Sewing-9

Thread Sizing

1. Metric Ticket Number system

eg if Nm 60/1 means 60m of it would weigh 1 gm.

of 120/2 means 120 m of it would weigh2 gms. In this case it would have a resultant count of 60 ( i.e. 60 gms) would weigh 1 m.

The metric ticket number of this thread based on a three fold equivalent is then three times that i.e.

Nm 80/2= Ticket Number 120
Nm 30/3 = Ticket Number 30 and so on..

2. Cotton Sewing threads are sized on the cotton ticket number system

eg. 3/60 Ne --> equivalent cT= 20--> Three fold equivalent = 60 ( Ticket Number)

3. Denier system--> Weight in gms of 9000 m of length

Thread Packages

1. Spool

a. Used for domestic sewing
b. Not suitable for delivering thread to high speed industrial machines.

2. Cops

a. Small cylinderical flangeless tubes onto which thread is cross bound for stability.
b. Lack of flanges facilitates regular offwinding from the top on sewing machines.
c. Their small diameter makes them less suited for the faster thread offtake of machines.

3. Cones

a. They contain 5000 m cross wound for stability and good offwinding performance.
b. They give troublefree thread delivery.
c. Ideal in situations where thread consumption is high.

4. Vicone- Contain any spillage

5. Large Package

a. Can hold in excess of 20000 m of spun or corespun thread

6. Container

cocoons: They are self supporting ie. centerless, thread packages.

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Thread Finish


The final aspect of thread construction to be studied is that of surface finish.

The most important finish is lubrication.

The requirement of a lubricating finish applied to a sewing thread is that it should produce a regular level of friction, and that for synthetic threads in particular, it should provide protection from needle heat.

Without a controlled amount of lubrication applied to threads, unacceptable damage would be inflicted on them during the sewing process which would result in thread breaks during sewing and seam breakdown in wear.

A lubricant


- Must not clog the needle eye
- should not stain
- Must allow thread to unwind evenly from the package
- Must reduce friction with m/c surfaces but without creating too much slippage
- Must not react adversly to high temperature
- Must be inexpensive
- Easy to apply to the thread during manufacturing.

Other finishes


- Mildew or rot resistant finish
- Water resistant finish
- Soil Release
- Flammability finish

Sewing-7

Sewing Threads

Threads can be

Spun


Threads made from spun yarn have good sewing performance, good dimensional stability and good stitch locking properties in the seam due to their fibrous surface.

Monofilament


One filament of large size. It is harsh on machine and rather inflexible because the cross sectional shape never varies as it would with multifilaments.

Its cut ends are harsh on the wearer. It has virtually no seam grip and stitches tend to unravel easily.

Its good advantage is a translucency which reduces the need for shade matching.

Multifilament Form


Their fineness enables larger thread packages to be used, thus saving operator time changing them.

Corespun


In this a continuous multifilament core is wrapped around a sheath of spun fiber, two or three of these yarns are then plied together.

The majority of these corespun threads consist of a polyester core and a cotton cover.

Sewing-6

Sewing Threads

Selection of sewing threads depends upon the following factors:

1. Performance properties during sewing
2. Performance in the completed garment under conditions of wear and cleaning

Appearance and perfomance of the threads depends upon:

1. Fiber Type
2. Construction
3. Finish

1. Fiber Type

a. Linen- Useful in making strong, rather stiff threads for heavy sweing and also for button sewing.

b. Slk - Advantage- Good appearance and performance, Disadvantage- High Cost

c. Cotton - Good Sewing Performance, Disadvantages- Strength and abrasion resistance are inferior to synthetic threads of equal thickness.
It is more stable at higher, dry temperature than synthetics- less affected by hot needles during sewing.

d. Viscose- 1. Do not have the strength or durability of synthetic fibres. 2. Low tenacity and low strength when wet. 3. High lustre- can be used for embroidery.

Nylon/ Polyester Threads
1. Not affected by rot, mildew or bectaria
2. High Tenacity
3. High resistance to abrasion
4. Good resistance to Chemicals

2. Construction

When the fibres occur in short lengths, they must be twisted together, initially into a single yarn, and then that twist must be balanced by applying a reverse twist, as two or three such yarns are combined to form the thread construction.

- Twist in singles yarn consolidates the strenth and flexibility provided by the fibres themselves.

- Without the reverse twist, known as finishing twist, a conventional thread cannot be controlled during sewing. The individual plies would separate during their repeated passages through the needles and over the sewing machine control surface.

- Remember that the frictional forces acting on a thread during its passage through a sewing machine also tend to insert some twist, predominantly in one direction.

Sewing-5

Needle Point

These are divided into two parts- Cutting points and cloth points.

Cutting Points: These are needed for fabrics like leather where there are no gaps in the structure.

