Process Wise Quality Defected Point of garments in appeal garments industry

There are many defects introduced to produce a garment in garments industry. The operator of garments pressured to produce a garment by the supervisor. That’s why it is possible to make any quality defects. This quality defects could be classified as critical defect, major defect and minor defect. Critical defect of garments could be summarized as those defective goods that do not comply with buyer’s safety requirements for babies and children’s wear. The major defect of garments could be defined as the defect is noticeable to the customer and visible when using the goods. The defect is not noticeable to the customer and not visible when using it is known as minor defect of garments manufacturing. Only the process wise defect identified in the garments by garments quality controllers is described bellow.

1. Defects in shoulder joint of garments:
  -Curve at Shoulder.
  -Tension loose At Shoulder.
  -Tension Tight At Shoulder.
  -Needle Cut At Shoulder Joint & Top Stitch.
  -Dirty Spot At Shoulder.
  -Shading at Back & Front Part.
  -Thread Shading At Shoulder Joint & Top Stitch.
  -Puckering At Shoulder.
  -Tension Loose At Shoulder Joint.

2. Defects in Neck Rib Joint of garments:
  -Uneven At Neck rib Width.
  -Shading At Neck rib joint.
  -Broken stitch at neck Rib joint.
  -Skip /Drop Stitch At Neck Joint &Top Stitch.
  -Puckering at neck Rib joint.
  -Pleated at neck Rib joint.
  -Needle Cut/ hole at neck Rib joint.
  -Center Out At Main/Size Label.
  -Not Position At Care Label.
  -Size Mistake At Size Label.
  -Tension Loose At Neck Rib Joint.                           

3. Defects in Sleeve joint and Top stitch of garments:
  -Size Mistake At Sleeve.
  -Pleated at Armhole.
  -Needle Cut/ hole at sleeve joint.
  -Shape uneven at sleeve joint.
  -Skipped stitch at sleeve joint.
  -Up-Down at sleeve joint.
  -Up-Down at under Arm Length.
  -Un-Even at arm hole top Stitch.
  -Shading At Sleeve /Back/Front Part.
  -Dirty Spot At Sleeve/ Back & Front Part.
  -Oil Spot At Sleeve /Back & Front Part.
  -Bundle Mistake At Sleeve Back& Front Part.
  -Tension Loosen At Sleeve Joint /Topstitch.

4. Defects in Side Seam of garments:
  -Curve at side Seam.
  -Needle Cut/Hole At Side Seam.
  -Dirty Spot At Side Seam.
  -Oil Spot At Side Seam.
  -Broken stitch at side seam.
  -Drop/Skip stitch at side seam.
  -Up-Down at Armhole Point.
  -Uneven At Side Top Stitch.
  -Tension Loose At Side Seam.

5. Defects in Body Hem & Sleeve Hem of garments:
  -Broken stitch at body Hem.
  -Uneven At Body hem.
  -Needle Cut/Hole At Body Hem.
  -Raw Edge At Body Hem.
  -Skip/drop stitch at body Hem.
  -Dirty / Oil spot at body & sleeve Hem.
  -Tension Loose At Body/Sleeve Hem.

6. Defects in Cuff joint make & Top stitch of garments:   
  -Skip / Drop at cuff make stitch.
  -Uneven at cuff topsin/ top stitch.
  -Uneven At cuff joint.
  -Point Up-Down at cuff joint.
  -Skip/ Drop at cuff joint top Stitch.
  -Shape uneven at cuff.
  -Size mistake at cuff.
  -Pair Mistake at cuff.
  -Oil Spot At Cup.
  -Dirty Spot At Cup.
  -Tension Loose At Joint/Top stitch.

7. Defects in Collar Joint Top sine & Make of garments:
  -Drop stitch at collar make /joint/ Top stitch.
  -Up-Down at collar point.
  -Uneven at notch point.
  -Up-Down at hala point.
  -Uneven at band top stitch.
  -Uneven at collar shape.
  -Tension Loose At Collar Joint/Make/ Top stitch.
  -Drop Stitch At Band Top stitch.                                       

8. Defects in Placket Joint & Topsin (Top stitch) of garments:
  -Slanted at Placket joint.   
  -Placket is not middle on garments.
  -Up-Down at Placket notch.
  -Uneven at Placket box.
  -Displace at button.
  -Tension Loose At Placket Joint & Topstitch.
  -Dirty Spot At Placket.
  -Oil Spot At Placket.

9. Defects in Button holing and button attach of garments:
  -Half stitch at button.
  -Fals stitch at button.
  -Insiquite button.
  -Reject at button.
  -Style Mistake At Button.
  -Tension Loose At Button Stitch.
  -Spot On Button.

10. Defects in Shoulder to Shoulder Back Tape of garments:   
  -Lop uneven at back tape.
  -Not Middle at back tape top stitch.
  -Broken stitch at back tape.
  -Drop stitch at back Tape.
  -Raw edge at back Tape.
  -Spot On Back Tape.                                        

11. Others Defect Point in Garments:
  -Running shade On Fabrics.
  -Yarn Contaminated On Fabrics.
  -Crease / Dia mark On Garments.
  -Back part Front part shade.
  -Slanted at V point.
  -Raw Edge at bottom.
  -Raw edge at sleeve hem.
  -Up Down at loop.
  -Displace at GSM  Hi-Low.
  -Ties Up –Down.
  -Uncut Thread.
  -Shading at Thread.

11. PC / Trim Card Follow:
  -Bulk Production time M/B follow this PC Card.
  -Fabric Color Check.
  -Thread Color Check.
  -Care, Main & Size label Check.
  -Twill Tape Check.
  -Mobilon tape Check.

12. Machine Adjustment:
  -Bulk Production time all machine S/B Adjust.
  -Machine Adjustments is the main subject make your good Garments.
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Garments defects and production procedure...........................

AUTOMATED PROCESS CONTROL IN TEXTILE AND APPAREL INDUSTRY

Textile and garments process control technology is not as specific as vision technology; process control encompasses all textile manufacturing sectors. The process controllers relevant to textile manufacturing are basic information-electronic systems that, installed on the textile and garments machine, control certain fundamental parameters relating to the production process carried out on the machine itself. Essentially, they can be broken down into 4 categories according to the technology of the controller involved, which is itself dependent upon the type of process being controlled.

AUTOMATION IN PROCESS CONTROL SYSTEM
1.Cycle programmers: These process control system are present on many dyeing machines and they are based on the general principle of activating outputs according to inputs of the process. But their actual functioning is more specific. Those control system are pre-programmed to manage a sequential cycle of operations automatically. This facilitates programming, because the only thing that has to be done is determine the sequence of the steps in the cycle and the conditions required for the passage from one step to the next (the reaching of a certain temperature, the expiry of a set time, the arrival of a go-ahead signal, etc.). There exist two types of cycle programmer: one based on a microprocessor whose hardware and software remains the property of the supplier, and one based on a PC- or PLC-formatted architecture, which offers all the advantages of standard hardware and flexible software of automated process control.

