Seam/Swing/Swing threads/Trimmings and

Accessories

Name : AZIZUL HAQUE JUELID: 112-23-2538Batch: 18th Batch (Session 2011-2015)Major: Fabric Manufacturing Email: azizulhaque230@gmail.comBlog: www.textilestudypoint.blogspot.comDepartment of Textile Engineering

PREPARED BY

Copyright © All Rights Reserve

DAFFODIL INTERNATIONAL UNIVERSITYDEPARTMENT OF TEXTILE ENGINEERING

102, SHUKRABAD, MIRPUR ROAD, DHANMONDI, DHAKA-1207BANGLADESH

SEAM A line along which two or more fabric parts

are joined by sewing is called seam.

Again A stitch line where fabrics are joined together by various fabric arrangements.

So we can say that the line of joining fabric is called seam.

5. Seam class – 5 ( Decorative seam )

This type of seam is made by making one or more adjacent stitch lines in one or more layer of fabric.

Multi -needle sewing m/c is used to produce seam. This type of seam is called Decorative stitching. This seam is produced and used to increase the beauty or

decorative value of fabric.

6. Seam class – 6 ( Edge neatening )

This type of seam is used to bind the edge of fabric so that the thread cannot open.

Various stitches are used to make this type of seam. It can be made by over lock m/c. Extensively used. If folder is used, the seam can be made easily.

7. Seam class – 7(Applied Seam) Similar to lapped seam (class – 2), but the joined

component is extended limited on both sides from sewn line.

This is used for joining of different parts of garments with additional thing as lace, elastic braid, and elastic.

8.Seam class – 8(Others) Mainly one piece of fabric is used. The edges of the fabric are sewn by folding in various

ways. Seam is made in one time completed by twine needle

m/c and folder. Belt and belt loops can be made by this seam.

STITCH Loop or loops of one or more threads

when bounds with each other, either by interlacing, interloping, intra-looping or combination of those when sewing fabric, each unit of such configuration is called stitch.

LOOPS FORMATION METHODS Interlacing: During stitching

when one loop of one thread passes over another loop of another thread is called interlacing.

Inter-looping: When loop of one thread passes through the loop of another thread is called inter-looping.

Intra-looping: When a loop of one thread passes through the loop of same thread during sewing is called intra-looping.

Stitch Type Stitches are grouped in 6 classes according to

British standard 3870:1991 as follows- Stitch class – 100 (Single thread chain stitch ) Stitch class – 200 (Hand stitch ) Stitch class – 300 (Lock stitch ) Stitch class – 400 (Multi thread chain stitch ) Stitch class – 500 (Over edge stitch) Stitch class – 600 (Covering chain stitch)

1. Stitch class – 100 (Single thread chain stitch )

• Stitches are formed by intra-looping.

• One or more needle thread is used for stitch formation.

• Security of stitch is very poor.

• Temporary joining, positioning, hemming, button holing, button attaching purposes.

• Used for gathered appearance as temporary joining i.e. collar positioning, flap positioning.

2. Stitch class – 200 (Hand stitch )• Looks like domestic hand

stitch.• It is produced from single

thread.• Needle thread is passed

from one side to another side in the fabric and makes a sewn line.

• This stitch is made by special type of needle and sewing m/c.

• Very rare used in the garments manufacturing unit due to higher cost and limited length of sewing.

• Time consuming operation.

3.Stitch class – 300(Lock stitch)• At least two groups of threads are required.• One group of thread is called needle thread and another group of

thread is called bobbin thread.• Extensibility is around 30%.• Appearance of lock stitch is similar in both sides of the fabric.• Security of stitches is very good. • Abrasion resistance of lock stitch better.• The main problem of lock stitch is the lower capacity of bobbin

thread requires frequent bobbin thread changing.• Not suitable for knit fabric sewing.• Extensively used in sewing and fabric attachment as pocket, collar,

cuff, facing etc.• Used in top stitching, button holing, button attaching, blind stitching

etc.

4. Stitch class – 400 (Multi thread chain stitch )• Stitches are formed by two or more groups of threads.• One group is called needle thread and another is called looper

thread.• Threads are bound together by interlacing and inter-looping.• Multi thread chain stitch is also called double locked stitch.• Possibility of seam pucker formation is less.• Extensibility is same as Lock stitch.• Used for long length sewing, heavy fabric sewing attaching lace,

braid, elastic etc.

5. Stitch class – 500 (Over edge stitch)• Stitches are formed by two or more groups of threads.• At least one group of thread passes around cut end of the fabric.• Fraying is stopped by the stitches of 500 class.• It is also called as over lock stitch.• Extensibility of over edge stitch is higher (may be up to 30%).• At the starting and finishing ends few inches thread to be left.• Extensively used for knit fabric sewing.• Also used for fabric sewing of denim, jeans, cord etc.

6. Stitch class – 600 (Covering chain stitch)• Stitches under 600 class are formed by three groups of threads.• One group is called needle thread and other is called top cover

thread and the other group is called bottom cover thread. • Stitches under this group are very complex and may need up to

9 threads.• Used for making knitted undergarments to attach tape, lace,

elastic.• Also used for decorative purpose.

