ttqc 3

INTRODUCTION

NAME:MD MONJURUL ALAMPROGRAM:BSC IN TEXTILE

ID:141-23-134

Basic ConceptOf

Quality

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Quality? The totality of features and characteristics of a product or

service that bear on its ability to satisfy stated or implied needs

The degree of excellence that a product posses.

Quality refers to the characteristics of a product or service that defines its ability to consistently meet or exceed the customer demand.

My perception about quality: The Quality of a product is like the blood of a human body.

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Aspects of quality Performance: This refers to appropriate functionality of the product

or whether the product performs satisfactory as desired or expected by the customer.

Conformance: Conformance means as per specification. It refers to how well or accurately a product or service correspond to designed.

Reliability: It refers to the ability of an item to perform a required function under stated conditions for a period of time.

Durability: This refers to useful technical life or longevity of performance of the product or service.

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Aspects of quality Innovative features: Innovative features refers to extra useful

characteristics of the product ,more than the desired primary ones

Service after sale: For many years, Service after sale had been considered as an extra business. But, now-a-days, because of increased focus on customer satisfaction, service after sale is considered as part of the product.

Maintainability/serviceability: Maintenance and servicing of engineering products are of importance now-a-days to a large cross-section of customers.

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Aspects of quality Ease of use: One of the recent trends of customers quality

requirement is ease of use of product. Customer never like a product which is complex to use. Thus, ease of use has become one of the major aspect of quality.

Aesthetics: Aesthetic of product, especially in case of customer goods, is a utmost importance to customers. Thus, aesthetic is also an important aspect of quality.

Others: Now-a-days, many other aspect, such as safety, health issues etc. are considered as part and parcel of quality.

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Factors affecting quality Customer: They are the ultimate users or beneficiaries of quality.

As such, any quality management drive should focus on this element while preparing a quality plan.

Processes: This element is responsible for transforming the inputs to quality outputs. Traditionally, people used to think that the process is only factor which needs to be controlled for ensuring quality. Modern quality management views that employees and materials should be responsible for quality.

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Factors affecting quality Employee: Now-a-days, role of employee in delivering quality

product is valued highly. Employees are considered as internal customers, who need to be kept satisfied in order to deliver quality product. Thus, they should be trained regularly with high degree of motivation and skill.

Materials (Suppliers): Role of suppliers in delivering quality goods is now well recognized. A good manufacturing process does not have much to contribute to quality if supplied materials are not of enough good quality.

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Quality Control?

Quality control can be defined as the checking, verification and regulation of degree of excellence of an attribute or property of something.

The operational techniques and activities that are used to fulfill requirements of quality.

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Type of quality controlMainly 2 types of quality control:

i) Process control ii) Product control

i) Process control: Controlling of process sequence or steps to produce desired quality product is called process control.

ii) Product control: The control which is used to decrease defective items within different lots of produced good is known as product control.It is applied after production process

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Type of quality controlProcess control is two types:

a) Online quality controlb) Offline quality control

a) Online quality control: This type of quality control is performed in process stage i.e. without stopping the production process, during the production running time, the machine automatically tests the variation and takes immediate step to rectify the variation.Checking and rectification of variation/fault in processing stage is known as online quality control.

Example: #Roving tension control device in simplex machine. #Sliver hank is controlled by autoleveller in carding & draw

frame.

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Type of quality controlb) Offline quality control: This type of quality control consists of laboratory tests which are done by stopping the production process.

Here necessary steps are taken according to test result.

Example: #Checking of count and TPI variation #Strength testing #Evenness testing

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Textile testing? Laboratory experiment to determine textile data of fibre,

yarn, fabric and end use product.

Textile testing is the application of engineering knowledge and science for the measurement of properties and characteristics of textile materials (Fibre, yarn, fabric etc.)

It involves the use of techniques, tools, instruments and machines in laboratory for the evaluation of the properties of these different textile materials.

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Importance of textile testing

To determine the properties and characteristics of fibre yarn, fabric and end product.

To compare the qualities of textile raw materials, intermediate products and finished products.

To maintain the standard established by different organization. Example: ISO, AATCC.BSTI etc.

To meet market and consumer demand standard.

To improve and control processing techniques for research and developments.

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Factors affecting test result

The sampling

Atmospheric condition for testing

Method of testing

Instrument used

Efficiency of the technicians

Etc.

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Application of Quality Control in

Spinning

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Critical difference(CD): Critical difference is a measure of the difference between two values

that occur due to normal or unavoidable causes.

When the difference between two values exceed that of the critical difference, the two values are said to be statically different.

