Quality Control Of Garment

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Quality Control Of Garment

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Transcript of Quality Control Of Garment

Quality Control Of Garment

QUALITY SYSTEMS FOR QUALITY SYSTEMS FOR GARMENTGARMENT

MANUFACTUREMANUFACTURE

ACHIEVING THE RIGHT FINAL PRODUCT ON TIME

1. 1. PLAN OF THE OVERALL FUNCTION OF QUALITY PLAN OF THE OVERALL FUNCTION OF QUALITY

CONTROLCONTROL

• The cost of quality

• Functions of Quality Assurance

• Commercial advantages form effective control systems

• Economic aspects of quality assurance

• The role of quality control

2. THE ROLE OF QUALITY CONTROL IN THE CONTEXT OF QUALITY

MANAGEMENT

• Outline of quality control systems requirements

• Data generated

• British Standard 5750

3. FINAL PRODUCT SPECIFICATIONSFINAL PRODUCT SPECIFICATIONS

• Quality control in the sampling/development department

• From sample to full production

• The Specification layout

• Process specification

• Sample garment specification

• Seam specification

• Performance specification

4. THE MAIN RAW MATERIAL - FABRICTHE MAIN RAW MATERIAL - FABRIC

• Fabric and garment dimensions - fabric stability and finished width

• Fabric inspection - examination of fabric on receipt

5. BASIC SEAMING TECHNOLOGYBASIC SEAMING TECHNOLOGY

• Basic technology of seams

• Stitch forming action

• Quality checks on seams

6. LAYING-UP AND CUTTINGLAYING-UP AND CUTTING

6. QUALITY MONITORING THROUGH QUALITY MONITORING THROUGH CUTTING AND GARMENT ASSEMBLYCUTTING AND GARMENT ASSEMBLY

7.1 RecordingRecording

• Recording systems - making up

• Supervisors check list

7.2 TolerancesTolerances

• Tolerance limits

7.3 The threshold of faults The threshold of faults

• Training quality standards and faults analysis

7.4 Sampling techniquesSampling techniques

• Checking levels of faults and seconds

7.5 Technology if InspectionTechnology if Inspection• Garment examination• Seeing colour and the effect of type of

illuminant on the apparent shade of a sample

• Effects of intensity, angle of illumination and type on the apparent shade of a sample

• Effects on shade of other colours in adjacent areas

• Mounting and displaying for viewing• Colour vision

7.6 checking operatives and examinerschecking operatives and examiners

• Assessment of operative effectiveness from records

• The supervisor and quality control

• Weather trials

7.7 Auditing Boxed StockAuditing Boxed Stock

• Boxed Stock Quality Audit

8. QUALITY COMMUNICATIONSQUALITY COMMUNICATIONS

• Control of quality in garment assembly

• Example of quality feedback - marks and stains

• Action checklist to improve garment cleanliness

• economics of cleanliness

• Fault cost assessment record

• Quality Control Requirements - Order of Priorities

""Quality"Quality" is defined as that combination of design and properties of materials of a product which are needed for the intended end use and level of the market in which it is sold. "Requisite Quality""Requisite Quality" is defined as the design and composition of a product, which has been thoroughly proved by adequate development work, in order to establish its reliability under the conditions to which it will be subjected in use and to avoid producing too high a grade of product for the intended market.

Quality Assurance Quality Assurance "The establishment and maintenance of ALL activities and functions concerned with the attainment of requisite quality"

Quality Control Quality Control "The systems required for programming and co-ordinating the efforts of the various groups in an organisation to maintain the requisite quality" As such Quality Control is seen as the agent of Quality Assurance or Total Quality Control

Quality for textile and apparel:Quality for textile and apparel:

Quality may be defined as the level of acceptance of goods or services.For the textile and apparel industry, product quality is calculated in terms of quality and standard of fibers, yarns, fabric construction, colour fastness, designs and the final finished garments. Quality control in terms of garment

manufacturing, pre-sales and posts

sales service, delivery, pricing, etc are essential for any garment manufacturer, trader or exporter.

