sewing room in apparel industry

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The central process in the manufacture of clothing is the joiningtogether of multiple 2-D fabric pieces to form a 3-D garment operations that all involve sewing in one form or another.

Although there are a large number of different categories of sewing machine, their actual sewing functions are all derived

from the same component of sewing.



Stitch formation consists of one or more thread supplies beingcombined together to form a stitch.

These are defined as

Intralooping: The passing of one loop of thread through another

loop of same thread supply; an example of this type is 101 singlethread chain stitch.

Interlooping: The passing of a thread through a loop formed byseparate thread supply; an example of this is a 401 two threadchain stitch.

Interlacing: The passing of a thread around, or over, a separatethread supply or a loop of that supply; an example of this is 301two thread lock stitch.



Class 100: Chain type Stitches

Class 200: Hand Formed Stitches

Class 300: Lock Stitches

Class 400: Locked Chain stitches

Class 500: Over- edging stitches

Class 600: Flat Seam or Covering Stitches.



The choice of seam types is determined by aesthetic standards,

strength, durability, comfort in wear, convenience in assembly inrelation to the machinery available, and cost.

Certain seam types are more appropriate for some products andfabrics than others.

A seam has three dimensions, length, width, and depth.

Seam length is the total distance covered by a continuous seriesof stitches, such as a side seam or shoulder seam.

Seam width considerations are width of a seam allowance, theseam heading of a lapped or a top stitched seam, and the widthof a line of stitches relative to the seam.

A seam allowance is measured from the cut edge of the fabricto the main line of stitches.

Seam depth is the thickness or compressibility (flatness) of aseam.



Seams are formed by sewing two or more pieces of fabrictogether, but the basis of seam classification is the position of the pieces relative to each other.

Many variations in fabric position and treatment account for the

many different types of seams in each classification.The Federal Standard 751a, which is the basis of stitch classesidentifies four seam classes and two stitching classes.

Each class includes many seam types.



The Superimposed Seam (SS) class - is formed by joining two ormore pieces of fabric, usually with seam allowance edges evenand one piece superimposed over the second.

These seams can be sewn with a lock stitch, chain stitch,

overedge stitch, or safety stitch.Some examples of superimposed seams are shown below:



The Lapped Seam (LS) class - is defined as two or more pieces of fabric joined by overlapping at the needle.

This is the largest seam class, including 101 different seamtypes, with a great deal of variety as to where a seam is lappedand how it is lapped.

These seams are used to attach front band to shirts, settingpockets, side seams of quality dress shirts, side seam or inseamof jeans, and so on.

Lapped seams may be stitched with a lockstitch or a chain stitchbut not an overedge stitch.

Some examples of Lapped seam types are shown below



The Bound Seam (BS) Class - requires a separate piece of fabricthat encompasses the edge of one or more pieces of thegarment.

These seams are used to finish plain necklines, edges of shortsleeves on some styles of T-shirts, and so on.

Bound seam may be sewn with a lock stitch, chain stitch, orcover stitch. They would never be sewn with an edge stitch asthe knife would cut off the binding.

Examples shown below:



The Flat Seam (FS) class - is the smallest class with only sixdifferent types.

The formation of this seam occurs with the butting together of two pieces of fabric, but not overlapping them.

Flat seams are constructed to remain flat through care and wear.They are commonly used for seams of sweatshirts, lingerie, andlong underwear.



Stitching Classes - The two stitching classes are ornamentalstitching (OS) and edge finishing (EF).

The finishing of either of these classes is performed on a singlepiece of fabric.

The fabric may be folded in a variety of ways so that thestitching may be through more than one thickness, but itremains a single piece of fabric.

Edge finishing is stitching that encompasses the cut edge orprovides a finish for a single ply of fabric with a folded edge

configuration.



Stitches from any of the classes may be used depending on thetype of fold and placement of stitching.

Ornamental stitching may be used on a single ply for decorativepurposes. It can be done anywhere on the garment except theedge.

The decorative stitching may be used on jeans pockets, logos,and pin tucks.



It has been estimated that there are over 3000 different types of sewing machines on the market.

This is not surprising in view of the number of products whichincorporate sewing in their manufacture.

Apart from all types of clothing, there are tents, curtains, bed-linen, upholstery, shoes, luggage, parachutes, etc. all of whichcontain sewn elements.

For the clothing industry there is a great diversity of regular andspecial machines for sewing every conceivable type of garment

and it is this variety which enables clothing manufacturers toemploy specialized equipment for their own particularrequirements.



S

e w i n g M a c h i n e

Basic Sewing Machines

Over-locking machine

Safety Stitching Machine

Blind Stitching

Button hole machine

Button Stitching Machine

Bar Tacking Machine



The single-needle lock stich machine has evolved considerably overthe past few decades.