Critical differences depends on:

i) CV%ii) No of test.

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Calculation of CD% CD%(New)=CD% (table)√(N1/N2)

Here, N1=Number of test recommended in the table N2= Number of test actually conducted

Table-1: No. of test and critical difference (%) for various fibre properties:

Fibre Property No. of tests CD(%)2.5% span length 4combs/sample 4Uniformity ratio 4combs/sample 5Microniare value 4plugs/sample 6Fibre strength 10breaks/sample 5Trash content 8 test/sample 7

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Calculation of CD%

Yarn Property No. of tests CD(%)Lea count 40 2Strength 40 4Single yarn strength 100 2.8Evenness 5 2.8

Table-2: No. of test and critical difference (%) for various yarn properties:

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Problem Problem-1

A mill wanted to purchase a cotton of 3.7 microns value to spin 50s count. The sample cotton received from a party was tested for micronaire and it was found to be 3.9 ( on the basis of 4 test).The mill is interested to know that whether the sample cotton conforms the mills requirements.

Problem-2. Mill C received 5 cotton samples from A & B. Their strength value were found to be 22 g/tex and 24 g/tex respectively (based on 5 tests). Which decision was taken by the mill?

Problem-3. Mill Z received yarn sample from gulshan spinning mill and karim spinning mill. Their strength was found 20 g/tex and 22 g/tex (Based on five tests). Which dicision will be taken by the mill?

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Uniformity ratio Staple length: Staple length is defined as the length of a

typical portion of sample of fibres i.e. full length or end to end length.

Span length: Span length is defined as the distance exceeded by a specific% of fibres extending from a random catch point.

2.5% Span length: 25% span length is defined as the distance of 2.5% of the fibres extended from the clamp where they are caught at random along their length.

50% Span length: 50% span length is defined as the distance of 50% of the fibres extended from the clamp where they are caught at random along their length.

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Uniformity ratio Uniformity ratio: Uniformity ratio is defined as the ratio of

50% span length to the 2.5% span length expressed as a percentage.

The uniformity ratio is a measure of the length variability of cotton fibre. If the uniformity ratio increases then the variability will be decreased.

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Yarn FaultThe undesirable and sometimes unavoidable defects that are found

in yarn are known as yarn fault. It is impossible to produce fault-free yarn. So the spinners try to produce yarn with considerable limit of fault.

Faults found in yarn are:

Count variation Unevenness & irregularity Frequently occurring fault Seldom occurring fault Hairiness Lot mixing

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Types of Yarn Fault Count variation: According to the textile institute, “ Count is

the mathematical expression of fineness which expresses the length per unit weight of weight per unit length”. Practically ± 3 count variation is acceptable. Count can be measured by wrap reel and balance or using count measuring software (CMS).

Unevenness or irregularity: It is the mass variation per unit length. Cut length is taken generally 1cm. This fault is expressed as U% or CV%. Evenness tester is used to measure unevenness.

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Types of Yarn Fault Frequently occurring fault: These faults occur in yarn 10-5000

times per 1000m of yarn. Yarn spun from staple fibres contains ‘imperfection’ which can be subdivided into three groups. These three faults are normally measured in no. of faults per 1 km. These types of faults are determined during evenness testing with imperfection indicator.

Here, D= Dia of normal yarn

Imperfection X-sectional size Fault length Thin place D-(30 to 60)% of D 4 to 25 mmThick place D+(35 to 100)% of D 4 to 25 mmNeps D+(40 to 400)% of D 1 mm

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Types of Yarn Fault Seldom occurring fault: These faults are referred as yarn fault

and characterized in the form of thick and thin places in the yarn which are so seldom-occurring that for their determination at least 1000 km of yarn must be tested.

Here, D= Dia of normal yarn

Fault Name Thickness Fault lengthShort Thick place Above +100% of D Approx. 0-8cmLong Thick place Above +45% of D More than 8cmThin place Above -30% of D More than 8cm

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Types of Yarn Fault Hairiness: Hairiness means the protruding fibres on yarn surface.

It is the ratio of the total length of hair in any unit to the length observed in same unit. Generally it is measured as the ratio of total length of protruding fibres (in cm) per cm of yarn. The hairiness value is the ratio of two lengths; so it has no unit.

Lot mixing: Sometimes two lots can be mixed at the stage of sliver, roving, bobbin, cone and cartoon in spinning mill, as well as in the preparatory section weaving and knitting mill. This type of mixing causes several problems in subsequent process.