Certain quality related problems, often seen in garment manufacturing like sewing, colour, sizing, or garment defects should never be over looked.

These defects are discussed below -

Sewing defects Sewing defects Open seams, wrong stitching techniques, non- matching threads, missing stitches, improper creasing of the garment, improper thread tension etc. are some of the sewing defects which can affect the garment quality adversely.

Colour defects Colour defects Variation of colour between the sample and the final garment, wrong colour combinations and mismatching dyes should always be avoided.

Sizing defects Sizing defects Wrong gradation of sizes, difference in measurement of various parts of a garment like sleeves of XL size for body of L size garment can deteriorate the garments beyond repair.

Garment defectsGarment defectsBroken or defective buttons, snaps, stitches, different shades within the same garment, dropped stitches, exposed notches, fabric defects, holes, faulty zippers, loose or hanging sewing threads, misaligned buttons and holes, missing buttons, needle cuts, pulled or loose

yarn,

stains, unfinished buttonhole, short zippers, inappropriate trimmings etc. all can lead to the end of a brand name even before its establishment.

Some of main fabric properties that are taken into consideration for garment manufacturing for export basis:

• Overall look of the garment.• Right formation of the garment.

• Feel and fall of the garment.

• Physical properties.

• Colour fastness of the garment.

• Finishing properties

• Presentation of the final produced garment.

Methods of quality control:Methods of quality control:

Basically two methods are used for garments quality control –i) Testingii) Inspection.

Maximum garments manufacturers apply inspection method due to high cost of testing equipments.

Inspection:Inspection: Inspection may be defined as the

visual examination in relation to some standards.

Objective:Objective: The main objectives of inspection are –

i. Detection of defects.ii. Correcting the defects or defective garments.

• To inspect garments an integral method named ‘Inspection Loop’ is used given below – Inspection

Correction of the defects Detection of defects

Inform defects to appropriate personnel

Determination of causes of defects

Fig: Inspection Loop.

Steps of inspection in garments industry:Steps of inspection in garments industry:

i) Raw materials inspection (Fabric and Accessories)ii) In Process inspection.iii) Final inspection.

Raw Materials Raw Materials

• Shade - checked to be within tolerance of standard pattern.

• Delivery weights - checked and any shortfall claimed.

Fabric Parameters, Fabric or Garment Blank Checks :Fabric Parameters, Fabric or Garment Blank Checks :

• Shade and appearance correct jacquard pattern correct, absence of barrenness.

• Width normal - (this is only a guide with grey fabric). • Fabric weights per square metre (or preferably weight

per predetermined revs) - checked to within tolerance of specification.

• Blank weight per dozen to be within tolerance of specification.

• Check fabric for faults and stains. • Finishing loss - on-going record of losses on scouring

etc. • Accountability of knitters.

Sewing thread inspection:Sewing thread inspection:A) Thread construction:Thread construction:

To know about thread construction the following should be tested –i. Thread count.ii. Thread ply.iii. Number of twist.iv. Thread balance.v. Thread tenacity.vi. Thread elongation

B) Sew ability:Sew ability: The sewing ability of a thread

is called sew ability. During sew ability test the following quality of thread should be tested –i. Imperfectionii. Finishiii. Package densityiv. Windingv. Yardage

What are the things used to check toWhat are the things used to check to

determine the quality of Zipper:determine the quality of Zipper:

i. Measuring Zipper Dimensionii. Top and Bottom stops should be securediii. Uniform in coloriv. Slider should ride freely but not so freev. Slider lock must be secured.vi. Durability of finish of zipper chain to laundering or dry cleaning.vi. Color fastness to zipper to light, to crocking (rubbing) and to laundering.

In-process InspectionIn-process InspectionSewing Checks

• Stitches per cm. and thread run-in ratio checked to be within tolerance of specification.

• Evenness, balance and correct bight, no stitching missed

• Extensibility and security correct (i.e. no cracking or laddering).

• Absence of skip stitching. • Accountability of machinist.

Final InspectionFinal Inspection

• Shade correct and not varying from one part of garment to another.

