Manufacturing Process of Cut and Sew Knitwear
BGMEA University of Fashion Technology
Knitting is a method by which thread or yarn may be turned into cloth. Knitting consists of consecutive loops, called stitches. As each row progresses, a new loop is pulled through an existing loop. The active stitches are held on a needle until another loop can be passed through them. Basically there are two types of knitting which are weft knitting, versus wrap knitting and another type is flat knitting versus circular knitting.
Types of knitted Fabrics
There are various types of knitted fabrics and each type has different appearance and characteristics. The construction of a knitted fabric depends upon the type being constructed. A knitted fabric that has more wales will be rigid and stable in width while a fabric that has more courses will be rigid and stable in length. A fabric having many Wales and courses per square inch will have better recovery from stretching than a fabric having lesser wales and courses. Such fabric that will have fewer wales and courses will be less rigid, stretch more easily, fit to body shape in a better way but will have poorer recovery ability. All the knitted fabrics are classified into two general categories:
- Weft knit fabric, where one continuous yarn forms courses across the fabric.
- Warp knit fabric, where a series of yarns form wales in the lengthwise direction of the fabric.
There are three basic stitches in weft knitting
- Plain-knit stitch
- Purl stitch
- Rib stitch
Any other stitch is a variation of these three stitches. Hand knitting is basically weft knitting. When done on weft knitting machines, individual yarn is fed to a single or multiple needles at a time.
Plain-knit stitch :
Plain knit, the basic form of knitting can be produced in flat knit or in tubular (or circular) form. It is also called jersey stitch or balbriggan stitch. A row of latch or beard needles is arranged in a linear position on a needle plate or in a circular position on a cylinder. The side by side evenly spaced needles are moved by cams, which act on the needle butts. The spacing of the needles is called guage, gage or cut which refers to the number of needles in one and a half inches, for example, a 60 guage machine will have 40 needles per inch. The needles inter mesh loops drawn to one side of the fabric, forming vertical herringbone like ribs or wales on the right side or technical face of the fabric. On the reverse side or the technical back, courses are visible as interlocking rows of opposed half circles. These fabrics have the tendency of curling up at the edges which is controlled to a level through certain finishes.
Plain knit allows the use of single or plied yarns produces comparatively lightweight fabrics than produced by other stiches. The production rate is higher, about 5 times more than weaving. It is inexpensive and a variety of designs may be produced including stripes, multicolored patterns, textured surfaces produced by raised designs and pile effects. Plain-knit fabrics stretch more in the width than in the length and as such, they are widely used for making underwear, gloves, hosiery and sweaters.
Purl stitch :
Purl stitch, also called link-and-link stitch, is made on flat bed knitting machines and circular machines by needles using hooks on both ends to alternately draw loops to the front of the fabric in one course and to the back in the next course. The fabrics look similar on both the sides resembling back of the plain knit. Heavy, jumbo stitch is also possible which gives a bulky effect to the fabrics. However, It is comparatively slower and a costly technique. The fabric doesn’t curl at the edges. Purl stitch is widely used in infant wear and kids clothing due to its crosswise stretch and excellent lengthwise stretch.
Rib stitch :
Rib stitch produces alternate lengthwise rows of plain and purl stitches and as such the face and back of the fabrics are a lookalike. Rib stitch can be produced on a flat rib machine as well as circular rib machine. In the flat rib machine, one set of needles is placed opposite the other set of needles in an inverted V position. In the circular rib machine, one set of needles is placed vertically in a cylinder and the other set of needles is placed horizontally on a dial. In both the machines, one set of needles pulls the loops to the front and the other set of needles pulls the loops to the back of the fabric. Each set of needles alternately draws loops in its own direction, depending on the width of the rib desired. For instance, rib stitches can be 1X1, 2X2, 2X1, 3X1, and the like. Accordion rib is the combination of 1×1 and 2X2. As a greater amount of yarn is required for rib stitch and the rate of production is also slower, it is an expensive method of fabric construction. The fabric doesn’t curl at the edges and as the fabric possess an excellent widthwise elasticity, it is widely used for making such clothing that needs an excellent fit such as wristbands of sleeves and waistbands of garments, underwear and socks for men and children.