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Causes of imperfection Causes of thick & thin places:

1. Short fibre content2. Improper draft3. Poor efficiency of carding & combing4. Twist variation

Causes of Neps: Immature fibre Improper ginning Improper carding speed & card setting Less efficiency of card Improper drafting speed

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Factors Affecting Yarn Strength1) Quality of Mixing:

Fibre Properties: Better length, strength & fineness of fibre gives better yarn strength.

Mixing Ratio: Proper mixing leads to higher & uniform yarn strength.

2) Quality of carding:

Mechanical condition of all carding surface Waste control in carding action Proper maintenance

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Factors Affecting Yarn Strength3) Quality of comber:

Level of comber waste. Mechanical condition of comber.

4) Quality of drafting at ring frame:

Mechanical condition of the drafting system. Total draft. Break draft. Types of drafting system

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Factors Affecting Yarn Strength5) Quality of twisting at ring frame:

Amount of appropriate twist. Level of twist Uniformity of twist

6) Other processing factor:

Atmospheric condition Static electricity Direction of feeding of fibre hooks.

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Fibre testing equipments HVI: For fineness, color, trash, length & strength measurement.

AFIS: For neps, size of neps, fibre length, short fibre content, fineness, immature fibre content, no. and size of trash measurement.

Shirley Analyser: For trash content measurement.

Nep counter: For fibre length, neps, short fibre measurement.

Moisture Regain tester: For MR% testing.

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Lap, Sliver & Roving testing equipments Lap length counter

Balance, Scale, Wrap block: For testing sliver & roving testing.

Nep counting board

Auto sorter: For sliver count testing.

Evenness tester.

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Yarn testing equipments Wrap reel and balance: Yarn count testing Auto sorter: For count & CV% analysis Evenness tester: yarn imperfection, U%, hairiness etc. Uster classimate: Yarn fault analysis. Yarn tension meter Twist tester Yarn strength tester

Software:

BIAS: For bale management CDS: For Automatic count measuring

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Quality Control in

Fabric Manufacturing

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Points to be maintained for quality winding

Appropriate winding tension

Free from different count mixing

Winding machine should be free from mechanical fault (For example, Free from defective traversing motion, fault free yarn guide etc.)

The knots & splices must have sufficient strength and stability.

Winding should be carried out at high speed in order to get high productivity. At high speed less time & auto coner will be required.

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Factors affecting the quality of warping

Condition of the beam flange: If the beam flange get damaged then unwinding at the two edges will not be satisfactory. There will also be problem in sizing and weaving. Beam flange get damaged due to improper handling and improper storage. Empty bobbin should be checked on a regular basis and repairment should be done on a regular basis.

Stop motion: Stop motion should be capable of stopping the machine immediately after any end break. Sometimes flying dust and tufts gets stuck in the stop motion so that the machine does not stop even after any end break. Creel fans should work properly.

Beam barrel diameter: Smaller dia gives high unwinding tension during sizing, though it can accommodate more yarns.

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Factors affecting the quality of warping Condition of the driving drum: Driving drum is used to drive

the warp beam by means of frictional force. In case of modern machines the warp beam is driven directly, however a drum is used to stop the rotating beam instantly. Any roughness of the drum is therefore dangerous for the safety of the yarn.

Length measuring motion: This device should work properly. Miss representation of the actual length may cause unnecessary wastage or shortage of yarn. The size% calculated from the length of the yarn. So a wrong length measuring will lead to incorrect estimation of the size%.

Density of the beam: In order to obtain satisfactory result the warp beam must be sufficiently compacted. The compactness should not be achieved by means of yarn tension rather it has to be achieved by means of creating pressure by drum

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Factors influencing size pick up % Viscosity of the size paste in the size box

Squeezing pressure & condition of squeezing nip.

Yarn tension

Yarn twist

Speed of the sizing machine

Duration of immersion in the size paste

Level of size paste

Density of the warp

Dia of the yarns

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Factors influencing drying efficiency Speed of sizing

No of end in warp sheet (density)

Pick up % of size to be applied

Linear density of warp

Box concentration

Temperature of the drying cylinder

Area of contact around the cylinder

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Consequences of fabric defects

The customer (garments manufacturer) may totally reject the defective fabric.

If the rate of defect is not very high in that case fabric is accepted with certain penalization in terms of either reduction of cost of the fabric or additional fabric is demanded by the buyer. This means that fabric defect may ultimately reduce the profitability of the concern entrepreneur.

The garment manufacturer will be in trouble in handling a defective fabric in the cutting table.

In spite of all preventive measures, garments are produced with fabric defects that result in ultimate rejection of the particular garment or even rejection of the whole lot.

