Thursday, 5 March 2009
Selection of sewing threads depends upon the following factors:
1. Performance properties during sewing
2. Performance in the completed garment under conditions of wear and cleaning
Appearance and perfomance of the threads depends upon:
1. Fiber Type
1. Fiber Type
a. Linen- Useful in making strong, rather stiff threads for heavy sweing and also for button sewing.
b. Slk - Advantage- Good appearance and performance, Disadvantage- High Cost
c. Cotton - Good Sewing Performance, Disadvantages- Strength and abrasion resistance are inferior to synthetic threads of equal thickness.
It is more stable at higher, dry temperature than synthetics- less affected by hot needles during sewing.
d. Viscose- 1. Do not have the strength or durability of synthetic fibres. 2. Low tenacity and low strength when wet. 3. High lustre- can be used for embroidery.
Nylon/ Polyester Threads
1. Not affected by rot, mildew or bectaria
2. High Tenacity
3. High resistance to abrasion
4. Good resistance to Chemicals
When the fibres occur in short lengths, they must be twisted together, initially into a single yarn, and then that twist must be balanced by applying a reverse twist, as two or three such yarns are combined to form the thread construction.
- Twist in singles yarn consolidates the strenth and flexibility provided by the fibres themselves.
- Without the reverse twist, known as finishing twist, a conventional thread cannot be controlled during sewing. The individual plies would separate during their repeated passages through the needles and over the sewing machine control surface.
- Remember that the frictional forces acting on a thread during its passage through a sewing machine also tend to insert some twist, predominantly in one direction.