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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AUTOMATED COLOR ANALYSIS AND COLOR CONTROL OF DYEING INDUSTRY

AUTOMATED COLOR ANALYSIS AND CONTROL OF DYE HOUSE

It is worth remembering that in the past the assessment of color reproduction was exclusively entrusted to the ability and to the experience of the eye of highly skilled operators working on the color kitchen, whose judgment, however, could be influenced by a number of physical, physiological and psychological restrictions. The success and the development of electronics have deeply transformed the color control task thanks to the introduction of new measuring instruments, which have allowed definitely scientific and objective assessment.

All the systems currently available on the market have basically the same fundamental structure and differ only in their performance and in the algorithms adopted for color analysis. These systems generally feature:

1. A spectrophotometer, which measures the different spectral components of the sample analyzed. Today the measurement is carried out by means of a xenon flash, a prism separating the chromatic components and a CCD sensor (of the type used for modern solid state television cameras that have only a single row of light-sensitive elements or pixels), which reads the intensity of all the components simultaneously;

AUTOMATION IN TEXTILE FINISHING

AUTOMATED OPERATION OF TEXTILE FINISHING:
Automation in textile finishing industry is not a new concept, but it is being modern day by day. The textile factory is characterized by a considerable fragmentation of the production cycle into a number of segments specialized in the production processing of different fibres/yarns; even the single steps of automated production are often considerably fragmented, which entails the need for them to be perfectly organized for guarantee good final results of automated production. The Initial steps for production of the textile cycle are less fragmented but fragmentation unquestionably increases during the finalized finishing stage, for this reason the large amount of processes required by the market. Modern automation technologies for textile finishing based on electrical and electronics, computer programmability and smart systems show great potential for textile applications and currently aim to the achievement of important objectives such as flexibility and quality, according to three reliable paths:
1) The automated standardization of components
2) The automated compatibility of systems
3) The popularity of personal computers in case of textile finishing.

The automated standardization of components takes place thanks to the concentration of automation technologies in some basic types of automated processes which must be done by the mechanical forces by machine. The machine is defined and summarized by a system made of inputs and outputs for automated textile production system. Inputs of textile production are sensors which transform the physical variables of the system into electrical values which can be read and processed by an electrical and electronic unit. Outputs of automated production are the actuators controlling the machine and consequently the process (motors, solenoid valves, thermo resistors).

Any system may usually refer to this operating scheme and can be controlled by making inputs operating in relation to the state of the output and following a preset sequence of times. The computer, by means of the appropriate automated operating software, supplies the logical links between inputs and outputs and controls the right operating sequence for Automation in textile finishing industry.

Through its gradual introduction, automation has affected:
1. Machines: the immediate objective was the reduction and simplification of the operator’s tasks;
2. Processes: the subsequent evolution stage has ensured the links between the various production steps with the automatic control of the textile mill, leaving the operator with only control and supervision tasks. The full insolvency of the different production areas (inventory control systems, preparation of dyes and auxiliaries, dyeing equipment, material storage, etc) and /or services such as planning, laboratory, design pattern development, technological planning of cycles and production still needs to be addressed. The most advanced integration solutions available today are mainly production cells.

The main difference between automated systems essentially lies in the quantity of variables controlled. Here are the finishing segments most affected by technological development:
1. Color analysis
2. Process control
3. Production control systems
4. Color kitchen
5. Automated inventory control systems
6. Transport and robotized systems
7. Machine control systems

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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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NEW INVENTION IN TEXTILE DYEING AND FINISHING

Ultra and new modern technologies are always regarded as likely for dyeing and finishing of textile. Usually the process of textile dyeing and finishing are very slower and the process takes almost 8 to 12 hours for dyeing cotton knitted fabric with winch or jet  dyeing machine and almost 5 to 8 hours for finishing that fabric in finishing machine. It takes too much time, costly, labor depended. If we use new technology in textile dyeing and finishing, we will get a very good result.

 

On 16 January, the Hong Kong Productivity Council (HKPC) organized a seminar on dyeing/finishing and functional treatments of textiles. The seminar decision provides new perspectives on industrial upgrade by promoting new technologies in textile dyeing and finishing which both is energy saving and waste reducing. As part of the Cleaner Production Partnership Programme, the seminar aims at helping enterprises achieve green production and cost reduction at the same time.