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Knitting faults Loop length variation: This problem arises in weft knitting due

to-1. Fluctuation in yarn variables2. Fluctuation in machine variables

1. Fluctuation in yarn variables: Yarn variables are-

a) Yarn count b) Twist c) Package hardness d) Flexibility e) etc.

2. Fluctuation in machine variables: Machine variables include-

a) Temp. b) Machine gauge b) Cam setting d) Yarn tension e) Fabric take-down tension f) Needle & sinker timing.

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Knitting faults Barre: This defect occurs in circular knitting machines due to-

1. Lot mixing of yarn2. Variation in package hardness3. Improper yarn tension4. Uneven dyed yarn

Holes: Holes are caused by-1. Broken needle2. Less strength of yarn, which breaks during loop formation3. Presence of mineral particle in fibre/yarn ( In this case, hole is

created during bleaching)

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Knitting faults Lycra out: This fault is occurred if the machine is not

immediately after the breakage of lycra during production. It is happened due to-

1. Careless supervision2. Faulty auto stop motion

Needle mark: Needle marks is caused by the defective needles and faulty needle setting.

Oil staining: Oil staining is occurred due to dirty machine or improper lubrication.

Fly yarn: This fault is occurred when the flying yarn get mixed with the yarn during knitting.

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Knitting faults Crease mark: Crease mark is caused by-

1. Yarn tension variation2. Lower GSM of fabric3. Faulty fabric take-up

Drop stitch: Main causes of drop stitch are- Defective needles Wrong setting of yarn feeder. Bad take up.

Sinker mark: Sinker mark is caused by the defective sinker. Etc.

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Fabric Quality Affected During Weaving

Fabric width Fabric length EPI in the fabric PPI in the fabric GSM Design of fabric Softness of fabric Air permeability of fabric Water permeability of fabric Strength of fabric Appearance of fabric

Of them fabric length and width may be decreased due to shrinkage. EPI and PPI may also be increased due to shrinkage of fabric.

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Common defects of woven fabrics

Bar: It is a band running across the full width of cloth due to difference in appearance from its adjacent surface. This term covers a number of specific defect as below:

1. Pick bar: A bar due to difference in pick spacing. The causes of pick bars are faulty gearing in take-up motion.

2. Starting mark: An isolated narrow marks along the pick. It is occurred due to restart of weaving after- a) Unweaving or Pulling back b) Prolonged loom stoppage.

3. Tension bar/Shiner: A bar due to difference in weft tension.

4. Weft bar: A bar due to difference in count, twist, luster, color or shade of adjacent groups of weft yarns

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Defects of woven fabrics Box mark: Box mark is a widthwise fine line showing stained or

injured weft due to the rubbing of shuttle when it rebounds. The causes of box mark are-

1. Dirty box2. Dirty shuttle3. Weft flying too freely4. Etc.

Broken pattern: This defect may be due to wrong drawing of threads, insertion of pick in wrong shed, incorrect lifting of warp threads.

Broken pick: A pick missing from a portion of the width of the fabric due to rough shuttle eyes, poor winding, weft yarn breakage, improper pirn insertion etc.

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Defects of woven fabrics Cut weft: It is occurred due to weak weft. It is like a pin hole.

Defective selvedge: There may be various types of defective selvedges as stated below:

1. Curled selvedge: It is occurred due to incorrect balance of cloth structure between body and the selvedge.

2. Cut selvedge: This is the selvedge with cuts or tears due to selvedge sticking to emery cloth.

3. Uneven selvedge: It is occurred due to variation in weft tension.4. Etc.

Fuzzy: This is the fibrous appearance of the cloth due to presence of hairy or abraded yarn

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Defects of woven fabrics Missing ends: The most common missing end is characterized by

a gap of one or more warp ends in the fabric.

Reed marks: Due to this fault, cloth shows irregular spacing between groups of warp yarns across the fabric width. It may be caused by damaged or defective reed.

Shuttle marks: Width wise marks due to abrasion of warp yarns by the shuttle.

Stains: Stains are major problem on woven fabric. Oil grease, dust, soil, carbon particles in the air, sweat etc. are the causes of stain. Most of the stains are caused by poor material handling and carelessness of workers. Certain stains can be removed by solvents.