2. PC-driven Programmable Logical Controllers (PLCs): these systems of process control are equipped to receive logical information (from switch or pushbutton contacts, limit switches, photocells, any kind of ON/OFF sensor) and to activate logical outputs (electric drives, relay contacts, etc). A controller checks continuously the status of inputs (openings/closures, presence/absence of electrical current), and according to the configuration of the inputs, activates its own outputs (activated/deactivated, ON/OFF, command presence/absence). The logical correlation between input status and the output status consequently imposed is determined when programming the system. Thus, the PLC can be regarded as a completely general purpose tool, capable of carrying out, when duly programmed by the user for proper process control, the most diverse functions. In practice, PLCs are used to resolve all those problems relating to automation and sequence management that used to be resolved using electrical systems and relay logics for process control. They feature on practically all the systems used for automated process control, in textile finishing, for operations such as washing, mercerization, dyeing, drying, calendaring, raising, pad-batching and steaming.

3. Numerical Controls of process control: these control system are electronic systems, specifically designed to control the positioning of a number of moving organs (e.g., robot axes). Using special languages, they programmed the sequences of the positions of the various axes, each of which is controlled through measurement of the position of the organ. This measurement is carried out by high precision transducers (encoders, resolvers, optical rulers), which transmit to the numerical control a number (hence the name of the system) which represents that position.

4. Special programmers: This automated process control system is developed specifically to carry out dedicated functions of textile process. These programmers are designed with and for the machine, in such a way that input and output signals and processing capacity are kept to the absolute minimum. In order to reduce costs, size and maintenance of production, they are often engineered in the form of single electronic cards. The four systems of process control described above are can be integrated with one another, and are often used together.

Benefit of automated process control
 -Better process quality
 -Reduction of errors
 -Greater production flexibility
 -Rationalization of the cycle according to scientific criteria
 -Rapid personnel training
 -Greater familiarity with production characteristics
 -Scope for integration with other company information systems
 -Repeatability of procedures
 -End quality no longer dependent upon the skill and experience of staff

Limitation of automated process control
 -Need for organizational changes
 -Difficulty personalizing the system to specific requirements
 -Difficulty interfacing with different IT products
 -Need for assistance and maintenance

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WORK STUDY OF APPAREL GARMENTS FACTORY

WORK STUDY
Work study is the analysis of the operations required to produce a style. Effective work study requires both methods analysis and work measurement. Methods are studied, analyzed, and the elements of the method measured in terms of time consumed. Data are collected, analyzed and used to support decisions on rates and methods. Work study is also important to ergonomic decisions, job design, and work station development. Decisions must be based on extensive study and documentation that is developed with work measurement procedures. Unsubstantial opinions are not sufficient justification for change.

OBJECTIVE OF WORK STUDY
- Explain mechanization and automation relative to general- and special-purpose machines
- Examine the basic components of sewing machines and work aids
- discuss the effect of equipment on product quality and performance.

BASIC TERMINOLOGY OF WORK STUDY
Capacity: Productive capability (output) of a plant. Machine or work center in a given period of time.

Created from: machine, time, space, capital, labor
Frequently measured in units of Output (no. of garments)
May be expressed in terms of input (no. of hours)

Maximum Capacity: Total hours available under normal conditions for a given period of time

Efficiency Factor: A factor used to adjust the maximum capacity to a realistic level of potential production capacity.
Efficiency = Standard minutes earned /Actual minutes attended
Realistically 90% is the efficiency factor for all the firms attributed to Down Time, Supervisor, intervention, absenteeism, and other demands in a work day

Down Time: The period of time that a machine is not operational because of setup, making adjustments, maintenance or mechanical failure.

Potential Capacity: Maximum capacity adjusted for efficiency

Committed Capacity: Total of hours previously allocated for production during a given time period, ensures the plant of a continuous flow of work employment. It affects potential start and completion dates of the succeeding orders.

Available Capacity: The difference between Potential Capacity and Committed Capacity for a given period. This is used to estimate deliveries on new orders.

Required Capacity: Standard Allowed Hours/Minutes (SAH’s /SAM’s) necessary to produce a specified volume in a certain period of time.

Excess Capacity: Difference between required capacity and potential capacity.

Work Study can be best expressed in the following manner:
WORK STUDY
   1. METHOD STUDY
       Record to Compare
       Seek best method
   2. WORK MEASUREMENT
       Time Study
       Synthetics

In a crux: “Methods are developed and rate set for each operation”

STEPS INVOLVED:
1. Analyze each style to determine its requirement for production.

2. Style Analysis is based on:
       -Firm’s quality standards
       -Amount of labor required
       -Available equipment
       -Volume to be produced
       -Expected “throughput time”

3. Style requirements are determined through analysis of samples and specifications

4. Apparel Engineers are concerned with:
       -Number, complexity and sequence of Operations
       -Equipment Required
       -Time and Skill Required

5. Operation Breakdown: Work in each style is broken down into operations
An operation B/down is sequential list of all the operations that involved in assembling a garment used to establish the workflow for each style.

6. Apparel engineers study each operation to improve its effectiveness and efficiency and to establish methods to ensure a consistent performance by operators and consistent products.

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GARMENTS MATERIALS HANDLING

Materials handling is concerned with the efficient movement of goods through the conversion process. From the time fabric is unloaded from the truck until finished garments are packaged and shipped, storage and movement of materials and work in process must be planned and tracked to facilitate throughput. Handling materials does not add value to a product, but it affects work flow and productivity.

Handling costs can be reduced by eliminating as much handling as possible and reducing the distance materials are moved. Three aspects of materials handling need to be planned and evaluated: (1) handling and processing of in coming goods, (2) movement of work in process, and (3) distribution of the finished product.

Materials handling methods used at work stations depend on how garment parts are presented to the operator, the degree of automation, and the disposal system used. Materials handling procedures are incorporated in the production method for each operation. Work aids such as slanted tables for positioning parts, folders and binders for positioning trims, and automated cutters are some of the many ways an operation may be simplified and handling kept to a minimum. Handling time may account for up to 80 percent of sewing operation time.

GARMENTS SPREADING AND SPREADING EQUIPMENT

Objectives of garments spreading:

 -Garments Spreading equipments and surfaces

 -Examine the role of fabric control devices of garments spreading.

Basic garments spreading equipment consists of:

(i) Spreading surfaces,

(ii) Spreading machines,

(iii) Fabric control devices during spreading, and

(iv) Fabric cutting devices.