• Cut is correct - e.g. neck, collar and sleeves balanced, pockets correct.

• Measurements within tolerance of specification, weight correct.

• Appearance correct, patterns matching. • Seams finished correctly, absence of miss stitching,

cracking and laddering. • Accessories correctly applied and working. • Absence of fabric faults and stains.• Correct labelling.

Recovery InspectionRecovery Inspection 

• Check whether remedial works satisfactory.

• Check on volume of work successfully recovered.

• Avoidance of work recycling.

Product Tests Product Tests • Colour fastness to agreed agencies: (e.g.

washing, rubbing, perspiration, lights) - checked and on-going continuity cards generated, showing rating, checked against specification.

• Stability: • Shrinkage, and extension recovery where needed

- to be within tolerance of specification• Endurance:• Abrasion, pilling or snagging - tested where

needed. Rating checked against specification• Flammability: Performance rating in appropriate test checkedagainst specification.

AQL Random Sampling InspectionAQL Random Sampling Inspection

# The AQL inspection takes the samples from a goods, inspect

them and depends on the quality of samples inspected and decide to

accept or reject them.# The standard is based on Military Standard 105D (MIL-STD-105D)

# It provides with the sampling plans, the number of samples to be inspected and the acceptable quality level (AQL)# AQL 1.5 is applied to very severe inspection on high-class expensive item. # AQL 2.5 is applied when textiles of normal/good quality are involved.

AQL (II)AQL (II)# Three types of sampling plans -single, double and multiple.# Each sampling plan can be performed in three level- normal, tightened and reduced, depending on quality of products.# In garment industry, single and double normal sampling plans are applied.

Sample Size Code LetterSample Size Code Letter

• The Sample Size Code Letter shows different lot sizes to different code letter.

• There are seven inspection level, four for general inspection and three for special inspection

• For garment inspection, General Inspection level II would be used.

Sample Size Code LetterSample Size Code Letter

Single Sampling Plan for normal inspectionSingle Sampling Plan for normal inspection

Double Sampling PlansDouble Sampling Plans

ExampleSingle Sampling Plan-Normal Inspection

• Assume AQL is 2.5% and lot size is 600 garments, find out the following :

– The total number of samples need to inspect

– The acceptable number of the samples

– The rejection number of the samples

AnswerSingle Sampling Plan• First, from Table 1 find out the code letter for

lot size of 600 and inspection level II is “J”• From Table 2 (single sampling plan), the

letter “J” corresponds to sample sizes of “80”.• So, 80 samples are needed to inspect out of

600• At AQL 2.5%, if defective garments are less

than or equal to 5, whole lots will be accepted, if it is found to be 6 or more, whole lots will be rejected.

Try this one

• If the garment lot is 300 dozens, and AQL is 4.0%, find out

• the number of samples to be inspected

• the acceptable number and rejection number

Example IIDouble Sampling Plan

• Assume AQL is 4% and lot size is 2000 garments, find out from double sampling plan on the following:– The total sample sizes need to inspect– What is the first acceptable number– What is the second acceptable number

AnswerDouble Sampling Plan

• First, Table 1 of 2000 lots at inspection level II is letter “K”

• Table 3, double sampling plan shows the sample size of letter K is 80.

• First inspection, at AQL 4%, the acceptable number is 5, rejection number is 9

• If any number between 5 to 9, second inspection is needed

AnswerDouble sampling Plan (II)

• For second inspection, the sample sizes again is 80

• At AQL 4%, the cumulated acceptable number is 12 and rejection number is 13.

• Conclusion– If the number of defective garments found

in the first sample is 6, and in second sample is 5, making a total of 11, then the whole lot of 2,000 pieces will be accepted.

References

• Garments and TechnologyProf. M. A. Kashem

• Jimmy K.C. Lam The Hong Kong Polytechnic University• Introduction to garments manufacturing

Harold Carr• Fashion dictionary• Engr. Mohammad Faizur Rahman (Rashed),

Assistant Professor (Garments Technology), Department of Textile Technology, AUST

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