This document provides information about sewing threads, including their functions, classifications, and applications. Sewing threads are designed to efficiently form stitches without breaking during use. They are classified based on their substrate (natural vs synthetic), construction (spun, core spun, filament), and finish. Thread selection depends on the required sewability, seam performance in terms of strength and durability, and appearance. Proper thread selection is important to ensure quality seams for different applications such as apparel, leather goods, upholstery, and more.

1. SPME-I
Assignment
on
Sewing Threads
Submitted to : Mr. Amit Phogat Submitted by : Bittu Singh
Radhe Kumar
Shubham Singh

2. Sewing Thread
• Special yarn- engineered and designed to pass through a sewing
machine rapidly.
• Form efficient stitches without breaking or becoming distorted during
the useful life of the product.
• Basic function- to deliver aesthetics and performance in stitches and
seams.

3. Factors Affecting Functions Of A Sewing Thread
Factors Affecting
Aesthetic
• Color Fastness
• Lustre
• Hue and shade
matching
• Stitch selection
• Uniformity of stitch
formation
Factors Affecting
Performance
• Seam strength
• Elasticity
• Abrasion resistance
• Chemical resistance
• Color fastness

4. Thread Classification
• Classified in different ways in which some common
classifications are:
Substrate
Construction
Finish

5. Classification Based on Substrate
Natural
• Its uses are now minimal in industry applications.
• Most commonly used- cotton thread.
Synthetic
• Exceptionally high tenacity, high resistance to abrasion
and good resistance to chemicals.
• Not significantly affected by moisture, rot, mildew, insects
or bacteria.

6. Classification Based on Construction
Spun thread
• It is made by natural and fibre substances.
• It is stronger than cotton threads of a comparable to wide variety of sizes
and colours.
• Spun polyester is one of the most widely used threads.
Core spun thread
• It is combination of staple and filament fibres.
• Most commonly used in multiple-ply construction.
• Each ply consisting of a polyester filament core with cotton or polyester
fibres wrapped around the core.
• Generally used for the high-speed sewing of many garment types,
especially those requiring high seam strength.

7. Filament thread
• Stronger than spun threads of the same fibre and size.
• Three types of filament thread are commonly used:
Monofilament thread
• It is made from a
single continuous
fibre with a specified
thickness.
• Monofilament is
strong, uniform and
inexpensive and lacks
flexibility .
• Normally restricted to
hems, draperies, and
upholstered
furniture.
Smooth multifilament
thread
• It is usually made
from nylon and
polyester.
• It consists of two or
more continuous
filaments twisted
together.
• Used to sew shoes,
leather garments, and
industrial products.
Textured filament
thread
• It is usually made
from polyester.
• It is used primarily as
the lopper thread for
covering stitches.
• Yarn more cover and
high extensibility.

8. Classification based on thread finish
Finishes are given to a thread for two purposes:
To improve sewability
• Some finishes involve
increasing strength, abrasion
resistance and lubrication of
the thread.
To achieve a specific
functional requirement
• Some finishes include bonding,
non wick, anti-fungal, fire
retardant, water repellent and
anti-static finishes.

9. Applications of Sewing Threads
• In Apparel, Leather & Tea industries
• For personnel in Fire-fighting, Defence & Police
• Hot metal industry
• In hospital for surgery
• Rain-wear
• Automobiles – air bag, seat cover, spare wheel cover
• Bedding & mattress – covers, quilts
• Shoes
• Sports – Leather balls, Hang gliders, Fishing lines, Racket cover

10. Thread Selection
• There is no perfect thread for all applications, however
there is a perfect thread for a specific application.
• The major selection criteria include:
Sewability
Seam Performance
Seam Appearance

11. Sewability
• The ability to be sewn or stitched.
Type of threads to be used in different perspectives :
• Apparel- Core, Spun, Textured
• Automatic Multi-directional Lockstitch- CW Core or PW Core
• Buttonsew , Buttonhole- Corespun or Spun
• Overedge, Coverstitch- Spun or Textured
• Excessive Needle Heat- Cotton or CW Core
• Excessive Seam Puckering- Perma Core Ultimate – Fine Tex Sizes; CW Core or PW
Core for heavier Tex Sizes
• Needle Cutting on Knits- Small as Possible, Tex Sizes
• Heavy Non-Apparel- Multifilament, Monocord

12. Seam Performance
• Chemical Resistance- Polyester, Polypropylene, PTFE
• Abrasion Resistance- Nylon
• UV Resistance- Polyester, Polypropylene, PTFE
• Long-term Heat Resistance- Meta-Aramid
• Short-term Heat Resistance- Cotton or Para-Aramid
• Stone Wash Resistance- Polyester
• Minimize Cut-Stitch- CW Core or PW Core
• Seam Elasticity- PW Core, Spun Poly, Textured

13. Seam Appearance
• High Sheen Appearance- Rayon, Tri-lobal Polyester, Metallic
• Low Sheen Appearance- Corespun & Spun
• 100% Cotton Garment Overdye- Cotton & Lyocel
• Color Fastness- Solution dyed Polyester, Polyester, Vat dyed Cotton
• Bold Size for Contrast Stitching- Large Tex Size
• Seam Coverage- Textured

14. Thread Numbering
• Systems to indicate thread size
• Metric count – synthetic, spun or core-spun threads
• English count – cotton thread
• Decitex or Denier – filament threads
Fixed weight system Fixed length system
Unit weight is fixed and length is measured. Unit length is fixed and weight is measured.
• English count(Ne) = number of hanks of 840
yards per pound
• Metric count(Nm) = number of hanks of 1000
metres per kg
• Denier – weight in grams of 9000 metres
• Tex – weight in grams of 1000 metres
• Decitex – weight in grams of 10000 metres
Yarn becomes finer as count number increases Yarn becomes coarser/heavier as count number
increases

15. Thread Numbering
• Ticket numbering – commercial numbering system
- manufacturer’s reference number for the size of a given
thread
• Systems used – Metric, Cotton & Denier
• Same ticket number for different threads doesn’t indicates the same type of
thread – Ticket 40 Cotton & Ticket 40 Core-spun are different
• Higher ticket number – finer thread
• Lower ticket number – thicker thread
• Calculation : Divide 1000 by the Tex number, then multiply by 3

16. Thread Numbering : Example
Tex dTex X ply
(when 2-ply)
dTex X ply
(when 3-ply)
Total Decitex
(dTex)
Ticket No. Calculation for ticket No.
40 200 X 2 133 X 3 dTex X 400 75 { (1000/40) * 3 }
60 300 X 2 200 X 3 dTex X 600 50 { (1000/60) * 3 }
80 400 X 2 267 x 3 dTex X 800 38 { (1000/80) * 3 }
100 500 X 2 333 X 3 dTex X 1000 30 { (1000/100) * 3 }

17. Reference
1. All about Sewing Threads. Retrieved from :
http://www.coatsindustrial.com/en/information-hub/apparel-
expertise/sewing-threads
2. Thread Science – Choosing The Right Thread. Retrieved from :
http://www.amefird.com/technical-tools/thread-education/thread-science/
3. Thread Selection Logic. Retrieved from : http://www.amefird.com/technical-
tools/thread-education/thread-logic/
4. Thread Numbering. Retrieved from :
http://www.coatsindustrial.com/en/information-hub/apparel-
expertise/thread-numbering
5. Carr H. & Latham B. Fourth Edition. Pages 109 to 137. Technology of Clothing
Manufacture.