Pre-Production, Production and Post-Production Process in Garment Industry

APPARELPOST-PRODUCTIONPRE-PRODUCTION

Pre-Production, Production and Post-Production Process in Garment Industry

The process of converting fabrics into garments

Garment production is an organized activity consisting of sequential processes such as laying, marking, cutting, stitching, checking, finishing, pressing, and packaging. This is a process of converting raw materials into finished products. It will be difficult to maintain the industry if production is not, up to the mark if the preproduction phase of preparation of material is not properly carried out.

Ready-to-wear apparel or garment manufacturing involves many processing steps, beginning with the idea or design concept and ending with a finished product. The apparel manufacturing process involves Product Design, Fabric Selection, and Inspection, Patternmaking, Grading, Marking, Spreading, Cutting, Bundling, Sewing, Pressing or Folding, Finishing, and Detailing, Dyeing, and Washing, QC, etc.

Apparel production, also known as garment production is the process of converting fabric into garments. The term apparel production is usually used when garments are manufactured in a factory. Traditionally, apparel manufacturing factories have been divided into two sectors: domestic and export. Based on the present apparel industry, garment manufacturing processes are categorized as:

• Pre-Production processes:?The processes that are done prior to the start of bulk garment production are known as the pre-production processes.
• Production processes:?In the production stage, the main activity is sewing.
• Post-production processes:?In the post-production stages, important activities include finishing and packing.

PRE-PRODUCTION PROCESS

Development of fabric sample, bit loom, print, and embroidery artwork :

• The fabric is developed as per the buyer’s requirement. Fabric development means sourcing customer-specific fabric with matching properties, dyed and finished for solid colors. For the solid color, lap dip approval is a very important process. Until the lap dip sample is approved merchants re-submit lap dips.
• In the case of yarn-dyed fabrics, merchants develop fabric samples with specified designs, stripes, or checks. These fabric samples are called Bit Loom. Other approvals such as print and embroidery artwork approval and color approval are done. It may be done at a later stage at the time of pre-production.

Costing of a garment (complete cost as well as manufacturing cost) :

• Merchants prepare a cost sheet with details of cost break up such as raw material cost, manufacturing cost, overheads, and margin. Costing is very a critical stage.
• Because whether a company will get an order or not depends on their cost. If the garment cost is very high then the manufacturer may lose the order and on the other hand, if the factory keeps their cost low, they will not earn profit from the order. Estimation of the garment cost should be done on a data-based.

Pattern making, correction of pattern, pattern grading

• In a factory, a pattern master prepares the first fit pattern. Then re-develop the pattern adding buyer comments and rectification on a fit sample. After fit approval, pattern master grade pattern for size set samples only for specified sizes. Once the order is ready for production they grade the pattern for the whole size range.

Fit sample, size set sample making, and approval from the buyer

• Each sample has a certain purpose. Samples are made in the sampling department and sent to the buyer for approval.
• Correction of fit samples according to buyer comments
• If the sample is not approved or further work is recommended by the buyer. Correction is done and re-submitted to the buyer.

Receiving Fabrics?

• Garment factories receive fabric from overseas textile manufacturers in large bolts with cardboard or plastic center tubes or in piles or bags.
• The fabric typically arrives in steel commercial shipping containers and is unloaded with a forklift. Garment factories often have a warehouse or dedicated area to store fabric between arrival and manufacturing.

Fabric Relaxing

• ?“Relaxing” refers to the process that allows the material to relax and contract prior to being manufactured. This step is necessary because the material is continually under tension throughout the various stages of the textile manufacturing process, including weaving, dyeing, and other finishing processes. The relaxing process allows fabrics to shrink so that further shrinkage during customer use is minimized.
• Garment manufacturers perform the relaxing process either manually or mechanically. Manual fabric relaxing typically entails loading the bolt of fabric on a spinner and manually feeding the material through a piece of equipment that relieves tension in the fabric as it is pulled through. Mechanical fabric relaxing performs this same process in an automated manner.

Assurance?

• Many garment manufacturers will also integrate quality assurance into this process to ensure that the quality of the fabric meets customer standards.
• This step is performed by manually spot-checking each bolt of fabric using a backlit surface to identify manufacturing defects such as color inconsistency or flaws in the material. Fabrics that fail to meet customer standards are returned to the textile manufacturer.

Spreading, Form Layout

Fabric spreading

After the fabric has been relaxed, it is transferred to the spreading and cutting area of the garment manufacturing facility. The fabric is first to cut into uniform plies and then spread either manually or using a computer-controlled system in preparation for the cutting process. The fabric is spread to:

1. Allow operators to identify fabric defects;
2. Control the tension and slack of the fabric during cutting; and
3. Ensure each ply is accurately aligned on top of the others.
4. The number of plies in each spread is dependent on the fabric type, spreading method, cutting equipment, and size of the garment order.

• The spreading process forms a lay by placing one or more fabric plies on top of one another for a required length.
• The length of the lay and the number of plies to be laid for a particular layer will be predetermined as per the cutting plan. It specifies the specifications of each lay type and the number of times the same specification lay has to be cut with different colored fabric plies to achieve the number of garments required in each color and size.

Automated Spreading Machine

• Spreading Equipment consists of spreading surfaces, that is, tables, spreading machines, pins, weight, bars, and fabric control devices as well as fabric cutting devices. Spreading surfaces will depend on the type of fabric, spreading equipment, cutting method, and also the firm’s quality standards. Spreading requires a flat smooth surface. For this purpose, normally a table is used.
• If the table is being used for cutting as well, (in most of the cases it is being used) then it should be leveled. The table must be constructed sturdily, to bear the weight of a spread. The width and length of the table will vary with the width of the fabric and production demands. Most often, the space available determines the dimensions of the table. Spreading surfaces need to be 10” wider than fabric width to allow the cutting knife to rest on the table.
• Spreading tables may have tracks or rails placed along one or both sides or just a few inches off the floor for the spreader to move up and down the length of the table. Spreading tables are usually covered with laminated or corkboard to provide a low level of friction. Special spreading tables may also have vacuum points that are used to compress the lay.
• Lay can be compressed up to 75%. This prevents the movement of slippery fabric and prevents the shifting of fabric during cutting. Air floatation tables allow easy movement of lay when activated.
• Spreading tables may also be connected to a conveyor that carries the fabric to the cutting table.
• A majority of the commercially available spreading tables come as modules. This allows a factory to configure the length as required. A special type of table is used for spreading checked and striped fabrics, which is called pintable.

