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4176 Demonstrate knowledge of yarn specification and measurement

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					                                                                               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)       Apparel and Textile Industry Training Organisation

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 2011
                                                                                  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        direct systems – tex, denier;
                       indirect systems – metric, Yorkshire skeins, Worsted, Galashiels,
                       Dewsbury, cotton.

2.2       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 2011
                                                                                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        dry weight, conditioned weight, moisture content percentage,
                       regain percentage.

4.2       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        strength, strength per count unit, strength variation, extension at
                       break.

5.2       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 2011
                                                                                4176 version 6
                                                                                   Page 4 of 5

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        extractable matter percentage.

6.2       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        light source, viewing conditions, preparation and storage of
                       standards.

7.2       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 2011
                                                                                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 the Apparel and Textile Industry Training Organisation
training@atito.org.nz if you wish to suggest changes to the content of this unit standard.




                                                                New Zealand Qualifications Authority 2011
f this unit standard.




                                                                New Zealand Qualifications Authority 2010

				
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