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-Quality Control

in Wet Processing

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Properties of raw materials for dyeingRaw materials Desired PropertiesGrey Fabric 1. Free from stains

2. Free from foreign matters and contamination

3. Free from manufacturing defectsCloth for dyeing 1. Good absorbing capacity

2. Free from impurities3. Even whiteness4. Smooth surface

Dyestuff 1. Sufficient strength of required quality2. Good fastness properties3. Availability of data and shade card

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Properties of raw materials for dyeingRaw materials Desired Properties

Chemicals and auxiliaries

1. Required purity2. Required strength and concentration3. Good efficiency4. Compatibility

Water 1. Softness, free from iron and metal salts2. Neutral pH 3. Required ppm of water ingredients

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Qualities of dye house water

Standard Permissible Concentration

Color Colorless

Smell OdourlesspH Value Neutral (pH=7)

Water hardness ‹ 5 degree dH

Dissolve solid ‹ 1 mg/L

Solid deposit ‹ 50 mg/L54

Qualities of dye house water

Standard Permissible Concentration

Organic Substance ‹ 20 mg/L

Organic Salts ‹ 500 mg/L

Iron ‹ 0.1 mg/L

Copper ‹ 0.005 mg/L

Nitrate ‹ 50 mg/L

Nitrite ‹ 5 mg/L55

Estimation of Scouring Effect

1) Determination of weight loss%: The weight of unscoured and scoured sample is taken at same MR% and from these figures weight loss% can be calculated from the following formula:

Weight loss={(Wt. of unscoured sample - Wt. of scoured sample)/ Wt. of unscoured sample}*100%

The standard weight loss is (4-8)%

If it is 8% then we may say that the sample is well scoured, but if it is more than 8% then it is not acceptable as it indicates that the fibre damage has been taken place. If it is less than 4%, it shows that the sample is not well scoured and there are some impurities still present in the sample.

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2) Absorbency test: 3 types-

a. Immersion test b. Drop test/ Spot testc. Wicking test

a. Immersion test: A sample is more absorbent when it is scoured. 1 cm×1 cm sample is placed on a water surface and time taken by it to be immersed is noted. The standard time is 5 second. It is up to 10 second. If it is greater than 10 second then it indicates that the scouring has not taken place properly.

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b. Drop/Spot test: Colored solution of 0.1% direct dye (Red) is used. The solution is dropped on to the sample by pippet and its absorbency is examined visually. The drop may have the following shapes:

Two things can be measured:* The time taken in second to absorb one drop of solution is

measured. Standard time is (0.5-0.8) sec; upto 1 sec is allowed. It may vary person to person’s perception.

* If the drop is circularly absorbed then we may say that the sample is uniformly scoured. If the drop is circular but has small area then the sample is uniformly scoured but not well scoured. If it is almost circular then it is uniformly scoured too. If not circular then it is not uniformly scoured.

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C. Wicking test: A sample of 5 cm x 18 cm is taken and a mark is made at 1 cm from bottom. Then 1cm portion is immersed into 1% direct dye solution for 5 minutes and then the distance traveled by the colored solution above 1cm mark is noted. The acceptable range is (30-50) mm.

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Fig: Wicking test

Sample (5cmmx18cm)

1% Direct dye solution

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Estimation of Bleaching Effect

Measurement of reflectance by Leucometer:

The light reflectance capacity of a bleached fabric is higher than of unbleached fabric. Standard bleached fabric has a reflectance of (84-86)%. The reflectance can be sometimes increased to (90-95)%. But it is very risky and such high bleaching can be done in kier boiling and in a very high temperature of about (110-120) °C. Such high percentage of reflectance may be accompanied by strength loss.

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Estimation of Mercerizing Effect

Determination of Barium Activity Number (BAN): This is the most effective test. Barium Activity Number is defined as the ration of the amount of Ba(OH)2 absorbed by mercerized sample to the amount of Ba(OH)2 absorbed by same amount of unmercerized sample expressed as a percentage.

BAN=(Ba(OH)2 absorbed by mercerized sample/Ba(OH)2 absorbed by same amount of unmercerized sample ) x 100

If the mercerization happens the percentage will be greater than 100 (usually 115-135 is acceptable).

Below 115 indicates mercerization has not been taken place and it will result uneven dyeing. 127 indicates very high rate of mercerization. If the result is 100 then it indicates that no mercerization has happened.

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Important Functions of QC Lab of a Modern Dye House

1. Judicious selection of raw materials.

2. Important in process quality control at all strategic points in processing.

3. Accurate evaluation of the end product for conformation to laid standards.

4. Planned research and development programmme.

5. Development of auxiliary product for in-house consumption.

Of the above, the first and third functions are routine quality control job. The second function is related to process control at every stage in day to day working to avoid damage or reprocessing. The last two functions are concerned with ultimate cost reduction and upgrading of quality of process material.