Sub-class of different type of stitchesA. Lock stitch family: Class 3001.Type-301: Lock Stitch2.Type-301: Lock Stitch (Single-step zigzag)3.Type-301: Lock Stitch (Double-step zigzag)4.Type-301: Lock Stitch (2-needle+1bobbin thread lock stitch)

(Piping seam)

B. Over edge chain stitch family: Class 5001.Type-501: Single thread over edge2.Type-503: 2-thread over edge3.Type-504: 3-thread over edge4.Type-512: 4-thread over edge5.Type-401.503: 5-hread over edge (2-thread over edge and

double chain stitch)

Continued………C. Flat stitch family: 1.2-needle thread+1-looper thread Appearance: 1-side zigzag, other side

2-needle thread

2.Type-602: Covering chain stitch(2-needle thread+2-looper thread)

Appearance: Both side zigzag.

Merits and demerits of 301 & 304:Stitch 301:Merits Seam extensibility is around 30 %. Seam strength is sufficient. Similar appearance on both sides of fabric. Stitches are secured. Abrasion resistance is better.Demerits: Lower capacity bobbin thread requires frequent bobbin thread changing. Not suitable in knitted garments.

Stitch 304:Merits Zigzag type. It is used for lace or elastic attachment on garments. Extensibility comparatively high than 301.Demerits: Not applicable to all attachment.

PRINCIPLE OF LOCKSTITCH FORMATION Lock stitch is formed with

two groups of threads i.e. needle thread and bobbin thread.

The needle moves downward and reaches the extreme lowest position. Again it rises up a bit and stops for a while. As a result, a loop is formed in the needle thread.

At the same time, thread take up lever also moves downward. So it aids the formation of needle loop.

Then needle loop is enlarged.

The bobbin holder hook catches the previously produced needle loop and passes it over the bobbin case.

Interlacing takes place between bobbin thread and needle thread loop.

The needle along with needle thread moves and the thread take up lever also moves up.

Here loop clears bobbin and take up starts to draw thread up.

Here take up draws thread up and loop is closed.

Here feed material moves for next stitch position.

Then needle descends to lowest point of stroke for subsequent stitching.

Finally new loop has been formed and is passing around bobbin.

At last loop is pulled up to make a complete stitch.

PRINCIPLE OF CHAIN STITCH (needle thread + looper thread) FORMATION

Difference between chain stitch & lock stitch

Chain stitch Lock stitch

1.Stitches are formed by two or more groups of thread- needle thread and looper thread.

1.At least two groups of thread-needle thread and bobbin thread.

2.Threads are bound together by interlacing and interloping.

2.Threads are bound by interlacing.

3.Strength and thread consumption is higher than lock stitch.

3.Strength and thread consumption is lower than chain stitch.

4.Extensibility is 30%. 4.Same, sometimes less than that.

5.Looks like lock stitch at top side and double chain at under.

5. Appearance of lock stitch is similar in both sides of the fabric.

6.Possibility of seam pucker formation is less than lock stitch.

6.Possibility of seam pucker formation is less than chain stitch.

SEWING MACHINE FEED MECHANISMBasic Function: To advance the fabric in the feeding zone of the sewing

m/c. To decide the length of individual stitch that is SPI. To form the individual stitches properly.

Necessity of sewing m/c feed mechanism: For better appearance and performance. For avoiding seam pucker. For avoiding any stitching defect. For feeding the fabric in the sewing m/c uniformly.

TYPES OF SEWING MACHINE FEED MECHANISMTypes of feed mechanism:

• Drop feed mechanism.• Differential bottom feed.• Adjustable top feed system.• Needle feed mechanism.• Unison feed mechanism.• Puller feed mechanism.

Puller feed mechanism• It is the modification of drop

feed mechanism.• This mechanism is a way of

providing positive control of the plies.

• Two rollers give a pulling motion on the fabric immediately behind the pressure foot.

• The top roller is generally driven by the m/c whilst the lower one moves in contact with the upper one.

• The surface speed of puller roller is more than feed dog surface speed due to which no possibility of ply shifting or roping.

• This feed is useful in multi thread stitching of parts.

Differential bottom feed• This feed mechanism is the modification

of drop feed mechanism.• In this system, the feed dog is divided into

two sections. • The movement of each section is similar

to the movement of the whole feed dog is the drop feed system but the speed of each part can be adjustable separately.

• When the speed of the front feed dog is greater than that of the back feed dog, the bottom ply is pulled by the back feed dog, which will overcome the tendency of the front feed dog to take in that ply.

• When the speed of the front feed dog is less than that of the back feed dog, we get a lacy or marginal effect because the feeding effect is greater than the delivery speed.

• Differential bottom feed is found in chain stitch, lock stitch and over edge stitch m/c.

Drop feed mechanism It is the most common and simplest feed

mechanism. It has 3 main components such as-• Feed plate / Throat plate:1. It is made of stainless steel and its

surface is of very smooth. Due to smooth surface fabric can be feed on it easily and it sometimes called needle plate.

2. It has one or more slots into which feed

dog can move forward and backward.

3. It has a hole through which needle can go up and down. The size of this needle hole should not exceed more than 30% of needle size.