Electrochemical Process Technology in textile dyeing and finishing:

A modern invention in textile dyeing and finishing is the development of Electrochemical process technology. Electrochemistry means the use of electrical energy in initiating chemical reactions, replacing traditional aid agents in direct chemical reactions. Taking sulphur dyes as example, in traditional technology, sulphides (such as sodium sulphide, Na2S) are used as reducing agents.

What ever the reduction process of dyeing is fast and direct, but it is wasted large amount of chemical energy and Green production has become necessary for enterprises under the update and conversion policy. The Hong Kong Productivity Council (HKPC) promotes new technologies in textile dyeing and finishing, injecting new thoughts to the industry.

New invention in Textile Dyeing and Finishing wastewater with high chemical oxygen demand (COD) value is produced, operation inefficiency become long-term. When electrochemical reduction is adopted, no reducing agents are needed and the

COD value of wastewater can be largely reduced, hence cost of wastewater treatment will be lowering. So using of direct electrochemical reduction is undoubtedly more efficient than the traditional technology, and the underlying chemical principle is also simple. However, as the stability and oxidizing/reducing power of different chemical substances are not the same, dyes can not be directly and effectively reduced by electrodes. Hence the scope of utilizing direct electrochemical reduction is quite narrow.

The system of indirect electrochemical reduction is the same, but in operation another strong oxidizing/reducing agent acts as medium, which makes the technology more applicable to different kinds of dyes. Taking indigo as example, traditional technology takes sodium dithionite (Na2S2O4) as a reducing agent, and the product should be re-oxidized in the air afterwards to fix the colour. Just like traditional reduction of

sulphides, large amount of chemical energy is wasted and wastewater with high COD value is produced.

Enterprises attempt to reduce the amount of sodium dithionite used in order to lower production cost, but such attempt produces other difficulties as well. For example, the oxidation of sodium dithionite can reduce by injecting nitrogen but is very costly. Addition of aldehydes or directly powering with electricity may devloped the reducing power of sodium dithionite, but the wastewater problem remains.

If electrochemical reduction is involved indirectly, sodium dithionite can replace as the reducing agent by the medium. The medium may supply both oxidizing and reducing substances and can regenerate so that both waste and pollution can be removed. Past experiments show that reduction by electrolysis can save about 90 percent of production cost when compared with reduction by sodium dithionite.

For reducing dyes, electrochemical process technology can be utilized in other aspects. Taking bleaching as example, the core principle of electrochemical mercerizing and bleaching is that bleaching chemicals can be produced by electrical energy and can be regenerated; hence the process is easily controlled, waste-reducing and energy-saving.

The process can be monitored so that bleaching occurs evenly. Also, the cost and danger of transportation is greatly reduced, particularly regarding hydrogen peroxide which is explosive.

Another emerging project is the technology of ozone electrolysis. Ozone is strongly oxidizing and can be used in decolorizing and other waterless dye treatments (e.g. ozone jets to prevent wearing out of jeans). As ozone can self decompose, it will not cause pollution problems once carefully treated. New perspectives on industrial upgrade by promoting new technologies which are both energy saving and waste reducing.

In conventional technology of dyeing with water, textiles should involved multiple processes with the help of aid agents, chemical salts, surfactants and reduction clearing agents. In contrast, for the supercritical waterless dyeing technology, only supercritical liquid is needed for dyeing and migration, after which the pressure and temperature can be lowered and the whole process is finished, without producing any wastewater. Also, as carbon dioxide automatically detaches from textiles and remaining dyes, the latter can be reused. More importantly, as operation procedures are reduced, the dyeing cycle is also shortened from several hours to 15 to 60 minutes; energy is also saved due to the lower operational temperature.

Regarding the cost, although the equipment required for the process is quite expensive, the supercritical substance (carbon dioxide) is cheap and the technology enjoys an overall advantage in cost. On the other hand, although the technology is not mature enough regarding application in natural fibres, the quality of the end-product made of synthetic fibres is high. Overall, the effects of interactions between different textiles with supercritical substances are yet to be fully discovered.