Warp knitting is different from weft knitting in the sense that in it each needle loops its own thread. The needles of warp knitting machines produce parallel rows of loops that are interlocked in a zigzag pattern. The stitches on the front side of the fabrics appear vertically having a slight angle. The stitches on the backside appear horizontally as floats at a slight angle. These floats are called laps or underlaps and are a distinguished features of warp knit fabrics. Warp knitting machine Warp knitting may be flat or tubular that can produce a variety of patterns. It is a very fast technique that can produce fabric with a dimensional stability almost equal to that of a woven fabric. It can also use yarns of man made fiber very efficiently. There are basically seven types of warp knitting- Tricot knit; Milanese knit; Simplex knit; Raschel knit; Ketten Raschel knit; Crochet and Weft-insertion warp. Warp knit fabrics are very popular due to their many properties such as smoothness, sheerness, wrinkle resistance, shrink resistance, strength and abrasion resistance.
Classification of Knitting Machinery
The machines used for the manufacturing of knit fabrics can be divided into machines with individually driven needles and needle bar machines. The former type of machine incorporates needles which are moved individually by cams acting on the needle butt; they are used for producing weft knits and are subdivided into circular knitting machines and flat-bed knitting machines.
The needles used can be latch needles or compound needles. The needle bar machines incorporate needles which move simultaneously, since they are all fixed to the same bar; we distinguish full-fashioned knitting machines and circular loop-wheel machines for the production of weft knit fabrics, which only use spring-beard needles, and warp knitting machines which use spring-beard needles, latch needles and compound needles.
Structure of Knitted Fabrics
Knitted fabrics are divided into two basic types: warp-knit fabrics such as tricot and weft-knit fabrics such as a hand-knit sweater. Weft-knit items have the drawback that they run when cut. Warp-knit fabrics are often used in lingerie.
- Knits shrink
- Knits have nap
- Ribs/wales versus courses
- Generally more elasticity along the course than along the wale
Over the long history of knitting across the world, hundreds of different knitting stitches have been created. The basic building blocks of all hand knitting are the following stitches: knit, purl, cast on, cast off, increase and decrease stitches. Use of a combination of these methods can provide a vast number of different textures to knitted fabrics.
In order to save space in knitting patterns, the names of stitches are normally abbreviated.
Styles of knitted fabrics
- Boiled wool
- Double knits
- Four-way stretch knits
- Interlock knits
- Power net
- Raschel knits
- Rib knits
- Single knits
- Stable knits
- Stretch knits
- Stretch velour
- Sweater knits
- Sweatshirt knits
- Two-way stretch knits
- Fleece knit
Stitch Formation with a Latch Needle
At the beginning of the process, the needle is positioned on the knock-over plane with the loop thread inside the hook, closed by the latch. The upstroke motion of the needle makes the thread slip downward touching the latch; this makes the latch rotate anticlockwise and open the hook.
Once the needle has reached its maximum height on the looping plane, the latch opens wide and the stitch moves along the stem. The needle now begins to move downward. On reaching the tuck-stitching plane, it catches a new loop thread.
In the further downstroke of the needle the stitch already formed touches the latch, making it rotate clockwise. As the needle continues its downward motion, this stitch begins closing the latch on the hook. The needle reaches the end of its stroke (i.e. its lower point) and the previous stitch, after having closed the hook completely, is knocked over on the new loop forming a new stitch.
The actual ready to wear apparel involves many more processes right from pattern drafting to garment construction which include pattern designing and pattern making, grading, marker making, apparel cutting, sewing, pressing and finishing.
Pattern Making Process
Once the pattern is graded, the fabric must be prepared for cutting. In order to spread the fabric properly, the spreader must know how the pattern pieces will be placed on the fabric. “Marking” refers to the process of placing pattern pieces to maximize the number of patterns that can be cut out of a given piece of fabric. Firms strive for “tight” markers largely because fabric is one of a manufacturer’s most significant business costs, often exceeding the cost of labor. Although markers can be made by hand or using CAD software, the computerized method is up to eight times faster. Once a marker is completed, a CAD system can use a plotter to print a full size layout on a long sheet of paper. This layout becomes the guide for the cutter.