Cloth Points: These are needed for those fabrics where there are gaps in the structure.

Cutting point Neeedles

a. Wedge Point: It produces most durable seam on leather. It resists great stress, the incision lie at right angle to the seam direction and high stitch density can be achieved.

b. Cross Point: Here strength is considerably weakened. The material is likely to tear if stress is at the right angle. The incisions lie parallel to the direction of the seam.

c. Twist Point: The strength is intermediate and the incisions like 45 deg. to the direction of the seam.


Cloth Point Needles

These are used for sewing textile materials rather than the sheet material already described. The points have a round cross section.

The needles are different for the various woven and knitted fabrics.

Knitted fabrics consist of yarns with spaces between them and if a yarn in a knitted fabric is broken the knitted structure may begin to unravel. The requirement in sewing knitted fabrics is :

a. A needle which will slightly deflate the yarns and enter the spaces.

b. A needle of as small a size as possible consistent with needle strength and sewing thread size.

c. A fabric which is sufficiently lubricated that it has flexibility in relation to the movement of the needle.

The shape of the tip of the neele point which best achieves this deflation is a ball shape and the needle is referred to as a ball point needle.

Woven fabric consist of yarns which can have greater or lesser amounts of twist, interlaced with each other at various degrees of density.

For that a needle is needed that goes between the fibres and does not strike and break them.

The shape of the tip of the needle point which best achieves this penetration between the fibres has the appearance of being slighly cone shaped. It is usually referred to as a set point needle.

Sewing-4

Size of Needle

Choice of size is determined by the fabric and the thread combination which is to be sewn.

If needle is too small for the thread, the thread will neither pass freely through the eye nor fit properly into the long groove. As a result it will suffer from excessive abrasion. It may result in

Costly thread breakage in production because the machinist must stop to rethread the needle and possibly also to unpick some of the stitching so that a joint does not show in an important part of the garment.

When sewing heavy plies of material, a fine needle tend to get deflated. It can affect the stitch loop pick up and cause slip stitches, or it can even lead to needle breakage

A break in the situation of multi-needle sewing with fabric running through the folders would be impossible to repair.

If the needle is too large, there will be poor control of the loop formation which may cause slipped stitches.

There will also be holes in the fabric which are too big for the stitches and give an unattractive seam appearance.

In closely woven fabric, there will be a pucker along the seam line due to fabric distortion.

Nomenclature for Needle Size

Metric

d x 100 = Metric Number, where d is in millimeter,

eg. For d = 0.65 mm, number of needle is 0.65x100 =65




Selection of needle and thread size for a particular seaming situation is a question of achieving a balance between the minimum damage due to pucker which is a matter of small needle size and seam strength which requires a substantial needle and thread.

Sewing-3

Sewing Machine Needle

The way in which the fabric is penetrated by the needle during sewing has a direct effect on seam strength and on garment appearance and wearable life.

The functions of the sewing machine needle in general are:

a. To produce a hold in the material for the thread to pass through and to do so without causing any damage to the material
b. To carry the needle thread through the material and there form a loop which can be picked up by the hook on the bobbin case

Anatomy of a Sewing Machine Needle



Butt: It is shaped end of the needle which facilitates insertion into the needle bar or clamp.

Shank:
It is the upper part of the needle which is located within needle bar. It is the support of the needle as a whole and is usually larger in diameter than the rest of the needle for reasons of strength.

Shoulder: It is the section intermediate between the shank and the blade.

Blade: The blade is the longest part of the needle down to the eye. The blade is subjected to the greatest amount of material through which the machine passes.

Long Groove: The long groove in the blade provides a protective channel in which the thread is drawn through the material during stitch formation. Sewing thread can suffer considerably from abrasion during sewing as a result of friction against the fabric. A correctly shaped long groove, of a depth matched to the thread diameter, offers considerable protection to the thread.

Short Groove: The short groove is on the side of the needle which extends a little above and below the eye. It assists in the formation of the loop in the needle thread.

Eye of the Needle: The eye of the needle is the hole extending through the blade from the long groove on one side to the short groove on the other.

Scarf or Clearance Cut: It is a recess across the whole face of the needle just above the eye. This ensures that the loop of the needle thread will be more readily entered by the point of the hook.

The Point of the needle is shaped to provide the best penetration of each type of material.

The Tip is the extreme end of the point which combines with the point in defining the penetration performance.

Sewing-2

Seam Types

Stitched seams are divided into eight classes according to the type and minimum number of components within the seam.

These components which can be the main fabrics of the garment or some additional items such as a lace etc, are termed as being of 'limited' or 'unlimited' width.


where a component is referred to as being limited on one side, that side might be the cut edge of the garment piece that is being seamed.