Many firms operate productively with manually operated equipment, while other firms find the automated, high-tech equipment to be cost-effective for their operations. Under-standing the parts and complexities of spreading equipment provides insight for troubleshooting problems and better preparation for the process.

Spreading Surfaces:

The appropriate type of spreading surface is determined by the fabric type, spreading equipment, cutting method, cutting equipment, and the firm's quality standards. Spreading requires a flat, smooth surface. If the spreading surface doubles as a cutting surface, it also must be level. Spreading and cutting may be done on the same surface, but automated cutting often requires spreading and cutting to be done in adjacent but separate locations.

Spreading and cutting surfaces are available in standard widths that correspond to fabric width. Narrow fabric can be spread on a wider table. A spreading surface needs to be about 10 inches wider than the fabric. Spreading tables may have tracks or rails placed along one or both sides of a tabletop or just a few inches off the floor. This track helps guide and control the spreader as it moves up and down the length of the table. With some types of equipment, the table tracks are geared to synchronize the movement of the spreading machine with fabric unrolling, in order to regulate tension.

Spreading tables may also be very specialized for certain types of fabric and cutting equipment. Pin tables have rows of pins located below the surface that can be extended through slats to hold fabric in a precise location for accurate matching of pattern repeats. Vacuum tables are used to compress lay-up and prevent shifting or movement during cutting. A spread is covered with a plastic film that forms a seal over the lay-up when a vacuum is applied. A lay-up of quilted fabric can be compressed as much as 75 percent when the vacuum is used. This allows more plies in the lay-up and restricts the movement of slippery fabrics for more accurate cutting.

Cutting equipment may be moved to a lay-up as another lay-up is prepared further down the table, or fabric can be spread on one surface and then transferred to the cutting surface. Air flotation tables, when activated, allow easy movement of a lay-up onto an adjacent cutting area. A layer of air between the table surface and the bottom layer of paper reduces friction and allows a lay-up to be moved easily without putting stress on the fabric or the operators.

Spreading tables with conveyorized surfaces carry the fabric to the cutting machine so that no time is wasted. Ideally one lay-up can be cut while is being spread. Conveyors may be used with computerized cutting systems, large die presses, and laser cutters.

Garments Spreading Machines:

Automatic Spreading Machine with fabric control devices

The fundamental purpose of spreading machines is to superimpose layers of fabric in a smooth, tension-free manner for accurate and efficient cutting. Manually operated spreading machines can be as simple a roll bar mounted on four wheels that is pushed up and down a spreading table by an operator. Manual spreaders travel only as fast as an operator moves them, while some of the faster automated machines can spread 100-150 yards per minute. Spreading speed can only be utilized on long spreads with few defects. Spreading speed may affect productivity, quality, and cost of the operation, but it should not be the primary focus for purchase of new equipment. Manual spreading machines may be used by small firms as the primary spreading device and by large firms for short spreads. As spreading machines become more sophisticated, they are motor driven and have fabric control devices included increasing productivity, decreasing variability, and making spreading more cost-efficient.

Fabric Control Devices during garments spreading:
Fabric control devices are mechanisms that control fabric as it is carried up and down the table and unrolled by the spreading machine. These devices include:
(i) Tensioning mechanisms,
(ii) Positioning devices, and
(iii) End treatment systems.

(i) Tensioning involves synchronizing the rate of spreading with the rate fabric is unrolled. A positive feed system utilizes a covered roller that is driven and timed to the movement of the machine. It prevents the momentum of a large roll from continuing to unwind when the machine slows down or stops. Roller covers of different materials may be used to give better gripping power for different types and weights of fabric.

(ii) Positioning devices and sensors monitor position and control fabric placement during spreading. These devices improve the quality of a spread. Electronic edge sensors monitor selvages as fabric is spread. A deviation from the proposed alignment triggers a motor that shifts the roll to the correct position. Alignment can be held to one-eighth inch tolerance with these devices.

(iii) Width indicators may sound an alarm to alert the operator whenever fabric becomes narrower than the established width. Width variations are analyzed to determine where in the marker they fall, whether the fabric will still fit the marker, or whether the variation should be treated as a defect and removed.

(iv) End treatment devices are used with spreaders but are separate and placed at the end of the spread. The specific end treatment equipment needed depends on whether the spreading mode is face-to-face or face-one-way. A face-to-face spread utilizes an end catcher and folding blade that work together. These are mechanical parts, mounted at opposite ends of the marker to catch and hold the fabric as the blade shapes and creases the fold. An overfeed device may be built into the spreading unit, which automatically feeds extra material when a fold is to be made. End treatments have a major impact on fabric waste. There must be enough fabric at the end of a lay to retain it in place, but any fabric beyond the end of the marker is wasted.

For F/O/W spreads, a knife box is needed along with an end catcher. A knife box contains a cutting unit (usually a small rotary knife) that operates in a track and cuts across the fabric width when engaged. With face-one-way spreads, each ply must be cut from the roll at the end of the marker. The catcher simply holds the fabric end in place for cutting. As multiple plies are spread, the fold blade and/or knife box must be elevated to the height of the top ply in order to fold or cut the fabric.

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THE LOCKSTITCH MACHINE; GARMENTS SEWING MACHINE USED MOST OF THE APPAREL FACTORY

Lockstitch sewing machine is very popular sewing machine and widely used in most of the conventional modern garments sewing system. The lockstitch machine is very easy to use but required more power to operate.

Principal feature and sewing elements of a flat-bed lockstitch sewing machine

The three-thread overlock sewing machine

Objectives of lockstitch sewing machine:
-Explain mechanization and automation relative to general- and special-purpose machines
-Examine the basic components of sewing machines and work aids
-Discuss the effect of equipment on product quality andperformance

Modern mass-production sewing requirements have resulted in many variations of the basic flat-bed lockstitch sewing machine. As we have seen, many of these developments are concerned with the form of the bed on which the material to be sewn rests. Cylinder-beds, post-beds, raised- and feed-off-the-arm beds have given rise to machines which differ greatly in appearance, although the actual stitch forming elements contained in these machines remain basically the same. These mechanisms may be grouped under one or other of the two main headings, Rotary hook or Oscillating Shuttle.

The principal features and sewing elements of a modern flat-bed lockstitch machine of the rotary hook type are as illustrated in the figure given below:

STATIONARY CUTTERS FOR FABRIC LAY CUTTING IN GARMENTS FACTORY

Stationary cutter of fabric cutting is important device of garments factory. Stationary cutter means the cutter is fixed and the spreading table is movable. This cutting system is time consuming and costly too. High power supply system is required for this cutting system.

