Lecture 15 Sewing Thread

Definitions….  Yarn: –Collection of fibers used to weave or knit textile fabrics  Thread: –Thread is used to sew different things

YarnThread Used for the manufacturing of cloth Used for the manufacturing of cloth Made by fibers Made by fibers Weaker Weaker Less uniform Less uniform Big package Big package Single ply Single ply Used for sewing purpose Used for sewing purpose Made by yarns Made by yarns Stronger Stronger More uniform More uniform Small package Small package More than one plies More than one plies Comparison…

Question ?  Sewing thread is selected before needle OR  Needle is selected before sewing thread

Sewing Thread…  It is made by reverse twisting single yarns or plied yarns.  Reverse twist is given for balancing  Yarn plies will be separated when passing through needle and tension disks if not balanced properly

Sewing thread…  Twist: – The number of turns per inch or centimeter –A thread with too little twist may fray or break –A thread with too much twist can cause snarling, looping or knotting  So balance is the key and a good sewing thread has it

Twist direction…  There are two types of threads – S twist – Z twist  Which is better for sewing and why?

Thread Types…  Basically there are two types – Natural  Animal Silk thread is used for silk and wool  Plant Cotton thread is used for Linen, cotton and rayon – Synthetic Nylon and Polyester threads are used for Synthetics and stretch knits

Thread Finishing… Thread is finished to enhance its suitability for different sewing purposes  Soft: –Just Dyed and lubricated  Mercerized –Thread is mercerized. Thread gets some luster and strength. Also good affinity for dying.  Glazed – Thread is treated with starches and then polished for a high luster. It gets hard, providing good abrasion resistance and ply security

Thread Finishing…  Bonded –Synthetic threads are treated with resins. Tough smooth coating results in a good abrasion resistance and ply security  Gassed – Passing thread from a flame at high speed. It reduces the hairiness on surface

Thread Properties…  Elongation  Uniformity  Ply security  Lubricity  Strength –Breaking strength –Loop strength

Thread breakage…  Wrong thread  Incorrect or damaged needle  Improper Machine adjustment  Operator handling  Wrong threading  Worn machine parts  Weaker sewing thread  Less elongation

Other Thread properties …  Color fastness  Wash fastness  Crock fastness  Light fastness  Cold water migration