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Causes of Shade Variation in Dyeing Variation in fabric preparation

Difference in fibre strength

Difference in quality of dyes, chemicals and water

Variation in length of fabric in batch

Wrong formulation of dyeing recipe

Improper maintenance in dyeing operation

Selection of wrong dyeing parameters

Wrong measurement of materials

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Fastness Definition: Fastness is the resistance of

textile materials to resist a load or destructive factor such as abrasion, heat, light, perspiration, wearing, acidic and alkaline conditions.

Categories of fastness: Producer’s fastness User’s fastness

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Fastness Color Fastness Test:

Light fastness Washing fastness Rubbing fastness Perspiration fastness Hot-pressing fastness Water fastness (Chlorinated, Sea, Saline water) Color fastness to bleaches and chemicals.

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Factors affecting colorfastness

the molecular structure of the dye

the manner in which the dye is bound to the fibre, or the physical form present

the amount of dye present in the fibre

the chemical nature of the fibre

the presence of other chemicals in the material

the actual conditions prevailing during exposure.66

Fastness Strength Test:

Breaking Strength Tearing Strength Bursting Strength Seam Strength

Performance Test: Pilling Resistance Abrasion Resistance Water Repellency Flammability Air permeability Etc.

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Fastness Objects of Fastness in Testing:

Research Selection of raw materials for manufacturing Process control Process development Products development as per standards Specification testing Etc.

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Fastness Scales for Assessment:

Numerical Rating Meaning 1 Poor2 Moderate3 Average4 Good5 Excellent

1. Grey Scale:

a. Grey Scale for Color Changeb. Grey Scale for Color Staining

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FastnessGrey Scale for Staining

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FastnessGrey Scale for Color Change

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Fastness Color Matching Cabinet/Light box:

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Fastness 2.Blue Scale

Numerical Rating Meaning 1 Little2 Poor3 Moderate4 Average5 Good6 Very Good7 Excellent8 Maximum

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Fastness Washing fastness:

Color fastness to wash is very important for dyed materials. There are varieties of testing procedure, because:

Washing condition may vary from one country to another

The methods depends on the use of dyed goods To evaluate, repeated washing accelerated test methods

are used.

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FastnessThe degree of fading and staining of dyed materials

for washing depends upon the following factors:

Temperature range may be from 40°C to 95 °C The type and amount of detergent added to the washing bath. In

many testing procedure a standard detergent is used. The extent of mechanical action which can be varied by changing

the agitation speed in a washing machine or by adding steel ball to revolving bath.

The washing liquor to goods ratio. The hardness of water The rinsing, drying or pressing methods used to restore the sample

after the washing test.

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Fastness Principle of washing fastness:

A specimen/dyed material in contact with specified adjacent fabric (MFF) is laundered, rinsed and dried. The composite sample is treated under appropriate condition in a chemical bath for recommended time. The abrasive action is accomplished by the use of liquor ratio and an appropriate number of steel balls. The change in color of the dyed sample and the staining of the adjacent fabric (MFF) is assessed by recommended grey scale.

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Fastness Apparatus and materials:

Wash-wheel with a thermostatically controlled water bath and rating speed of (40± 2) rpm.

Stainless steel container. Stainless steel ball (dia=0.6 cm, weight=1gm) Multifibre fabric (Acetate, Cotton, Nylon,

Polyester, Acrylic, Wool) Thermometer Dryer Color matching cabinet ISO scales

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FastnessTest Specimen: Cut a sample of dyed goods (10 cm x 4 cm) and sew it with same size multifibre fabric. This the composite test specimen.

Specimen

Acetate Nylon Acrylic

Cotton WoolPolyester

Multifibre Adjacent Fabric

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Fastness Test Procedure: Any one procedure recommended by ISO.

Test Temperature (°C)

Time(MIN)

Steel Ball Chemicals

Iso-105-CO1 40 30 0 Soap(5 g/l)

Iso-105-CO2 50 45 0 Soap(5 g/l)

Iso-105-CO3 60 30 0 Soap(5 g/l)+Soda(2 g/l)



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Fastness Evaluation: Compare the contrast between the treated and

untreated sample with grey scales for changing color of dyed sample and staining of adjacent fabric in a color matching cabinet.

Reporting format:Test Description Result

Color fastness to wash GradeColor change in dyed sample 4Color change in shade staining in acetateColor change in shade staining in cottonColor change in shade staining in NylonColor change in shade staining in PolyesterColor change in shade staining in acrylicColor change in shade staining in wool

444-54-544

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Standards Something that is established by authority, custom or

general consent as a model or example to be followed.

Something established for use as a rule or basis of comparison in measuring or judging capacity, quantity, content, extent, value, quality etc.

The type, model or example commonly or generally accepted adhered to; criterion set for usage or practice.

