hoklas supplementary criteria no. 22 · hoklas supplementary criteria no. 22 ... test category 1...

HOKLAS SC-22

Issue No. 5

Issue Date: 1 June 2017

Implementation Date: 1 September 2017

of 14

HOKLAS Supplementary Criteria No. 22

‘Textiles and Garments’ Test Category

1 INTRODUCTION

1.1 This criteria document elaborates the generally stated requirements of HOKLAS 003

for the accreditation of testing under the test category of ‘Textiles and Garments’.

This criteria document shall be read in conjunction with current issue of

HOKLAS 003 and other relevant criteria documents. In areas not covered in this

document, the requirements stipulated in HOKLAS 003 and HKAS 002 and other

relevant criteria documents shall apply.

1.2 Laboratories should note that complying with this document might not necessarily

meet all the requirements of test standards. Individual test standards may have

specific requirements which shall be met when conducting the concerned tests.

2 SCOPE OF ACCREDITATION

2.1 HOKLAS offers accreditation in the following areas:

(a) Care performance test/dimensional stability

(b) Chemical analysis

(c) Colour fastness test

(d) Construction test

(e) Performance test

(f) Feather and down analysis

(g) Fibre analysis

(h) Flammability test

(i) Strength test

(j) Colour measurement

(k) Microbiological test (The specific requirements for the accreditation of this test area

are not detailed in this supplementary criteria. Laboratories seeking accreditation for

this test area shall read HOKLAS SC-08.)

3 TERMS AND DEFINITIONS

3.1 The term “shall” is used throughout this document to indicate those provisions which

are mandatory. The term “should” is used to indicate guidance which, although not

mandatory, is provided by HKAS as a recognised means of meeting the requirements.

3.2 Appendix B gives a list of selected documents which are useful for laboratory

operation.

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4. ORGANISATION

4.1 The technical management of the laboratory shall include at least a member with

in-depth knowledge and extensive experience in textiles and garments testing covered

in the scope of accreditation. The minimum qualification and experience

requirements for the technical management members are the same as those for the

approved signatory mentioned in section 6.6. He/she is responsible for the technical

operation of the laboratory with respect to textiles and garments testing.

5. PURCHASING SERVICES AND SUPPLIES

5.1 Critical consumables having an effect on the validity of tests shall be verified

according to the requirements stipulated in the test standards or the recommendation

given by the manufacturer, if no such requirements in the test standards. Procedures

for verification shall be documented and records shall be maintained. Typical

examples are:

(a) chlorine content of hypochlorite,

(b) size and mass to area ratio of dummy loading fabrics,

(c) dimensions and friction of liner for pilling tests,

(d) service time (in hours) of the illumination source (e.g. xenon lamp tubes and

filters) for colourfastness to light,

(e) light intensity and colour temperature of the illuminant simulator used in the

visual assessment, etc.

6. PERSONNEL

6.1 Supervisory personnel of the laboratory shall have a higher diploma in Textile

Technology, Textile Chemistry or Fashion and Clothing Technology, or higher

qualification or equivalent academic qualification, with not less than three years

relevant working experience. Staff members having equivalent academic

qualification and experience are acceptable.

6.2 Technical personnel shall have sufficient technical knowledge of the technology

stipulated in the test standards. They shall have satisfactorily completed the in-house

training of the tests to be carried out.

6.3 Laboratories shall provide adequate training to new technical personnel. The training

programme shall at least cover the following areas:

(a) techniques involved in the tests, including factors that may affect test results and

precautions to take for minimising such effects

(b) principles and operation of the equipment

(c) understanding of the need of equipment calibration and the measurement

traceability

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(d) recording of test details and results

(e) drawing conclusion based on test results

(f) understanding of the laboratory’s management system

Laboratories shall also provide training to the technical personnel for new and

infrequent used techniques.

6.4 Technical personnel are only allowed to perform a test independently after their

performance has been assessed to be satisfactory. The continuing competence of

technical personnel shall be evaluated regularly. Records of training, competence

assessments (including any raw data), and authorization shall be maintained.

6.5 When the training provided is for specific techniques rather than specific test methods,

laboratories shall define and document which techniques are required for performing

what tests, and hence the trained technical personnel have been assessed to be

competent in performing what tests.