Objectives of stationary cutter:
 -Understanding of the cutting process
 -Cutting equipments and their operations

Stationary cutters are those cutting machines that have blades or cutting devices that remain in a fixed position. The two basic types of stationary cutters are (i) band knives and (ii) die cutters. Operators must move the fabric or lay up to the machine and engage the cutting action.

BAND KNIVES:
The band knife cutting machine contains a narrow, sharpened, endless steel band moving vertically through the layers of fabric. The fabric layers are guided by hand against the blade. An air cushion will often be provided below the fabric layers to make it easier to guide the material. The plies may be stapled together to prevent slippage. Band knives are used for precision cutting to a depth of up to 300mm. Corners, tight curves and pointed incisions are cut precisely.

Band knives have fine blades that rotate through a slot in the cutting table while cutting. The operator positions, controls, and guides the fabric block around the knife. A band knife can be used to make only lateral cuts into a spread, as the operator must propel the fabric into the rotating blade. Band knives blades are finer and narrower than reciprocating blades, which make it easier to manipulate tight curves and intricate patterns. Band knives are more accurate than vertical knives when used to cut small blocks or shave small amounts off precut blocks. Band knives are used to trim precut blocks of small or mid size pieces. They would not be used for cutting a whole spread or large pieces because of having to maneuver the block around the blade.

DIE CUTTING:
Die cutting is the most accurate means of cutting because each and every piece is cut to the exact same shape. Dies are reshaped metal outlines with one cutting edge. Die cutting involves use of a die to cut out a specific garment part or trim from a single piece or small block of fabric. The die-cutting operation involves placement of the fabric, positioning the die on the fabric, and engaging the machine to press the die into the fabric.

A die cutting machine is provided with prefabricated cutting tools, (cutting dies) having the exact shape of the garment pieces. Die cutters are used mainly for leather, coated and laminated materials and in areas where the same patterns are used over a long period, e.g., production of working clothes. The dies are expensive to make. Dies are frequently used to cut small pieces that require high accuracy, such as collars, pocket flaps, and appliqués. Leather goods are frequently die cut. Gloves with their fine detail are usually die cut as are shoes that require consistency of parts.

SERVO CUTTERS:
The bridge between computer-controlled and manual cutting is the servo-cutting system. This type of system has an overhead servo motor with adjustable speed and a suspension system that supports the knife perpendicular to the cutting table. This reduces problems with tilting the blade and in accurate cutting. The knife is mounted on a swivel arm, which is extended above the cutting table. It also has a small base plate and narrow blade guide for easier maneuvering by the operator. It can make tighter turns with less distortion in the lay. It combines vertical cutting and band knife cutting into one machine. This type of system enables the operator to cut deeper spreads with greater accuracy than with a freestanding straight knife and for a lesser investment than computerized cutting.

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DIMENSIONS & TYPES OF MARKERS; SPLICING

 DIMENSIONS  AND TYPES OF MARKERS; SPLICING

Objectives:

 -Examine how material utilization is impacted by dimensions of markers

 -Understanding different techniques of marker making for specific order quantities

DIMENSIONS ; TYPES OF MARKERS; SPLICING

Markers are made to fit specific widths of fabric and quantities of sizes. If a marker is narrower than the fabric, the unused fabric is wasted. If a marker is wider than the specified fabric, garment parts located on the edge of the marker will not be complete. Fabric is purchased by width but often it runs wider than the required width. When fabric width is grossly inconsistent, fabrics in a lot may be grouped by width and different markers produced for each width. Using the extra width in planning markers can save significant yardage.

Markers may be produced in sections or blocks or be continuous. Blocked or Sectioned Markers contain all of the pattern pieces for one style in one or two sizes. Sections may be used separately or joined together to form an extended multisize marker. Blocked or sectioned markers are easier to visualize and handle, but they may not produce the best utilization of fabric.

Sectioned markers may be used to adjust the volume requirements for various sizes or as a remnant marker. High-volume blocks can be placed on one end of the marker and low-volume blocks placed at the other end so the fabric can be spread to correspond with the volume needed for each block. Blocking keeps garment parts for one size in close proximity, which facilitates bundling and handling. Sectioned markers are advantageous if there is an en-to-end shade variation of the fabric. The following picture shows a spread that could be used with a sectioned marker and an unequal distribution of sizes.

A stepped spread for a sectioned marker may consist of plies of varied length, spread at different heights. The most frequently used configuration for a stepped spread consists of a group of plies that are spread the full length of the marker and another group of plies beginning at the section line. Stepped spreads are used to adjust the quantity of piece goods to the number of garments to be cut from each section of the marker

Continuous markers contain all the pattern pieces for the all sizes included in a single cutting. They may be lengthy and often require more juggling of pattern pieces. Pattern pieces are grouped by size and shape of the pieces rather than by garment size. Continuous markers often have better utilization because there is more flexibility in grouping and maneuvering large pieces and small pieces. Splice marks are planned into continuous markers to avoid excessive fabric waste and incomplete pieces.

Splice marks are points in a marker where fabrics can be cut and the next piece overlapped to maintain a continuous spread. Splice marks may be one inch or several inches depending on the overlap needed to accommodate the pattern pieces in the area of the splice. The rectangular box indicates the amount of overlap needed. The lower ply should be cut at the end of the box and the new ply of fabric should be aligned with the beginning of the box. If fabric needs to be cut before there is a splice mark, the cut should be made at the last splice mark and the extra fabric used for recuts or smaller markers. Splice marks are inherent when markers are planned in blocks. Piece goods may be spliced at any point where the sections of a marker are joined together. Splices are needed when flaws are removed, a roll change is made, or a short length of fabric is used.

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MARKER PLANNING & MARKER MAKING FOR PARTICULAR GARMENTS.

Objectives of marker planning and marker making:
 -Optimizing fabric utilization through marker making 
 -Understanding the importance of the same in apparel and garments manufacture

Garments manufacturing is very important part of textile production and proper marker planning and marker making is the heart of garments manufacturing. The results of cut order planning are cutting orders that direct marker planning and lay planning. Optimum use of textile material and cutting systems are important considerations in planning cutting orders as more firms incorporate new technology. The purpose of marker planning is to determine the most efficient combination of sizes and shades for each order and to produce the best fabric yield and equipment utilization. One garments cutting order may require several markers to achieve optimum efficiency of marker. Usually one of these is a remnant marker for the short pieces and ends of rolls left over. This helps to reduce fabric waste. Each marker requires a lay of fabric.

A marker is a diagram of a precise arrangement of pattern pieces for a specific style and the sizes to be cut from a single spread. Marker making is the process of determining the most efficient layout of pattern pieces for a specified style, fabric, and distribution of sizes. The process of arranging Pattern pieces in the most efficient manner requires time, skill, and concentration. Markers may be made by manually tracing master patterns onto fabric or paper or by manipulating and plotting computerized pattern images.