Computer software helps the technicians create the optimum fabric layout to suggest so fabric can be used efficiently. Markers, made in accordance to the patterns are attached to the fabric with the help of adhesive stripping or staples. Markers are laid in such a way so that minimum possible fabric gets wasted during cutting operation. After marking the garment manufacturer will get the idea of how much fabric he has to order in advance for the construction of garments. Therefore careful execution is important in this step.
Computer marking is done on specialized software’s. In computerized marking there is no need of large paper sheets for calculating the yardage, in fact, mathematical calculations are made instead to know how much fabric is required.
Not every marking is on every pattern because some are specific to a certain style or construction technique. Layout and cutting markings don’t need to be transferred to the fabric. Construction markings, on the other hand, are very helpful during the sewing process and transferring them to the fabric is a good idea.
Patterns initially are made in only one size. In order to produce clothing that fits various body types and sizes, the pattern pieces must be increased or decreased geometrically to create a complete range of sizes. The process of resizing the initial pattern is called “grading.” Each company determines its own grade specifications for each size, and size specifications vary slightly from manufacturer to manufacturer.
Although many small firms still use traditional grading methods, grading, like pattern making, is becoming increasingly computerized. Using a CAD system, the pattern can be resized according to a predetermined table of sizing increments (or “grade rules”). The computerized plotter can then print out the pattern in each size. Because the productivity gains are so great, small to medium-sized manufacturers are beginning to acquire their own CAD systems for grading.
Alternatively, they may use an outside grading service to perform this function.
Fabric is the most important basic material for apparel making and it accounts for around 50 per cent of the ex-factory cost of a garment. Thus, material optimization or maximizing fabric utilization is the fundamental factor for every apparel firm. Marker making is done to avoid material wastage. While making markers, fabric width, length, fabric type and subsequent cutting method, all are taken into account. Both single size and multiple size paper markers are made using automated marker making tools and Computer Aided Design Computer Aided Manufacturing (CAD/CAM) along with traditional manual methods. The firms providing this service use previously graded pattern or the digitized copy of styles provided by the apparel manufacturers.
Spreading or Laying
Spreading is the process of unwinding large rolls of fabric onto long, wide tables in preparation for cutting each piece of a garment. The number of layers of fabric is dictated by the number of garments desired and the fabric thickness. Spreading can be done by hand or machine. Depending upon the fabric and cutting technology, up to 200 layers of fabric may be cut at one time. Fabrics that are more difficult to handle are generally cut in thinner stacks.
Spreading and cutting is smooth laying out of fabric in superimposed layers or piles of specified length. The cutting marker is laid on the topmost layer. The maximum cutting width is the usable fabric width minus selvedge or needle marks caused by stencil marks. Fabric utilization is the amount of fabric actually utilized in the marker as the percentage of the total fabric area.
Types of Lay Plan
- Half Garment Lay includes only half of the garment pieces for example one side left or right. Generally used for tubular fabrics.
- Whole Garment Lay includes garment pieces, left and right sides. Generally used for Open width fabrics.
- Single Size Lay is used using all garment pieces of one single size. Disadvantageous as the consumption of fabric is higher.
Types of Lay
- Single Ply is a single layer of fabric generally to make samples
- Multiple Ply is a number of fabric layers stacked on one top of other
- Stepped Lay is multiple lay in which groups of layers have different lengths generally used for getting best utilization and consumption of fabric.
Forms of Spreading
- One Way Cutting is when fabric is laid the same way up with grain or print pattern running in the same direction. Fabric has to be cut at the end of each ply.
- Fact to Face Cutting is when the plies are laid in pairs face to face. The grain or pattern runs in the same direction.
- Two Way Cutting is when plies are laid continuously from left to right and right to left without cutting at the end. Most Efficient method of spreading. Cannot be used with grain restrictions or one directional printed fabric.
Presentation of Fabrics
Presentation depends on type of materials, their application. Generally fabrics are Open width (rolled), Doubled (wound) and Tubular (plaited)
Ideal Lay height for cutting
- Fabric weight …………Woven…….. Knits
- Heavy Weight …………..4-5″ ………..5-4 “
- Med Weight ……………..3-4″ ………..3-3.5″
- Light Weight …………..2.5-3″ ………2-2.25″
Cutting is the process which cut out the pattern pieces from specified fabric for making garments. Once the marker is made, pattern pieces must be cut out of the specified fabric, a process called “cutting.” Currently, several cutting techniques exist, ranging from low- to high-tech. Although scissors are used very rarely-only when working with very small batches or sensitive fabrics-cutting continues to be done by hand, particularly in many lower volume establishments. Here, cutters guide electric cutting machines around the perimeter of pattern pieces, cutting through the fabric stack. An electric drill may be used to make pattern notches. The accuracy and efficiency of this system is considerably less than in computerized cutting systems.