Some of the features of the machines in common use today are:

Speeds of up to 6000 rpm with electronic controls whichreduce the time required for acceleration and deceleration

Automatic positioning of the needle in an up and downposition

The automatic cutting of top and bottom threads

A back tacking mechanism actuated through the foot pedalor automatically by means of an electronic seam-end sensor.

Automatic foot lifting actuated by the foot pedal instead of amanual knee lift

Programmable sewing sequences via a microprocessor forrepetitive operations.



SNLS - High Speed machine.flv



This is the generic name given to the over-edge stitch machines

used to trim and cover the rough edges of the fabric in order topresent a clean and neat appearance where seam edges arevisible.

Over lock machines are also used for the assembly of the someof the knitted articles such as T-Shirts.

The over-edge stitch can be formed from one to four threads.Some of the technological highlights of these machines are

Speeds of up to 10000 rpm

Automatic thread cutting

A vacuum system for extracting cloth waste and threadends

Variable feeds for sewing problem materials

Creating continuous or intermittent f ullness on the top or

bottom when joining two plies.



Safety stitching machines have the same features as over lockmachines and are used for the simultaneous seaming and overlocking of many garments where there is no necessity forpressed open seams.

There are two types of safety stitching machines in general use,the main difference between them being the number of threadsused to construct the stitching, which consists of a locked chainstitch parallel to an over locked edge.

With four thread machine, one of the looper threads of the over

lock stitch is used as the bottom thread for the chain stitch.On a five thread machine, each row of stitches has its ownthreads, i.e. three for the over lock and two for the chain stitch.



These machines are used for the fastening of the hems or

facings and, the name suggests, they perform this operationwithout the stitch impression showing on the right side of thegarment.

This class of machine uses a curved needle which is designed toslightly penetrate the surface of the fabric but emerges on the

same side as it entered.Some of the features of the blind stitch machines are

Sewing speeds of up to 2000st/min

Automatic thread clipping

Automatic needle positioningPneumatic opening and closing of the work plate

One or two thread versions, and with the two threadmachine the stitch is locked in order to prevent itunraveling.



A button hole is a straight or shaped slit cut through the

garment and then sewn round its edges to prevent fraying andstretching.

The cut shape of the button hole and the number of threadsused to cover its edges depend upon on the garment type andquantity.

For example, the buttonholes in a mans jacket would bestrongly constructed to withstand frequent opening and closing,whereas the buttonholes for the womens blouse would have alighter construction because they are used far less during wear.

The advance of the electronic and microprocessor technologies

has also made it possible for button holes machines to beprogrammed to do different lengths and shapes of button holes,enabling greater flexibility and efficiency



Buttons with two holes, four holes or shanks can be sewn on the

same machine by simple adjustments to the button clamp andthe spacing mechanism.

The sewing action consists of a series of parallel stitches whoselength is equal to the spacing between the centers of the holes.

The needle has a vertical movement only and the button ismoved from side to side by the button clamp.

Buttons can be sewn on with one or two threads, the number of stitches depending on the type of the machine used.

Each machine has a maximum number of stitches, i.e. 16, 24 or

32, and can be adjusted to sew the full amount or half, i.e. 8 or16, 12 or 24, and 16 or 32.



The bartack machine has many applications in the clothingfactory; one of them is the sewing of the dense tack across theopen end of a button hole.

Each machine sews a fixed number of stitches with the option tochange stitch density, and machines are available which sew

bartacks containing 18-42 stitches.Some of these types of bartack machines are fitted with

A mechanism which signals audibly and visually when thespool thread is below certain level.

Automatic thread cutting at the end of the sewing cycle.

A two stage pedal which opens and closes the work clampand also operates the machine.

A brake wheel base which enables the machine to beeasily moved.



Embroidery is an art form that uses close or overlapping stitches

to form intricate, three dimensional, surface designs toembellish piece goods, trims, or garments.

Embroidery has evolved from hundreds of years of handwork bydozens of cultures to an established art form today.

Today, the embroidery process uses advanced technology toembellish styles and mass produce trims for the garmentindustry.

Embroidery is a flat trim that adds interest and differentiation toa product



Embroidery machines operate on a predetermined stitch cycle

that is specific to each design that is sewn.A computer disk or punched tape controls the stitching patternsand needle action.

The stitch pattern controls the sequence and time that machinestitches.

All needle beds on a machine are controlled by the stitchpattern and operate at the same time or stop at the same time.

Stitch patterns are developed by digitizing or punching.

There are three types of embroidery machines, each serving a

special function.(1). Schiffli Embroidery Machines

(2). Single Head Embroidery machine

(3). Multi Head Embroidery Machine.