THERE ARE TWO TYPES OF MARKER MAKING:
1.Manual marker making
2.Computerized marker making.

1. Manual marker making: Manually produced markers may be created by arranging full pattern pieces on marker paper or directly on the top ply of fabric in a spread. Pattern pieces are traced using a pencil or tailor's chalk. Manual methods of marker planning and making are time-consuming and require a great deal of space. Full-size pieces must be manipulated, adjusted, and readjusted on normal fabric widths. Manually made markers are also subject to errors and inconsistencies that may occur in grain variations, poor line definition, placement and alignment of pieces, and omission of pieces. Accuracy of a manually made marker depends on the skill of the individual who laid out the marker and traced it.

2. Computerized marker making: Computerized marker making is more accurate and provides the greatest opportunity for pattern manipulation, marker efficiency, reuse of previously made markers, and shortest response time. Production patterns may be developed on the computer and/or digitized or scanned into the computer. In addition, parameters for markers are entered into the computer from cutting orders. These might include style numbers, size distribution, and fabric width. Technicians manipulate pattern images on computer screens and experiment with various configurations to determine the best fabric utilization for the marker.

Plotting is the process of drawing or printing pattern pieces or markers on paper so they can be reviewed or cut. Computer-driven plotters may draw pattern pieces, graded nests of patterns, and/or markers with complete annotation, depending on the needs of the apparel firm. New multihead jet plotters are much faster and can print variable line density and width, text identification information, and bar codes. Some garment manufacturers have devices to copy original markers when multiple copies are needed. Plotting is often the bottleneck in the preproduction processes, especially if a firm runs a lot of copies. Many firms run their plotters 24 hours a day to keep up with demand. Firms using computerized cutters may not need paper markers to guide the cutting process and therefore may only print identification information for bundles.

Cut order planning determines how many markers are needed, how many of each size should be in each marker, and the number of ply that will be cut with each marker. Size distribution in a marker depends on the volume of orders for specific sizes, fabric width, how the pieces fit together, and the firm's standard practices for marker making. An efficient size ratio is often 1:2:2:1. For example, an order for one marker may contain one small, two medium, two large and one extra large. Additional markers may include only medium and large, depending on the assortments in the line plan or orders from merchandise buyers. Cutting orders may require making new markers, copying previously made markers, or modifying previous markers.

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MARKER MODES

Marker could be described by the form of the fabric and whether it is symmetrical and/or directional determine the appropriate type of marker for a style. Markers may be open or closed depending on the form that the fabric is presented for cutting. Rolled fabrics are open and flat when spread. Markers for this type of spread require pattern pieces for each part to be cut. Markers made with full-pattern pieces for each part to be cut. Markers made with full-pattern pieces are called open markers. Tubular knit fabrics are closed on both edges and therefore require pattern pieces that utilize the folds. Markers with half-pattern pieces for laying along the folds of the tube are called closed markers. Garment parts must be symmetrical if half-pattern pieces are used.

Objectives of marker modes:
 -Understanding the impact of fabric nap on marker planning
 -Examine the role of symmetry and directionality of fabric

Marker makers must also consider the symmetry (side-to-side) and directionality (end-to-end) differences in fabrics. Symmetric fabrics are the same side-to-side. Asymmetric fabrics such as border prints are different side-to-side. Non-directional fabrics are the same end-to-end. Directional fabrics are different end-to-end. Examples of directional fabrics include knits, n fabrics, and prints with flowers all growing in one direction.

The marker mode is determined by the symmetry and directionality of fabric. There are three types of marker modes: nap-either-way (N/E/W), nap-one-way (N/O/W), and nap-up-and-down (N/U/D). In this case, the term nap is " to indicate the fabric is directional - it is different end-to-end. The nap of a fabric is created by its structure (corduroy or an unbalanced plaid), a finish, or a directional print. With symmetric, nondirectional fabrics, pattern pieces can be placed on a marker with only consideration for grain line. This marker mode is called nap-either-way (N/E/W). Pieces are placed for best fabric utilization.

On some directional fabrics, such as corduroy, it may be possible for all the pattern pieces of one size to be placed in one direction and another size placed ill the opposite direction. This is called nap-up-and-down (N/U/D). With this type of marker, the nap of corduroy jeans may run down for a size 7 and up for a size 9. The critical factor is that the nap must run the same direction in all the pieces of one garment. Napped fabric such as corduroy will appear shaded if the pieces in one garment have the nap running in different directions. Generally N/U/D will yield a better utilization of fabric than N/O/W.

A marker is made for a specific style, fabric, and number of sizes. The length of the marker determines the length of the lay that will be spread. Completed markers are sent to the cutting room electronically or in hard copy for the spreading and cutting processes.

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MARKER EFFICIENCY; EFFICIENCY MAINTAINED DURING MARKER DESIGN IN GARMENTS PRODUCTION

MARKER EFFICIENCY
Marker efficiency is the important part of garments manufacturing. Direct cost of garments could be utilized by marker efficiency. Salary of a marker planner truly depends upon the capability to increase the marker efficiency.

Marker efficiency is determined by fabric utilization, the percentage of the total fabric that is actually used in garment parts. The area not used in garment parts is waste. Marker efficiency depends on how tightly the pattern pieces fit together within the marker. The total surface area of the pattern pieces is compared to the total area of the marker to calculate the percentage of fabric that is used. This is determined automatically by marker-planning software. If marker-making and marker planning technology is not available, the area of each pattern piece may be determined by a planimeter – a mechanical device that calculates the surface area as the outline of the pattern is traced. Factors that affect marker efficiency are fabric characteristics, shape of the pattern pieces, and grain requirements.

Objectives of marker efficiency:
 -Examine how fabric utilization affects marker efficiency
 -Enumerate the factors affecting material utilization

INTERNATIONAL SOURCING OF GARMENTS

SOURCING CRITERIA AND PROCESS:

Once we are clear about the emergence of the readymade garment industry and its growth as well as India’s contribution to the global trade in garments, we now move forward to yet another important facet, which is of sourcing. At this juncture it is important that we first know what is it that we exactly mean when we say sourcing? Sourcing is basically procuring inventory required for the manufacturing process or it could also refer to procuring finished goods at the best price and of the utmost quality. Quality and Cost are the two major factors that determine most of our buying/sourcing decisions.

GLOBAL MARKETING AND SOURCING:

Global marketing directs goods into multiple foreign markets. The process of directing products into global markets must be approached with considerable care and planning. The aggressiveness, method and speed of the global marketing strategy depends on:

(1.) Whether the firm’s products are known among consumers in the foreign country;

(2.) The customs, laws, and regulations in the foreign country;

(3.) The political stability of the foreign country; and

(4.) The expertise among management of the apparel firm.