Plasma Treatment Technology in textle dyeing and finishing:

When a substance in its gaseous phase absorbs enough energy, the outermost electrons in the atoms will escape the nucleus’ control and become free electrons, while the atoms become positively charged. This chemical status of a substance is called plasma. As it is volatile, it can discharge electricity under certain physical conditions and react with other substances (including textiles), leading to various chemical fusions and fissions. These effects can alter the surface structure of textiles; hence plasma is suitable for surface treatment.

Since only the surface structure of materials is altered by plasma, the substrate characteristics of textiles will not be affected. Also, as small amount of plasma is enough to produce profound effect and one set of equipment can accommodate to different kinds of gaseous chemicals, the equipment is relatively cost effective and user friendly. The kinds of plasma undergoing testing are varied, including silanes (SinH2n+2) (waterproof), freons (increasing surface tension and oil- and dirt-proof effects) and phosphoruscontaining organic monomers (fireproof), etc.

Plasma treatment technology can also improve existing dyeing technology, including the newly developed technology of metallised fabrics. On the other hand, HKPC attempts to integrate plasma treatment technology and supercritical fluid dyeing technology, and replace supercritical fluid with plasma in the dyeing process. The lowpressure plasma dyeing technology is still being developed.

The textile dyeing and finishing industry is considered energy-wasting and highly-polluting, which will be forced to withdraw under the upgrade and transformation policy. However, with technological development on a full swing, traditional industries are able to overcome technical difficulties and revive after the financial crisis.

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DYEING WITH DYES

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DYEING

The color of a textile product may be its most important marketing attribute. It is the color of the dyed (or printed) fabric that first attracts and then draws consumers to particular items for sale. It is often the color of a product that sells the product. Dyeing is impregnating fiber, yarn, fabric or garment with a dyestuff. Dyes are colorants that are applied to, or formed in, a textile substrate in a molecularly dispersed form. they derive their color from the conjugated double bonds in their molecular structure.

The definition stresses that for use in textiles, dyes must be soluble or capable of being made soluble in the medium in which they are applied, or they must themselves be molecularly dispersible into the fibers. It is this property that distinguishes them from pigments. When a dye colors a fabric directly, without the aid of a fixing agent its called Direct Dye. In some other dyeing processes, a fixing agent is required to fix dye to fiber; the fixer is called mordent

Fastness of color is its ability to remain unchanged. Color fastness may be affected by such factors such as perspiration, dry cleaning, sunlight, salt water etc. Adding color to textiles, thus making fabrics marketable as fashion component, is a sophisticated and complex area where art and creativity meet with science and technology. Although the chemistry of dyes and dyeing are extremely complex, the development of electronic and computer science applied to the dyeing process has opened the world to rapid global trading and quick response systems. Matching shades of dyeing and the approval of colors may now be executed by phone and fax (without the necessity of seeing visual samples that must be sent by mail or courier) thus saving many weeks in international and domestic trade cycling. Details covering electronic and computer usage are included in this chapter as are explanations of the traditional processes of textile dyeing.

Although color is recognized as the most important element in textile sales and merchandising, it is also the source of most problems that consumers and the textile industry encounter in the production and use of fabrics. Fading, bleeding, color staining and color streaking are typical examples. Understanding the dyes and dyeing processes discussed in this chapter can aid in reducing or eliminating many of these problems.

Colorfastness of dyeing:

A fabric that retains its color during care and use is said to be dyeing colorfast. Fastness that is affected by the factors discussed above is an important concern of consumers. Small aggregates of dye molecules distributed evenly throughout the fiber make for a more satisfactory result than do surface applications of dyes. Fabrics may be more or less colorfast to a variety of different substances or conditions.

The importance of colorfastness of dyeing depends on the use of the fabric. Colorfastness to laundering is, of course, important in those garments and household textiles that must undergo frequent laundering. Some dyes are not fast to laundering but are fast to dry cleaning, or vice versa. Perspiration may cause some color change and/or color transfer, and some colors are may be lost or diminished by hear. Dyeinf colorfastness to sunlight may be important in evaluating the - usefulness of fabrics for curtains, draperies, carpets, and outdoor clothing in case of dyeing.

Light fastness of dyeing is usually a function of the dye structure rather than its retention within the fibers. The molecular structure that provides the color can be interrupted by light, particularly ultraviolet light. Additives or finishes are available to stabilize dyes from this type of action in case of dyeing.