According to ISO, standards are documented agreements containing technical specifications or other precise criteria to be used consistently as rules, guidelines or definitions of characteristics to ensure that materials, products, processes and services are fit for their purpose.

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Standards Benefits of Standards:

Standards facilitate communication and prevent misunderstanding

Standards make parts interchangeability possible and as a result mass production is possible

Standards can be used in marketing strategy to promote purchase of products that meet nationally recognized requirements, especially, when conformance is backed by a certain program.

Standards reduce cost and save money.82

Standards Sources of Standards:

Standard Full NameASTM American Association for testing and

materialsAATCC American Association of Textile

Chemists and ColoristsANSI American National Standards InstituteBSI British Standards InstitutionISO International Organizational for

StandardizationBSTI Bangladesh Standards and Testing

Institute83

Standards Sources of Standards:

Standard Full NameCGSB Canadian General Standards BoardAS Standards AustraliaDIN Deutsches Institute Fur NormungJIS Japanese Standards AssociationNF Association Trancaise de NormalizationUS CPSC The US Consumer Product Safety CommissionANSI American National Standards Institute

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StandardsISO

Worldwide federation of national standards bodies from nearly 140 countries.

Established in 1947 to promote development of standardization of related activities in the world.

Mission is to facilitate the international exchange of goods and services and to develop cooperation in the sphere of intellectual, scientific, technological and economic activity

ISO publishes various international agreements as international standards.

ISO sets standards for many diversified field like information, textile, packaging, distribution of goods, energy production and utilization.

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StandardsISO 900 Series Standards

The ISO 900 series is a set of five individual, but related, international standards on quality management and quality assurance. They are generic, not specific to any particular products. They can be used by manufacturing and service industries. They are:

ISO 900: It is the first standard in the series and is entitled “Quality Management and Quality Assurance Standards-Guidelines for Selection and Use”.

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StandardsISO 9001: Quality system model for quality assurance in design, development, production, Installation and servicing.

ISO 9002: Quality system model for quality assurance in production, Installation and servicing.

ISO 9003: Quality system model for quality assurance in final inspection and testing.

ISO 9004: Guidelines for quality management and quality system elements.

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StandardsInternational Environmental Standards-ISO14000

The ISO 14000 series, currently being developed by the International Organizational for Standardization (ISO), is a collection of voluntary standards that assists organizations to achieve to achieve environmental and financial gains through the implementation of effective environmental management. The standards provide both a model for streamlining environmental management and guidelines to ensure environmental issues are considered within decision making practices

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StandardsEnvironmental Management System (EMS)

An environmental Management System is a tool for managing the impacts of an Organization’s activities on the environment. It provides a structured approach to planning and implementing environment protection measures.

An EMS can be a powerful tool for organizations to improve their environmental performance and enhance their business efficiency. An EMS is not prescriptive; rather it requires organizations to take an active role in examining their practices, and then determining how their impacts should be managed. This approach encourages creative and relevant solutions from organization itself.

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StandardsBenefits of an EMS

An EMS can assist a company in the following ways:

Minimize environmental liabilities Maximize the efficient use of resources Reduce waste Demonstrate a good corporate image Build awareness of environmental concern among employees Gain a better understanding of the environmental impacts of

business activities Increase profit, improving environmental performance

through more efficient operations.

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StandardsSteps towards ISO certification

Step-1. Management commitment

Step-2. Quality system requirement and quality policy manual

Step-3. Planning

Step-4. Training, Education and quality awareness.

Step-5. Implementation

Step-6. Auditing and Corrective action

Step-7. Certification.

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Quality Assurance and Statistical Quality Control

Quality Assurance (QA): The decisions, plans and actions that are necessary to provide adequate confidence that a product or service will satisfy given requirements for a particular quality. The purpose of quality assurance is to ensure certain quality.

Statistical quality control (SQC): Control of quality with the help of statistics is statistical quality control or SQC can be defined as the method of QC where a series of results are analyzed with the help of statistical tools and techniques and decision is made about controlling the process. The purpose of SQC is to generate authenticity and significance about a series of test result.

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Total Quality Management (TQM)

In the past quality used to be regarded as a textile process. With the introduction of the WTO’s free trade agreement quality and cost has become the most important parameters for choosing a product. Therefore, the protocol of existing quality control philosophy will assume a new horizon. Various national and international organizations have already designed various models for future quality control system.

TQM is one of the most widely accepted quality control system. According to the TQM concept an organization involves all the resources like raw materials, suppliers, almost all persons working in the company, the whole seller, retailer and consumers to undertake decisions to achieve a target quality.