Pintables

• Pintables consist of pins beneath the spreading table. The spreading operator can raise the pins at the points where they are required. While laying the fabric the spreading operator pins the fabric down. This allows the fabric to be spread without giving any extra allowance for block cutting. The layers can be cut as per the patterns if the marker is done as per check matching. Spreading machines are of various types. Stationary, portable, or fixed and traveling machines – manual, semi-automatic, and automatic.
• Stationary spreading remains in one position i.e. at the end of the table, while traveling machines move along the length of the table. Manual speeds are the same as operators’ speeds. They basically consist of a frame or carriage, wheels traveling on the tracks, fabric support, and guide rolls to aid correct unrolling of fabric.

Manually Operated Spreaders

• Manually operated spreaders can be as simple as a roll bar mounted on four wheels that is pushed along the table by an operator. In manual spreaders, the spreading speed can be controlled by the operator who moves the machine. The cloth is pulled carefully from the fabric roll by hand and is cut to the appropriate length.
• Mechanical devices can be provided to facilitate the unrolling and cutting operations, but the proper alignment of the fabric edges is the responsibility of the human operator. It is suitable for short lays and for frequent changes in fabrics and colors. It is often used in small businesses.

Spreading Carriage

• The cloth is unwound, and spread semi-automatically, using a manually–driven carriage. The carriage is moved back and forth over the laying-up table. A built-in mechanism takes care of aligning the fabric edges and smoothing the plies. This system is favored when long and broad and/or if the fabric is presented in large batches for relatively large orders. This method is very efficient and suitable for small businesses.

Automatic Spreaders

• These machines are therefore ideal for increasing productivity and quality.
• These machines may include various features, such as a motor to drive the carriage, a platform on which the operator rides, a ply cutting device, automatic catchers, ply counters an alignment shifter (edge guides), a turntable, and a direct drive on the fabric support and tension devices.

• Tension mechanisms ensure that the art of spreading is synchronized with the rate of fabric that is unrolled. The alignment shifters are actuated by photo–electric mechanisms since any deviation from the required alignment. In this case, they shift the roll to the correct position.
• End catchers hold the fabric at the end of the lay and overfeed device that feeds extra fabric when a fold is made. Ply cutting devices cut the fabric across the width at the end of the lay. It usually consists of a rotary knife blade mounted on rails.

Types of stitching or sewing machines, stitch machine components such as needles, feed systems, sewing machine motors, type of stitches, stitching defects, and safety measures

• Turntables permit face one-way spreading on every trip. The turntable rotates 180 degrees at the end of the spread. During deadheading, the machine may travel at a higher speed. A very highly automated spreader may be preset to a selected number of plies.
• A sound indicator alerts the user when it has reached the selected number or has come to the end of a piece of fabric. Some machines are equipped with automatic sensing of previously marked flaws and damages. As the machine comes across a flaw, the sensor will halt the spreader, the ply cutter will cut across the ply, and the spreader will reverse direction to the nearest splice mark on the marker plan and then continue its run.

Laying

• Laying of paper pattern helps one to plan the placement of the pattern pieces in a tentative manner.
• Lay large pieces first and then fit in the smaller ones
• It is very economical in laying the pattern and cutting. Even a small amount of material saved in a single layer will help to bring about a large saving of money as hundreds of layers of fabric will be laid and cut simultaneously.
• When laying, the length of the garment should be parallel to the selvedge of the material. Be sure the pattern is placed in the correct grain. Fabrics drape and fall better on the lengthwise grain and also last longer.
• Parts that have to be placed on the fold should be exactly on the edge of the fold.
• All laying should be done on the wrong side of the material.
• When laying the paper pattern, consider the design of the fabric. Care should be taken to see that the design runs in the same direction throughout the garment. All checks and strips should match the seams both lengthwise and across.

Marking

• This can be a manual or a computerized technique
• The marker planner uses full-size patterns and arranges them in an economical manner on marker paper.
• This is a specially printed paper having symbols on it that enable the marker planner to visually control the positioning of components according to specified grain lines.
• Markers produced on paper are fixed to fabric with pins, staples, or on an adhesive paper which is heat-sealed to the top layer of the fabric.
• Marker planning provides details of the spreads. In the cutting room, the fabric is laid manually or a spreading machine is used to arrange fabric inlays 100 (layers) and markers for the production, any in orders planned. Here planning is done also for fusible, linings, trims, pocketing, etc.
• The supervisors of the marker planner plan and allocate the cut orders to various operations to be carried out in the cutting room.

Fabric Cutting?

• In this stage, fabrics are layered on a table layer by layer up to a certain height. Then, using a cutting machine, the fabric is cut into garment shapes or patterns and separated from the layer.
• Cut parts are then numbered, bundled, and sent to the sewing room.
• A cutting department of a garment manufacturing unit includes the following sub-processes:?Fabric relaxation, fabric spreading and layering on a cutting table, marker making, cutting – These are of three types: manual cutting (using scissors), machine cutting, and automatic cutting, numbering of garment plies, sorting and bundling, an inspection of cut components, shorting of printing and embroidery panels, re-cutting of panels, fusing garment components.
• Cutting can help save fabric, as well as add value to the quality of a garment. The quality of the end product, (the garment) depends first, on good cutting. Secondly, the main raw material of the garment represents about 70% of the total cost of the garment.
• Cutting can either be manual or automated. Cutting depends on the skill of the operator. This equipment can be portable or stationary. Portable knives are moved through the spread while the stationery cutters require the operator to position and control fabric blocks through the blade. There are two types of portable cutting knives, mainly the vertical reciprocating?straight knife and round knife.

