NZQA registered unit standard
27900 version 1
Page 1 of 3
Title
Evaluate chrome leather wet post tannage processes
Level
5
Credits
Purpose
6
This unit standard is for experienced people wishing to develop
their technical skills in leather manufacture.
People credited with this unit standard are able to: demonstrate
knowledge of wet post tannage stages; evaluate the
mechanism of chrome leather neutralisation and chemicals
used in dyeing, fatliquoring, and retanning; evaluate chrome
leather wet post tannage methods; and evaluate dyed chrome
leather product properties.
Classification
Fellmongery and Leather Processing > Leather Processing
Knowledge
Available grade
Achieved
Explanatory notes
None.
Outcomes and evidence requirements
Outcome 1
Demonstrate knowledge of wet post tannage stages.
Evidence requirements
1.1
Wet post tannage stages are outlined in correct sequence in terms of their
purpose in achieving specified finished leather properties.
Range
1.2
stages include but are not limited to – neutralisation, dyeing,
retanning, fatliquoring.
Wet post tannage machinery is outlined in terms of mechanical principle and
function.
Range
evidence is required of a process vessel plus two others, which
may include– sammer, splitter, shaver, setter, wet wheeler.
Primary Industry Training Organisation
SSB Code 101558
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
27900 version 1
Page 2 of 3
Outcome 2
Evaluate the mechanism of chrome leather neutralisation and chemicals used in dyeing,
fatliquoring, and retanning.
Evidence requirements
2.1
Chrome leather neutralisation is evaluated in terms of chemical mechanism.
2.2
Chrome leather dyestuffs are evaluated in terms of type and the properties that
influence finished leather.
Range
2.3
Chrome leather fatliquoring agents are evaluated in terms of type and the
properties that influence finished leather.
Range
2.4
evidence is required of three, which may include but are not
limited to – acid, basic, direct, premetallised.
evidence is required of three, which may include but are not
limited to – cationic, amphoteric, sulphated, sulphited,
sulphonated.
Chrome leather retanning agents are evaluated in terms of type and the
properties that influence finished leather.
Range
evidence is required of three, which may include but are not
limited to – syntans, vegetable tans, acrylic resins, mineral tans,
aldehydes.
Outcome 3
Evaluate chrome leather wet post tannage methods.
Evidence requirements
3.1
Neutralisation, retanning, dyeing and fatliquoring techniques are evaluated in
terms of their use in manufacturing different leather types.
Range
3.2
Factors that influence dye levelness are evaluated in relation to chrome leather
wet post tannage methods.
Range
3.3
evidence is required of one of the following – upper, clothing,
gloving, upholstery.
evidence is required of four of the following – levelling agents, hide
and skin uniformity, dyestuff properties, temperature, pH, float,
mechanical action, process control.
An alternative to the drum or paddle process for dyeing chrome leather is
evaluated and its advantages and disadvantages explained.
Primary Industry Training Organisation
SSB Code 101558
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
27900 version 1
Page 3 of 3
Outcome 4
Evaluate dyed chrome leather product properties.
Performance criteria
4.1
Dyed chrome leather product properties are evaluated in relation to their
suitability for leather product uses.
Range
evidence is required of four, which may include but are not limited
to– light fastness, rub fastness, wash fastness, perspiration
fastness, dry cleanability, strength, stretch, softness.
Replacement information
Planned review date
This unit standard replaced unit standard 8403.
31 December 2017
Status information and last date for assessment for superseded versions
Process
Version Date
Last Date for Assessment
Registration
1
21 February 2013
N/A
Consent and Moderation Requirements (CMR) reference
0033
This CMR can be accessed at http://www.nzqa.govt.nz/framework/search/index.do.
Please note
Providers must be granted consent to assess against standards (accredited) by NZQA,
before they can report credits from assessment against unit standards or deliver courses
of study leading to that assessment.
Industry Training Organisations must be granted consent to assess against standards by
NZQA before they can register credits from assessment against unit standards.
Providers and Industry Training Organisations, which have been granted consent and
which are assessing against unit standards must engage with the moderation system that
applies to those standards.
Requirements for consent to assess and an outline of the moderation system that applies
to this standard are outlined in the Consent and Moderation Requirements (CMR). The
CMR 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 Primary Industry Training Organisation standards@primaryito.ac.nz if
you wish to suggest changes to the content of this unit standard.
Primary Industry Training Organisation
SSB Code 101558
 New Zealand Qualifications Authority 2016