By:
Aravin Prince. P

B.Tech, D.T.P
MDP, TEXPORT SYNDICATE (I) LTD
BANGALORE

ABSTRACT:

There are large number of tests available for assessing the quality of sewing threads and the most common tests conducted by the manufacturers and users are physical and fastness properties. However, the most critical test for sewing thread is the �sewability� in the dynamic conditions. The principles and methods for evaluating some of the important sewing thread properties are discussed in this paper.

INTRODUCTION:

Sewing thread is considered to have been the first textile material. History tells us that some 25000 years ago sewing threads were made by the persons living in caves and jungles by rubbing and twisting together the long fur fibers pulled from animal skins. The crude threads, by means of needle ,were used to join animal skins to form the primitive clothing of the early civilization.

The most affected was the textile industry especially the textile fabrication and sewing thread industry. In India till 1990 we are used cotton threads only, but technical developments have given us a wide range of synthetic threads which are for most purpose now superior to cotton threads

TESTING ON SEWING THREADS:

In Generally the sewing threads are tested by 2 methods .There are

� Physical Test
� Chemical test

PHYSICAL TESTS:

THREAD COUNT:


Count or number of sewing thread is in general measured by the ASTM test method designated D-1059 for short-length specimen and skein method (ASTM-1907) for long specimen length.
The direct system of thread number is based on measuring the weight per unit length of a yarn, where as the indirect system is based upon the length per unit weight of a thread.
In the short-length method, the specimens of prescribed length, usually 1m or less, are cut from a conditioned sample, which is under prescribed tension, and weighed. For skein method, the specified lengths of thread are wound on reels as skeins, and weighed. The count or thread number is then computed from the mass and length of thread.

THREAD DIAMETER:

The diameter of sewing thread is an important parameter for effective sewability. It must be appropriate to the size of the needle eye. If the thread diameter does not match with the size of the needle eye, the thread may break during sewing deteriorating the appearance of the seam. When the diameter of the thread is large enough, it displaces the yarn in a fabric, resulting seam puckering. Generally the width of the needle eye is about 40% of the size of the needle. Sewing thread must not occupy more than 60% of the width of the eye to avoid the fraying of thread during sewing.

Sewing thread diameter is also a consideration in selecting sewing thread for embroidery, contrast stitching, or other decorative applications, since cover is important with such threads. So, diameter of a sewing thread is an important parameter to measure.