Computerized cutting systems are achieving more widespread use as technology costs decrease and labor costs rise. These computer-driven automated cutters utilize vacuum technology to hold stacks of fabric in place while cutting. Cutting blades are sharpened automatically based upon the type of fabric being cut. Gerber Garment Technology manufactures one of the most commonly used cutting systems. This technology has the advantage of being highly accurate and fast, but does cost considerably more than other cutting techniques.
- Precision of cut: To ensure the cutting of fabric accurately according to the line drown of the marker plan.
- Clean edge: By avoiding the fraing out of yarn from the fabric edge. Cutting edge must be smooth clean. Knife must be sharp for smooth or clean edge.
- Consistency in cutting: All the sizing safe of the cutting parts should be same of knife should be operated of the right angle of the fabric lay.
Types of Cutting
- Hand operated scissor
Manually operated power knife:
- Straight knife
- Band knife
- Round knife
- Die cutting
Computerized methods of fabric cutting:
- Computer controlled knife cutting
- Cutting by Laser beam
- Cutting by Water jet
- Cutting by Plasma torch
Bundling – reassembling cut pieces
Bundling is the process of disassembling the stacked and cut pieces and reassembling them in production lots grouped by garment unit, colour dye lot, and number of garments.
“Bundling” is the process of disassembling the stacked and cut pieces and reassembling them in production lots grouped by garment unit, colour dye lot, and number of garments. Manufacturers use a variety of bundling methods depending upon their needs, with four basic systems being the most common among local manufacturers:
- Item bundling – all pieces that comprise a garment are bundled together.
- Group bundling – several (10-20) garments are put together in a bundle and given to a single operator or team to sew.
- Progressive bundling – pieces corresponding to specific sections of the garment (such as sleeves or a collar) are bundled together and given to one operator. Other operators sew other parts of the garment, which are then assembled into the finished garment in the final phase.
- Unit production system (UPS) – individual garment pieces are delivered to sewers using a computerized, fully mechanized “assembly line” that runs throughout the manufacturing facility. Using a UPS computer monitoring system, a manufacturer can fully track the production of a garment, identify where sewing slowdowns are occurring, and reroute garment pieces to other sewers who work more quickly. Gerber Garment Technology Inc. manufactures a UPS system, which eliminates the need for passing apparel piece bundles from worker to worker. This lowers labour costs because employees spend less time handling bundles and more time sewing. It also facilitates short-cycle manufacturing.
- Modular or “team based” manufacturing is another type of bundling that combines some of the above characteristics. Developed in Japan, it is the grouping of sewing operators into teams of eight to ten. Rather than each sewer performing a single task, they work together on a garment from start to finish. One-third of the U.S. apparel industry has switched to either unit production or modular manufacturing. In Los Angeles, however, only a few major manufacturers engage in computerized unit productions (constituting about ten percent of total production) while the majority of contractors still use progressive bundling.
Bundling workers also carry out important quality control functions. They inspect the garment pieces for cutting problems, fabric irregularities, or any other problems that may have occurred in production thus far.
The basic process of sewing involves fastening of fabrics, leather, furs or similar other flexible materials with the help of needle and threads. Sewing is mainly used to manufacture clothing and home furnishings. In fact, sewing is one of the important processes in apparel making. Most of such industrial sewing is done by industrial sewing machines. The cut pieces of a garment are generally tacked, or temporarily stitched at the initial stage. The complex parts of the machine then pierces thread through the layers of the cloth and interlocks the thread.
Although it seems to be a simple process, industrial sewing is quite a complex process involving many preparations and mathematical calculations for the perfect seam quality. Good quality sewing also depends on the sound technical knowledge that goes into pattern designing and making. Flat sheets of fabric having holes and slits into it can curve and fold in three-dimensional shapes in very complex ways that require a high level of skill and experience to manipulate into a smooth, wrinkle-free design. Aligning the patterns printed or woven into the fabric also complicates the design process. Once a clothing designer, with the help of his technical knowledge, makes the initial specifications and markers, the fabric can then be cut using templates and sewn by manual laborers or sewing machine.
