Quality Control of Garment

PLAN OF THE OVERALL FUNCTION OF QUALITY CONTROL • The cost of quality • Functions of Quality Assurance • Commercial advantages form effective control systems • Economic aspects of qualit

Quality Control Of Garment

QUALITY SYSTEMS FOR

GARMENT MANUFACTURE

ACHIEVING THE RIGHT FINAL PRODUCT ON TIME

1 PLAN OF THE OVERALL FUNCTION OF QUALITY

CONTROL

• 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 SPECIFICATIONS FINAL 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 - FABRIC THE MAIN RAW MATERIAL - FABRIC

• Fabric and garment dimensions - fabric stability and

finished width

• Fabric inspection - examination of fabric on receipt

5 BASIC SEAMING TECHNOLOGY BASIC SEAMING TECHNOLOGY

• Basic technology of seams

• Stitch forming action

• Quality checks on seams

6 LAYING-UP AND CUTTING LAYING-UP AND CUTTING

6 QUALITY MONITORING THROUGH QUALITY MONITORING THROUGH

CUTTING AND GARMENT ASSEMBLY

7.1 Recording Recording

• Recording systems - making up

• Supervisors check list

7.2 Tolerances Tolerances

• Tolerance limits

7.3 The threshold of faults The threshold of faults

• Training quality standards and faults analysis

7.4 Sampling techniques Sampling techniques

• Checking levels of faults and seconds

7.5 Technology if Inspection Technology 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 examiners checking operatives and examiners

• Assessment of operative effectiveness from records

• The supervisor and quality control

• Weather trials

7.7 Auditing Boxed Stock Auditing Boxed Stock

• Boxed Stock Quality Audit

8 QUALITY COMMUNICATIONS QUALITY 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" 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" 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

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

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 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

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

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

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 defects

Broken 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.

Methods of quality control:

Basically two methods are used for garments quality control –

i) Testing

ii) Inspection

Maximum garments manufacturers apply

inspection method due to high cost of testing equipments

• 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:

i) Raw materials inspection (Fabric

and Accessories)

ii) In Process inspection

iii) Final inspection

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:

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 –

What are the things used to check to

determine the quality of Zipper:

i Measuring Zipper Dimension

ii Top and Bottom stops should be secured

iii Uniform in color

iv Slider should ride freely but not so free

v 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 Inspection

Sewing Checks

• Stitches per cm and thread run-in ratio checked to be

within tolerance of specification

• Evenness, balance and correct bight, no stitching

Final 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 Inspection

• Check whether remedial works satisfactory

• Check on volume of work successfully recovered

• Avoidance of work recycling

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 checked

against specification

AQL 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)

# Three types of sampling plans

-single, double and multiple

# Each sampling plan can be

performed in three

normal, tightened and reduced, depending on quality of products

# In garment industry, single and

double normal sampling plans are applied

Sample 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 Letter

Single Sampling Plan for normal inspection

Double 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

Single 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

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

• Garments and Technology

Prof 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

THANK

YOU

ALL