Presented by T. Srivani, Asst. Prof., FP.

In textile and clothing manufacture, a wide range ofyarns is used, from coarse to very fine.

The appearance and the properties of fabrics areinfluenced by the fineness of the yarns.

Yarn fineness is indicated by a number which is based on The relationship between weight and length.

This method of expressing fineness is calledYARN NUMBERING or YARN SIZE

The relationship between unit length and weight also reflects the diameter or thickness of a yarn.

A yarn of low weight per unit of length would be finerThan a yarn with higher weight per equal unit of length.

The diameter of the yarn may vary for any given yarn number because of differences in the specific gravity of the fibres from which yarns are made.

Linear density and its effect on yarn diameter

There are two main yarn numbering systems in use.

They are Denier system used for filament yarns and Yarn Count system used for spun yarns

A third system known as Tex system was developed tobring all yarn numbering systems in to a single systemfor all types of yarns but is not successful.

The metric yarn-count system is used in international tradeand many countries of the world for all spun yarns.

Numbering SystemsDirect Systems Indirect Systems

Number of mass units per unit of length

Number of length units per unit of mass

titre tex

Tt

Mass in grams (g)

Length =1km

titre denier

Td (den)

Mass in grams (g)

Length=9km

Metric Number

Nm

Length in meters

Mass=1gram (g)

English Number

cotton Nec

Length in hanks*

Mass=1pound(lb*)

titre = linear density1 hank= 840 yards, 1 yard=91.44cm1lb=454 g

Tex System (Tt) The tex system is the only one which is internationally standardised.

Tex is the mass of the yarn per km of its lengthThe unit g/km has been given the name tex

20 tex means 1km of yarn has a mass of 20g50 tex means 1km of yarn has a mass of 50g

Tt (tex) = mass (g) / length (km) The finer the yarn, the smaller the number.

Denier (td)

Denier was originally used for silk yarn numbering butis now applied to all filament yarns

Td is the mass (g) of 9km yarn.Td 12 means that 9 km of yarn has a mass of 12g.

Td = 9 x mass (g) / length (km)The finer the yarn, the smaller the number.

Metric Number (Nm)

The metric number is the length in meters of 1 gram of yarn

Nm = length (m) / mass (g) = length (km)/mass (kg)The finer the yarn, larger the number.

Nm 40 means that 40 m of yarn has a mass of 1gNm 100 means that 100m of yarn has a mass of 1g

English Number, Cotton (Nec)

The English cotton number is the number of hanks, each of 840 yards, per pound (lb) of yarn

Nec = length (hanks) /mass (pounds)The finer the yarn, larger the number.

Conversions

Nm =1.69336 x Ne

Nm =1000/tex

Ne=0.590541 x Nm

Ne =590.541/tex =1000/Nm

tex=590.541/Ne

Filament yarns are sold by indicating the number offilaments the yarn contains, and the twist as well as the denier size.

For Ex: a 300-10-1/2 Z filament yarn indicates a yarn of 300 denier in size, containing 10 filaments with ½ tpi of Z twist.

Each filament in the yarn would be of 30 denier.

Spun yarn count:

Yarn number of spun yarns differs by fibre content.

Cotton and cotton-blend yarns are expressed by two no’s.

100% cotton indicates the single’s count50/1 means a size-50 single yarn.

Cotton blend indicates the cotton ply.60/2 means a size-60 2ply

.

Worsted yarns are indicated in the reverse order.1/50 indicates a single yarn of 50-count size.

Woolen yarns are designated by the term run such as4-run yarn. They are rarely plied and are single yarnsunless otherwise indicated.

Linen yarns are expresses by the term lea, such as50 lea or 130 lea yarn.They are never plied and are single yarnsunless otherwise indicated.

Spun yarns are also expressed in Metric system

Several classifications are used for determining yarn counts. These classifications are called yarn count standards and are different for each fibre spinning system.

The yarn count standard represents the number of yards in one pound of a N1 Count of that specific yarn

The following standards are in general use.