While handling the fabric and in the process of sewing, the cloth must be held stiff and unwrinkled. The seam quality is very sensitive to cloth tension that varies from time to time in the whole sewing process. These undesirable variations in the cloth tension affect the product quality. Therefore, there arises the need of strict control over the whole process. The work of sewing is focused on the handling of fabrics lying on the working table and guide them towards the sewing machines needle along the seam line. The attention is equally focused on the control of appropriate tensional force so as to maintain high quality seam.
Pre sewing functions
Before the actual task of sewing begins, there are certain other tasks that have to be taken care of which can be termed as fabric handling functions- Ply separation; Placing the fabric on working table; Guiding the fabric towards sewing needle; and tension control of fabric during the sewing process.
While ply separation, stacks of fabric plies are sequentially positioned with the help of some feeding apparatus in an unloading position. The uppermost ply in such a stack is individually and sequentially separated from the stack. In the process, an edge of the separated fabric is presented between the jaws of a gripping device. A proximity switch determines the spacing between the gripper jaws. When this spacing confirms that only one fabric ply is in place between the jaws, the single ply is transferred over onto the receiving end of a conveyor for further processing. In aerodynamic technique, the uppermost ply of fabric is lifted by suction from the remainder of the stack.
When the fabric is placed on the working table, the tasks that are performed before the sewing process include – recognizing the fabric’s shape, edges that will be sewn, planning of the sewing process and identification of the seam line.
Recognizing the fabric’s shape:
The appropriate tensional force depends on the fabric properties. So the fabrics have to be identified into categories like knitted fabrics, woven fabrics etc. depending on their physical properties. Various shapes of the fabrics such as, convex, non-convex, with straight or curve edges, also have to be considered and each of them require different handling strategies. In brief, the sewing methods done by automatic systems require classification of fabrics into various categories and certain preliminary scheme of the path that the fabric must follow so as to produce the required stitches.
Fabric Edges to be sewn:
There are two basic types of stitches- one is that are for joining two parts of cloth together and the second one is done for decorative purposes. Sometimes, both types of stitching have to be done on some parts of cloth, for example, a pocket has to be joined on three sides with the apparel as well as it may be given some decorative stitches too. At what points and which type of stitching has to be done- all such information is stored digitally on automated devices through Computer-Aided Design (CAD) and accordingly sewn.
Planning of sewing process:
Sequence of seams to be stitched is determined before the sewing starts. Which part will be joined first, what stitches will follow one another, etc. are decided. However, some stitches have to be necessarily done before or after another stitch. In the example above, the decorative stitches must be done first followed by the joining stitches. Embroidered patterns also follow the same sequence but sometimes in clothing items like hats, decorative stitches or embroidery is done after the production of hats and with the help of embroidery machine.
Identification of seam lines:
Sewing process is performed on seam lines situated inside the fabric edges, some millimeters inside the fabric’s outer line. For the straight lines, the seam line is found by transferring the outer lines inside the fabrics and the intersection of these lines makes the vertices of the seam line. Therefore, the seam line is parallel to the outer edge and the distance between the two has to be determined as it is different for different parts of the cloth. This distance is greater for trousers legs than for a shirt sleeves. Seam allowance is the area between the edge of the fabric and the line of stitching. It is usually 1.5 cm away from the edge of the fabric. Seam allowance is usually 2.5 cm or more for standard home dressmaking. Industry seam allowances vary but they are usually 0.6 cm.
The sewing process consists of mainly three functions- guiding fabric towards needle; sewing of the fabric edge; and rotation around the needle. The fabric is guided along the sewing line with a certain speed that is in harmony with the speed of sewing machine. The orientation error is either manually monitored or if monitored automatically then error is fed to the machine controller so that the machine corrects the orientation of the fabrics. When one edge of seam line is sewed, the fabric is rotated around the needle till the next edge of the seam line coincides with the sewing line. The sewing process is thus repeated until all the edges of seam line planned for sewing, are sewed.
Significant Aspects of Sewing
There are certain aspects that have to be carefully considered while the sewing process as they are very crucial for high quality sewing.
