Sewing thread properties & their effects on seam

KHULNA UNIVERSITY OF ENGINEERING & TECHNOLOGY

PRESENTATION TOPIC:

SEWING THREAD PROPERTIES & THEIR EFFECTS ON SEAM

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Dept. of Textile Engineering, KUET.

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SEWING THREAD

• Sewing thread is a smooth, evenly spun, hard twisted ply yarn, thread by a special finishing process to make it resistance to stresses in its passage through the eye of a needle and through the material involved in seaming and stitching operation. [1]

[1] https://www.slideshare.net/roopbalaarya/sewing-thread-and-its-types

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SEWING THREAD

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PROPERTIES OF SEWING THREADS

Tensile strength Tenacity Loop

strengthLoop

strength ratio

Minimum loop strength

Elongation at break

Stress strain curve Elasticity

SEWING THREAD

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TYPES OF SEWING THREAD

Polyester corespun

thread

Spun polyester thread

Staple spun cotton thread

Textured polyester thread

Polyester cotton corespun

thread

Trilobal polyester thread

SEWING THREAD

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1.POLYESTER CORESPUN THREAD [1]

This type of thread is produced by spinning staple polyester

fibre around a core of high tenacity continuous filament polyester in yarn-spinning operation. Two or more of these composite yarns are then twisted together to give the necessary size and tensile strength.

e.g. Epic(Coats).

Uses: Mainly used in topstitching of shirts blouses, trousers,

sportswear , jeans & work clothes.

SEWING THREAD

[1] https://www.slideshare.net/2008000400034/sewing-thread

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Key Characteristics: [1]

Exceptionally strong. The continuous filament core Having high tenacity It is resistance to abrasion Fine threads can be used for delicate fabric without

compromising on strength, thereby avoiding problems like seam pucker.

SEWING THREAD


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2.SPUN POLYESTER THREAD [1]

Staple polyester fibres are spun into polyester yarn. Then two or more of spun polyester yarns are twisted together to produce spun polyester thread.

e.g. Astra (Coats)

Key Characteristics:- High tenacity of polyester ensures greater strength and thereby high

abrasion resistance.- Very least amount of shrinkage (less than 1%) compared to cotton thread.

Uses: Mainly for overedging. Also used for general seaming of shirts, trousers,

knitwear, jackets, blouses etc.

SEWING THREAD


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3.STAPLE SPUN COTTON THREAD [1]

Normally long staple cotton fibres are spun into cotton yarn. Then two or more ply of spun cotton yarn are twisted together to produce spun cotton thread.

Key Characteristics:- 100% cotton thread have relatively low strength and elongation compared to

those in synthetic thread , therefore they need relatively light sewing tension and high stitch densities.

- Very high amount of shrinkage compared to synthetic thread.

SEWING THREAD

https://www.slideshare.net/2008000400034/sewing-thread

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STAPLE SPUN COTTON THREAD [1]

Key characteristics:During sewing , cotton thread is not damaged at high temperature generated by

needle.- 100% cotton thread is mercerized (treatment with caustic solution under

tension) to provide greater luster and higher strength.

Uses: Mainly used in sewing cotton garments that are to be post dyed.

SEWING THREAD


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4.TEXTURED POLYESTER THREAD [1]

- Made from textured continuous polyester filament.

(Note- texturing means modification by applying crimp to the filament) .

e.g. Gramax (Coats).

Key features:- Provides high softness and comfort.- High extensibility and seam strength enhance higher seam security.

Uses: Mainly used in “next to the skin” seams for high softness .e.g. underware,

swimwear, babywear etc.

Also widely used in overlocking and covering stitches for high extensibility and seam security.

SEWING THREAD


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5.POLYESTER COTTON CORESPUN THREAD [1]

- Made of polyester filament in the core and staple cotton fibre which wraps polyester filament. Two or three plies of this yarn are twisted together to make thread.

e.g. dual duty (Coats).

Key features:- This thread has been developed to improve the properties cotton and to get the opportunities of

both cotton and polyester fibre.

- Very low shrinkage, good strength and cotton core protects poly core from needle heat and high ironing temperature.

Uses: fine cotton denim shirts , outdoor wear etc.

SEWING THREAD


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6.TRILOBAL POLYESTER THREAD [1]

- Newly developed polyester fibre to improve the dullness of usual polyester fibre.

- Trilobal poly is a multiple filament, twisted, high-sheen continuous fiber thread. It has the bright appearance of rayon or silk. Triangular shaped fibers reflect more light and give an attractive sparkle to textiles.

Uses:

Embroidery for garment.