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Acceptance Sampling Plan

Acceptance sampling plan is an important field of statistical quality control. Dodge reasoned that a sample should be picked up at random from the lot and on the basis of information that was yielded by the sample; a decision should be made regarding this character of the lot. This process is called Lot Acceptance Sampling or just Acceptance Sampling.

Advantages:1. It is economical2. It requires less time and less effort3. It requires fewer personnel.

Disadvantages: 1. There is always high risk for the producer and the consumers2. Requires expertise

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Rectifying Inspection Plan

The inspection of the rejected lot and replacing the defective pieces found in rejected lot by the good ones to improve the lot quality is called rectifying inspection plan. This plan was first introduced by Harold F. Dodge and Harry G. Roming of Bell Telephone Laboratories before world war II. This plan enables the manufacturer to have an idea about the average quality of the product that is likely to result at given stage of manufacturer through the combination of production, sampling inspection and rectification of rejected lot.

Dodge and Roming have developed a number of sampling plans and the most common two of these are-

1. Single Sampling Plan2. Double Sampling Plan

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Dodge and Roming’s Sampling Plan

Single Sampling Plan: If the decision about accepting or rejecting a lot is taken on the basis of one sample only, the acceptance plan is described as single sampling plan.

Let N be the lot size; n be the sample size; c be the acceptance number i.e. maximum allowable number of defectives in the sample. The single sampling plan may be described as follows:

Select a random sample of size n from a lot size N Inspect all the articles included in the sample. Let d be the number of

defectives in the sample. If d ≤ c, accept the lot; replacing the defective pieces found in the

sample by non-defective (standard) ones. If d > c, reject the lot. Inspect the entire lot and replace all the

defective pieces by standard ones.

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Double Sampling Plan: In this method second sample is permitted if first sample fails, i.e. if the data from the first sample is non conclusive on either side ( about accepting or rejecting the lot) then a definite decision is taken on the basis of the second sample.

Let, N=lot size, n1=First sample size, n2=Second sample size, C1=Acceptance number for first sample, C2=Acceptance number for both the samples combined, d1=No. of defective items in the first sample, d2=No. of defective items in the second sample.

Procedure: Take a sample of size n1 from lot size N

If d1 ≤ c1, accept the lot; replacing the defective pieces found in the sample by non-defective (standard) ones.

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If d1 > c1, reject the lot. Inspect the entire lot and replace all the defective pieces by standard ones.

If c1+1< d1 ≤ c2, take a second sample of size n2 from the remaining lot.

If d1+d2 ≤ C2, accept the lot; replacing the defective pieces found in the sample by non-defective (standard) ones.

If d1+d2 > c2, reject the whole lot. Inspect the rejected lot 100% and replace all defective items by standard ones.

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Quality Control in

Apparel Manufacturing

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Fabric InspectionBefore the production of garments the quality of fabric should be inspected. When fabric received in store, at least it is needed to inspect 10% fabric. This inspection is done by point systems.

Some point system for fabric inspection are: 4-point system 6.5-point system 10-point system Dallas point system

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Fabric Inspection 4-point system

The 4-point system, also called the American Apparel Manufacturers Association (AAMA) point-grading system for determining fabric quality, is widely used by producers of apparel fabrics and by the department of defense in United States and is endorsed by the AAMA as well as ASQC (American Society for Quality Control).

The system in which the penalty point of a defect is maximum 4 is called 4-point system of quality control.

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Fabric Inspection Basic Principle: Defect point values should be counted in

100 yd fabric. If defect point values are 40 or less then it indicates first quality fabric. The grading range is given below:

Point Grade≤ 40 A

Above 40-60 BAbove 60-80 C

Above 80 Rejected

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Fabric Inspection Procedure:

Should select 10% fabric randomly from the fabric received quantity.

The defects are located, marked and recorded on a frame. Fabric defect point values are taken based on the following:

Length of Defect Point AllocatedUp to 3 inch 1Over 3 inch-Up to 6 inch 2Over 6 inch-Up to 9 inch 3Over 9 inch 4≤1 inch (Holes) 2Over 1 inch 4

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Fabric Inspection Calculation:Point/ 100 yd = {(Total point scored in a roll x 3600)/ (Total yds inspected x Fabric width in inch)}

Exercise-1. A fabric roll of 1200 ydS long and 48 inch wide contains the following defects:

2 defects up to 3 inch 5 defects over 3 inch but up to 6 inch 1 defect over 6 inch but up to 9 inch 1 defect over 9 inch

Find out the grade of fabric based on 4-point system.

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AQL

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