Thread tension and consumption:
Correct balancing of the stitch and the tension given to the threads is very important for quality stitch formation. Thread consumption, which is closely associated with correct stitch geometry and thread tension, is usually measured by digital encoders.
Presser- foot displacement and compressing force:
Presser- foot is the part of the sewing machine that holds the fabric in place as it is being sewn and fed through by the feed dogs. The feeding system is one of the most important constituting systems of the sewing machine. If this system is not efficient then it results into irregular seams and many other defects, especially when running on high speed. To evaluate feeding efficiency, the force on the presser foot is measured with the help of electric or other sensors.
Needle penetration force measurement:
The interaction of needle with fabric is very crucial. Fault-free needle penetration depends chiefly on the properties of fabric and needle choice. Needle penetration force is one of the variables whose measurement is important for the analysis of quality problems or “sewability testing” and also quality monitoring. It takes various factors into consideration, such as the needle geometry (including the point angle and point length of the needle), the friction between the needle and the fabric, the friction between the needle eye and the thread along with fabrics’ property, and the sewing conditions.
Common machines used for garment manufacturing
An effective cutting room with good cutting machines is the best foundation in any production unit. The major operation is the cutting room is to cut the spread out fabric. This is the most decisive function – because once the fabric has been cut, very little can be done to correct serious mistakes.
Some of the main features of a Cutting Machine
- Power Session: Is often used in the sample room and is used to cut one or two layers of fabric.
- Round Knife: Is a very fast machine. It is excellent for cutting straight and curved line. Blade size ranges from 4 cm to 20 cms is diameter and the cutting height is about 40% of blade diameter.
- Straight Knife: Commonly used for cutting and if correctly used is best and accurate for most cutting rooms.
- Band Knife: The narrow blades allows finest of shapes to be cut very accurately. Some band knife machines have air flotation tables which support the block of work a fine air cushion which helps the worker to cut fabric with minimum disturbance to the layers of cloth.
- Computer Controlled Cutting: The marker data it transferred to the cutting unit by means of tapes, floppy discs or directly from the marker planning system itself. This is 6-8 times faster and produces accurate cut component. Although costly intially it is the best investment for large scale production.
The clothing industry requires special sewing machines for sewing a wide variety of garments. Specialised sewing equipment for their own particular requirement is a basic necessity in the garment manufacturing unit.
Single Needle Lock Stitch Machine
- Works with electronic controls
- Functions at a high speed of 6000 rpm.
- Automatic clipping of top and bottom threads
- Has several special sewing machine attachments which can be used to help the operator maintain consistent standard of quality particularly when stitching collars, cuffts, yokes etc.
Double Needle Overlock Stitch
- Works with electronic controls at a high speed of 6000 RPM.
- Machine consists of two needles which function together. You get double rows of stitching in a single operation.
- Used particularly for sewing jeans, safari suits etc, where double seams are required.
- Produces quick and uniform stitches and thus saves production time.
Over Lock Machine
This could be a three or five thread overlock machine
- This name is given to the this machine as it stitches the edges of a garment to be finished.
- It covers rough edges of fabric in order to present a clear and neat appearance where seam edges are visible.
- It speeds up to 8500 rpm and does automatic edge trimming and thread clipping.
- It is also used for assembling knited articles such as T-Shirts.
Button Sewing Machine
- This is also a high speed electronic machine.
- Buttons with 2,4 holes or shanks can be sewn on the same machine by simple adjustments to the button clamp and spacing mechanism.
- The needles has a vertical movement only and the button is moved from side to side by the button clamp.
- Each machine has maximum number of stiches i.e.16, 24 or 32 and can be adjusted to to sew the few or half the stiches i.e. 8 or 16, 12 or 24, and 16 or 32.
- Generally decorative buttons can be sewn with half the number of stitches used for functional buttons.
Button Hole Making Machine
- This is a very expensive machine.
- The machine automatically slits through the garments and sews round its edges to prevent fraying and stretching.
- The number of threads used depend on the garment type and quality.
- In standard types of garments such as shirts the operator simply positions the work in the machines wherever button holes at predetermined distances which the machine automatically stitches and trims the thread ends.
