4176 version 6
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Demonstrate knowledge of yarn specification and measurement
Level
4
Credits
20
Purpose
People credited with this unit standard are able to demonstrate knowledge of:
yarn constructional properties; yarn count measurement and calculation; yarn
twist measurement and calculation; yarn moisture content measurement and
calculation; yarn strength measurement and calculation; yarn oil and fatty
matter content measurement and calculation; yarn shade specification,
assessment, and measurement; and yarn evenness specification and testing.
Subfield
Textiles Manufacture
Domain
Core Yarn Processing
Status
Registered
Status date
23 April 2008
Date version published
23 April 2008
Planned review date
31 December 2013
Entry information
Open.
Accreditation
Evaluation of documentation and visit by NZQA and
industry.
Standard setting body (SSB)
Competenz
Accreditation and Moderation Action Plan (AMAP) reference
0030
This AMAP can be accessed at http://www.nzqa.govt.nz/framework/search/index.do.
Special notes
Information to support the learning required for this standard can be obtained from papers
and articles published by AgResearch. These may be obtained by contacting AgResearch
http://www.agresearch.co.nz and searching using the keyword Textiles.
 New Zealand Qualifications Authority 2016
4176 version 6
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Elements and performance criteria
Element 1
Demonstrate knowledge of yarn constructional properties.
Performance criteria
1.1
Yarn properties that are commonly used to specify yarn construction are
described in terms of their nature, method of specification and their effect on
yarn processing and product performance.
Range
yarn count, yarn twist, yarn strength and elongation, moisture
content, extractable matter content, shade, evenness, bulk,
friction.
Element 2
Demonstrate knowledge of yarn count measurement and calculation.
Performance criteria
2.1
Yarn count systems are defined, described, and compared in terms of their
measurement basis and relationship with each other.
Range
2.2
direct systems – tex, denier;
indirect systems – metric, Yorkshire skeins, Worsted, Galashiels,
Dewsbury, cotton.
Count measurement is described in terms of methods used to assess absolute
count and count variation.
Range
describe – equipment used, sample selection, test procedure,
calculation of results, calculation of variance, interpretation of
results;
methods – laboratory test using wrap reel, doff weight and length,
cross-card test.
Element 3
Demonstrate knowledge of yarn twist measurement and calculation.
Performance criteria
3.1
Factors used to define or calculate yarn twist are described.
Range
twist level, twist direction, single twist, ply twist, twist take-up, twist
on twist effect, twist against twist effect, twist factor, ply
combinations.
 New Zealand Qualifications Authority 2016
4176 version 6
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3.2
Twist measurement is described in terms of methods used to assess twist level,
direction, and variation.
Range
describe – equipment used, sample selection, test procedure,
calculation of results, calculation of variance, interpretation of
results;
methods – calculation from machine settings, laboratory
measurement using parallel fibre or ply, laboratory measurement
using extension-contraction.
Element 4
Demonstrate knowledge of yarn moisture content measurement and calculation.
Performance criteria
4.1
Factors used to define or calculate yarn regain are described.
Range
4.2
dry weight, conditioned weight, moisture content percentage,
regain percentage.
Moisture content measurement is described in terms of measurement methods.
Range
describe – equipment used, sample selection, test procedure,
calculation of results, calculation of variance, interpretation of
results;
methods – dry to constant weight, electronic measurement.
Element 5
Demonstrate knowledge of yarn strength measurement and calculation.
Performance criteria
5.1
Factors used to define or calculate yarn strength are described.
Range
5.2
strength, strength per count unit, strength variation, extension at
break.
Strength measurement is described in terms of measurement methods.
Range
equipment used, sample selection, test procedure, calculation of
results, calculation of variance, interpretation of results.
 New Zealand Qualifications Authority 2016
4176 version 6
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Element 6
Demonstrate knowledge of yarn oil and fatty matter content measurement and calculation.
Performance criteria
6.1
Factors used to define or calculate oil and fatty matter content are described.
Range
6.2
extractable matter percentage.
Oil and fatty matter content measurement is described in terms of measurement
methods.
Range
describe – equipment used, sample selection, test procedure,
calculation of results, calculation of variance, interpretation of
results;
methods – rapid extraction, soxhlet extraction.
Element 7
Demonstrate knowledge of yarn shade specification, assessment, and measurement.
Performance criteria
7.1
Factors that influence the assessment and measurement of shade are defined
and described in terms of their effect on assessment and measurement.
Range
7.2
light source, viewing conditions, preparation and storage of
standards.
Assessment and measurement of yarn shade are described in terms of
methods used.
Range
describe – equipment used, sample selection, test procedure,
interpretation of results;
methods – visual assessment, colour measurement.
Element 8
Demonstrate knowledge of yarn evenness specification and testing.
Performance criteria
8.1
Factors used to define or calculate yarn evenness are described.
Range
count variation, Uster evenness index.
 New Zealand Qualifications Authority 2016
4176 version 6
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8.2
Yarn evenness measurement is described in terms of measurement methods.
Range
describe – equipment used, sample selection, test procedure,
calculation of results, calculation of variance, interpretation of
results;
methods – wrap board, analysis of count variation, Uster evenness
tester.
Please note
Providers must be accredited by NZQA, or an inter-institutional body with delegated
authority for quality assurance, before they can report credits from assessment against
unit standards or deliver courses of study leading to that assessment.
Industry Training Organisations must be accredited by NZQA before they can register
credits from assessment against unit standards.
Accredited providers and Industry Training Organisations assessing against unit standards
must engage with the moderation system that applies to those standards.
Accreditation requirements and an outline of the moderation system that applies to this
standard are outlined in the Accreditation and Moderation Action Plan (AMAP). The
AMAP also includes useful information about special requirements for organisations
wishing to develop education and training programmes, such as minimum qualifications for
tutors and assessors, and special resource requirements.
Comments on this unit standard
Please contact Competenz info@competenz.org.nz if you wish to suggest changes to the
content of this unit standard.
 New Zealand Qualifications Authority 2016