6.6 Laboratories shall nominate at least one supervisory personnel for signatory approval.

The approved signatories shall have a higher diploma in Textile Technology, Textile

Chemistry or Fashion and Clothing Technology, or higher qualification and with not

less than three years relevant working experience. Staff members possessing

equivalent academic qualification and related work experience are acceptable. In

addition, he/she shall have at least six months of experience in the testing areas for

which signatory approval is sought. For individual staff member at supervisory level

who does not possess the required academic qualifications but has extensive

experience (at least ten years) in the testing area concerned, special consideration may

be given provided that records giving full details of employers, and the nature of

experience received are available. If a nominated signatory holds a qualification

conferred by an education institute outside Hong Kong, the laboratory shall provide

supporting evidence to substantiate that such qualification is equivalent to or above the

minimum level stated above. In all cases, candidates shall demonstrate to the

assessment team that his/her technical competence in the test areas under

consideration before signatory approval can be granted.

6.7 The technical personnel responsible for visual assessment of colour difference of

textiles, as well as approved signatories for the visual tests concerned, shall have

normal colour vision for the colour discrimination test methods. The technical

personnel and approved signatories shall undergo a colour defect check to ensure any

deficiency does not affect the quality of the examination results. A list of all

qualified technical personnel shall be maintained.

7. ACCOMMODATION AND ENVIRONMENTAL CONDITIONS

7.1 Where a conditioning room or chamber is used for conditioning and testing of textiles

and textile products, the standard atmospheric conditions defined in the test standards

shall be maintained throughout the room or chamber. Appropriate devices for

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measuring and recording the temperature and relative humidity in the room or

chamber shall be used. Multiple measuring devices may be required to ensure

adequate monitoring of the atmospheric conditions throughout the room or chamber,

appropriate monitoring position(s) shall be properly selected and recorded. In order

to determine the standard atmospheric conditions within the room or chamber are

within the tolerances given in the test standards, the measurement uncertainty of the

temperature and relative humidity measuring devices being used shall be taken into

account. The resolution and the measurement uncertainty of the measuring device

should meet the requirements stipulated in the test standards, if any. Atmospheric

conditions records shall be kept. Any measuring device used shall be calibrated

regularly, and the results shall be recorded. Cases where atmospheric conditions fall

outside the acceptable ranges shall be recorded and the effects on test results shall be

evaluated. Appropriate actions shall be initiated if the cases are identified as

nonconforming work.In addition, laboratories shall maintain the records of start and

end time of conditioning when a sample is placed in a conditioning room or chamber.

Laboratories shall ensure that the sample is fully conditioned to the stated

environmental conditions before the test.

7.2 A dedicated space, if not a separate room, shall be used for visual assessment of colour

differences or determining appearance of textiles after tests (e.g. colour fastness,

pilling, smoothness and wrinkle, etc.). The space or room shall be so constructed

such that the rating results will not be affected by the lighting of neighbouring areas,

the reflection of the clothing of technical personnel on the test specimen and reflection

from surrounding surfaces. Laboratories shall be equipped with viewing boards and

viewing cabinets specified by corresponding test standards. The colours of the

boards and cabinets shall be checked regularly for conformity with test standards.

The checking records shall be maintained.

7.3 Laboratories shall take necessary precautions to prevent contamination from the

environment when performing chemical analysis.

8. TEST AND CALIBRATION METHODS AND METHOD VALIDATION

8.1 General

8.1.1 Laboratories may use a common test procedure to cover several similar tests specified

in national and international test standards (e.g. colour fastness to sea water (AATCC

Test Method 106 and ISO 105-E02)). However, differences between these test

standards, if any, shall be clearly identified in the common test procedure.

8.1.2 For visual assessment results, such as the grade of the test results of colourfastness,

pilling, smoothness, wrinkle, etc., laboratories shall define a verification system. The

verification system shall define the minimum number of raters or assessors and the

maximum allowable differences between their assessment results. Laboratories shall

take corrective actions when the difference is higher than the documented defined

limit.

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8.2 Chemical tests

8.2.1 For chemical tests such as pH and formaldehyde, it is essential to avoid contamination

of test samples and/or standard solutions by labware. Laboratories shall have

documented procedures for washing labware and selecting the types of labware to be

used (glass, PTFE, etc.) for specific tests. Attention shall also be given to the

possible presence of analytes in commercial detergents. In most cases, laboratories

are expected to have different washing, storage and segregation procedures for

labware used for different analyses.

