19842 version 2
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Demonstrate knowledge of wet processing of wool carpet yarns
Level
4
Credits
20
Purpose
People credited with this unit standard are able to demonstrate knowledge of:
yarn scouring; chemical setting of wool yarns; twist setting and twist setting
technologies; and yarn and carpet properties.
Subfield
Textiles Manufacture
Domain
Woollen 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
19842 version 2
Page 2 of 4
Elements and performance criteria
Element 1
Demonstrate knowledge of yarn scouring.
Performance criteria
1.1
Contaminants in carpet yarn removed by scouring are identified and described
in terms of type and origin.
Range
1.2
Yarn scouring methods are identified and described in terms of their operating
principles.
Range
1.3
natural, acquired, applied.
tape scouring, Twistset machine, brattice scouring, scouring in a
dyebath.
Detergents used in yarn scouring are described in terms of their scouring
action.
Element 2
Demonstrate knowledge of chemical setting of wool yarns.
Performance criteria
2.1
The molecular structure of wool fibre is described in terms of its elementary
characteristics.
Range
2.2
protein chain, crosslinks.
Chemical setting processes are identified and described in terms of their degree
of set on wool fibre.
Range
permanent setting, semi-permanent setting, temporary setting.
Element 3
Demonstrate knowledge of twist setting and twist setting technologies.
Performance criteria
3.1
Reasons for twist setting wool yarns are identified and described in terms of the
effect on yarn and carpet properties.
Range
yarn stability, carpet texture and durability, tuft definition.
 New Zealand Qualifications Authority 2016
19842 version 2
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3.2
The twist setting processes for wool yarns are identified and described in terms
of their function and operation.
Range
water setting, chemical setting in a dye vat, batch autoclave,
continuous autoclave, chemical setting in a tape scour, Twistset
process.
Element 4
Demonstrate knowledge of yarn and carpet properties.
Performance criteria
4.1
Yarn properties that influence twist set are described in terms of their effect on
yarn and carpet appearance and quality.
Range
4.2
Effects of yarn setting treatments are described in terms of changes to
structural properties and yarn colour.
Range
4.3
randomisation mixing, twist liveliness, cohesive regain.
The carpet faults arising from inadequate scouring or setting processes are
identified and described in terms of appearance and carpet quality.
Range
4.5
loss of physical properties, colour change.
Yarn handling procedures for wet processing are described in terms of their
effect on yarn and carpet properties and quality.
Range
4.4
twist levels, yarn bulk, fibre type.
colour stripes and steaks, texture stripes and streaks, carpet
bands.
Tests for assessing scouring efficiency and level of set are identified and
described in terms of test methods.
Range
extractable matter, twist stability, WRONZ Set 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.
 New Zealand Qualifications Authority 2016
19842 version 2
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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