10.4028/www.scientific.net/AMR.627.357

All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of TTP,www.ttp.net. (ID: 131.151.244.7, Missouri University of Science and Technology, Columbia, USA-18/08/14,10:38:09)

Experimental

Equipment

High Speed Spinning Machine; Full-Automatic Yarn strength machine (YG023A), U STER 3 Yarn

Levelness machine (German)。

Materials

Nylon 6 chips from BASF Nylon Co. Ltd., USA., Self-made masterbatch, etc.

Preparation of Self-made masterbatch

After vacuum drying the lanthanum chloride at 160˚C for 10hrs, the anhydrous lanthanum

chloride powder blends Nylon 6 chips in appreciable proportion. And followed by melt extruding, the

masterbatch is acquired.

Figure 1 Schematic diagram of the superfine-denier Nylon 6 fiber spinning process

Result and Discussion

The Processing technology of Porous Super-fine Denier Nylon 6 fiber for FDY

As mentioned above, the most efficient way for improving the elongation and drawing ability of

Nylon6 molecule during the spinning process is to disrupt hydrogen bonding in polyamide. LiCl

could partially disrupt the inter-molecular hydrogen bonding in Nylon 6 chain through the

coordination interaction between the Li+ ions and carbonyl group, which clearly restraints the quickly

crystallization and improves the deforming and elongating abilities of Nylon 6 molecules.

Furthermore, the coordinating interaction favors the cross-linking formation between Nylon 6

molecules in the molten state and accompanied with the clearly increase of molten viscosity, which

can endure the large tensile force and fewer fracture of Nylon 6 fiber tow during spinning processing.

As a result, the porous superfine-denier Nylon fiber could be easily produced with the addition of the

self-made masterbatch into the Nylon 6 chips.

In spite of the coordinating interaction could disrupt the hydrogen binding and favor the spinning

process, however, with the LiCl compound content increasing in the blends, the positive effect

becomes weaker and finally becomes worse. The reason could be clarified as follows. Firstly, with

increasing the LiCl, the melting viscosity of Nylon 6 quickly increases, which make hardly

well-dispersing for LaCl3 granules. Secondly, the LiCl granules are inclined to aggregate to form

larger particles because of the nanosize effect. Finally, the relationship between the spinneret draft

(DDR) and the spinneret orifice (d0) complies the formula as follows:

The larger of d0, the greater of the DDR is. As for the spinning of porous superfine-denier fiber, due to

the smaller strength of per-fiber, the fiber tow could easily break out because of the great pulling

tension. So the spinneret orifice need be smaller and decrease the value of DDR in case of the tow

breaking out during the spinning process.

' 2

0 / lDDR K d ρ=

358 Advances in Textile Engineering and Materials

Figure 2(A) shows that the diameter of superfine-denier fiber is c.a. 6-7µm, and the one of normal

fiber is over 12µm (Figure 2(B)). So when the size of aggregating particles is near to diameter of the

spinneret orifice, the orifice would be easily chocked, accompanied with the pressure of spinnerets

clearly increasing and the tows frequently breaking out, which obviously affects the spinning process

of the superfine-denier Nylon 6 fibers. As a result, the rare-earth compound content should be

controlled in a reasonable arrange. As shown in table 1, when the content of the LiCl is 0.04%

(wt/wt %), the spinning process is the most successful and the properties of the fibers are the best.

Figure 2 The morphology of superfine-denier fiber (A) and normal fiber (B)

Table 1 The influence of masterbatch on the mechanical properties of Nylon 6 FDY fiber

In addition to the influence of rare-earth content on the spinning process, other parameters, such

as the spinning temperature, oiling agent concentration, quenching unit and spinning speed, etc.,

could affect the spinning process and the fiber properties as well. And the special process parameters

are listed in table 2.

Table 2 The process parameters of superfine-denier Nylon 6 FDY fiber

Conclusions

The preparative and applied technologies are the key factor for producing the porous

superfine-denier Nylon 6 FDY(22dtex/35f). The results show that the LiCl masterbatch’s content has

obviously influence on the spinning process and properties of the porous superfine-denier fibers, and

Advanced Materials Research Vol. 627 359

the optimized important spinning parameters are as follows: the LiCl compound content is 0.04%, the

temperature is 255-265oC, and the diameter and length-diameter ratio of spinneret orifice is 0.2mm

and 3.0 respectively.

Acknowledgements

This work was financially supported by the Major Science and Technology Projects of Science and

Technology Department of Zhejiang Province (contract grant number: 2010C11043) and the funded

by National High Technology Research and Development Program 863 (2010AA03A406).

References

[1] R. Wang, D. S. Zhang: Process and Application of the Superfine Fibers (China Textile&Apparel

Press, China, 2007).

[2] A. E. Zachariades, T. Kanamoto. J Appl Polym Sci Vol. 35(1988), p. 1265.

[3] Y. D. Kwon, S. Kavesh, and D. C. Prevorsek, U.S. Patant. 4,440,711 (1984).

[4] Y. D. Kwon, S. Kavesh and D. C. Prevorsek, Eur. Pat. Appl.0,144,793 (1985).

[5] A. R. Postema, P. Smith. Polym Commun Vol. 31(1990), p. 444.

[6] M. F. Roberts, S. A.Jenekhe. Chem Mater. Vol. 2(1990) , p. 224.

[7] S. A. Jenekhe, M. F. Roberts. Macromolecules Vol. 26(1993), p. 4981.

[8] Y. J. Wu, Y. Z. Xu. J Apply Polym Sci Vol. 91(2004), p. 2869-2875.

[9] Z. K. Yang, Z. D. Liu. J Apply Polym Sci Vol. 118(2010), p. 1996-2004.

[10] C.W. Hao, Q. F. Ma, G. Q. Lai. Advanced Materials Research Vols. 332-334 (2011) p 549-552.

360 Advances in Textile Engineering and Materials

Advances in Textile Engineering and Materials 10.4028/www.scientific.net/AMR.627 The Processing of Porous Superfine-Denier Nylon 6 FDY Yarn 10.4028/www.scientific.net/AMR.627.357