8.2.2 The grade of reagents used (including water) shall be stated in the procedure together

with guidance on precautions to be observed in their preparation or use. Laboratories

shall ensure that reagents used are suitable for the applications. Reagents, where

critical, prepared in the laboratory shall be labelled to identify their substance, strength,

solvent (other than water), date of preparation and/or date of expiration and any

special precautions and restrictions of use. The person responsible for the

preparation of the reagent shall be identifiable from records.

8.2.3 Water is one of the most widely used reagents in chemical and colourfastness tests.

Hence, means to ensure that reagent water is of the required quality is necessary. The

performance of any water purification system shall be checked regularly to confirm

that the water produced continues to meet testing requirements. Records of such

checks shall be kept.

8.2.4 For compliance testing for a chemical parameter, it is essential to select a method

which gives a limit of detection well below the compliance limit and that it gives

reliable results at the limit.

8.3 Selection of test methods

8.3.1 If test methods are stipulated in legislation, the specified methods shall be used for

compliance testing against the legislation.

8.4 Validation of methods

8.4.1 Non-standard methods shall be validated and authorised before use. The validated

non-standard methods shall be documented and scope of application, performance

characteristics, quality control plans and calibration shall be defined.

8.4.2 The performance of a validated method may change due to many reasons. It is

therefore necessary to review the performance characteristics of test methods on a

regular basis and revise, if necessary. Such reviews may also be required when

performance of the method is affected by changes in equipment or environmental

conditions, etc.

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8.5 Estimation of Uncertainty of Measurement and Determination of Conformity with

Specification

Testing laboratories shall have and shall apply procedures for estimating uncertainty of

measurement for all tests having a numerical value as the final result or as an

intermediate result. In determining the overall measurement uncertainty for a test,

the uncertainty caused by the measurement equipment and those caused by the

measurement method and the operators must be taken into account.

It is recognised that there is more than one method for estimating measurement

uncertainty and there is no consensus on the method to be used for textiles and

garments testing. HOKLAS accepts methods for estimating uncertainty of

measurement given by reputable professional and standard writing bodies. However,

the uncertainty value obtained should be in line with the definition given in the

“International Vocabulary of Basic and General Terms in Metrology” (VIM) and

should include all major components of uncertainty in its estimation. Reference to

the ISO GUM Guide and EURACHEM/CITAC document “Quantifying Uncertainty in

Analytical Measurement” may be useful.

For assessing conformity with numerical specifications, international guidelines, such

as ILAC-G8:03 Guidelines on the Reporting of Compliance with Specification or

APLAC TC 004: Method of Stating Test and Calibration Results and Compliance with

Specification shall be followed.

9. EQUIPMENT

9.1 General recommendations on equipment calibration are given in the HOKLAS

Supplementary Criteria No. 2. - Specific recommendations on equipment

calibration/verification requirement. Recommendations on calibration for the test

equipment used in textiles and garments testing are given in Appendix A of this

document. These recommendations may be adopted in the absence of specific

recommendations from the equipment manufacturer, the test standards or reliable

calibration history.

10. MEASUREMENT TRACEABILITY

10.1 Evaluation tests

Evaluation tests here refer to assessments of change in properties of a sample, such as

colour, pilling, smoothness, etc., after it has undergone the testing steps. Usually, a

numerical grade, such as 1 to 5 for the change is given as the evaluation result.

Results shall be traceable to reference standards or materials specified in test standards.

Typical examples of acceptable traceability are listed below:

(a) Gray Scale or Chromatic Transference Scale for colour change and colour

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staining of colourfastness tests;

(b) durable press replicas for appearance of durable press after repeated home

laundering;

(c) photographic comparative ratings for single and double needle seams for

appearance of seams after repeated home laundering;

(d) photographic comparative ratings for crease retention for appearance of crease

after repeated home laundering;

(e) photographic pilling standards for pilling tests;

(f) spray test rating chart for water repellency test; and

(g) wrinkle recovery replicas for wrinkle recovery of fabrics.

10.2 Chemical tests

10.2.1 Reference materials used for calibration shall provide the necessary measurement

traceability. The requirements given in HOKLAS Supplementary Criteria No. 1

‘Acceptability of chemical reference materials and commercial chemicals used for the

calibration of equipment’ shall be followed.