Cotton and cotton blends 840

Spun silk and all spun 100% 840Manufactured fibre yarns except acrylic

Worsted and worsted blends and acrylic 560

Woolen and woolen blends (run) 1600

Linen (lea) 300

All spun yarns (metric) 496.055

Ply yarn counts and Singles Equivalent

Spun yarns that are plied are expressed as 40/2.This means that two yarns of 40/1 each have beenTwisted together.

The singles equivalent of a 50/2 is 25 count and of a 45/3 is 15 count.

Filament yarns if plied the usual method of expressing two-ply 40 denier yarn would be 80 denier.

Sewing threads are special kinds of yarns that are engineered and designed to pass through a sewing machine rapidly, to form a stitch efficiently, and tofunction while in a sewn product without breaking or becoming distorted for at least the useful life of the product.

The performance of sewing threads depends on proper thread selection for specified fabric and seam type used.

Fibres used for sewing threads are

Cotton is a major fibre used because of its low cost and high versatility

Nylon and Polyester

Rayon is used primarily for embroidery or fancy stitch work rather than for seaming

Types of threads

Sewing threads may be of spun, filament or core spun type.

All sewing threads are ply yarns

Sewing threads are more highly twisted and firmer than regular yarns and are often treated with Special finishes or lubricants to improve sew ability

Spun threads

Lower strength than filaments

Most versatile – adaptable to a wide variety ofmachine adjustment conditions

Less likely than filament thread to cause seam pucker

Less costly

Filament threads

Higher strength than spun

Permits use of finer yarn without compromise for strength

Produces neatest seams

Careful machine adjustments necessary

Greater possibility of seam pucker

Costly than spun thread, texture filament threads for knits

Core spun threads

Combines the best features of spun and filament threads

Useful in seaming durable press garments (resin coated)

Most Costly

Same seam puckering tendency as spun threads

Reduce heat generated during high speed sewing

Sewing thread finishes

Sewing threads are produced with various finishesSuch as

•Mercerized•Soft•Glace and •Bonded

In addition to the above, special finishes are also givenwhich include,

Flame resistant andHeat resistant

Mercerized sewing threads

Description: Treated cotton thread that is stronger more lustrous, more stable than soft finished threads

Sewing Properties and Uses:

Increased tensile strength lustrous appearance and brighter shades Better sew ability than soft threads More costly and used in premium products

Soft finish sewing threads

Description: Natural cotton thread without finishes that appears somewhat fuzzy.

Small amount of lubricant sometimes added to improve sew ability

Sewing Properties and Uses:

Excellent sew ability, lowest cost.

Glace finished sewing threads

Description: Highly polished cotton thread that is difficult to unravel.

The polish and finish are obtained with waxes and starches

Sewing Properties and Uses:

Strongest cotton threads Rarely used in apparel Used in the manufacture of shoes, luggage,

Canvas goods and similar applications.

Bonded sewing threads

Description: Applied to threads of manufactured fibresboth filament and spun

Waxes and resins produce high polish,eliminate fuzz, bond together filaments andplied yarn and imparts smooth protective coating

Sewing Properties and Uses:Increased strength and sew abilityused in apparel of heavy weight and coated

fabric

Used in the manufacture of shoes, luggage, tents and heavy-duty applications.

Numbering of Sewing Threads

Unfortunately there is no coherent and rationalized system of numbering for sewing threads.

Sizes (weight per unit length) of thread are mostlymarketed and expresses with their Tex numberDesignation.

Threads made from silk, man made fibres and wrapped yarns are usually designated by metric number (Nm 70/3; Nm 80/3; Nm 120/3; Nm 120/2).

If the number of components is not given, then it is always the most common, three-ply yarn.

With cotton threads, the English number is used.(Nec 50/3; Nec 40/3)

The number of components often is not given butusually is 3. If it is not 3, then the yarn number given is chosen so that division by 3 will give the number ofThe single yarn component.

Ticket Number System: older method for sewing threads based on count and denier systems.