4. If needle hole size is 30% larger of needle size, the fabric can be pushed into the hole with each penetration of the needle which called Flagging and create defective stitch.

Continued……. Feed dog: The main task of feed dog is to

move (advance) the fabric along by a predetermined amount between successive stitches.

Pressure foot: Stationary pressure foot is used to give pressure on fabric with spring. So that fabric can not move up and down with needle. The lower surface of the pressure foot is very smooth so that friction of pressure foot with fabric becomes less.

Problems and remedies of drop feed mechanism Problem:

• When piece of feed dog and piece of stitch is equal then fabric may be damaged and seam strength can be decreased.

• When two plies of fabric are sewn by drop feed system two plies of fabric can not move forward at the same speed. Here lower ply is more feed than upper ply.

Remedies:• Skill ness of the operator.• Need manual technique such that stitch length and pitch of

feed dog may not be equal.

NEEDLE Needle is used to sew the fabric by thread.

Way of needle movement is related to: Seam strength. Seam appearance. Seam durability.

Functions of needle in the sewing m/c: To make a hole in the fabric without damaging the threads of

the fabric. To make a needle thread loop. To pass the needle thread loop through the loop or loops of

the looper thread, in case of other m/c than lock stitch.

Different components of a needle 1.Butt2.Shank3.Shoulder4.Blade5.Long groove6.Short groove7.Needle eye8.Scarf9.Needle point10.Tip

Functions of different components of a needle Butt: For setting the needle on to the needle bar or clamp.

Shank: Upper part of the needle which is tied in the needle bar and which supports the needle.

Shoulder: Middle part of the shank and blade is shoulder. It helps to make the hole of the fabric and strengthen the needle blade.

Blade: Longest part of the needle from the shoulder to needle eye. In this portion, friction between fabric and needle is maximum. Blade is gradually tapered to tip.

Long groove: The long and thin groove between shoulders to needle eye in the blade is called long groove. When the needle penetrates the fabric with needle thread, needle thread takes position in the long groove.

Continued……. Short groove: It extends little above and below the needle

eye. It helps to make the needle loop.

Eye: The hole present in the front of the needle is called eye. It extends from long groove to short groove. Eye through which sewing thread is passed.

Scarf: The groove of the needle above the eye is called

scarf. Its purpose is to enable the closer setting of hook or looper to the needle.

Point: The portion from the eye to the tip of the needle is called point. Point should be different for different type of fabric.

Tip: the last (extreme end) part of the needle is called tip. It helps to create hole in the fabric during sewing.

Classification of needle point The portion from the eye to the tip of the needle is called needle point.Two types of needle point-A. Cutting point.B. Cloth point.

• Ball point.• V – Point / set point.

A. Cutting point: Cutting point needles are used for sewing of sheet type materials like leather, plastic etc. In these materials, there is no gap within the structure. Three types of cutting points:

1. Wedge point.2. Cross point. 3. Twist point.

Continued…….. B. Cloth point: Cloth point /

Round point needles used for sewing cloths. The point of cloth point needle is round.

Two types of cloth points:1.Set point.2.Ball point. Set point: Set point needles

used for sewing woven fabrics.

3 types of set points namely:• Slim set point: For sewing

densely woven fabric or top stitching like collar, cuff and pockets.

• Set point: For sewing medium densely woven fabrics.

• Heavy set point: For sewing buttons ( attaching buttons)

Continued…….. Ball point: Ball point needles used for

sewing knitted garments. Ball point needles are of 3 types: Light ball point. Medium ball point. Heavy ball point.

Needle size expression Metric system (Nm): Easy process, most usable, based on blade diameter.

Needle size = Blade dia in mm X 100 = 0.8 mm X 100 =80 Nm.

Singer system: 5, 7, 9, 10, 11, 12, 13, 14, 15, 16, 17.

Needle system number more, needle coarser.

Relation between metric and singer system:Metric no. Singer no. 55 7 65 9 75 10/11 80 12

The effect of needle size If the needle finer than thread: The thread can not pass easily through the needle eye. Thread can not set in long groove. Friction between needle and thread increases so thread

may break or burn. Friction between thread and fabric increases so high

heat produces. As a result, fabric will be damaged.

If the needle coarser than thread : Thread can pass freely through needle eye. Coarser hole in the fabric due to coarser needle. So

fabric may be damaged as well as seam pucker may be formed in compact woven fabric.

Causes of damaging needle point Needle heats with m/c parts specially throat

plate. Faulty fabric handling during sewing by m/c

operator. Needle deflection during sewing. During sewing of hard and harsh fabric, needle

point wear on fastly. e.g: jeans Improper needle size selection. Improper needle point selection.

Factors considered for needle selection: Needle size. Shank dia. Butt to needle eye length. Total needle length.

Why fabric damage / Factors: Needle point; improper selection of needle point. Quality of needle. Condition of needle; damaged needle. Needle size. Thread size.

Fabric damages due to needle point damages: In woven fabric, the thread of fabric or fibres in thread may be tear

off; As a result• Seam strength reduced.• Fluffy along sewing line.

In knitted fabric, the thread loop in fabric may be tear off ; As a result • Bad looking.• Seam strength reduced.

Fabric damaged even using good needle: Wrong damaged selection of needle point. Wrong selection of needle size. Less sew ability property of fabric.