SEWING THREAD


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SEAM• The line along which a number of layers of fabrics are joined is called the

seam• It can be created by sewing of fabrics or by joining of fabrics in any other

alternative way (Welding, Fusing, Moulding, Adhesive)• The seam which is created by sewing of fabrics, known as stitched seam

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SEAM CLASS

Superimposed seam

Lapped seam Bound seam Flat seam

Ornamental seam Applied seamEdge Neatening seam Others

http://www.coatsindustrial.com/en/information-hub/apparel-expertise/seam-types

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CHARACTERISTICS

Seam strength Elasticity Durability

Security Comfort

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Seam Properties

Seam Performance

Seam Strength

Seam Elasticity Durability Security Comfort

Seam Appearance

SEAM PROPERTIES

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Sewing thread is one of the most important factors.Determines-

SEWING THREAD EFFECT ON SEAM

Seam strength

Seam elasticity

Durability Comfort

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1.1 Seam appearance

Hairiness of sewing thread is important to decide seam appearance.The shrinkage potential of the thread.


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1.2 Seam failureThe failure due to thread breakage

1.3 Seam breakage The failure due to the slippage of cloth yarns at right angle

to the seam.


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1.4 Seam Puckering:

Evaluated immediately after the sewing process or shortly after it.Relevant to sewing thread which undergo different loads,

stretched, flexed and otherwise deformed during sewing process.Deformation of threads may crease seam which known as ‘Seam

puckering’.


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Seam pucker Photographic seam puckering


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2.1 Effect of thread type on seam strength and seam opening [1]

Affects the seam strength. Does not affect the seam opening.

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Fig-1: Seam strength for different thread structure

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Thread breaking tenacity [1]

• Multifilament thread structure-highest seam strength.• Staple thread structure-minimum seam strength.

Seam slippage [1]

• Core-spun thread-maximum resistance against the seam opening.

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No significant difference between the values of seam strength.Only for 635 twists/m thread- higher seam strength.So, twist does not influence seam properties too much.


Fig-2: Seam strength for different twist

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2.3 Ply number on seam strength and seam opening [1]

Affects the seam strength. Does not affect the seam opening.A significant difference between 2 and 3 plied

threads.3 plied thread- higher seam strength.

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Fig-3: Seam strength for different ply numbers

TENSILE STRENGTH: [1]

• If an external force is applied to a material, it is balanced by internal forces developed in the molecular structure of the material

• The straight strength and elongation of sewing thread must be adequate for good sewing performance as well as good seam Strength

• The loop strength of a thread contributes directly to the stitch strength and hence to the seam strength.


[1] http://www.ptj.com.pk/Web-2010/01-10/Jan-2010-PDF/Sumit-Manda.pdf

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FRICTIONAL PROPERTIES [1]

• The frictional forces are developed in the sewing thread are mostly due to the friction between the fabrics and machine parts.

• Friction must not be too high , which causes the thread breakage, and not too low, which causes loss of thread control.

• Although coarse and medium fine yarns showed a more hairy appearance, resulting in poor seam appearance after friction.



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DIMENSIONAL STABILITY [1]

• Both dry and wet dimensional stability are important for seam quality.• Heat often causes of burn marks on natural fibres and it causes synthetic

fibre to soften or melt, leaving a weakened seam or a melted residue on the fabric surface.

• In wet condition cotton sewing thread increases in diameter and shrink in length is the cause of seam puckering in sensitive fabric and ultimately affect the seam appearance of fabric



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BENDING PROPERTIES [1]

• The flexibility of a fibre depends on its shape, its modulus, its density and fibre is the basic raw material in yarn manufacturing

• Thus all the thread must be flexible to ensure it passes through the sewing machine and imparted into the seam as smoothly as possible

• Soft thread whose bending rigidity is low is the causes of low seam puckering.



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SPUN POLYESTER(CHAMPION THREAD

COMPANY)Features:• It is provides a uniform construction.• Highly resistant to UV light.• Resistant to chemical degradation.• It provides dependable sewing performance including high speed

& critical sewing condition.

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SPUN POLYESTER(CHAMPION THREAD

COMPANY)Features:

• Proprietarily and superior lubrication translates into excellent sewing performance

• Extensive color pallet kept in stock for immediate delivery• Resistant to sunlight and chemical degradation• Certified to Öko-Tex Standard• Strong uniform construction• Excellent seam strength.• Color fastness properties are very good

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SPUN POLYESTER(CHAMPION THREAD COMPANY)

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SPUN POLYESTER(HUBEI TRITRUST IMPORT AND EXPORT CO.

LTD.)

Featurs:• High Tenacity• Low Shrinkage • Chemical Resistance• High Temperature Resistant• Abrasion Resistance

• Pattern: Raw White• Count: 30s/2• Spun Polyester: Sewing Thread• Trademark: HUBEI TRITRUST• HS Code: 5509220010

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SPUN POLYESTER(HUBEI TRITRUST IMPORT AND EXPORT CO.

LTD.)

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THANK YOU