Yarn Hairiness

One of the important difference between continuous filament yarns and yarns spun from staple fibers that the latter are 'hairy' that is fiber ends and loops of fibers stand out from the main body of the yarn.It is not intended to discuss this yarn property in the present volume but the interested reader may refer to a recent paper by barella, who has himself investigated the hairiness of yarn.In his conclusion Barella states that: 'The non-existence of a method sufficient satisfactory from both a scientific and a practical point of view for the easy measurement of hairiness in routine industrial process has been noted.The scientific method are slow and the quicker ones are open to criticism in that they are not soundly based.It would therefore be desirable to devise a new method that is superior to the existing ones.Furthermore, according the nature of the fabrics and the characteristics they must possess,the yarn hairiness can either be a desirable or an undesirable,property, so that its measurement and control are important.

Textured Yarn

In recent years there have been important development in the production of special
yarns based on thermoplastic continuous filament yarns.These yarn may be classified as follow:
(1) BULK YARN:- These are multifilament yarns which have been processed to produce an increased mass or bulk per unit lenght.
(2) STRETCH YARN:- As the term implies,these yarn have the ability to be stretched to high elongations; further, they have the power to recover rapidly from elongation,hence their use in stretch-to-fit apparel.
(3) MODIFIED STRETCH YARN:- These are basically stretch yarns which have had the characteristic modified to suit particular end use.
It will be appreciated that new types of yarn may require new testing technique, for research and development of the yarns and foe the routine quality control checks on the yarn supplied to the fabric producer.Several test methods have been reported but at the moment the testing situation is little fluid.The test described below has been in use for several years but even so the method has its critics.