SEWING THREADSewing thread variation depends on: Appearance and performance of a seam is

related to sewing thread. Thread construction fibre type and thread

finish size is also related to seam appearance and performance.

Thread size is related to needle size.

Classification of sewing thread • Fibre type:

• Natural.• Linen.• Silk.• Cotton.• Viscose

• Synthetic.• Polyester.• Nylon thread.• Aramid.• PTFE.

• Construction.• Mono filament.• Multi filament.• Textured thread.• Core spun thread.

Properties of different types of sewing thread

Linen• Made of flax fiber.• Strength and lusture – high.• Problem – stiffness.• Used only for higher strength of seam like tent, canvas, shoe

making.• Not used in garments.

Silk• Made of both continuous filament or broken filament.• Strength – comparatively high.• Extensively – higher.• Lusture – high.• More expensive.• Used in costly garments or items silky ladies wear.• Limited use due to cost.

Continued…….Cotton

Produced from natural fibre (cotton fibre). Normally made from higher grade cotton

fibre. Strength – less. Abrasion resistance – less. Cotton thread do not damage due to

generation of high heat. Widely used in gts in needle during sewing. In garments dyeing, cotton thread

unavoidable.

Continued…….Cotton thread are of 3 types: Soft cotton thread:

• Securing, bleaching, dyeing, as well as finishing by lubricant.• Shrinkage when wet and seam pucker formed during washing.

Mercerized cotton thread:• Finishing applied with caustic soda soln on tension.• Does not shrink.• Seam pucker less.• Strength and lusture – greater than soft cotton.

Glaced cotton thread:• Glaced cotton thread made by surface coating on glaced

cotton.• Stiffness, smoothness, Frictional resistance power increase.

Continued……Viscose

Made of continuous filament or staple fibre of regenerated cellulose. Strength and durability – low due to frictional resistance low. Lusture – high. Very cheap. Used in embroidery purposes. Suitable for the fabric which is not washed.

Polyester Made of staple fibre or filament. Strength – high. Elastic property – Good. Colour fastness – Good. Shrinkage property – good / reasonable. Not shrink up to 150ºC or does not create problem in washing even in

150ºC. Low cost. Available found and maxm used.

Continued…….Nylon thread

Made of staple or filament fibre. Extensibility – higher than polyester. Possibility of seam pucker unavoidable. Suitable used in the garments where crease are made. Used in knitted wear, swim wear. Limited used.

Aramid Thread Made of aramid fibre. Limited use because costly. Flame retardancy power. Used in flame retardant garments.

PTFE ( Polytetra Fluro Ethylene ) Limited use due to costly. Flame retardancy power. Melting retardancy power. Chemical resistance power. Used in protective clothing.

Continued…….Mono filament

Made of one continuous filament. No twist on thread. Strength – More. Due to more stiffness, seam locking power is less. It has tendency of opening of sewing thread, causes

discomforts. It cut edge come in contact with skin, it causes skin diseases. No problem of shade matching due to filament being

transparent. Used in the garment which is not body or skin contact. e.g.

Over coat, rain coat. Restrict to normal garments.

Continued……..Multi filament

Made of one more continuous filaments. May have twist or not. Used in single or plied or corded forms. For flexible threads, filament yarns are

twisted, set, dyed, and lubricated. Strength and durability – high. Different types of threads have different

properties. Used in garments or leather goods.

Continued……Textured thread

Made by textured yarn or texturing multifilament.

Crimp is made in filament by texturing (False twisting, air jet, edge crimping).

No twist Hand feeling – Comfortable. Seam locking power – good. Made from polyester and Nylon filament. Used in knit wear, soft wear.

Continued…….Core spun thread

Made of combination of continuous filament and staple fibre.

Polyester filament as core and cotton fibres staple. Core spun threads are made by twisting of two or more

yarns. Strength equal to synthetic thread. Quality like cotton fibre. Shrinkage – less. No possibility of thread damage. At present, core spun thread produced by polyester

filament and polyester staple fibre. Used in high quality garments.

Thread finishObjectives of finishing: To reduce friction between thread and

needle / fabric. To reduce damage of synthetic thread

with heat. To sewing easily and properly. To adjust special purposes. To reduce sewing thread breakage.

Characteristics / properties of lubricants used for thread finish: /Features good quality thread lubrication:

• Lubricants should not close the needle eye.• It must not create any stain on needle.• It should not create any trouble to unwind threads from the thread

package.• It must reduce the friction between m/c and thread.• It should not cause any harm at high temp.• Easy to apply on threads.• Comparatively cheaper.• Easily available.• In water proof fabric/gts, must not damage the water resistance

power of threads.• In flame proof fabrics, the lubricants applied on sewing threads,

must not damage the flame reterdancy power of threads.

Sewing thread finish Lubricant finish. Anti mildew finish. Water proof finish. Flame retardant finish. Root proof finish.Anti mildew and root proof finish:

• In warm and dam condition, mildew effect is found in thread then mildew proof and root proof finishing is necessary.

• Anti mildew effect is found by applying special finishing materials.