Some dyes tend to crock, or rub off on fabrics or other materials with which they come in contact. Others will bleed into water during laundering and may be picked up by lighter-colored fabrics. Chlorine bleaches will remove color from most dyed fabrics, but some dyes are more sensitive than others to the action of chlorine bleaches of dyeing.

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MORDANTS; DYE FIXATION OF NATURAL DYES

BATCH DYEING OF WOOL WITH REACTIVE DYES

WOOL DYEING PROCESS WITH REACTIVE DYES
Batch dyeing of wool with reactive dyes is a very popular process. In batch dyeing process reactive dyes are usually applied to wool at pH 5–6 using ammonium salts, and acetic acid as required. At higher pH values, exhaustion is too low, and at lower values rapid dyes uptake gives unlevel dyeings in batch dyeing process. Slightly higher pH values are used for dyeing paler shades (pH 5.5–6.0) and lower values (pH 5.0–5.5) for deep shades in batch dyeing of wool. Fibre Reactive dyes often give quite good exhaustion at temperatures below the boil but the dyeing temperature will eventually be raised to 100 °C to ensure that reaction with the wool is as complete as possible. Some procedures recommend a holding stage at an intermediate temperature of 65–70 °C for 15–20 min to allow the dye to migrate before it reacts with the wool.

Batch dyeing machine for with reactive dyes.

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REACTIVE DYES FOR WOOL FIBRES - Details about wool dyeing,

Because of their tendency to give unlevel, skittery dyeings, reactive dyes are usually applied to wool in the presence of proprietary levelling agents in case of batch dyeing process of wool. These are often amphoteric, having both cationic and anionic groups in the molecule. In contrast to most levelling agents, which decrease the dyeing rate, the auxiliary products for dyeing wool with reactive dyes accelerate dyeing. The anionic dye complexes with the cationic site in the auxiliary product but the remaining anionic site provide substantivity for the wool surface. The bulky dye–auxiliary complex exhausts well onto the fibre surface at relatively low temperature, better than the dye alone, but cannot penetrate into the fibres. The complex breaks down as the dyeing temperature increases so that the smaller liberated dye molecules can then absorb into the wool. The use of such products avoids unlevel, skittery dyeings and provides better compatibility of dye mixtures during the batch dyeing.

Deeply dyed wool fibre or fabric with reactive dyes in batch dyeing process must be aftertreated to remove unfixed dye so as to give the best wet fastness. This is particularly important to ensure that there is no staining of adjacent undyed material during washing. After dyeing of wool with reactive dye, the material can be washed at 80 °C for about 15 min using a dilute ammonia solution at pH 8.0–8.5, and then rinsed in water with a little acetic acid. To avoid any alkali damage to the wool after batch dyeing, washing can be done with hexamine (hexamethylenetetramine from formaldehyde and ammonia) at pH 6.5, or with sodium bicarbonate. Certain proprietary chemicals can be added to the dyebath on completion of dyeing and their hydrolysis increases the bath pH to around 7. For example, hydrolysis of sodium trichloroacetate gives chloroform, carbon dioxide, both of which are volatile, and sodium hydroxide (Scheme 16.6). The actual colour removed may consist of unreacted dye, hydrolysed dye and products of the reaction of the dye with soluble wool hydrolysis products such as ammonia and hydrogen sulphide or amino acids.

Reaction related to dyeing wool with reactive dyes:

CCl3 CO2Na + H2O = HCCl3 + CO2 +NaOH

Shrink-proof wool, which has been treated with resins in the Hercosett process, remains cationic on the surface and gives rapid uptake of reactive dyes. The usual auxiliary levelling agents may be less effective in this case. The deposited resin protects the wool from damage and the best fastness results for deep shades are obtained by dyeing at 110 °C for 30 min.

Wool dyed in deep shades with reactive dyes is better protected from damage during dyeing. A number of explanations for this have been proposed. These involve protein chain crosslinking, reaction with thiol groups that interferes with 357 the reformation of disulphide links, and reaction with non-keratinous proteins in the cell membrane complex and endocuticle. So reactive dye is best for dyeing wool fibre in batch dyeing process but proper care should be taken other wise shade will be uneven.

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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.