Straight Knife

• The Straight knife consists of a base plate with rollers for ease of movement, an upright carrying the straight blade, the power system consisting of the motor and switch, the cutting blade which can have various edges, operating handle, sharpening device, and the blade guard. These machines are also available with a blade cooling system.
• The vertical knives have an up and down cutting action. Blades vary in length from 6 to 14”. Blade length and the adjustable height of the blade guard are factors determining the spread height that can be cut. This feature must be considered in choosing a straight knife machine. The blade guard not only acts as a safety device for the operator but also holds the top plies of the fabric, thus preventing them from lifting up during cutting.
• Metal mesh gloves are also available as a safety device for the cutting operators. The cutting blade is available in various edges such as straight, serrated, and wavy-edged. The most commonly used is the straight knife. Wavy edges help to reduce heat generation and are used for cutting plastics and vinyl, whereas, saw edge type is used to cut canvas.
• This machine is most commonly used in the industry today because of its adaptability and flexibility to various kinds of fabrics and spread heights. Due to the shape of the cutting knife, it is a good choice for accurately cutting sharp corners and angles. However, it has its limitations too. It does not give very accurate cuttings along the curves due to the blade shape. The broader the width of the blade, the less accurate the cut along the curves will be. As the machine enters the spread, the base plate lifts up the plies of fabric causing a slight distortion. To overcome this, the edges of the base plate are sloped and the front is curved.
• The base plate is the foundation that supports and helps balance the cutting machine and maintains the position of the blade at 90 degrees. During cutting, it is very important that the machine is not tilted as the cutting would not be proper. The straight knife machine can make only lateral cuts into the spread and cannot be used to cut areas from the center of garment parts.

• Brands:?KS-AU, Straight Knife Cloth Cutting Machine

The Supporting Arm in straight knife

• A further advancement to the straight knife machine is the use of a supporting arm that supports the machine from above. Therefore, the heavy base plate can be replaced by a small, flat base plate which reduces distortion of plies, narrower blades, therefore, enabling cutting along sharper curves. Further, there are lesser chances of tilting the blade during cutting.

Rotary or Round Knife

• The Rotary or Round knife is a portable cutting machine. It consists of a round blade, a motor above it, and a handle to direct the machine.
• The knife rotates in the anticlockwise direction. It cuts the fabric with one-way thrust, as compared to the up and down motion of the straight knife. The cutting capacity or spread height depends on the blade diameter, motor power, and speed.

• Brands:?Usha Round Knife Cloth Cutting Machine,??DE-TECH Round Knife Cutting Machine

End Cutters

End cutters are a special type of round knife machine. A small-diameter round knife is placed on a rail or track with a pushing arm. This ensures an accurate straight cut. End cutters are used to cut the end of the fabric after each spread while spreading.

Notchers

• Garment parts require notches in order to align them accurately during sewing and assembly. Operator-controlled cutters can be used for this purpose; however, accuracy depends on the skill of the operator.
• It is also necessary that the layer must be absolutely vertical, otherwise, some pieces will be marked too deep while others may not be marked at all. Special notching machines such as straight notchers and vee notchers are available for this purpose. Hot notchers have a heating element that fuses the fibers adjacent to the notch in order to prevent fraying and the disappearance of the notch. It is a good choice with natural and knit fabrics, however, it cannot be used for thermoplastic fibers. It may also be available with adjustable heat control.
• Brands: Eastman’s Hot Notcher, ZXUY 1x pattern notched

Drills

• When markings have to be made inside garment parts, for example, marking the position of pockets, appliqués, darts, etc., drills are used. This machine consists of a motor that rotates the needle, a base plate, and a long needle. The needle penetrates completely at the specified point creating a hole or just shifting yarns.
• Certain drill machines are also equipped with a hollow needle that carries marking fluid that leaves a mark on the fabric plies. It is important that the marks remain till the particular sewing operation. Drills are problematic to use on loosely woven thick textured fabrics. Marking can also be done using thread markers which carry the thread through the entire spread and then individual threads are cut. It may also be done manually, on every ply using a template, but it is time-consuming.

• Brands:?Eastman Drill machine

Embroidery

• Embroidery: processes that occur only if directly specified by the customer; therefore, these processes are commonly subcontracted to off-site facilities. Embroidery is performed using automated equipment, often with many machines concurrently embroidering the same pattern on multiple garments. Each production line may include between 10 and 20 embroidery stations. Customers may request embroidery to put logos or other embellishments on garments.
• Brands:?SWF MAS-12 12-Needle Embroidery Machine,??Brother Model PR 1000 Computerized Embroidery Machine

Fusing Machines

• Fusing and interlining are needed for the manufacturer to:

1. Maintain consistent quality against hand operations.
2. Save time and labor.
3. Enable easy handling of small components.
4. Reduce differential shrinkage between top cloth and interlining to controllable levels.

• Stitch, pucker and distort sewn products.

1. Create garments with a cleaner and fresher appearance.
2. Increase durability of garments.
3. Modify slightly by interlining the handle of the cloth.
4. Retain the garment’s original shape after repeated dry cleaning and washing.
5. Reduce crease recovery time.

• Brands: Rudolf Sewing Systems – Industrial Fusing Machine, Electric Fusing Machine, Bharath Fussing – Automatic Fusing Machine

Interlinings

• Interlinings are additional pieces of fabric applied to particular garment sections, that may require further support.
• However, interlinings can also serve many other purposes, including to:

1. Stabilize garment sections.
2. Reinforce sections that may be weakened by subsequent operations.
3. Maintain the shape of parts such as collars and lapels.
4. Prevent seam impressions.
5. Stiffen the garment or fabric.
6. Strengthen the garment or fabric.
7. Mask the transparency of fabric with sheer characteristics.
8. Provide additional warmth, for example, quilting.

Garment production is an organized activity consisting of sequential processes such as laying, marking, cutting, stitching, checking, finishing, pressing, and packaging. This is a process of converting raw materials into finished products. It will be difficult to maintain the industry if production is not, up to the mark if the preproduction phase of preparation of material is not properly carried out.

Ready-to-wear apparel or garment manufacturing involves many processing steps, beginning with the idea or design concept and ending with a finished product. The apparel manufacturing process involves Product Design, Fabric Selection, and Inspection, Patternmaking, Grading, Marking, Spreading, Cutting, Bundling, Sewing, Pressing or Folding, Finishing, and Detailing, Dyeing, and Washing, QC, etc.