Continued……..Water proof finishes: Water resistant finishes are applied to those threads

which are used for water proof like rain coats. The water repellent finish must be fast to washing or dry

cleaning.Flame retardant finishes: Flame retardant thread must be used for flame retardant

garments. Threads will be flame repellent when special fibres or

special chemical finishes applied on them. Flame retardency may be damaged because of using and

frequently washing of garments.

Sewing thread sizeSewing thread size / sewing thread number: The number

which is used to express the fineness of a sewing thread is called ticket number.

Ticket number is expressed in Cotton system. Metric system.Cotton ticket number system: This system is derived from English cotton count (Ne).

Which refers to the no. of 840 yds hanks per 1 lb. Resultant count of the cotton sewing thread multiplied by

3 is the cotton ticket number. i.e. Ticket no. in Ne = 3. X

ply of NoNecount Yarn

= Resultant count X 3.

Continued……Metric ticket number system: This system is derived from metric count

system which refers to the no. of hanks of 1000m per kg.

Resultant metric yarn number multiplied by 3 is the metric ticket number. i.e. Ticket no. in Nm =(Thread count in Nm/No. of ply)x3

Higher the metric ticket number, finer the thread.

Conversion: Ne = 0.59 X Nm Nm = (1000 meter /Tex) X 3. Ne = (590.5 / Tex) X 3.Factors considered for thread size selection: Types of fabric. Wt of fabric. Stitch type. Types of seam. Needle size. Seam strength. Desired uses of thread.

Sewing thread packages1.Spool: Smallest flanged bobbin package. Bobbin made of wood or plastic. 100 – 500 m threads parallely wound on it. Except textured all kinds of threads wound onto it.2.Cop: Small cylindrical and flange less tube. Thread cross – wound onto it for stability. 1000 - 2500m threads can be wound onto it. Glaced thread and fine filament can not be wound.

Fig: spool

Fig: Cop

Continued……….3. Cone: Angular hallow tube made of plastic. Above 5000m can be cross – wound. All kinds of threads are wound on it. Un wind of threads fastly. This is an ideal and most used package in garments.

4.Vicone: Parallel tubes or low angled tubes. Polished thread and filament thread wound. Less possibility of winding the threads on package. Mostly used for smooth thread on filament like embroidery thread.

Fig: Cone

Continued………..5. Container: Large package. Filament sewing thread wound onto it. Threads which are not controlled in general

packages wound onto it.6. Large package: Thread wound on large cone or tube. 20,000m or above it wound onto it. Used in over edge and cover stitch m/c.

Continued…….7. Cocoon: Special type of thread package without support. Used in shuttle of special quilting m/c.8. Pre – wound bobbin Precision wound thread package without support. Used instead of bobbin in lock stitch m/c. More time required to wind thread.

Fig: Cocoon

Fig: Pre – wound bobbin

Properties of sewing thread Tensile strength Tenacity Loop strength Loop strength ratio Elongation at break Stress / strain curve: Elongation Property more Curve big.

Elongation property less curve small. Elasticity Shrinkage Abrasion resistance Color fastness

Sewing Machine The joining of the fabric with needle and sewing thread is called sewing.

Sewing machine is very essential part of the garments industry.Types of sewing m/cs: Two types of sewing m/cs Manually operated sewing m/c: Electrically operated sewing m/c:Most common Manufacturing of sewing m/c: JUKI – JAPAN. BROTHER – JAPAN. SINGER – ENGLAND. BUTTERFLY – CHINA. PUFF. SERUBA. PEGASUS.

Features of basic sewing machine Basic machines in garments industry used for numerous

application. Generally available in three versions:

• Sewing with light material.• Sewing with medium material.• Sewing with heavy material.

Speed up to 6000 r.p.m with electronic controls for acceleration and declaration.

Electronically controlled thread cutting, needle positioning mechanism through the foot pedal available in this machines.

Programmable sewing sequence via a micro processor for repetitive operations.

A great variety of feed systems, attachments and apparatus available to make the machine more versatile.

Different parts of a sewing machine A sewing machine consists of the following parts-1. Hand wheel2. Bobbin winder pin3. Horizontal spool pin4. Thread guide5. Bobbin winder tension disk6. Thread guide7. Take up lever8. Face plate9. Needle thread tension dial10. Pressure foot

11. Needle plate12. Free arm13. Needle clamp14. Thread guide15. Reverse push button16. Stitch length dial17. Pattern selector dial18. Pressure foot lifter19. Thread cutter20. Feed system21. Slide of plate

Functions of different parts of a sewing machine Hand wheel: helps to move the needle for sewing the

fabric. Bobbin winder pin: It winds the thread into the bobbin. Horizontal spool pin: helps to take the yarn package Thread guide: The threads are passed by the help of

thread. Bobbin winder tension disk: It controls the tension. Take up lever: helps the machine for defect free sewing. Needle thread tension dial: It maintains the tension of

needle thread. Pressure foot: It is used to give pressure to the upper

plate and make effective the sewing mechanism.

Continued……… Needle plate: Needle penetrates into the fabric by the needle

plate. Needle clamp: Needle is attached with it for appropriate

position. Thread guide: Threads are passed through guide which

maintains uniform sewing and distance. Reverse push button: To make the machine reverse speed. Stitch length dial: It controls the stitch length or density. Pattern selector dial: It helps to sew according to the required

pattern. Pressure foot lifter: It helps to lift pressure foot. Thread cutter: It is used to cut the thread after sewing.