Marketing of Man-Made Fibers

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Man-made fibres Market analysis:
Man-made fibres are marketed as commodities, as brand name fibers or as controlled brand name fibers. Fibers marketed as commodities are used without identification of source and are sold to any buyer in the open market. A dress labeled 100% Polyester has been made with commodity polyester fibers. Brand name man made fibers are identified by source through the brand names used. The fiber producer spends much Promotion money to establish his brand name and expects manufacturers, wholesalers and retailers down the line to take advantages of it. The man made fiber producer, however, frequently does not have complete control over the use of his brand name after the mill buys the finer. It is possible that a quality fabric could be used to make a poorly constructed garment and that this article would carry the fiber brand name on a label or hang tag. He controlled brand name approach enables the fiber maker to rigidly control the selling and subsequent use of the fiber.

Relationships are established with specific textile mills and fabric users who will utilize the fiber properly. A quality control program by the fiber producer insures that only products, which have satisfactorily passed various tests related to the end use, are allowed to use the fiber brand name. Unfortunately, consumer is usually unable to distinguish between a controlled brand name fiber and an uncontrolled brand name fiber.

Most of the fiber companies will sell their regular type fibers as a commodity as well as with a brand name. Under a licensed brand name or trademark program, the licensing company allows its brand name or trademark to be used by other companies in return for a specified remuneration.
In some cause, the product made by the licensee is carefully checked for quality by the licensor, but in other cases, it is not.

Man-made fiber producers license their Fiber brand names to certain mills that buy their fibers. The fiber brand name hangtags are later attached, for examples, to garments or draperies made from the licensed mill’s fabric. The fiber producer is compensated by receiving a slightly higher price from the mills than if the fibers were sold unbranded.

A licensed controlled brand name or trademark program means that the product also has satisfactorily passed various tests related to its end use before the brand name can be used. The tests are specified by the licensor. Such a program requires the maintenance of a quality control program to insure that the comp anises to which the trademarks or brand names have been licensed are making products that meet certain levels of quality.

In this way, the licensor can best attempt to insure that the brand name or trademark will not lose its value. Unfortunately, the levels or quality are not the same for each program and the consumer frequently does not know which controlled brand names indicate the best quality products.

The licensed controlled brand name programs of the textile industry became important in the early 1930’s when Cluett, Peabody & Company started to license their fabric shrinkage processes using the name Sanforired and Joseph Bancroft and Sons started to license their Everglaze Process, which insured fabric luster. In the 1960’s, the Celanese Corporations became the first major proponent among fiber producers of the licensed controlled brandname programs. Fabrics, as will as garments and other articles containing its branded fibers, had to pass specified quality tests before a Celanese hang tag would be placed on t he item. The program is still continuing.

The following are some of the textile licensed controlled brand name or trademark programs presently in use to market of man made fibre:

A. Polyextra ® textured polyester yarn program for upholstery fabrics—BASF Corporation.
B. Sanforized ® program for shrinkage control of woven fabrics and Sanforized Plus- 2 ® which is durable press program – Cluett, Peabody & Company;
C. Trevira ® polyester program for fabric quality – Hoechst Celanese Corporation;
D. Zepel ® program for fabric water and stain repellency quality
E. I. Du Pont de Nemours & Company. Inc.

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FABRIC RESOURCES

Primary Sources of Fabric
A primary source of fabric is a company that makes or creates the material. The Firms in this category are mills and mills and converters. Some of the mills produce woven fabrics exclusively; others make only knit fabrics, while some of the giant mills manufacture both.

In the Primary fabric market, most sales are based on contracts with shipments to be made months later. The converters and mills work closely with their customers designer’s and merchandisers to create designs and working samples. Sales of fabric either in inventory or about to be ready for sale (called spot or nearby goods) also occur, but on a much smaller scale. Unusually, very small orders will not be take, this being the function of the jobber.



 Fabric Resources (Mill)
The mill is a company that owns textiles machinery and makes fabric. The large textile mills are vertically integrated. They not only make the fabric, but also produce their own yarn and perform the finishing processes required after the fabric has been completed. However, they do not make their own fibers.
The mills sell their finished fibroin to various customers. The converter, discussed in the next section, is a major buyer.