10.2.2 Calibration curves shall be constructed as specified in the test standards. As a

general guideline, at least three standards (excluding blank) shall be used to establish a

linear calibration graph. The standards used should cover the range of concentration

found in test samples. The lowest standard should be at a level at or below the

reporting limit of the test method. Criteria for the correlation coefficient of linear

calibration graph should be set and implemented. Guidelines given in

‘ISO 11095: 1996 - Linear calibration using reference materials’ should be consulted

for further details.

10.2.3 Calibration graphs shall be checked using mid-point calibration standard. The

frequency of such check depends on the stability of the equipment. A frequency of

around 5 per cent is normally considered as adequate, except otherwise specified in the

test standards or the stability of the equipment merits more frequent checking.

Acceptance criteria shall be established and the criteria shall commensurate with the

testing uncertainty.

11. SAMPLING

11.1 Sampling from sample lot or site is not covered in this document. Customers taking

their own samples should be made aware of proper storage, sampling and

transportation procedures.

11.2 Preparation of laboratory samples and test portions shall be based on national or

international standards unless otherwise specified in the relevant test standards.

General guidance is given in ISO 1130: 1975 Textile fibres – Some methods of

sampling for testing and ASTM D2258/D2258M - 16 – Standard Practice for

Sampling Yarn for Testing. Procedures for taking test portions from laboratory

samples shall be documented.

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12. HANDLING OF TEST AND CALIBRATION ITEMS

12.1 Laboratories shall examine and record the condition and appearance of the samples

upon receipt. The information to be checked includes, where appropriate, number,

colour, pattern, garment type, etc. The laboratory should retain a swatch for sample

identification.

12.2 Test samples shall be suitably stored as soon as practicable. Laboratories shall define

the storage conditions for different types of samples. The storage conditions shall be

monitored and recorded to demonstrate that the requirements are fulfilled.

12.3 Frequently, it is necessary to split the sample for testing of different properties. It is

essential that such sub-samples represent the original samples and their identities are

maintained at all times. A system for identifying the test portions for colourfastness

tests, dimensional stability to washing tests, etc. shall be documented.

13. ASSURING THE QUALITY OF TEST AND CALIBRATION RESULTS

13.1 The quality control plans for monitoring the validity of tests undertaken shall define

the frequency of performing different programmes (e.g. proficiency testing

programmes, inter-laboratory comparison, etc.). The plans shall also define the

acceptance criteria of the programmes and actions to be taken in cases of acceptance

criteria not being met. A written corrective action plan and documentation of

corrective actions are required.

13.2 Laboratories shall establish regular schedules for participation in proficiency testing

programmes or inter-laboratory comparison. The number of laboratories participated

in inter-laboratory comparisons prefers to be more than two. Where practicable, at

least one of the participating laboratories shall have been accredited for the tests under

comparison. The frequency of participation shall commensurate with the volume of

work for each test parameter. The minimum frequency of participation shall be once

every four years for each test area according to the categorisation in section 2 of this

document.

13.3 Laboratories shall have documented procedures for rectifying unsatisfactory

performance in proficiency testing programmes or inter-laboratory comparisons. All

findings in connection with unsatisfactory performance shall be recorded.

14. REPORTING THE RESULTS

14.1 A description of the samples as received shall normally be given in test reports. The

description shall include, where relevant to the interpretation of test results, a

description of the number, appearance and colour, type of fabrics or garments and care

label when received. Any deviation from the test standard requirements shall be

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given.

14.2 Some test standards require the reporting of additional information. In these cases,

the test reports shall include all the information required by the test standards.

14.3 It is an acceptable practice for a customer to provide its specification to the laboratory

and request the laboratory to include a statement of compliance with the specification

in the report. However, if a specification is not provided and the laboratory compares

the test results with its commercial specification, any statement of compliance shall be

considered as opinions and interpretations. The technical criteria governing reporting

of opinions and interpretations as stated in HOKLAS 003 shall be followed.

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Appendix A

(informative)

SPECIFIC CALIBRATION RECOMMENDATIONS

If the test standards do not specify the requirements for the equipment calibration /

verification, the following table sets out recommended parameters and maximum periods

between successive calibrations for equipment used in textiles and garments testing.