Schiffli embroidery machines are large, loom like machines used

to stitch designs on lengths of piece goods.They are used to embroider piece goods, produce emblems, andmake novelty and Venise lace trims.

Most machines operate with two frames that hold two fabriclengths of 10, 15, or 21 yards that span the frame.

Machine size varies with the production needs. Frames, whichare mounted vertically, have controlled vertical and horizontalmovements directed by a punched tape or a computer disk.

Actions of some types of schiffli machines are controlled by an

automat, which is a system of rods, cams, and levers used toread punched tapes and direct embroidery frames in forming adesign.



Needles are mounted on two horizontal fixed tracks that spanthe length of the frames

Needle bars move needles horizontally in and out of piece goodsin synchronization with frame movement.

Borers, which produce fabric and push aside yarns prior tostitching, are mounted directly below the needle bars make

eyelet fabrics and trims.Schiffli embroidered fabrics may experience a reduction inyardage because of heavy concentration of stitches.

Because of complexity, size, and cost of Schiffli equipment andthe specialized training and expertise required to operate it,

most of the firms use contractors that specialize in schiffli work.Fabrics can be sent to the contractors to embroider, orembroidered trims can be special ordered.



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Single head embroidery machines are similar to basic lock stitchsewing machines.

They were developed for producing small orders and are usedfor customized garments.

Single head machines are most often used for custom work andmono programming.

They may be manually operated or computer controlled.

Manually operated machines depend on the skilled operator toposition and manipulate materials under the needle.

Computerized embroidery machines are programmed to stitchthe selected design and operator must do is place the garment



Multi-head embroidery machines are similar in operation to

single-head machines except they contain two or more headsthat stitch the same pattern simultaneously.

Smaller areas are the best embroidered with more close-setheads; larger patterns require wider needle range and fewerheads.

Each head utilizes 1 to 6 needles and up to 6 colours in stitchinga design. Machines are purchased with a specific number of heads.



The optimal number of heads is generally dependent on thefirms average order size, average number of stitches per design,and size of the area to be stitched.

Higher stitch counts are more efficiently produced on machineswith more heads.

Loading time, which entails inserting the fabric or garmentcomponent under the machine head, should be less thanstitching time if the operation is to be productive.

More heads require more loading time, and for designs with a

lower stitch count, there is more idle time during the loadingprocess.



Materials required for all embroidery designs are

Piece goods (also called ground or base fabric).

Thread

Digitized patterns or punched tapes

Backings



Piece goods must be sewable, durable enough to withstand ahigh stitch count and able to maintain dimensional stability.

Durable ground fabrics make it possible to use a high stitchcount and more overstitching without damaging the piecegoods.

When ground fabrics are the background for designs, color andsurface texture are important factors.

Solid stitching designs depend on ground material for supportand strength.

Medium and light weight fabrics may require backing foradditional support.



Threads used for machine embroidery must be lustrous,sewable, and compatible with care procedures for the garment.

Thread breakage has a major impact on the productivity of theembroidery process.

Thread breakage on one machine head stops production on allthe other heads of the machine.



Fibre contents most used for embroidery threads are 100%rayon and 100% polyester.

Cotton threads have very limited use.

Rayon is the most used embroidery thread because of its luster,wide range of colors, and sewability.

Color fastness can be a problem in some care procedures on

garments.Polyester thread is stronger and is color fast, and improvementshave been made to provide better luster and sewability.

Thread size is an important factor in interpreting and digitizing adesign.

Fine thread requires more stitches to form a design and to fill inan area, but it is frequently regarded as better-quality execution.



Backings are used with embroidery.

Embroidery is often backed to provide support, preventdistortion, and produce more aesthetically pleasing designs.

Backings for embroidery are usually pieces of non-woven

material placed under garment components as they are hoopedfor stitching.

Backings are of varied weight and hand.

Backing is often in a place to provide support and betterappearance for stitched design, but it can also be very irritating

to the wearer.



Machine embroidery uses several basic stitchtypes that can be varied and manipulated toproduce a wide variety of effects.

A design should contain more than one type of stitch for best execution.



Steil Stitiches are small, closely aligned stitches thatfollow a tight back and forth pattern.

They are used for edges and reinforcement forscallops, finishing edges of eyelet embroidery and so

on.



Blatt stitches are wider (1/8 inch or more) with someback and forth configuration and less tension.

Often called satin stitches, they create dramatictextured effects when used in different directions.

Blatt stitches require more stitches per inch unless anunderlay is used to prevent gapping.



Running stitches form a design with one thickness of thread. They can be placed in any direction and may ormay not be covered by other stitching.

Running stitches are often used for shading and

connecting parts of design.Changing stitch direction changes the way light reflectsoff the thread and creates an interesting effect.

Many variations and combinations of these are used by

the digitizer in creating embroidered design.

sewing room in apparel industry

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