Ticket Number is based on greige or unfinished thread rather than finished thread.

Ticket number in filament threads is based on denierDesignation except that the last digit is deleted.A 230 denier thread would be labeled size 23 or TN 23.

Mercerized cotton thread sizes are designated by a letter symbol system rather than numerical sizesFinest mercerized threads- 00000The coarsest are size F.

The weight and diameter of the un mercerized spun thread is indicated by a ticket number.

This number is equal to the yarn count of the threadbased upon a three ply cotton count yarn since originally all threads were made 3 ply.

Ex: 30/3 yarn, if it is a thread, would have a TN of 30

Ticket Number system is indirect. So, 40TN is lighter and thinner than 30TN.

Threads were also made with other plies like 2ply forcheap threads and 6ply for more prominent.

Therefore, the designation also included number of ply along with ticket number.

Ex: Thread with 36TN and if made 4ply is indicated as 36/4 expressed as 36TN and 4ply.

Thus the TN36/4 = TN36/3=TN36/2

All threads with same TN will have same weight and diameter and so will fit the same sewing needle.

The single yarns used for TN36/4 are finer than the yarns used in 36/2

A deviation in the designation of ticket number occurs with threads finer than 40.

Ex: for a thread size of 50, the TN is really 45. for a thread size of 60, the TN is really 50 for a thread size of 70, the TN is really 60.

This is because the length of the thread decreasedue to the further twist given to singles for 3ply

The American Society for Testing and Materials (ASTM)has developed a Ticket Number system based on Tex SystemWhich can be used for all types of threads

The Tex system of designating thread TN considers the Rounded off Tex Number as Ticket Number.

Ex: If the Tex yarn number of the thread is 48, the TN would be 45

Tex Number (Direct System) = weight in grams / 1000m of yarn.(Lesser the count, finer the yarn)

Important factors in thread selection

Thread size should be as fine as possible and should be consistent with the strength requirements of the seam

Finer threads require finer needles which causes less fabric distortion

The breaking strength of the seams should be less thanthat of the fabric (60% of the fabric strength)

Thread should have excellent fastness to colour change

The thread should not shrink as result of washing

Important thread factors that govern seam appearance

Woven filament yarn fabrics – More puckeringLight weight fabrics – More puckering

Puckering of the seams can be eliminated throughawareness of following points like..

•Direction of seam•Thread tension•Stitches per inch•Sewing machine adjustments•Sewing machine operator skills

sSewing applications by thread size:

Fine Tex Medium Tex18-30 30-60

Blouses Aprons JeansDresses Athletic wear Rain wearLingerie Caps PantsSleepwear Coats ShortsSwimwear Draperies Wind breakersOther light articles Foundation garments

Heavy Tex Extra Heavy Tex60-105 105-135

Foot wear Decorative stitchingGolf bags Bold Design LookLuggageOver coatsParkasProtective ClothingWork Wear

Sewing threads as available in the market: 1.    Bonded  Thread (including bonded Nylon 66 and 6 and Bonded Polyester Thread)             210D/2 ,210D/3 ,210D/4, 280D/3,420D/3,630D/3,840D/3...             1000M/cone.....3000M/cone...       2.    Nylon Thread,              138D/2,138D/3,210D/2,210D/3,420D/3,630D/3,840D/3.      3.    High Tenacity Polyester Thread,             150D/3 ,210D/2,210D/3,250D/2,250D/3,300D/3

      4.    100% Rayon Embroidery  Thread,                1000M/cone ....5000M/cone ......             75D/2,120D/2,150D/2,250D/2,300D/3,300d/2x3..     

5.    100% Polyester Embroidery Thread, 120D/2 ,150D/2

      6.    100% Spun Polyester Sewing Thread              20s/2, 20s/3,20s/4,30s/3,40s/2,50s/2,60s/2....

      7.    Metallic Yarn             For the use of lace ,underwear and outwear             125G/cone ....

      8.     Knitting Yarn             150D/1 ,150D/2 . 300D/1              1kg/cone /0.5kg/cone