Where a component is referred to as being unlimited on one side, that edge might be the far edge of the garment panel irrelevent to the seam under consideration.( Figure-1)



Class-I (Superimposed Seams)

It is produced with a minimum of two components both limited on the same side. A variation of the superimposed seam is the french seam.



Class-II ( Lapped Seam)

Seams in this class are produced with a minimum of two components but with these, one is limited on one side and the second is limited on the other side. The components are opposite and at different levels and overlap each other.

Class -III ( Bound Seams)

In this class, seams are produced with a minimum of two components , one is limited to one side with the second is limited on both sides.

Class-iV (Flat Stitching)

In this class, seams are produced with a minimum of two components of which one is limited on one side and the second on the other. The two components are opposite and on the same level. These seams are referred to as flat seams because the fabric edges do not overlap. They may be butted together without a gap and joined across by a stitch which has two needles sewing into each fabric.

Class-V (Decorative Stitching)

Seams in this class are produced with a minimum of two components unlimited on two sides. Any other component is either limited on one side or limited on two sides.



Class-VI (Edge Neating)


It is produced with only one component limited on one side (either on the right or the left). Seam types in this class include those where fabric edges are neated by means of stitches as well as folded hems and edges.

Sewing-1

Sewing

1. Seam: A seam is the application of a series of stitches or stitch types to one or several thicknesses of material.

Stitching is applied to situations where there is only one piece of fabric, such as when fabric edges are neated or hems created, and where decorative sewing is involved.

Objective of Sewing: Are the construction of seams whcih combine the required standards of appearance and performance with in appropriate level of economy in application.

Good Apppearance of Seams: It means smooth fabric joins with no missed or uneven stitches and no damage to the material being sewn.

Performance of Seams: It means the achievement of strength, elasticity, durability, security and comfort, and the maintenance of any specialised fabric properties such as waterproofing or flameproofing.

1. Seams must be strong as the fabric, in directions both parallel to and at right angles to the seam.

2. Seams must be durable to the kind of abrasion experienced in washing and wearing as well as secure against fraying apart or the unravelling of the stitches.

3. A seam in a close fitting garment must not present an uncomfortable ridge or roughness to the skin.

4. It must not damage the fabric along the stitch line.


Factors to be considered while sewing

1. Seam Type: Particular configuration of seams in fabrics.

2. Stitch Type: Particular configuration of threads of in the fabric.

3. The Sewing machine feeding mechanism- It moves the fabric past the needle and enables a succession of stitches to be formed.

4. The needle which inserts the thread into the fabric.

5. The thread which forms the stitch which either holds the fabric together, neatens it or decorates it.

Back ground to the clothing industry: Why Garment Manufacturing Is Labour Intensive

Background to the Clothing Industry

The clothing industry is one of the most interesting industries because it combines fashion, fabric, labour, machines, speed, skill and market demand. A garment factory may employ only a few people, or it may employ thousands. This wide variation is mainly because of the special nature of fashion and clothing manufacture.

Unlike many other industries, garment manufacturing is not only a machine-based activity. It is strongly dependent on human handling, judgement and coordination. The fabric has to be spread, cut, bundled, stitched, finished, checked, packed and delivered according to market requirements.

Simple understanding:

The clothing industry is shaped by two major realities: fashion changes quickly, and sewing still needs a large amount of human skill.

1. Fashion Requires Quick Response

The first important feature of the clothing industry is the need for quick response. Fashion changes fast. Colours, styles, silhouettes, prints, trims and garment details may change from season to season, and sometimes even faster.

Because of this, clothing companies must be able to produce and deliver garments quickly. A delay in production may mean that the style becomes less attractive in the market.

Two Broad Types of Clothing

Clothing may be broadly divided into two categories:

Type of Clothing	Meaning	Production Nature
Fashion or couture garments	Garments strongly influenced by style, design and current fashion trends.	Usually produced in smaller quantities and often at higher cost.
Staple garments	Regular garments such as underwear, shirts, school uniforms and basic clothing.	Produced in larger quantities because demand is more stable.

The level of technology used in garment manufacture is closely related to the quantity produced and the length of the production run. If a style is produced in very large quantities for a long period, more mechanisation can be justified. But if a style is produced only in small quantities, too much investment in special machines may not be economical.

Practical point:
A basic school shirt may run in thousands of pieces, so production can be standardised. A fashion blouse or designer kurta may run in small quantities, so flexibility becomes more important than heavy mechanisation.

2. The Fashion Industry Is Labour Intensive

The clothing industry is also labour intensive. Entry into garment manufacturing is relatively easy compared with many other industries because the central operation is sewing. A small factory can begin with sewing machines, cutting tables, pressing equipment and trained operators.

However, this simplicity is also the reason why garment production depends heavily on people. Sewing may appear to be a simple operation, but it needs continuous fabric handling, alignment, judgement and control.