PRODUCTION

Sewing

• ?Stitching or sewing is done after the cut pieces are bundled according to size, color, and quantities determined by the sewing room.
• Sewing Garments are sewn in an assembly line, with the garment becoming complete as it progresses down the sewing line. Sewing machine operators receive a bundle of cut fabric and repeatedly sew the same portion of the garment, passing that completed portion to the next operator. For example, the first operator may sew the collar to the body of the garment and the next operator may sew a sleeve to the body. Quality assurance is performed at the end of the sewing line to ensure that the garment has been properly assembled and that no manufacturing defects exist. When needed, the garment will be reworked or mended at designated sewing stations. This labor-intensive process progressively transforms pieces of fabric into designer garments.
• The central process in the manufacture of clothing is the joining together of components.
• Stitching is done as per the specification is given by the buyer.
• High power single needle or computerized sewing machines are used to complete the sewing operation.

Dressmaking Machines

Stitching machines (assembling machine) – for stitching dress components different types of sewing machines are used. For example, single needle lock stitch machine, overlock, double need lock stitch machines, etc.

Sewing Machine parts

• Handwheel: Turn this wheel to adjust needle height. Always turn the handwheel toward you.
• Spool pin: The spool pin keeps the spool in place while the thread feeds through the machine. Some machines have both horizontal and vertical spool pins.
• Spool cap: The spool cap slips onto the end of the spool pin and holds the spool in place.
• Bobbin pin/winder: Built-in bobbin winders may be found on the top, front, or side of a sewing machine. Most winders consist of a bobbin pin to hold the bobbin while the thread is being wound, thread guides for maintaining tension, and a start/stop lever. Some bobbin winders have built-in thread cutters.
• Thread guide: Thread guides may be hoops, discs, or flat metal shapes that pinch or direct the thread to feed it through the machine without tangling and at the correct tension. metal finger with a thread guide that moves up and down, pulling the thread from the spool and feeding it through the machine.

• Take-up lever: The take-up lever is a metal finger with a thread guide that moves up and down, pulling the thread from the spool and feeding it through the machine.
• Stitch selector: Use the stitch selector to choose which stitch you’d like to use. Many machines feature a number of built-in stitches: straight stitch, zigzag, buttonhole, blind hem, etc.

• Presser foot: The presser foot works with the feed dog to move fabric evenly through the machine. When the presser foot is lowered, it engages the tension discs and presses the fabric beneath the foot against the feed dog. The upper part of the foot, called the ankle, is usually screwed onto the machine securely; the lower part may include a quick-release mechanism for changing presser feet.
• Foot pressure control: This control adjusts the amount of pressure the presser foot applies to fabric as it feeds beneath the needle. Increase pressure when sewing heavy fabric and decrease pressure when sewing lightweight or thin fabric.

• Presser foot lifter: This lever, located above the presser foot at the back or side of the machine, raises and lowers the presser foot. When the presser foot is lifted, the tension discs are disengaged, and the fabric will not feed through the machine.
• Needle: The needle carries the upper thread through the fabric to create a stitch. Specialty needles are available for specific stitching needs.
• Needle threader: Some machines have built-in needle threaders. Threaders have a tiny hook that swings through the needle eye catches the thread, and pulls it back through the eye when the threader is released.
• Thread cutter: Some machines have a built-in thread cutter near the needle area. To use the cutter, raise the presser foot and remove the stitched piece from the machine. Pull both the threads over the cutter’s shielded blade to cut them.
• Needle clamp screw: Tighten and loosen this screw to release or secure the needle in place.

• Stitch plate: The stitch plate, also called a needle or throat plate is a flat metal piece below the presser foot. Slots in the plate allow the feed dog to push the fabric along. A hole or slot admits the needle carrying the top thread through the fabric.
• Feed dog: The feed dog is a toothed metal piece below the stitch plate that moves up and down to push the fabric along, beneath the needle. Stitch length is controlled by how much fabric the feed dog moves.

• Throat: The throat of a machine refers to the open space between the needle and the machine housing. A large throat is helpful when sewing bulky fabrics and large projects like quilts.
• Bobbin cover: The bobbin cover is a plate or hinged door that protects the bobbin mechanism. Open the bobbin cover to replace the bobbin and clean the bobbin area or case.
• Foot control: Like the gas pedal in a car, the foot control regulates the machine’s speed.

Overlock machine

An overlock / over edge machine is a high-speed sewing machine. This is the quickest performing machine for giving over edge stitches.

Technical adjustments of OVERLOCK machine

1. Basic Machine Practice
2. Technical Specification
3. Installation of needle
4. Needle bar height adjustment
5. Needle to lower looper timing
6. Upper Looper Timing
7. Chain looper timing (Safety Stitch)
8. Upper Knife Adjustment
9. Lower Knife adjustment
10. Feed Dog height adjustment
11. Cam Timing
12. Thread Adjustment

Overlock Machines are available in the following Specifications-

Machine typeNo. of threads2 T Overlock machine113 T Overlock Machine124 T Overlock Machine225 T Overlock Machine236 T Overlock Machine33

Brands

• Janome CoverPro 1000CPX Coverstitch Machine.
• SINGER 14T968DC Professional 5-4-3-2 Thread Overlock with Auto Tension.
• Brother 1034D Overlock Home Lock.
• SINGER 14CG754 ProFinish Overlock Machine.
• Brother 2340CV Cover Stitch Overlock Machine.

Overlocking application in garments

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Single needle lockstitch machine

These kinds of sewing machines are generally used for sewing fabric, leather, etc. particularly one that uses two threads such as an upper and a lower thread. One side of the needle has the eye and a sharp tip while the other side is attached to a needle bar that moves up and down to form a stitch. The arm also secures a presser foot which presses the fabric while sewing. The needle penetrates into the fabric from the top, to bring the needle thread through the fabric to the bottom to form a stitch.

Single needle lock stitch machine (SNLS):

The Single Needle Lock Stitch Machine is the most popular and versatile sewing machine in the industry. It is designed to produce consistent results in sample and production rooms. The Lockstitch forms precise and secured straight stitches on the top and the underside of the fabric as the needle thread and the bobbin thread lock.

