Abstract
Pilling is undesirable property that affects handle and appearance of fabrics. It happens when washing and wearing of fabrics causes loose fibers to begin to push out from the surface of the cloth, and over time, abrasion causes the fibers to develop into small spherical bundles, anchored to the surface of the fabric by protruding fibers that haven’t broken. This article illustrate show pilling resistance of plain woven polyester/wool blended fabrics is minimized by mechanical support like heat setting, singeing.
Introduction
Polyester blended fabrics with wool are used in many textile applications due to excellent properties. Because of fashion and cost, the present trends in manufacturing light fabrics have led to certain
Increase in pilling phenomenon. Many technical developments have been reported over the years in the field of reducing pilling tendency. The present article involves studying the various properties and behavior of polyester /wool blended fabrics subjected to different mechanical treatments to improve pilling and at the same time finishing with amino-silicon softeners in order to pick up the hand feel.
Pilling property
It is observed that pilling tendency of the blend fabric samples can be minimized with taking the help of mechanical support like heat setting, singeing. The greater the number of polyester fibers migrated on the surface of yarn with increase in the polyester content of the blend and hence the pilling increased and converse is true for wool fibers used in the blend. Wool fibers fuzz more readily than polyester fibers but this fuzz wears off easily.
Yarn count has significant effect on pilling tendency of the fabric samples, the yarn count becomes finer with pilling decreasing, which may be due to the fact that fine yarns are used to weave fabrics, where the number of intersections is greater than when coarse yarn is used. On the other hand coarse yarn is less compact and results in more slippage of fibers as compared to fine yarn. These are the factors which contribute for pilling formation. Now our main target how to diminish this pilling by applying mechanical support.
Formation of pilling in different fabric
Satin woven fabrics have lower pilling resistance as compared to twill and plain-woven fabrics. In case of plain-woven fabrics, there is higher number of intersections between the warp and weft yarns which offers an increase to slippage of fibers and difficult to easily fuzz formation on fabric samples surface.
Minimization of pilling
Mechanical finishing plays a critical role in pilling. Its main role is to stabilize the fibers inside the yarn and remove the surface nap. This can be achieved via heat setting, singeing etc.
Heat-set and singeing:
Heat setting is a thermal process with stream under vacuum.
Heat temperature set has significantly affected pilling tendency of fabric samples, with increasing heat temperature that may be due to the heat temperature set the fiber within the fabric surface and improves proportional pilling resistance. Polyester wool fabrics can be heat-set at temperatures of 180°C ± 5°C. This is illustrated that Heat setting helps to minimize pilling which is signified from below table.
Table 1: Effect of heat setting on pilling of polyester/wool blended fabrics-
| Blended Composition | Weave structure | Heat setting | Singeing | Heat setting duration(Seconds) | ICI(*) Pill-box |
| 70% PES: 30% Wo | Plain | No | No | III | |
| 70% PES: 30% Wo | Plain | 180 degree Celsius | No | 180 | II TO I |
| 55% PES: 45% Wo | Plain | No | No | III | |
| 55% PES: 45% Wo | Plain | 180 degree Celsius | No | 180 | II |
| 30% PES: 70% Wo | Plain | No | No | III | |
| 30% PES: 70% Wo | Plain | 180 degree Celsius | No | 180 | II |
(*) ICI pill-box rating: I = no pilling, II = slight pilling, III = sever pilling.
Fabric-pilling resistance significantly increases with singeing treatment at 40 m/min speed. This may be due to the fact that singeing removes the neps on fabric samples surface. Although singeing is very effective in removing the surface neps it imparts some harshness to the fabric surface. For that after singeing, softener can be added during washing to improve fabric surface.
Table 2: Effect of heat setting & singeing on pilling of polyester/wool blended fabrics-
| Blended Composition | Weave structure | Heat setting | Singeing | ICI(*) Pill-box |
| 70% PES: 30% Wo | Plain | 180 degree Celsius | Yes | I |
| 55% PES : 45%Wo | Plain | 180 degree Celsius | Yes | I |
| 30% PES: 70% Wo | Plain | 180 degree Celsius | Yes | I |
| 70% PES: 30% Wo | Plain | 180 degree Celsius | Yes | I |
| 55% PES: 45% Wo | Plain | 180 degree Celsius | Yes | I |
(*) ICI pill-box rating: I = no pilling, II = slight pilling, III = sever pilling.
Heat setting & singeing influences the extent of pilling formation. These processes are very effective in removing the surface neps on fabric surface.
Some characteristics of finished polyester/wool blended fabrics:
Preliminary experiments revealed that singeing and heat setting conferred stiff handle to polyester/wool blended fabrics. However, improved pilling performance and soft handle can be enhanced if the fabrics are finished with amino-silicone softeners. This could be attributed to the modification of wool fiber properties.The influence of amino-silicon softeners on performance of polyester/wool blended fabrics exhibithigher dry crease recovery and soil removable. On the other hand, the hydrophilicity of the fabric surface is enhanced with both softeners. This may be due to production of new sites by heat as hydrolytic fission of peptide chains and/or disulphide linkage.
This suggests that presence of amino-silicon softeners seems to induce stabilization of the fabric in dry state by virtue of its involvement in reactions with amino and or carboxylic group of wool peptide chains. This can be attributed to the presence of amino or sulfonic groups in its molecules.
The extent of changes in chemical properties of finished polyester/wool fabrics to impede pilling formation was assessed by carrying out various analytical measurements.
Fig. 1: Amino-silicones
Where:
C R`, R = (cH3)3 – NH – (cH2)2 – NH2
C (AEAP); Amino – ethyl – amino – propyl silicones
C w = wool
C x = OH, SH, COOH or NH2
Conclusion
The pilling is formation of ugly looking small balls of fibers on fabric surface. Pilling does not depend only on single factor but it is the result of several factors. Here we discussed how the pilling can be minimized with the help of mechanical support. Heat setting & Singeing play a critical role than various studied factors for pilling resistance. This can’t be said that mechanical contribution is the only way to get better pilling result as there are others chemical finishes which also play role in this case.
References:
- Acknowledgement to Bangladesh University of Textiles and Square Knit Fabrics Limited for laboratory facilities and materials.
- Handbook of Textile Fibers, S.H. Abdel – Fattah and E.M.El-Katib, Textile Research Division, National Research Center,Dokki, Cairo, Egypt.
- Li; M. Zhu; X. Wei. 2014, Pilling Performance of Cashmere Knitted Fabric of Woolen Ring Yarn and Mule Yarn, Fibres & Textiles in Eastern Europe 22(1(103))
