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.
- 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.
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.
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
- Basic Machine Practice
- Technical Specification
- Installation of needle
- Needle bar height adjustment
- Needle to lower looper timing
- Upper Looper Timing
- Chain looper timing (Safety Stitch)
- Upper Knife Adjustment
- Lower Knife adjustment
- Feed Dog height adjustment
- Cam Timing
- Thread Adjustment
Overlock Machines are available in the following Specifications-
|Machine type||No. of threads|
|2 T Overlock machine||1||1|
|3 T Overlock Machine||1||2|
|4 T Overlock Machine||2||2|
|5 T Overlock Machine||2||3|
|6 T Overlock Machine||3||3|
- 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.
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
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.
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.
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
- 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.
- 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
- Every rotation of the main shaft moves the needle a full cycle of up and down movements.
- 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.
Motion transfer from the main shaft to the bottom shaft
- Every one revolution of the main shaft is connected to every revolution of shuttle hook to make one unit stitch.
- 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.
- 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.
- 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.
Bottom main shaft and mechanism
- 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.
Feed dog movement from bottom shaft connection
- All these motions work together from the single motion of the main shaft and help the machine to form the stitch.
- 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
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
Bead attaching machine
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
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:
- High speed: Over 400 pearls per minute so as to increase production efficiency substantially.
- Low air consumption: Only 50% air content is consumed compared with the same product manufactured by averages so as to save electricity by 40%.
- Low defect rate: originally imported cylinder and chips ensure high quality.
- The Computer board is made of industrial chip PIC, and the performance is stable.
- The four Claw nail is equipped with a vibrating disc to control the nail’s working.
- With 5 different sizes of punching needles, with 5 different models of Mould, apply to more than five types of Pearl.
- Adopt a high-precision nail structure, reducing the number of nail clips.
- Adopt the rotating Pearl bucket, change beads more conveniently.
Brands & models
- Unix Single Head Pearl Attaching Machine
- 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:
- Thread guide – Pass the thread around the thread guide plate when threading the upper thread.
- Thread guide cover – Like treading through the thread guide plate, pass the thread around the thread guide cover when threading the upper thread.
- Spool pin – Place a spool of thread on the spool pin.
- Bobbin winding thread guide –Pass the thread around this thread guide when winding the bobbin thread.
- Top cover – Open the top cover to place the4 spool of thread on the spool pin.
- Bobbin winder – Use the bobbin winder when winding the bobbin.
- Display panel – It displays the current operations of the machine. From the display panel patterns can be selected and edited.
- Embroidery unit connector slot – Plug in the connector for the embroidery unit.
- Presser foot lever – Raise and lower the presser foot lever to raise and lower the presser foot
- Operation buttons – Use these buttons to operate the machine.
- Embroidery unit – Attach the embroidery unit to the machine, and then attach the embroidery frame.
- Thread cutter – Pass the threads through the thread cutter to cut them.
- Needle threader lever – Use the needle threader lever to thread the needle.
- Thread take-up lever check window –Look through the window to check the position of the take-up lever
Embroidery stitch type used in the dress:
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
- Brother PE800 Embroidery Machine
- Best for Patches: Brother Embroidery Machine, PE770
- Best Wireless: Elna Wireless Embroidery Machine
- 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.
Used in garment
- Cutex (TM) Brand Invisible Zipper Foot
- Singer Snap-On Feet Models
Waist Band Folder
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
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
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
The best way to carry out quality checks is by :
- Establishing a standard as a criterion for measuring quality achievement.
- Production results can be measured and compared to the planned quality standard.
- Corrective measures are to be carried out if there are any deviations in the plans.
- 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
- 100% inspection of all finished goods
- Loading supervision
- 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.
- 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.
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.
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
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.
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.
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.
The WebSPECTOR by Shelton Vision Systems and IQ-TEX 4 by Elbit Vision Systems (EVS) are two such products that can perform full inspection automatically.