Mechanism of a sewing machine Motor is driven by electricity which drives the drive wheel. Drive wheel is related with upper drive shaft and lower

drive shaft with the help of pulley or belt. Upper drive shaft is connected with needle bar which

moves the needle up and down. Again thread tightening arm is related with needle bar for

uniform tension to the sewing thread. Lower drive shaft drives the feed dog as well as bobbin

and hook assembly. These operations are repeated and subsequent stitching

is done through needle movement.

Precautions considered before sewing/Points considered before sewing

The following maintenance points are to be considered carefully:

M/c should be cleaned every day. Essential parts of the m/c should be lubricated or oiled regularly. Needle should be adjusted carefully. Needle thread, bobbin thread or looper thread should be threaded

correctly and their tension should be adjusted. The pressure of pressure foot should be adjusted. Stitch density should be adjusted. Switching (on/off) should be proper. M/c should be handled according to instruction. The hand wheel should always be rotated towards the operator. During fabric feed and with drawl, the needle should be picked at

the top most position and the pressure foot is lifted.

Yarn path of the sewing machine In the sewing machine the sewing thread are passed through

the various thread guides to the needle position. First the thread comes from the horizontal spool pin then thread

guide. After passing the guide the thread goes to the thread guide

through the bobbin winder tension disk. Then passes the needle thread tension dial. Then the thread comes to the thread guide and passes the

needle clamp. Finally the thread penetrates the fabric for sewing by the help of

needle.

Features of different types of sewing machine

• Lock stitch m/c: No. of needle –1 or 2. SPM (stitches per minute) 1500 – 5,500. Stitch length – 5mm Most commonly used for sewing of woven garments.

• Chain stitch m/c: No. of needle – one or more needle. No. of thread – one or more thread (Single thread or

multi thread). SPM – 1800 – 6000. Stitch length – 1.4 to 4.5 mm. Used in knitted wear and jeans.

Continued……….• Over lock /Over edge m/c:

No. of needle – one or 2 needle. No. of thread 2 – 5 threads. SPM 6500 – 8500. Stitch length – maxm 4mm and stitch length can be changed

by push button. Used for sewing both woven and knitted goods but

extensively used for knitted goods.• Zig – zag stitching m/c:

No. of needle – 1. No. of thread – two. Stitch length 2 – 2.5mm. SPM – 5500. Used in edge neatening or decorative top stitching or to fit

extra component e.g. elastic, tape, braid etc.

Continued………• Flat lock m/c:

No. of needle – upto 4. Thread – 4 to 9. SPM – 6000. Stitch density – 8 to 16 per inch. Both for woven and knitted gts but mainly used for knitted

gts.SIMPLE AUTOMATIC SEWING MACHINE :

• Button holing m/c: Stitch group – lock or chain stitch. Arrangement of button hole size being small or larger. Arrangement of stitch density being increased or reduced.

Continued………• Button attaching m/c:

Produces lock stitch, chain stitch or hand stitch. Various types button clamps needs for attaching various sizes

and types of button. In fully automatic m/cs, button feeding and positioning inside the

button clamp is performed by a hopper and pipe. It can attach predetermined no. of buttons at a predetermined

distance in a cyclic order.

• Bar tack m/c: Strong sewing in very short length in cyclic order. Used for jeans (mostly) sewing of belt loops, closing the ends of

button holes, for increasing strength at the ends of the pocket. After making tack stitch in short length (1 – 2cm), cover stitch

(zigzag) is made on tack stitch and the no. of cover stitch.

Work aids The extra m/c parts which may be attached to

speed up the production and improve quality in the sewing m/c are called work aid.

Objectives: To increase the production. To improve the quality of garments. To reduce the work – load on operator. To reduce the time for handling. To control the garments quality.

Different types of work aids• Guide: Guides are used for correct sewing in predetermined position

or in a determined and proper distance from edge of fabric.• Compensating foot: Used to sew at 1-2 mm (very little distance)

from the fabric ends.• Specialized pressure foot: Specialized pressure foot used for

attaching of braid or elastic.• Rack guide: Rack guide is used for the attachment of lace, braid,

elastic with the garments parts.• Light: Special marker used which are not visible in normal light but

visible in ultra violet ray.• Folder: Folder is device which is used to fold the fabrics prior to

sewing.• Compressed air: Compressed air helps to increase the quality of the

products.• Stacker: The gts are shifted from m/c to m/c in bundle or box form.• Thread cutter: After sewing is completed, the thread is cut.

Sewing problemsSewing problems consist of- Problem of stitch formation. Seam pucker. Fabric damage at the seam line.

1. Problems of stitch formationa) Slipped stitch: If the upper thread in continuous stitches

can not pick the lower thread i.e. binding miss during stitch formation is called stitch.

Causes: • Loop size or needle is small.• Needle deflection or bending.• Tension variation in lopper and needle thread.• Hook or lopper or needle is not able to hold the thread

loop in proper time.Remedies:• Timing of (hook or lopper) with needle should be adjusted

properly.• Adjust needle and thread size.• Adjust tension property.• Change of thread.