Technical adjustments of SNLS machine

• Basic Machine Practice (Loop Exercise)
• Technical Specification
• Installation of needle
• Needle bar height adjustment
• Hook Set Timing
• Feed Dog adjustment and alignment
• Feed Dog Eccentric cam Adjustment
• Pressure foot to the Pressure adjustment

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Working

The needle thread in a spool is threaded through the thread guides, tensioning mechanism, and into the sewing needle eye. The bottom thread (bobbin thread) is wound onto the small package called a bobbin before sewing and is secured inside a bobbin case. For stitch formation, the needle brings the needle thread loop to the bottom of the fabric where a small hook on the bobbin case catches it. As the bobbin hook rotates, it takes the needle thread around the bobbin to produce a stitch and then the take-up lever takes back the extra loop of top thread to tighten the stitch. As the needle is out of the action of fabric, the feed dog comes above the throat plate and pushes or moves the fabric up against the presser foot for the next stitch.

Stitch Formation Sequence in Lock Stitch Machine

The first stage in making a stitch is the formation of a loop from the needle thread. If the needle thread loops are not formed properly, then it leads to several stitching problems like skipped stitches, breakage of sewing thread, loose stitches, etc.

Loop formation

Proper loop formation of the needle thread depends on the propensity of the needle thread to bulge away from the needle due to inertia and friction against the fabric as it is pulled in an upward direction subsequent to reaching the lowest point of its stroke. This is normally called ‘flagging’ and in this situation, either no needle loop is formed at all or it is formed too late leading to skipped or broken stitches.

Fabric flagging:

The second stage is receiving the top needle thread to go around the bobbin. This is accomplished using a bobbin hook coming across at the precise time and catching the top needle thread and drawing it around the bobbin.

Stitch formation in Single needle lock stitch machine

• Step 1: After the sewing needle reached its lowest position, it starts to rise which causes the needle thread to bulge away from the needle to form a loop
• Step 2: The needle thread loop is then picked up by the point of the bobbin hook.
• Step 3: As the needle keeps rising and the hook progresses in its rotation, the take-up lever provides extra needle thread so that it can be drawn down through the fabric to increase the size of the loop.
• Step 4: On the first rotation of the sewing hook, it carries the needle thread around the bobbin case, the inside of the loop sliding over the face of the bobbin case while the outside passes around the back, to encompass the bobbin thread. As the take-up lever starts to rise, the needle thread loop is drawn up through the ‘cast-off’ opening of the bobbin hook before the revolution is complete.
• Step 5: During the second revolution of the bobbin hook, the take-up lever completes its upward stroke, pulling the slack needle thread through the fabric to set the stitch. In the meantime, the feed dog moved the fabric along with it against the presser foot drawing the required length of under thread from the bobbin.

Working principle of Single needle lockstitch sewing machine

1. The single needle lockstitch sewing machine is getting driven from the electric motor which is mounted in the sewing table. The main parts of the sewing machine are flywheel, eccentric or cam, needle bar, bobbin holder, feed dog, and presser foot.
2. The flywheel is driven by a motor belt and it drives the sewing machine’s main shaft. Another end of the main shaft is connected with eccentric or cam, which drives the needle bar’s up and down movements for every revolution and take-up lever.

Needle bar and Pressure foot mechanism

1. Every rotation of the main shaft moves the needle a full cycle of up and down movements.
2. The main shaft is further connected with a bevel gear and two connecting rods to transfer the motion to the bottom of the machine. The bevel gear rod is used to transfer the motion to the bottom center shaft, which is the main shaft for connecting the bobbin shuttle mechanism. This connection helps the bobbin shuttle to move. The bevel gear mechanism helps to transfer the motion without any energy loss.
3. Motion transfer from the main shaft to the bottom shaft
4. Every one revolution of the main shaft is connected to every revolution of shuttle hook to make one unit stitch.
5. The other two connecting rods from the main shaft are used to connect with the feed dog, which has a synchronized movement with needle and bobbin shuttle mechanism.
6. The feed dog has to perform four-stop motions for every cycle of stitch formation. The feed dog gets driven from the main shaft in two ways, one is rotation – to deliver the unit length of the fabric for sewing and another motion is the up and down movements above the throat plate of the sewing machine.
7. Rod 1 helps the feed dog to move up and down for the selected distance based on the settings kept. Rod 2 is used to move the feed dog to and fro as required.
8. Bottom main shaft and mechanism
9. Whenever the stitch regulator is adjusted, the feed dog delivers the required amount of fabric needed by adjusting the feed bracket. The revolution per minute of the feed dog is the same as the needle stroke.
10. Feed dog movement from bottom shaft connection
11. All these motions work together from the single motion of the main shaft and help the machine to form the stitch.
12. Brands:

• Jack Single Needle Lock Stitch Machine 6380BCQ, Max Sewing Speed: 2000-3000 (stitch/min)
• CC-540D-01A Small Pattern Sewing Machine
• Juki Single Needle Sewing Machine, For Light Material, Automation Grade: Semi-Automatic
• Gemsy Plastic Single Needle Lock Stitch Sewing Machine

Use in the garment

Manual sewing of collar making process

The most basic one is manual sewing wherein one mandarin collar ply (shell fabric) is sewn over the other ply (fused fabric) with a Single Needle Lock Stitch machine and the edges are cut with a vertical edge trimming attachment.

The trimming can be done simultaneously or cut separately. This technology is mostly used in medium-sized factories as it requires very little investment in machines. It also justifies the order quantity. It is very suitable for lighter fabrics or sensitive fabrics as stitching collars out of them will depend on the skill of the operator. The time taken is much more and there is a lack of consistency in the quality of the stitch, making it more susceptible to defects.

Making collar using Auto Jig and Template

The next level of sewing collar is the use of jig which is a template having slots through which the sewing will follow automatically on feeding it to the sewing needle, thus eliminating the need for a human hand in the process. With this, there is a consistent stitch throughout the bulk which makes it suitable for a large number of orders. Only dimensionally stable fabrics can be used as no human hand will be there for adjustments with stretch in the fabric. Jig templates are not suitable when the order quantity is low as it will require the making of the templates for each and every order.

Collar run stitch using multiple jigs

The third level is the use of multiple jigs or the large area jig template sewing. Here the template remains constant and the sewing machine moves according to the jig slot. Since the machine moves along the jig, more than one number of machines can be synchronized to move if placed next to each other. It is an upgrade from the single jig and again it is most efficient with huge order quantities. The advantages and disadvantages are the same as above but the productivity is much higher than the above. It is expensive as a different setup is required thus making it inaccessible for medium-sized factories.