Why Sewing Dominates Garment Production

Sewing is the central process in garment manufacture. A garment is formed by joining different fabric components such as fronts, backs, sleeves, collars, cuffs, waistbands, pockets and linings.

In many sewing operations, the actual needle stitching time is only a part of the total operation time. A large part of the time is spent in handling activities such as:

• Picking up the fabric parts
• Matching and aligning edges
• Folding or creasing fabric
• Positioning under the presser foot
• Trimming threads
• Marking or checking seam positions
• Disposing the sewn piece after stitching
• Bundling parts for the next operation

This is why the productivity of a sewing line depends not only on machine speed, but also on operator skill, workplace layout, bundle movement, handling method and production planning.

Important learning:
In sewing, the machine may be fast, but the fabric must still be controlled by the operator. Therefore, garment manufacturing remains highly labour dependent.

Why Is Garment Manufacturing Difficult to Automate?

Garment manufacturing is difficult to automate mainly because fabric is not rigid. It behaves differently from metal, plastic or wood. A fabric piece bends, stretches, slips, folds and changes shape during handling.

1. Fabrics Are Limp

Fabrics bend in many directions. They do not remain fixed like a sheet of metal. This makes it difficult to design jigs, fixtures and automatic equipment for many sewing operations.

For example, while joining a sleeve to an armhole, the operator has to control curves, ease, seam allowance and fabric movement at the same time. This type of operation is difficult to fully mechanise.

2. Fabrics Vary in Extensibility

Different fabrics stretch differently. Some fabrics have very little extensibility, while knitted fabrics or stretch fabrics may extend considerably.

A minimum amount of yarn and fabric extensibility helps the sewing needle penetrate the fabric properly. If the extensibility is too low, sewing may become difficult. If the extensibility is too high, the fabric may distort during stitching.

3. Fabrics Vary in Thickness

Fabric thickness also affects garment manufacturing. A fine voile fabric, a denim fabric, a wool coating fabric and a quilted fabric cannot be handled in the same way. Seam formation, needle selection, thread selection, feed mechanism and pressing conditions all depend on fabric thickness.

4. Sewing Must Match the Fabric Behaviour

The method of joining must be compatible with the flexibility, drape and handle of the fabric. A garment seam should not only hold two fabric pieces together; it should also move with the fabric.

This is why sewing has remained the most widely used method of joining garments. Mechanically, a stitch is one of the few joining methods whose flexibility comes close to the flexibility of fabric itself.

Textile concept:
A good garment seam should be strong, but it should not make the fabric unnecessarily stiff. The seam must support the garment without spoiling its drape and handle.

Cutting Room Mechanisation

While sewing is difficult to fully automate, cutting room mechanisation is more practical and is widely used in many garment factories. This is because cutting deals with fabric in layers before garment components are separated for stitching.

In the cutting room, activities may include:

• Fabric spreading
• Marker planning
• Manual or automatic cutting
• Numbering and bundling
• Sorting garment components

Modern garment factories may use computerised marker making, automatic spreading machines and automatic cutting machines. These technologies help reduce fabric wastage and improve cutting accuracy.

Why Cutting Is Economically Important

Cutting is very important because fabric is usually the largest cost component in a garment. In many garments, material cost forms a major part of the total cost.

Therefore, even a small saving in fabric consumption can have a large impact on profitability. This is why marker efficiency, lay planning and cutting accuracy are very important in garment manufacturing.

Area	Main Concern	Why It Matters
Cutting room	Material utilisation	Fabric is a major cost, so wastage must be controlled.
Sewing room	Labour productivity	Sewing depends heavily on operator skill and handling time.
Finishing section	Appearance and quality	Pressing, checking and packing influence final garment presentation.

Difference Between Cutting and Sewing Activities

Cutting and sewing are both essential, but they are very different in nature.

Cutting	Sewing
Can be mechanised more easily.	More difficult to automate fully.
Main concern is fabric saving and accuracy.	Main concern is operator skill, quality and productivity.
Fabric is handled in layers.	Fabric components are handled individually or in small assemblies.
Marker planning can improve material utilisation.	Workplace design can improve handling efficiency.

Conclusion

The clothing industry is a unique industry because it must respond quickly to fashion changes while still depending heavily on human skill. The central process of garment manufacture is sewing, and sewing remains labour intensive because fabric is limp, flexible, extensible and variable in thickness.

At the same time, some areas such as cutting can be mechanised more easily because fabric can be handled in layers and material saving can be calculated systematically.

For a textile or fashion student, the most important understanding is this: garment manufacturing is not only about stitching. It is about managing fabric behaviour, labour skill, production flow, material cost and market speed together.

Key takeaway:
The garment industry remains labour intensive not because machines are unavailable, but because fabric is a difficult material to control automatically.