Continued……..b) Staggered stitch: If the stitches produced by needle are

not parallel with the seam line, staggered stitches formed.Causes: Needle vibration or deflection. Blunt or wrong needle point. Not proper adjust of needle size and thread size. Faulty movement controlling of fabric into the feed

mechanism.Remedies:

Needle size should be increased. Change of needle or thread size. Change of feed mechanism.

Continued……..c) Un balanced Stitch: If the interlacement of the needle

thread and bobbin thread does not takes place at the middle of two layers of the fabric then unbalanced stitch is produced.

Causes: Incorrect tension of sewing thread. Incorrect passage of thread through the guide. Due to insufficient lubrication, (uneven) tension variation

increased.Remedies:

Adjust thread tension. Correct the passage of thread. Use good quality of thread.

Continued……..d) Variable stitch density: If the no. of

stitch varied in the seam line per unit length, then variable stitch density occurred.

Causes: Insufficient pressure of pressure foot,

causing uneven feeding. Feed mechanism is not working

properly. Wear of feed mechanism. Lose of parts. Improper unwinding of thread. Twisting of needle in the bottom of

thread package. Fraying of thread in the needle. More tension in the thread. Becoming of more heating of thread

and hook. Use of low quality of thread.

Remedies: Uses of improved feed mechanism. Increase of pressure of pressure foot. Proper threading of sewing thread. Thread can be changed. Proper use of lubricant. Use of good needle. Finer thread can be used. Tension in thread must be adjusted.

Continued……..e) Frequent thread breakage:Causes:

Improper unwinding of thread from package. Higher thread tension. Excess needle heating. Lower quality of thread. Remedies: Reduce tension in tension in tension disc. Reduce thread tension. Use of strong yarn. Change the needle if required. Use coarser needle. Use of high quality needle. Use lubricant. Use needle cooler. Confirm oil supply. Change of thread.

Problems of seam puckerPucker is a wrinkled appearance along with sewing line.a) Unequal stretch on fabric:Causes : If two or more plies fabrics are sewn together, one ply will be feed more

than other and seam pucker create due to uneven stretch. This pucker formed due to limitation of feed mechanism.Remedies: Improved feed mechanism of sewing m/c. Skilled operator and fabric handling would be special process.b) Fabric dimension instability:Causes: When two or more layers of fabric are sewn together and one layer shrinks

more than after washing differential seam pucker is formed.Remedies:: Shrinkage difference must be less than 2 %. We should test shrinkage of two types of fabric before sewing.

Continued………c) Extension in sewing thread:Causes: While sewing threads are subjected to tension and for tension thread will

be extended and after sewing when thread get chance of relaxation then seam pucker formed.

Remedies: Tension of the thread should be kept as low as possible. By changing the sewing threads.d) Sewing thread shrinkage:Causes: After sewing, if the sewing threads shrinks due to wash or iron, then seam

pucker occurred.Remedies: Shrinkage of sewing thread must be equal to the fabric shrinkage. Before sewing, the shrinkage property of both thread and fabric should be

known.

Continued……..e) Fabric construction:Causes: In a compact fabric high EPI and PPI, while sewing of such fabrics,

the threads are displaced around the needle and because of lack of space, pucker may be seen along the holes created by the needles.

Remedies: Very difficult to overcome this type of problem but to reduce the

problems following steps should be taken:• By using fine / thin needle and fine / thin thread.• Reduction of stitch density.• Change the fabric if possible.

e) Mismatched patterns: If two pattern pieces of unequal length are joined, then one is

joined with another by creating contraction, seam pucker creates.

3. Fabric damage at the seam lineCauses:• This type of fault is mainly due to needle specially bent, blunt

or damaged needle.• For this fabric damage, sewing strength becomes low and due

to more fabric damage, fabric may be tear off at the sewing line.

• Fabric may be damaged with new and good needle if needle size and needle selection is wrong.

• This fault is visible after washing and wear.

Two types of fabric damage can be occurred with needle at the seam line:

Mechanical damage. Needle heating damage.

Continued……….a) Mechanical damage: To minimize the damage, the following steps are

taken:• Needle size and point should be properly selected.• M/c speed should be reduced.• Application of lubricant.• Test the sew ability before sewing of fabric.

b) Needle heating damage:• The temperature in needle due to friction between needle and

fabric is up to 300 – 350ºC.In this temp, needle or fabric both may be damaged.

• As synthetic fibers is melted at around 250ºC of needle. Groove in needle and eye are closed.

We can solve the problem by- Less speed of machine, proper needle size and shape, short

length of sewing, cool air use, lubrication.

Trimmings and Accessories All the materials except fabric required to make a garments

are known as trimmings or accessories. Example: sewing thread, button, zipper, label etc.

The name of sewing trimmings are: Sewing thread. Button. Lining. Interlining. Rivet. Label and motif. Zipper. Hook and loop fastness (VELCRO ). Lace, braid and elastic. Shoulder pad.

Label Label is a part or

component of garments which indicates varies instructions about the garments.