Full automatic collar run stitch machine

Finally, the most advanced method is complete automation in collar sewing. There will be a set of machines that will be responsible for the complete sewing of the collar and everything will be automatic. The setups are also able to change stitch length at the corners to make the seam stronger. The jig sizes are adjusted automatically which effectively reduces the frequency and cost of changing the jig. Not many factories are seen using this method but it has a huge potential for contributing to Industry

The use of jig templates and automation is not being preferred with the decrease in the order number and fabric limitations, thus making manual sewing more common and efficient in present industries.

Brands & models: UAM 03 Collar and Cuff Sewing Machine

Automatic pocket setting machine

Application of automatic pocket setting machine: Automatic shirt pocket attaching on the chest

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The machine automatizes a series of pocket setting processes such as the folding of a pocket, placement of the pocket on a garment body, sewing, bar-tacking, and stacking, thereby increasing productivity and achieving production without requiring the operator to have any special skill. This promises consistent finished quality.

With the need for production improvement and reduction of labor requirement in garment stitching semi-automated and fully automated machines are developed. These automatic machines are currently used for making garment parts. Pockets are common components in a dress. The pocket setting and attaching in the dress panel are done automatically. The whole garment-making machine (automatically) is not yet developed.

Pocket attaching operations involved the following process

• Pocket edge folding with a template,
• Pressing the fold by iron
• Position pocket on the back panel
• Attach the packet in the back panel by stitching

By using an automatic pocket setter, manufacturers get better quality products, consistency in design and quality, and higher production. Many of the industrial sewing machine brands have developed auto pocket setters.

Brands & models:

• Duorkopp adler Model: Duorkopp adler 805
• PFAFF 3588 Programmable automatic pocket setter
• Richpeace Twin Heads Automatic Sewing Machine
• Juki -AP 875S
• Brother auto pocket setter. Model: BAS 760

Application of pocket setting

Bead attaching machine

Bead attaching machine helps to attach buttons or embellishments on the front pocket

Bead Stringing Machine/Nail Bead Attaching Machine/ Pearl Rivet Fixing Machine

A case study on Men's shirt manufacturing in a Garment factory in Bangladesh

Introduction :

The multi-function pearl and nail riveting machine through the four claw nails make pearls immediately fixed into the material. At the same time move the material accordingly by hand after the red light locate, then the machine will fix pearls on the material quickly.

The function of Bead Stringing Machine/Nail Bead Attaching Machine/ Pearl Rivet Fixing Machine:

Uses: Can be used for women’s clothes, underwear, children’s wear, T-shirts, embroidery patterns, belts, handbags, gloves, scarves, hats, etc.

Material can be Denim, Cotton, Jeans, Hemp fabric, Woolen, Synthetic Fiber, Silk, Knitwear, Synthetic Leather, Velvet, and so on.

Features of Bead Stringing Machine/Nail Bead Attaching Machine/ Pearl Rivet Fixing Machine:

1. High speed: Over 400 pearls per minute so as to increase production efficiency substantially.
2. Low air consumption: Only 50% air content is consumed compared with the same product manufactured by averages so as to save electricity by 40%.
3. Low defect rate: originally imported cylinder and chips ensure high quality.
4. The Computer board is made of industrial chip PIC, and the performance is stable.
5. The four Claw nail is equipped with a vibrating disc to control the nail’s working.
6. With 5 different sizes of punching needles, with 5 different models of Mould, apply to more than five types of Pearl.
7. Adopt a high-precision nail structure, reducing the number of nail clips.
8. Adopt the rotating Pearl bucket, change beads more conveniently.

Brands & models

1. Unix Single Head Pearl Attaching Machine
2. Unix Double Head Pearl Attaching Machine

Used in a garment

Embroidery stitching machines – The embroidery logo can be made by using an embroidery stitching machine.

Parts of embroidery sewing machine:

1. Thread guide – Pass the thread around the thread guide plate when threading the upper thread.
2. Thread guide cover – Like treading through the thread guide plate, pass the thread around the thread guide cover when threading the upper thread.
3. Spool pin – Place a spool of thread on the spool pin.
4. Bobbin winding thread guide –Pass the thread around this thread guide when winding the bobbin thread.
5. Top cover – Open the top cover to place the4 spool of thread on the spool pin.
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7. Bobbin winder – Use the bobbin winder when winding the bobbin.
8. Display panel – It displays the current operations of the machine. From the display panel patterns can be selected and edited.
9. Embroidery unit connector slot – Plug in the connector for the embroidery unit.
10. Presser foot lever – Raise and lower the presser foot lever to raise and lower the presser foot
11. Operation buttons – Use these buttons to operate the machine.
12. Embroidery unit – Attach the embroidery unit to the machine, and then attach the embroidery frame.

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1. Thread cutter – Pass the threads through the thread cutter to cut them.
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3. Needle threader lever – Use the needle threader lever to thread the needle.
4. Thread take-up lever check window –Look through the window to check the position of the take-up lever

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Embroidery stitch type used in the dress:

Running Stitch:

Uses: outlining, straight and curved lines.

• Work from right to left.
• Bring the thread up at 1 then down at 2, up at 3, and down at 4, and continue.
• The spaces between the stitches can be the same length as the stitches or shorter for a different look.

Brands & models

1. Brother PE800 Embroidery Machine
2. Best for Patches: Brother Embroidery Machine, PE770
3. Best Wireless: Elna Wireless Embroidery Machine
4. Best Splurge: Janome Memory Craft 400E

Folders and footers used in the dressmaking

Zipper footer: zipper foot allows you to sew zippers with your sewing machine. A zipper foot is able to adjust, so it is on the left or the right side of the sewing machine needle. This adjustment allows you to sew the zipper without the presser foot, applying pressure to the zipper teeth, which will not move when caught in the feed dogs because of pressure from a presser foot.

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Used in garment

Brands

1. Cutex (TM) Brand Invisible Zipper Foot
2. Singer Snap-On Feet Models

Waist Band Folder

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It is used for attaching waistband by using a double-needle lockstitch machine. It binds the seam on the waistband.

Used in garment

Bias Binding Folder

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It is used to cover the raw edge by using a single needle lock stitch machine. Here stripe of fabric inserted on the folder. It binds the fabric edge evenly. Output piece seam line diagram is shown in the image.

Used in a garment

Back Yoke attaches folder

• Purpose: Single needle topstitch attaches the yoke to the back of the dress.
• Suitable machine application: Single needle lockstitch machine.