The wide variation in customs and trade practices among cultures must be explored before deciding to enter a foreign market.

Exporting means domestically produced goods are sold in foreign markets. Indirect exporting involves selling merchandise through a trading company that specializes in selling domestically produced goods in foreign markets. The primary advantage of indirect exporting is that the manufacturer gains the expertise of an exporting specialist. The greatest disadvantage of indirect exporting is that the manufacturer loses control of the promotion and distribution of the product in the foreign country.

If a manufacturer uses direct exporting, the goods are sold by the domestic

Objectives of international sourcing of garments:

 -Enumerate the sourcing criteria

 -Understand the sourcing process

 -Examine the sourcing operations and flow

manufacturer’s sales representatives to retail buyers from a foreign country. Direct exporting gives a firm more control over the distribution of a product, but it also requires more expertise among the firm’s management and sales representatives. Trade missions into foreign countries are sometimes organized by industry trade associations and local or state governments to establish exporting systems that many firms can then use. Sales might also be accomplished through export fairs or markets held within the country or abroad, where foreign buyers are invited to purchase goods.

Global sourcing determines where materials come from and/or where apparel is made that enters domestic markets. For the most part, global marketing results in exporting, while global sourcing results in importing. Global sourcing has become common practice for most apparel firms.

 SOURCING CRITERIA, BUYING OPERATIONS AND FLOWS 

The buying operations are generally guided by the overall policies and philosophy of the companies and macro-environmental variables. The specific inputs, which influence these operations, are:

 -The fashion viewpoint of the stores,

 -Price-points,

 -Promotion methods,

 -Organizational structure,

 -Retailing mix, and

 -Geographical locations.

The import and sourcing policy and import decisions are taken, by and large, by the corporate office and the buying operations are delegated to buyers/merchandisers based on the overall budget, open-to-buy (the budget available for purchase), turnover ratios, lead time, retail square footage productivity, sales expectation, mark-up, margin and profitability.

In a typical retailer structure, for example, considering a department store, there are separate merchandise managers for different product groups and divisional merchandise managers for major groups of products and buyers for different items. The import decision and the policy implication are generally handled by the headquarters of the companies, where the open-to-buy budgets of various product groups are divided among different countries based on quota availability and other sourcing criteria. In some cases, the actual budget for buying from a region is given for instance, to the companies’ office in Hong Kong and then that office would decide whether to buy from India, Sri Lanka, Bangladesh etc., for example, and how much of quantity allocation to make. It is very clear, therefore, that knowing the distribution channels, understanding the type of retail outlets involved in marketing, sourcing systems of buyers and the practices and policies of the company become very critical in improving exports and unit value realization. The quality standards and the communication of the same are also linked to the type of sourcing systems and buying network available to the company in question, whether it is department stores, specialty chains or 'brand-manufacturer'. For instance, in the case of Liz Claiborne, as the company sources from 60 countries, the quality standards are centralized and communicated to each country representative, whose responsibility it then becomes to implement the quality standards. Even the computation of CMT, etc. is standardized. The retail sourcing decisions will depend on the type of retailer (department store, specialty chains, catalogue houses, etc.) and the type of consumers they represent.

The retailers have merchandisers and buyers who are generally in charge of the buying operations. The larger retailers have import departments for general import decisions and buying departments for merchandise development and selection. Certain companies develop specialized sourcing arms, as this activity is the key to successful retailing, by providing the right merchandise, in the right quality, at the right channel and at the right price. For instance, the Geoffrey Beene in the USA has 'Triburg' in New Delhi as the sourcing arm whereas C & A, Brussels has 'Mondial lnternational' as the sourcing arm in India. But there are companies like Hennes & Mauritiz (H&M) from Sweden and GAP from USA, which have set up full-fledged buying offices in India. Department stores like Macy has also set up their own buying office in other countries as in India. In another instance, Hertie, the import policy decisions are taken in Frankfurt but buying and merchandising decisions are taken at their Hong Kong office, which handles the sourcing from India and other South-Asian supplying countries. In Sri Lanka, many buyers like Mast Industries, USA have entered into three-way or two-way joint ventures with manufacturing factories. The exporters have to understand the difference in operations in order to develop competitive advantage. For instance, the ability required by an exporter to satisfy a mail order house is very different from the ability required to satisfy a department store or a brand-manufacturer.

Quick response, price performance ratio etc. are very important for the buyers, though again it is a function of the type of merchandise and the channels. The price quality-delivery-fashion performance expectations are guided by the nature of the retail operation. For instance, department stores and specialty stores have private label and national brands in their merchandise groups. A private label is a brand introduced by the stores in order to improve their profitability, fashion orientation and life-style positioning. Examples of these are Aeropostale and ThorntonBay by Macy's, Bloomies by Bloomingdale, St. Michael by Marks and Spencer and STOP! by Shoppers’ Stop. A national brand is one, which is marketed by brand manufacturers, like Levis, Seidensticker or Liz Claiborne. The private labels may work on more seasons and the national brands on fewer seasons. Likewise, importers and wholesalers also have their own wholesale brands. The specialty chains, department stores and importer-wholesalers have the option of getting fabrics from the Far-East, Pacific Rim, China, etc. and the manufacture of garments can be done again in the Far-East, Latin America, East Germany, C.I.S. countries, South-East Asia, South Asia and such other low-cost countries. This again involves backward pricing (determining the f.o.b. price based on the ultimate selling price at the retail level) based on the type of merchandise, level of labor cost involved, fabric availability, lead time requirements, possibility of fill-ins and replenishment and such other factors. Thus, the sources of competitive advantage exist in all the links of the value chain.

The basic requirements of a fashion retailer could be quick response, small quantities and flexibility in assortments. These characteristics when turned into specific sourcing criteria could mean price-performance ratio, fashion-price or quality-price-speed expectations. However, the objectives in most cases are:

1. Reduced inventory

2. Maximize profits/square footage sales

3. Optimize seasonal sales

4. Obtaining exclusivity for building customer loyalty.

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CUTTING SYSTEMS IN GARMENTS FACTORY; AUTOMATED, NUMERICALLY CONTROLLED

Automated cutting is the best system for fabric lay cutting in garments. Automated cutting more faster than manual cutting system. Automated cutting system is operated by computerized numerically controlled cutting system. Required low labor cost and the lowest man power for automated cutting system.

Objectives of Automated cutting system:
 -Equipments and their operations
 -Recent development in equipments and techniques

 The four types of automated cutting systems are:
(I) blade cutting,
(II) Laser cutting,
(III) Water jet cutting, and
(IV) Plasma jet cutting.