Label

Main label

Sub label

Size label

Care label

Price labelComposition

label

Types of label:

Care label: Indicates the care instructions of the garments by some internationally recognized signs. It shows washing, bleaching, drying, laundering, ironing, dry cleaning.

Washing - Chlorine bleach - Ironing code - Dry cleaning condition - Drying condition -

Continued…….This 5 symbols are different types:1. Washing:

950C

600C

-Can be washed up to 950C

-Can be washed up to 600C

-Hand washing but not in washing machine.

-Can not be washed.

Continued……2. Bleaching condition:

Chlorine bleach is

allowed.

Chlorine bleach is not allowed.

3. Ironing condition:Ironing in cold state (110C)

Ironing in cold state (150C)

Ironing in cold state (200C)Can not be ironed. Can not be ironed

Cl

Cl

Continued………4. Dry cleaning condition: Dry cleaning is allowed in any types of solvent.

Para-Chloro-Ethylene, white spirit, solvent-113 and solvent-11 can be used.

White spirit of solvent-113 can be used.

A

P

F

Continued………5.Drying condition: Tumble drying is allowed.

Tumble drying is not allowed.

Drying in hanging state is allowed.

Drying should be done in a state parallel to the ground but can be hanged.

Motif: To increase the attractiveness of garment a special component named motif is attached on outside of garments. Some times motif contain company name, trade mark or various kinds of symbols.

Types of buttons:a) According to Ligne number (12 L, 16L, 18L, 24L etc.) Ligne no. is the measuring unit of button and indicates the dia of button.1 Ligne = 0.025 inch.

b) According to material used: 1. Plastic button 2. Metal button 3.Wooden button 4.Horn button 5.Chalk

button 6.Printed button

c) According to no. of holes: 1. 2 hole button 2. 4 hole button.

d) Special button.1.Shank button 2.Snap button 3.Decorative button.

ZipperTypes of Zipper: According to manufacturing

material, zipper are of 3 types: Metal zipper Plastic – molded zipper Polyester / nylon coil zipper

Zipper elements in its construction:1.Tape2.Chain3.Slider4.Top and bottom stop5.Pull tab

Fig: Zipper.

Quality of trimmings The important qualities of trimmings are-• Life time: The life time of garments and that of the

trimmings should be equal. • Shrinkage: The shrink ability of the garments and the

trimmings should be checked earlier.• Color fastness: The fastness properties of

accessories should be good. • Rust: To avoid this problem, the metal trimmings

should be electroplated or they should be made up of non – rusting materials.

• Comfort ability: Trimmings should not create any uncomfortable feeling to the wearer.

Alternative method of fabric joining Introduction: The process which have been developed as alternative to sewing are

known as alternative methods of joining. Three methods are used instead of sewing, these are:

1. Welding & Adhesive2. Moulding3. Fusing Welding: Welding is the process of garment manufacturing which involve the joining

together of thermoplastic materials by applying heat externally. It is mostly used in hems.

Basic procedure of the method:1. Heat applied on the fabric2. Melting of thermoplastic materials3. Applying pressure on melted material4. Creation of bonding5. Cooling6. Fabric joined

Continued……….Adhesive: Adhesive is a substance which is sticky

and used for joining the fabric. It is mostly used in edge neatening, water proofing seam etc. Adhesive can be used by the following ways-

A coating of thin adhesive film on silicon paper which is transferred to the fabric and the plies of the fabric are joined.

A material which melts by applying heat and helps to join the fabric layers.

Continued….Moulding: By moulding method the required definite shape of garments

is found without creating seam. Basic procedure of the method: 1. The desired shape by shrinkage 2. Heat apply3. Thermoplastic fiber in fabric becomes soften4. Cooling5. Desired shape

Continued………Fusing: It is most useable alternative method of fabric joining. The joining of interlining by sewing is replaced b fusing. The main fabric of interlining contains resin or polymer coating. Resin or polymer coating side of interlining is placed on the

underside of shell fabric. By spreading this on smooth surface heat and pressure is

applied uniformly. As a result of heating polymer coating or resin melts and for

pressure this melted polymer enters into the fibre of interlining and shell fabric.

After drying shell fabric and interlining is joined by the forming bonds between them.

Basic principle of Flat bed press for fusing materials First place shell fabric on to the buck Placed interlining on to the shell fabric Keep head on to the buck Select time and pressure Switch on Then head will give pressure and heat Polymer coating or resin will melt for heating For pressure melted polymer will enter into the fibre of

shell fabric and interlining After drying formation of boning After certain period time machine will automatically stop Finally we will get the fused components

Pressing and finishing Pressing is the process to remove unwanted crease and crinkles

from the fabric to give it smoothness, lustrous and fine appearance.

Objects of pressing: Removal of unwanted creases and crinkles To apply crease where necessary Shaping Under pressing Final pressingCategories of Pressing:

• No Pressing.• Minimum Pressing.• Under Pressing.• Final Pressing.• Permanent Pressing.

Continued………Pressing equipment & methods: Different

types of pressing machine is used for different types of pressing as follows-

Iron (traditional, electric, steam iron) Steam process( Head and buck) Steam air finish or dolly press (form or dummy

without sleeve:8 sec steam+ 8 sec hot air) Steam tunnel (hanger with moving rail,

temperature controlling chamber)