Use in the garment

Hemming Folder

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It is excellent for continuous hemming on automatic sewing operations. It’s suitable for double-needle lockstitch machines. Used to make narrow hems, prior to ruffling, curtains, and other straight hemming operations.

Uses in garment

Checking :

The best way to carry out quality checks is by :

1. Establishing a standard as a criterion for measuring quality achievement.
2. Production results can be measured and compared to the planned quality standard.
3. Corrective measures are to be carried out if there are any deviations in the plans.
4. Ideally, any system should detect possible deviations before they occur through forecasting. Work produced with minus defects will produce quality products, enhance economy and productivity.

Garment Inline Inspection

A sampling of both semi-finished and finished products to assure the quality of the entire production batch works with the factory on developing and implementing corrective action plans based on inspection findings provides housekeeping, social compliance, and safety visual checks.

Before delivery: Final random inspection

1. 100% inspection of all finished goods
2. Loading supervision
3. Dress quality by identifying varying levels of defects in your products, including

• Critical Defects – hazardous or unsafe conditions or non-compliance with regulations, includes sharp points or edges, stray needles left in the garment, loose studs or missing suffocation warning labels
• Major Defects – overall product failure or reduced usability of the product that prevents it from being placed on the market, can include open seams, holes or broken stitches
• Minor Defects – unlikely to reduce product usability, includes items such as loose threads

During textile and apparel inspections, conducts the following

• Fabric Check – assesses weight (sweaters), print quality, defects, hand feel to standards
• Garment Labeling – to ensure label contains all required information, including registered identification number (RN), country of origin, fabric content/care and attachment of label in the proper location
• Workmanship Assessment – evaluates stitching, construction, attachments and fasteners, embellishments, shading within a garment, pattern continuity/matching, tapes and linings
• The textile and apparel inspection procedure also ensures that fabric width, fabric length and fabric appearance (weaving quality, splices, odors) comply with the relevant standards and regulations during the production process.
• Prior to shipping, apparel inspectors review the packaging list to ensure it includes overall carton count and carton numbers, carton dimension and weight, shipping label, style or shade identification and corresponding counts in the carton and packing slip.
• Once the carton is packed, the carton is packed as specified, appropriate carton dimensions are displayed, poly bags are checked, hangtags are included to confirm SKU/price, barcodes are included and the garment shade identification is correct.

Inspection technologies and machines

• Basic level of technology: Manual Fabric Inspection
• Introduction: At the very basic level one can visually inspect fabric on Horizontal or Slanting Inspection tables illuminated from the top and bottom.
• Advantage: In this very simple entry-level machine, which is usually low-cost.
• Working: A fabric inspector pulls the fabric over the lighted inspection table and the defects are located, marked, and recorded on an inspection form manually. For the easy flow of fabric, a top fabric guide roll is provided, with the option of adding an edge guide and a meter counter.
• The rolls of fabric are mounted behind the inspection table under adequate light and re-rolled as they leave the table, the mechanical length counter measures the length of fabric inspected. Usually, a tray is provided to keep the loose fabric for inspection. In the mechanically driven version, the fabric movement is generally from the bottom to the top, while it is reversed in the case of manually driven ones with the standard width of the fabric to be inspected varying between 60 to 75 inches.
• Brand: The Checkmate by Paramount and Table Type Fabric Inspection machine by Konsan are some of the best options available.
• Intermediate level of technology: Mechanical/Semi-automatic fabric Inspection
• Introduction: The intermediate level of fabric inspection machines are power-driven with variable frequency drive inverter for precise speed control and proximity sensors to control the uniformity of edges, with an auto-stop option. The machine speed can vary between 12 meters/minute to 60 meters/minute and some models have the provision for the option to inspect delicate fabrics at zero tension to avoid damage to the structure of the fabric.
• Advantage: of semi-automatic inspection machines is the electronic wheel type encoder provided to measure the length of the inspected fabric as well as monitor the width of the fabric. While the length measurement is helpful in defining the number and length of lays, even the width of the fabric maximizes fabric utilization.
• This is the most widely used technology for fabric inspection and helps in achieving better and faster inspection, the results are still dependent on the roving inspector’s skill and expertise.
• Working: The mechanism is such that the fabric runs smoothly through the roller systems (with tensioning adjustments) and then under a meter counter, onto a holding pipe. Fabric speed on inspection machine must not be more than 15 yards per minute, that being the ideal speed at which an operator can comfortably detect faults.
• The two-way lighting provision, at the top and bottom, and safety sensors and emergency stop function support better control over the fabric inspection. The machine comes fitted with a meter counter to keep a check on the quantity of fabric being inspected as well as a fabric holding tray to ease out the fabric handling.
• Brands
• RF 101 E by Ramsons and check MASTERIITM by Paramount are some of the best examples available in this category.
• 101 E from Ramsons is a Semi-Automatic Fabric Inspection System and is most widely used in the industry

Software add-ons for defect documentation

To document defect patterns for analysis and decision making, ‘fabric inspection defect analysis software’ (FIDAS) is available in the market which can be installed on every fabric inspection machine of any brand and make.

It is used for defect entry through a touch screen monitor and performs automatic fabric gradation based on a number of defects, providing aid in choosing appropriate fabric roll with fewer defects and can be easily integrated with all the existing CAD and ERP software in the unit to obtain efficient marker and cutting plan. The software works on the 4-point system for fabric inspection as per ASTM standards, the most commonly used system for inspection.

Advantage

Some of the advantages of using the software are increased production rate due to faster process, reduced dependency on manpower, achieving process transparency between interrelated departments, and increased profits through improved fabric realization.

Brands

Some of the service providers who are selling this software in India are Almac Group, Gayatri Engineers, and Amith Garment Services; they also manufacture and provide fabric inspection machines.

Advanced level of technology: Automated Visual Inspection

Introduction

The textile industry worldwide has experienced dramatic technological changes during the last decade.

An automated visual inspection system is an example of such advancement in the fabric inspection process.

Advantage

The most important change is to switch over from dependency on the human eye to scan by CMOS/CCD camera. The process is such that the location, size, and image of the defects are recorded in the system. After the inspection, the product is graded in terms of severity and the detailed report gets printed. The aim is to obtain savings of manpower and time, as well as increased accuracy in the inspection process.