Electronic microchips control the cutting device, travel pattern, and speed. Computer-generated markers are stored and used to guide the operation of the cutting head. Printed markers are not required for cutting but may be used to assist with bundling. The primary advantage of computerized cutting systems is the accuracy of the process.

Automatic Blade Cutting is the most highly developed and widely used computerized cutting system. Systems are specific to the standard volume to be cut. Numerically controlled knives cut multiple plies with great accuracy and speed. Information can be downloaded directly to the cutting system when needed. Easy data entry and instant communication with the main control unit allow technicians to preprogram multi-step commands, set parameters, and start the process with a single keystroke.

The central control unit operates the components of the system such as the cutting head, cutter carriage, knife sharpening, and conveyorized cutting table. A cutting head is a sophisticated mechanical component with the capacity to cut, mark, and drill as dictated by the computer. Automatic knife sharpening is done at preset intervals during the cutting operation. The cutter carriage moves the cutting head and provides lengthwise and crosswise motion during the cutting operation. The reciprocating blade can be adjusted to the height of the spread and density of the fabric. Knife speed automatically adjusts to the forward speed of the cutting head. As the cutting head slows for corners, curves, or notches, the reciprocating blade also slows to reduce heat and possible fusing. Most reciprocating knife systems use a vacuum to hold down the fabric. Placement of plastic film over a spread helps compress the fabric into a firm stationary lay-up when the vacuum is applies. The effect of the vacuum is to reduce the height of the spread and eliminate fabric movement during cutting. An intensified vacuum force is automatically applied to the area directly under the knife to further restrict material shifting

Laser Cutting focuses a powerful beam of light projected onto a minute area to cut fabric by vaporization. The fine, V-shaped beam is only 0.004 of an inch. The beam cuts without pressure on the fabric, which is a major advantage for some types of fabric. The fabric remains immobile during the cutting operation.

Lasers cut with incredible speed (twice that of automatic knife cutting), accuracy, and multidirectional ability, but with some heat emission. Laser-cut edges are sharp and clean. The heat produced tends to seal fabric edges, which can be an advantage for fabric that ravels and a disadvantage for cutting multiple plies as edges may fuse together. Laser-cut garment parts are easier to assemble, as they are consistent in size with smooth sharp edges to align.

Water Jet Cutting is another computer-operated, multidirectional method that has limited usage at this time. Water jet cutting is performed by propelling a tiny jet of water (0.0010-0.0015 inch) through fabric at very high pressure (70,000 pounds per square inch). The forward edge of the jet stream shears the fabric as it moves along the cutting line but does not wet the fabric, generate airborne contaminant, or exert an appreciable force on the ma-terial. The water jet will cut multiple plies without fusing, but it may fray and tangle the yarns of some fabrics, which makes it difficult to separate the plies. It is used when heat build up must be avoided and water absorption is not important. At the present time its use is limited to cutting leather and vinyl fabrics.

Plasma Jet Cutting is a computer-operated, high-speed, single-ply cutting device that offers many of the same features of a laser cutter but at a lower price. Along with the plasma jet cutting system, Investronica has developed a Matching System for automatic matching and cutting of striped, checked, or printed fabric. A TV camera reads the fabric on the conveyor, and a digital image processor decides the best way to match and layout the pattern pieces based on determined matching rules. Matches can be made among different prints, selvages, and fabric characteristics. This system eliminates recutting parts for more precise matching.

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GARMENTS SEWING MACHINE FUNDAMENTALS- PRINCIPLES OF STITCHING (MECHANIZATION PROCSS)

Sewing machine is an important part of apparel and garments manufacturing technology. Production of garments factory depends on the performance of sewing machine and principles of stitching. Principles of stitching and perfection of stitching depends on the quality of sewing machine.

Mechanization is the process of replacing human labor with machines. Mechanization of the garments sewing process encouraged mass production of apparel garments product. Garments sewing that had long been performed by hand sewing machine could be done more rapidly by garments sewing machine. By about 1900, most garments sewing processes could be performed by machine

Automation is a state of operating without external influence or control. In manufacturing of garments and apparels it is often viewed as highly desirable because it eliminates the potential for garments workers error. Automated garments sewing systems are capable of feeding themselves cut garments parts from a stack, completing multiple sewing tasks, and delivering finished parts of garments. Automated equipment for garments sewing may be cost effective for some apparel manufacturers, while the high costs of acquisition, installation, and maintenance are prohibitive to others.

Robotics is the most advanced form of automation in garments sewing operation. Robots are computerized, reprogrammable, multifunctional manipulators designed to move materials, parts, tools, or specialized devices through variable programmed motions for the performance of a variety of tasks. Flexible reprogrammability is one of the hallmarks of robotic automation. This manufacturing flexibility differentiates robotics from fixed-purpose, hard-wired automation, which has to be torn apart and reconfigured for every new application.

Garments sewing and Apparel pressing equipment may be either general or special-purpose. General-purpose garments sewing machines are manually operated by garments worker and can perform a variety of sewing operations. Special-purpose garments sewing machines are designed to perform a specific garments related or sewing related operation and more likely to be semiautomatic or automatic machine.













 





Objectives of garments sewing machine:
 -Discuss issues related to equipment selection
 -Explain mechanization and automation relative to special- and general-purpose garments sewing machines
 -Examine the basic components of garments sewing machines and work aids

GARMENTS SEWING MACHINE FUNDAMENTALS:
A basic garments sewing machine or apparel sewing head, as it is sometimes called, consists of the fundamental parts required to form a stitch, sew a seam, or perform a specific garments sewing operation. The major components of a basic garments sewing machine include a sewing casting, a machine lubrication system, a stitch-forming system, and a garments feed system. The speed at which a sewing machine can operate depends on the engineering of the garments machine’s components.

The Sewing Casting:
The sewing machine casting is the metal form that provides the exterior shape of the garments machine. Shapes vary with the bed type, the garments sewing function that is to be performed, and how piece goods are to be presented to the needle. The casting houses the internal workings, such as the gears, cams and shafts, that operate the stitching and feeding mechanisms of the sewing machine.

Bed Type:
The bed is the lower portion of the sewing machine under which the feed mechanisms and loopers are located. Sewing machines are frequently described by bed types.

