NZQA registered unit standard
5671 version 5
Page 1 of 4
Title
Explain principles of paper tissue manufacture
Level
3
Credits
Purpose
5
People credited with this unit standard are able to: explain the
processes involved in tissue manufacture; identify furnish
components and explain the effects of wet end chemistry; and
explain tissue manufacture forming principles, the functions
and operation of the felt section in tissue manufacture, the
operation of a yankee cylinder, and the operating principles for
crepeing of tissue.
This unit standard aims to provide knowledge of the principles
and equipment used in the manufacture of tissue.
Classification
Wood Fibre Manufacturing > Pulp and Paper Technology
Available grade
Achieved
Explanatory notes
All evidence requirements must be demonstrated and assessed in accordance with the
reference text: Explain principles of paper tissue manufacture published by Competenz
and available from Competenz at http://www.competenz.org.nz/, or Competenz, PO Box
9005, Newmarket, Auckland 1149.
Outcomes and evidence requirements
Outcome 1
Explain the processes involved in tissue manufacture.
Evidence requirements
1.1
Crepeing processes used to categorise tissue products are explained.
Range
1.2
wet crepe, semi-dry crepe, dry crepe.
Techniques for tissue manufacture are identified and explained.
Range
Competenz
SSB Code 101571
conventional, recreped, through dried, layered.
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
1.3
5671 version 5
Page 2 of 4
Tissue properties are identified and their importance is explained.
Range
substance, moisture, bulk, strength, machine direction to cross
direction ratio, wet tensile, stretch, absorbency rate, absorbency
capacity, softness, brightness.
Outcome 2
Identify furnish components and explain the effects of wet end chemistry.
Evidence requirements
2.1
Characteristics of pulps used for tissue manufacture are explained.
Range
2.2
bleached softwood kraft, bleached softwood sulphite, bleached
hardwood kraft, mechanical, secondary.
Chemical additives are identified and their use and effects are explained.
Range
dyes, wet strength resin, dry strength agents, retention aids,
defoamers, dispersers.
2.3
Effects of electrostatic surface charges are explained in terms of dispersion,
coagulation, and deposition.
2.4
Operating conditions affected by changes in wet end chemistry are identified.
Range
2.5
drainage, flocculation, retention, strength, adhesion.
Stock processing operations for tissue are identified and explained.
Range
slushing, blending, refining, cleaning, screening.
Outcome 3
Explain tissue manufacture forming principles.
Evidence requirements
3.1
Factors contributing to tissue formation are identified and explained.
Range
3.2
consistency, head box conditions, drainage, retention, support.
Formers are identified and their operating characteristics are explained.
Range
fourdrinier, periformer, crescent, twin wire, layering.
Outcome 4
Explain the functions and operation of the felt section in tissue manufacture.
Competenz
SSB Code 101571
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
5671 version 5
Page 3 of 4
Evidence requirements
4.1
Designs of a felt section are explained and their operating characteristics
compared in terms of single run, double run, moisture, showering, and pressing.
4.2
Position and function of felt cleaning showers are explained.
4.3
Pressure roll operating variables are identified and their effects are explained.
Range
nip pressure, dwell time, flow, temperature.
Outcome 5
Explain the operation of a yankee cylinder.
Evidence requirements
5.1
Reasons for the use of yankee cylinders are identified in terms of evaporation
rate, draw, and product property development.
5.2
Evaporative drying is described and the functions of the various components
are explained.
Range
5.3
heat transfer, hood air.
Through drying is described and its advantages are explained in terms of bulk,
absorbency, opacity, and softness.
Range
components – drum, hood, air heaters.
Outcome 6
Explain the operating principles for crepeing of tissue.
Evidence requirements
6.1
Properties affected by crepeing are identified.
Range
6.2
Factors affecting the result of the crepeing operation are identified.
Range
6.3
softness, bulk, absorbency, stretch.
fibre flexibility, formation, strength, moisture, adhesion, pocket
angle, blade geometry.
Factors affecting crepeing blade wear are identified and the effects of worn
blades are explained.
Range
Competenz
SSB Code 101571
factors – coating properties, blade geometry, stability, pressure,
contaminants, surface uniformity, material;
effects – sheet passing, crepe coarseness, crepe variability.
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
Planned review date
5671 version 5
Page 4 of 4
31 December 2019
Status information and last date for assessment for superseded versions
Process
Version Date
Last Date for Assessment
Registration
1
23 November 1995
N/A
Revision
2
27 January 1997
N/A
Review
3
25 February 1999
N/A
Review
4
18 December 2006
N/A
Review
5
24 October 2014
N/A
Consent and Moderation Requirements (CMR) reference
0173
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 Competenz qualifications@competenz.org.nz if you wish to suggest
changes to the content of this unit standard.
Competenz
SSB Code 101571
 New Zealand Qualifications Authority 2016