Working

At the first level of processing, the image of the fabric is transformed into a threshold image which is a digital image in grey shades, this helps the software to read and differentiate between the image of the defect and the fabric. Post the conversion, the software marks the region with defects in the form of a window and the location of each defect is stored in the data.

The defect window is further probed at the secondary level of image processing based on five attributes, namely, height and width of the defect window; the ratio of total defect area to the overall window area; the total number of defects in the overall defects window, and finally the ratio of the smallest defect area over the largest defect area.

Based on the above-mentioned attributes, data regarding each defect is generated, which helps in the recognition and classification of defects based on standard inspecting systems such as the 4-point system. The system utilizes high-resolution color line scan technology and enhanced Defect Sorting Algorithms (DSA) to achieve defect detection and interpretation.

Garment production is an organized activity consisting of sequential processes such as laying, marking, cutting, stitching, checking, finishing, pressing, and packaging. This is a process of converting raw materials into finished products. It will be difficult to maintain the industry if production is not, up to the mark if the preproduction phase of preparation of material is not properly carried out.

Ready-to-wear apparel or garment manufacturing involves many processing steps, beginning with the idea or design concept and ending with a finished product. The apparel manufacturing process involves Product Design, Fabric Selection, and Inspection, Patternmaking, Grading, Marking, Spreading, Cutting, Bundling, Sewing, Pressing or Folding, Finishing, and Detailing, Dyeing, and Washing, QC, etc.

POST-PRODUCTION PROCESS

Spot Cleaning and Laundry

Spot cleaning and laundry addition to identifying manufacturing defects, employees tasked with performing quality assurance are also looking for cosmetic flaws, stains, or other spots on the garment that may have occurred during the cutting and sewing processes. Spots are often marked with a sticker and taken to a spot-cleaning area where the garment is cleaned using steam, hot water, or chemical stain removers.

• Some customers request that a garment be fully laundered after it is sewn and assembled; therefore, garment factories often have on-site laundry or have subcontract agreements with off-site laundry operations. Commercial laundry facilities are equipped with at least three types of machines: washers, spinners, and dryers. Some facilities also have the capability to perform special treatments, such as stone- or acid-washing.
• Laundering is done by highly sophisticated washing machines if any articles are soiled during the manufacturing process. However, this step is required only if the garments are soiled.

Pressing

• Pressing is two processes that have the greatest influence on the finished look of a garment. Fusing creates the foundation and pressing put the final seal of quality on the garment.
• Ironing After a garment is fully sewn and assembled, it is transferred to the ironing section of the facility for final pressing. Each ironing station consists of an iron and an ironing platform. The irons are similar looking to residential models but have steam supplied by an on-site boiler. Workers control the steam with foot pedals and the steam is delivered via overhead hoses directly to the iron. In most facilities, the ironing platforms are equipped with a ventilation system that draws steam through the ironing table and exhausts it outside the factory.

The basic components of pressing are

• Steam and heat are necessary to relax the fabric and make it pliable enough to be molded by manipulation.
• Pressure: when the cloth has been relaxed by steam, the pressure is applied which sets the fibers into their new positions.
• Drying: After the application of steam and pressure, the component or garment must be dried and cooled so that the cloth can revert to its normal condition. This is done by a vacuum action which removes surplus water from the fabric and at the same time cools it. For some pressure operations hot air or infrared heating is used instead of vacuum for drying;

Machinery used for pressing and finishing are

Hand irons with a vacuum press table

A vacuum board is a professional ironing table that has a heated pressing surface and a motor. Stepping on the pedal activates the motor, which creates a vacuum on the pressing surface to remove moisture from the garment.

Scissors press

It consists of a frame housing the buck which is normally in round shape for pressing different garments and linkages to close the head by a scissor action. Similar operations are carried out for completing the pressing of the garment and then the garment is hung on the hanger.

Steam dolly

This equipment is known as a firm press or a ‘dolly’ press. It has a compressed air system, a frame for a steam distribution system, and a pressing form made of a canvas bag in the suitable silhouette of the garment to be pressed.

Finishing

Finishing is the last step of garment production. All mistakes made during the process accrue and can become a huge problem at this stage. The Quality Department also has a huge potential to improve products, and thus requires special attention. In almost every factory surveyed, it has been proven that the costs involved in this department are excessive. It is vital that this department is given importance since there is a great potential to make financial savings. The material here illustrates the priorities of the finishing and quality departments.

• Surveys have shown that the time taken to finish garments is surprisingly high. Some companies examine the garment as many as 5 times, and the number of repairs is excessive. Further,
• Finishing departments are over-staffed in most of the factories studied. This is obviously driven by the fear of rejection of orders or re-works. Work content can be reduced by installing a proper work control system and a culture for quality production.
• Surveys have shown that the layout and workflow in garment factories were generally poor and disorganized. Not one of the finishing departments has adequate systems of control. Rather, the emphasis is only directed to delivery and not productivity. This is understandable in the present circumstances, but must be re-thought since it is excessively expensive.
• Studies have found, that finishing times are excessive in almost every company; with the average finishing time per garment varying from 11.2 minutes to 57.6 minutes. It has also been found that none of the finishing departments use bundle systems for control, nor do any of them have any form of scientific performance measuring techniques. There are no monitoring controls except to record the number of repairs.

Packaging and Shipping

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• It is the last step of making a product retail-ready, garments are folded, tagged, sized, and packaged according to customer specifications. Also, garments may be placed in protective plastic bags, either manually or using an automated system, to ensure that the material stays clean and pressed during shipping. Lastly, garments are placed in cardboard boxes and shipped to client distribution centers to eventually be sold in retail stores.
• Most garments are packed in plastic bags, either at the end of production or when they enter the finished goods store. Products like shirts and underwear are usually bagged and boxed directly after final inspection and enter the stores in prepacked form. For these and similar types of products, many automatic machines are used.
• Other hanging garments such as Jackets, dresses & skirts are usually bagged by manual machines, semi-automatic machines, and fully automatic machines. Some of these automatic machines bag, seal, and transport in trolly; some 500 garments per hour.
• When the boxed or hanging garment has to be transported in bulk the garment or boxes are packed into cartons which can be sealed by adhesive paper or plastic Manual and automatic machines are available for both.