NZQA registered unit standard
27902 version 1
Page 1 of 3
Title
Evaluate vegetable 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 used in vegetable
leather manufacture; evaluate the chemistry of wet post
tannage stages used for vegetable leather manufacture;
evaluate vegetable leather wet post tannage methods; and
evaluate dyed vegetable 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 used in vegetable leather
manufacture.
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
evidence is required of four of the following – stripping, clearing,
bleaching, retanning, dyeing, fatliquoring.
Wet post tannage machinery used for vegetable leather manufacture is outlined
in terms of operation and function.
Range
evidence is required of process vessel plus two others, which may
include but are not limited to – sammer, splitter, shaver, setter,
roller.
Primary Industry Training Organisation
SSB Code 101558
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
27902 version 1
Page 2 of 3
Outcome 2
Evaluate the chemistry of wet post tannage stages used for vegetable leather
manufacture.
Evidence requirements
2.1
Chemical mechanism of wet post tannage stages is evaluated in terms of the
chemicals used and their interaction with the vegetable leather.
Range
2.2
Vegetable leather dyestuffs are evaluated in terms of type and the properties
that influence finished vegetable leather.
Range
2.3
evidence is required of three, which may include but are not
limited to – acid, basic, direct, premetallised.
Vegetable leather fatliquoring agents are evaluated in terms of type and the
properties that influence finished vegetable leather.
Range
2.4
evidence is required of two of the following – stripping, clearing,
bleaching, retanning, dyeing, fatliquoring, currying.
evidence is required of three of the following – cationic,
amphoteric, sulphated, sulphited, sulphonated, currying oil.
Vegetable leather retanning agents are outlined in terms of type and properties
that influence finished vegetable leather.
Range
evidence is required of two of the following – vegetable tan,
mineral tan, syntan.
Outcome 3
Evaluate vegetable leather wet post tannage methods.
Evidence requirements
3.1
Vegetable leather wet post tannage processes are evaluated in terms of the
tannery practices used for the manufacturing of different vegetable leather
types.
Range
3.2
evidence is required of one, which may include but is not limited to
– upholstery, upper, sole, saddlery, belt, industrial.
Factors that influence dye levelness in vegetable leather are evaluated in terms
of wet post tannage methods.
Range
evidence is required of four of the following – levelling agents, hide
and skin uniformity, dyestuff properties, temperature, pH, float,
mechanical action, process control.
Primary Industry Training Organisation
SSB Code 101558
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
27902 version 1
Page 3 of 3
Outcome 4
Evaluate dyed vegetable leather product properties.
Evidence requirements
4.1
Dyed vegetable leather product properties are evaluated in relation to the
suitability for leather product uses.
evidence is required of four of the following – light fastness, rub
fastness, water proofness, water spotting, perspiration fastness,
strength, stretch, abrasion resistance.
Range
Replacement information
Planned review date
This unit standard replaced unit standard 8405.
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