Garment and home furnishings manufacturers use fabrics in making their products. Jobbers, who help dispose of excess or surplus merchandise for the mill, are another customer. Large retail stores, which in turn sell to the home sewer, also buy from the mills. Most of the staple fabrics are sold by the mills. A staple fabric is one, which is produced continuously each year with no change in construction or finish, and includes poplin, taffeta, tricot and sheeting. There are, however, many fancy or novelty fabrics also offered for sale by the mills.

The converter is an individual or organization that buys greige (or grey) goods (unfinished fabric), usually from mills, has the fabric dyed or printed and finished buy other companies, and then sells the finished fabric. All aspects of the fabric, including construction, design color and finish, are determined by ther converter.

Fabric Resources (Importer)
Many textile fabrics (and yarns) are made overseas and then imported into the United States. Since about 1980 the volume of textile imports has risen dramatically and today accounts for a large percent of the fabrics used domestically. While the greatest amount of textiles and textile products comes from the Far East. They are also received from many other parts of the world.

The textile importing companies are of two types. The direct importer buys fabrics or manufactured textile products (e.g.., clothing or soft luggage) from a foreign mill or other supplier. The other type, the import mills, is a foreign company that owns textile machinery and makes the fabric (or yarns) that is then exported. A secondary source of fabric is a company, which buys cloth and then sells it. Such a company is not involved in the making or creating of the material. Therefore, any seller of fabric other than mills and converters is considered a secondary source.

Fabric Resources (Jobber)
The jobber buys from mills, converters and garment manufacturers and other users. Although their purchases of a specific fabric type. Print or color are usually relatively small, jobbers nevertheless are valuable customers of the mills and converters. Jobbers often buy mill or converter fabrics that would otherwise be difficult to sell, including discontinued styles and colors and mill overruns. ( A mill overrun or tailing occurs when a mill produces more dyed, printed or finished fabric than the order specified . An overrun occurs for various reasons, including allowances for damaged yardage and short pieces unacceptable to the customer.) The jobber also sometimes buys fabric from users who have excess cloth. The excess cloth usually results from a decline in anticipated sales.

Fabric Resources (Retail Store)
Fabrics sold in the retails store are called over the counter sales and are bought by home sewer for their own needs. Put-up is the tern used to indicate the way fabric is packaged when it is sold. Most fabrics sold to garment and other manufactures are in a rolled, in either open width or tubular form. Some fabrics are doubled and rolled. Such fabrics are folded in half lengthwise, and then wound around a flat piece of cardboard. Cloth when sold to retail stores is usually in this put-up, in under 30 yard lengths. Velvet and other plush fabrics are usually not rolled because.

The resulting pressure would flatten the surface. The fabric is placed on a frame so the surface3 doses not contact any other part of the cloth. Pieces of woven fabric less then 40 yards in length are called shorts. These pieces are usually sold in either 20 to 40 yard pieces ( called 20 ‘ to 40 ‘s ), 10 to 20 yard pieces ( called 10 ‘s to 20’s ) or 5 to 10 yard pieces (Called 5’s to 10’s). Jobbers normally are the buyers of these short pieces of woven fabric.

Pound goods are usually very short pieces of fabric (often containing pieces less than one yard in length). They are sold by the pound and not by the yard. Fabric that cannot be sold in nay other manner is sold this way. These goods are bought at the buyer’s risk and receive the lowest price. End cases include stuffing for furniture and clothes for dolls.


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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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FABRIC DICTIONARY (E-BOOK FOR FREE DOWNLOAD)

Textile fabric dictionary or glossary of fabric terms and definitions is an important free e-book for textile engineering, fashion design or apparel merchandising students. I try to provide important textile terms and definitions on knitted, woven and non-woven fabric in this free e-book.

This Complete Textile Fabric Glossary is intended to be a convenient reference for textile terminology. Although it covers all types of textile terms broadly, its special emphasis is on manufactured fibers - what they are, how they are produced, and how they are used.

The first edition of this textile fabric dictionary was published as a book by Md Tariqul Alom Ansari in Bangladeshi market. The author is my friend. By taking his permission, I try to publish his TEXTILE FABRIC DICTIONARY book in my blog as an e-book. With in short days, I am going to publish the full edition of this book named by “TEXTILE FABRIC DICTIONARY; GLOSSARY OF TEXTILE FABRIC TERMS AND DEFINITIONS”. It must be pdf file formatted free e-book.
Let see the Fabric dictionary:

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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