Different Types of Machine Beds:

Types of Garments Sewing Machine	Sewing Stitch Type	Features and Uses
Flat bed sewing machine (basis type)	Lockstitch sewing, Chain stitch sewing	The large working area allows a wide range of sewing application; the material can easily be guided around the needle and the presser foot. This basic type garments sewing machine used for all kinds of flat sewing operation.
Raised bed sewing machine	Lockstitch sewing, Chain stitch sewing	The bedplate is in the form of a plinth. It facilitates the assembly of pre-sewn parts and is especially suitable for the fitting of accessories and special attachments. This is the basic form for various specialized garments sewing machines such as buttonholers.
Post bed sewing machine	Lockstitch sewing, Chain stitch sewing	This type of sewing machine has an increased working height. Special sewing applications are found in the working of three-dimensional products. e.g. shoes and bags. The post makes it easier to work on tight curves and corners, to sew in sleeves and to complete large, half-assembled products.
Cylinder bed sewing machine	Lockstitch, Chain stitch	This type of garments sewing machine has an increased working height and a bed in the shape of a horizontal arm. It is especially suitable for sewing on tubular parts, such as cuffs, sleeves, and trouser legs, and also for button sewing and bar tacking. This sewing machine is used extensively in the making of clothing from knitted fabrics.
Side bed machine	Chain stitch, Over-edge	Machines which are specialized for sewing at edges need only a small working area

CUTTING AND CUTTING ELEMENT OF GARMENTS IN APPAREL FACTORY

Cutting is the production process of separating (sectioning, carving, severing) a spread into garment parts that are the precise size and shape of the pattern pieces on a marker. The cutting process may also involve transferring marks and notches from the marker to garment parts to assist operators in sewing. Chopping or sectioning a spread into blocks of piece goods may precede precision cutting of individual pattern shapes. This is often done to allow for accurate matching of fabric design or easier manipulation of a cutting knife.

CUTTING AND CUTTING ELEMENT OF GARMENTS IN APPAREL FACTORY

Fabric pieces may be cut to predetermined lengths for matching patterns or for additional processing such as screen printing. Spreads of plaid fabrics may be presectioned into blocks so the design of the fabric can be perfectly matched before cutting to the shape of the pattern piece. Presectioned pieces may also be garment parts knitted to specific finished lengths such as sweater bodies. Presectioned pieces such as leather or other specialty fabrics may be and cut as a single ply or laid up and cut as a multiple-ply spread. 


Objectives of cutting:
 -Understanding of the cutting process
 -Cutting equipments and their operations

Cutting often is carried out in two stages: rough cutting (separating the individual pieces) and the final cutting (accurate cutting of the individual shapes). Different types of cutting tools have different degrees of precision.

PORTABLE CUTTING KNIVES:
Portable knives can be moved to and through a spread by an operator. There are two main types of portable knives:
(i) vertical reciprocating straight knives and (ii) round knives. Structurally and mechanically the two types of machines share many similarities. Structurally, both types of knives have a base plate, power system, handle, cutting blade, sharpening device, and blade guard. Round knives operate with a one-way thrust as the circular blade makes contact with the fabric, and vertical knives cut with an up-and-down action. Circular cutters and straight knives are pushed by hand through the stationary material.

CIRCULAR CUTTERS:
Circular cutting tools use a rotating circular blade. The smallest devices (power shears) is used for cutting single ply lays and for cutting fabric plies to length during manual spreading. Depending on the size of the device it is possible to cut to a depth of about 10mm. The larger circular cutter is used mainly for dividing a lay into sections. It is suitable only for cutting in straight lines or very gradual curves, in depths of about 150mm.

STRAIGHT KNIVES:
A straight knife cutter has a vertical blade, which reciprocates up and down. It is capable of both coarse and precise cutting to a depth of about 300mm. Corners and curves can be cut accurately. Since all of the layers are cut at the same place (unlike a circular cutter), and provided that the knife is held vertical, then all of the pieces cut from a lay are identical.
Vertical straight knives with reciprocating blades are the most versatile and commonly used cutting devices. Reciprocating blades have a vertical cutting action. Blades vary in length from 6 to 14 inches. Blade length and the adjustable height of the blade guard are factors in determining the spread depth that can be cut. The 90-degree angle of the narrow, thin blade to the cutting surface makes this knife a good choice for accurately cutting sharp corners, angles, and curves.
Vertical straight knife machines make only lateral cuts into a spread therefore cannot be used to cut out areas from the center of garment parts.

Basic Components of Portable Knives:
Blades are mounted in a vertical position at a 90-degree angle to the cutting surface. Blades vary in shape, size, cutting action, and fineness of the cutting edge. A straight blade contacts the spread at a 90-degree angle; assuming the blade and spread are kept vertical, all plies are cut at the same time. A rotary blade does not cut all plies evenly at the same time. A round blade contacts the spread at an angle; thus, the top ply is cut before the bottom ply.

(i) Knife blades can have a major affect on the quality of the cut. Factors that affect the performance of a blade are the blade edge, surface texture of the blade, coarseness or fineness of the blade edge, and blade composition. Blade edges may be straight with a flat surface, saw-toothed, serrated, or wavy with a striated surface. Straightedge blades with a flat surface are general-purpose and the most widely used, while the other types are more specific to certain types of fabrics. Striated blades are used to reduce heat buildup during cutting, wavy edges are used for plastics and vinyls, and saw-type blades are use for cutting canvas.

(ii) The base plate is the foundation that supports and helps balance the cutting mechanism. Bases vary in shape and size, depending on the size and weight of the knife it supports and the maneuverability needed. The base plate guides the knife in relation to the table surface and elevates the spread off the cutting table for contact with the blade. Base plates are supported by bearing rollers to facilitate maneuverability and ease of movement. Edges of the plate are sloped and the front curved to easily slide under the bottom ply and provide less fabric distortion and drag as it is maneuvered during cutting. The base plate helps maintain the position of the blade at a 90-degree pitch.

(iii) The power system controls the motor and the potential cutting speed. The amount of power needed to cut a spread depends on the height of the spread and the density of the fabric to be cut. The horsepower of the motor determines the amount of thrust or cutting power of the blade. Higher speeds allow operators to move knives faster. Greater horsepower increases machine power but it also may increase weight of the motor, which must be balanced by the blade housing and base plate. Larger, more powerful knives, which may weigh approximately 35 pounds, are often more cumbersome, heavier, and harder to manipulate and maneuver. Motors with variable speeds provide more versatility.

(iv) Sharpening devices appropriate for the specific blade type are found on almost all mechanized cutting equipment. Blades dull quickly when cutting deep spread or dense fabric. As a blade becomes dull, it creates friction and may cause rough, frayed, or fused edges. Sharpening devices may be stone or emery wheels or abrasive belt sharpeners. Cutting blades are sharpened frequently during the cutting operation simply by touching the control.

(v) All manually operated cutting devices have a handle for the operator to grip, guide, and propel the knife through the spread. The operator's other hand is used to stabilize the plies ahead of the knife to prevent bunching of fabric.

(vi) A blade guard, when positioned at spread height, rests on the top ply to help stabilize the spread and to protect the operator's hand. Metal mesh gloves are available as a safety device for cutters using vertical knives.

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