Type of equipment

Abrasion Tester

(Inflated

Diaphragm)

Calibration/verification parameter

Dimension of clamping ring and collar

Dead weight

Recommended maximum

period between successive

calibrations/verification

Initial

Initial

Thickness of diaphragm

Pressure gauge

Prior to installation and

thereafter once a year

1 year

Reciprocating motion, stroke length 1 year

Abrasion Tester

(Martindale)

Dimensions of specimen holder

Weight of holder and spindle

Initial

Initial

Rotational speed 1 year

Stroke of peg 1 year

Counter 1 year

Lissajous figure 6 months

Inflated Diaphragm

Bursting Tester

Dimensions of base plate and clamping rin

Thickness of diaphragm

g Initial

1 year

Pressure gauge 1 year

Performance check by busting 5 pieces of

standard aluminium sheet

6 months

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Type of equipment

Crimp Tester

Calibration/verification parameter

Scale

Recommended maximum



Initial

Reel perimeter, if applicable Initial

Tensioning gauge 1 year

Crockmeter Dimensions (diameter of finger peg,

reciprocating rubbing distance)

Initial

Rubbing downward force 1 year

Cutting die Dimensions Initial

Performance check 1 year

Drycleaning

Cylinder

Dimension of cylinder

Angle of cylinder

Initial

1 year


Elmendorf Tearing

Tester

Augmenting weights

Dimension of clamp

Initial

Initial

Slit length 1 year

Calibration of scale 1 year

Fade-o-meter Black panel temperature 1 year

Flammability Tester

(16CFR 1610)

Angle of specimen rack

Igniter tip alignment

1 year

1 year

Impingement time 3 months

Timer 3 months

Flammability Tester

(16CFR 1615)

Dead weight

Angle of burner

Initial

1 year

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Type of equipment Calibration/verification parameter

Angle of metal hook

Recommended maximum



1 year

Flex Stiffness Tester Angle deflection 1 year

ICI Pilling Box Dimension of PU

dimensions of box

tube, template, inner Initial


Counter 1 year

Performance check by reference fabrics 6 months

Perspiration Tester Dead weight Initial

Dimension of plate Initial

Rain tester and

Spray tester

Dimensions of the tester

Number, size and position of nozzles

Initial

Initial

Random Tumbler Timer 3 months

Rotational speed and gas flow 1 year

Rotary Platform

Double Head

Abrader

Dimensions of abrasive wheels

Weight set

Initial

Initial

Platform speed 1 year

Tensile Tester Force accuracy 1 year

Crosshead speed 1 year

Zero check 6 months

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Type of equipment

Tumble Dryer

Calibration/verification parameter Recommended maximum



Temperature of delicate and permanent

press cycle

1 year

Note:

1. If the standard specifies the cooling time,

this parameter should also be verified

regularly, say yearly.

2. Some test standards may specify certain

dimensions for the tumble dryer and that

the drum action should be reversible and

these should be checked initially.

Wascator Verification of all program cards Initial

Temperature, liquor level, time

washing, rinse and spin speed of selected

program

1 year

Washer Agitation and spinning speed 1 year

Washing time 1 year

Washing temperature 1 year

Liquor level 1 year

Wira Steam

Cylinder

Steam generation rate

Dimension of cylinder

1 year

Initial

Dimension of supporting frame 1 year or more frequently,

depending on usage

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Appendix B

(informative)

BIBLOGRAPHY

VIM, ‘International Vocabulary of Basic and General Terms in Metrology’

GUM, ISO/IEC Guide 98-3:2008 ‘Uncertainty of Measurement – Part 3: Guide to the

Expression of Uncertainty in Measurement’

EURACHEM/CITAC, ‘Quantifying Uncertainty in Analytical Measurement’

ILAC-G8:03, ‘Guidelines on the Reporting of Compliance with Specification’

APLAC TC 004, ‘Method of Stating Test and Calibration Results and Compliance with

Specification’

APLAC TC 005, ‘Interpretation and Guidance on the Estimation of Uncertainty of

Measurement in Testing’

ISO 11095: 1996, ‘Linear Calibration Using Reference Materials’

ISO 1130: 1975 Textile fibres, ‘Some Methods of Sampling for Testing’

ASTM D2258/D2258M – 16, ‘Standard Practice for Sampling Yarn for Testing’

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