There are several kinds of fusing machines ranging from small table models to large floor standing machines. Basically this type of press consists of padded top and bottom bucks with heating elements in one or both of the bucks. The bottom buck is static with the top buck raised or lowered to open or close the press. Relatively speaking, fusible interlinks are precision products and it is essential that they are fused on correct equipment. Under strict temperature control. The duration of time required is also programmed.
During fusing it is necessary to apply equal pressure over the component to ensure the following factors.
- Intimate contact between top cloth and interlianing.
- Heat transfer is correct.
- There is even transfer of the resine into the fibre of the top cloth
Pressing or Folding
Some pressing, termed “under pressing,” may be done in the course of assembling a garment, for example, pressing seams open or ironing a collar. Most pressing is done after assembly to improve the appearance of a garment. In other cases, especially with knits, garments are simply folded instead of pressed. Although pressing remains largely a manual task, new automated process exists that apply force and steam to garments placed over a body form.
Finishing and Detailing
“Finishing” is the addition of special detailing such as pleats, embroidery and screen printing to a garment. This includes hand stitching (unseen handwork done inside collars and lapels to give them shape) and its automated substitutes. This may also include adding buttons, hooks, eyes, or trims, as well as clipping loose threads. All finishing of moderate- and lower-priced garments is done by machine.
Quality control helps to ensure that all garment products meet production standards and match the original sample.
There are two main aspects to quality of garment.
- Design Quality: It is concerned with materials, fit and construction methods.
- Manufacturing Quality: Manufacturing quality is concerned with degree to which the garment produced agrees with the sample or specifications.
Who decides the quality level
The consumer of the number of the public who buys a garment from a retail shop also influences the quality requirements. In many cases this can be negative.i.e he does not buy, all though in the bigger organization where marketing programs are carried out the consumer can effect the design quality.
In the majority of cases the customer decides the acceptable levels of quality both from design and manufacturing aspects. The customer may be a professional buyer for a large wholesale or retail organization.
The main objective of quality control is to ensure that goods are produced to the first customer (Direct Order) and hopefully to the second customers(Re-order/Alter Order/New Order) as well.If both customers can be satisfied then the manufacturer’s products are more likely to be continued in demand. Satisfactory quality can only be ensured through( from the manufacturers point of view):
- Knowing the customers needs
- Designing to meet them
- Faultless construction
- Certified performance and safety
- Clear instruction manuals
- Suitable packing
- Prompt delivery
- Feed back of filed experience
Satisfied quality can be ensured from the customers point of view by providing:
- Right Product
- Right Quality
- Right Time
- Undamaged Condition
How can quality be achieved?
- Goods must be designed to meet customers needs and make manufacturing process and maintenance easy.
- They must be made exactly and consistently to the specified design.
- Marketing must ensure accurate advertising, trade description with constant feedback for improved design.
- Total commitment to organized design.
Principles of Quality Management
The objectives to prevent errors by early detection and action are:
- The need to make the requirement complete and clear at all levels, from this specification of a large system to the individuals work construction and terms of reference.
- The detection error by monitoring both product and the method by which it is produced
- The prevention of errors at the earliest(right at first time)
- The total involvement of all concerning the contribution to the final products quality.
- Establish a total forward or backward control system, allowing flexibility for change.
Purpose of Quality control
It is a long standing tradition of any organization to offer the customers first quality merchandise. The purpose of this control program is to assist manufacturers in meeting our high standards.
In, addition company’s quality control program can also help the suppliers with their operation. Quality control program not only help spot and reject defective items, but more importantly they pinpoint production operations that need special attention, there by reducing the number of defects in future production. This type quality control provides basis for management decisions in the manufacturer’s plant. The defect refers to the condition that renders merchandise of second quality or unacceptable because the defect is one or more of the following:
- It is conspicuous
- It will affect the salability of the product
- It will affect the serviceability of the product
- It is significantly different from the specification
It is understood that all performance and legal requirements should be following the letter( L/C or any other contract between the buyer and seller) with no deviation allowed, including (but not limited to ) requirement for the following:
A manufacturer realizes the following benefits from the Quality control programme:
- Getting most for the quality control dollar.
- Using the entire quality control staff most effectively
Ensuring that even with turnover of personnel quality is maintained.
- cut and sew knit manufacturing; usha sewing machine with stand;