ELEMENT

PERFORMANCE CRITERIA

1. Prepare or interpret mill flow sheet

1.1 Identify all breaking, reduction and dressing stages in mill.

1.2 Destinations for all stock separations are shown.

1.3 Identify all optional and ancillary equipment.

1.4 Identify all bins, silos, chutes, conveyors and exhausts.

1.5 Maintain diagram showing all equipment and stock flow.

2. Prepare for flour and byproduct production

2.1 Establish customer requirements for shift or production period.

2.2 Follow recipe required to meet desired production quality and quantity targets.

2.3 Check availability of required wheat stock.

2.4 Determine if any changes to grist stock will be required and plan for changes to settings.

3. Determine break system settings

3.1 Adjust break rolls for desired percentage release.

3.2 Conduct visual inspection and test sieving where required to monitor release percentage.

3.3 Monitor break roll passages to avoid saturation of later stages.

3.4 Set bran finishers.

3.5 Set plansifters for desired grading including adjusting spaces between plansifters for varying grains and moisture levels.

3.6 Monitor performance of break system to ensure system is free from semolina.

4. Determine settings for purifiers where fitted

4.1 Maintain and monitor sieve covers.

4.2 Monitor feed rate to purifiers.

4.3 Monitor horizontal and vertical movement of sieve covers.

4.4 Set and monitor air pressure for each aspiration section.

4.5 Select destinations for throughs and lifted bran and other particles.

4.6 Ensure purifier stock is free from flour.

5. Determine settings for scratch or sizing system

5.1 Set scratch equipment or sizing rolls.

5.2 Monitor performance of scratch and sizing rolls.

6. Determine settings for reduction passages

6.1 Set each set of reduction rolls for desired flour and capacity of succeeding reduction passages.

6.2 Monitor covers on sifters for effective dressing from each reduction roll.

6.3 Monitor flake disrupters and impact detachers where fitted.

6.4 Set and monitor reduction settings to achieve required starch damage.

6.5 Specify collection conveyors and bins for each flour stream.

7. Determine settings for final production stages

7.1 Specify use of flour divides for blends.

7.2 Monitor redressing equipment.

7.3 Monitor weighing, infestation destroying and metal removal equipment.

7.4 Send finished flour to packing or storage.

8. Monitor mill equipment

8.1 Check flutes and rolls for wear and defects.

8.2 Monitor temperature of reduction rolls and performance of water cooling if used.

8.3 Check automatic roll adjustment and protection mechanisms are working correctly.

8.4 Adjust mill settings when required for effect of breakdowns and urgent maintenance.

9. Monitor mill performance

9.1 Ensure all grain and flour tests are carried out to required schedule and procedures.

9.2 Adjust settings where required for variation in grain, grist and atmospheric conditions.

9.3 Monitor milling and invisible loss per production period.

Required skills include:

Ability to:

interpret mill flow diagrams

perform contingency planning for equipment breakdown including failure mode effects analysis

balance dressing surfaces across break and reduction stages

adjust break rolls to take into account:

number of break stages

grist composition

specification of finished product

estimate break roll percentages through visual examination, hand stratification and test sieving.

Required knowledge includes:

Knowledge of:

alternative and historical milling techniques including:

stone grinding

"low" or one pass through grinding

use of small manual or electric milling machines

semolina process vs traditional flour milling process

conventions and techniques in drawing mill flow diagrams

characteristics of different grists and their milling requirements

purpose design and steps in the break process including:

overall aim of removing bran from endosperm in large pieces while minimising bran powder and flour

roller design

flute design

roller speed

number of passages

destinations of product from each break roll

purpose, design and principles of the purification process including:

sieve design

role of sifting, shaking, gravity and aspiration (upward air)

screening decks

exhaust ports and chambers

collection of throughs

overtails

relationship of purification to later reduction stages

scratch equipment and process to remove small pieces of bran and germ from endosperm after sizing or purification

relationship of particle size to reduction roller efficiency

reduction which grinds flour into required fineness while controlling damage to starch granules and minimising abrasion to any bran and germ particles present

features and performance characteristics of milling equipment as specified in manufacturers reference material

relationship between total dressing surface ratio to mill capacity

calculation of break roll percentages

mill balance requirements and techniques including:

ensuring that stock does not return to immediate preceding passage or equipment

feed to first break at a constant rate

evenness of feed into rolls

maintenance of conveyor and air settings to achieve constant feed

calculation of mill performance including:

invisible loss rate

theoretical and actual milling loss rate.

The evidence guide provides advice on assessment and must be read in conjunction with the performance criteria, required skills and knowledge, range statement and the Assessment Guidelines for the Training Package.

Overview of assessment

Assessment must be carried out in a manner that recognises the cultural and literacy requirements of the assessee and is appropriate to the work performed. Competence in this Unit must be achieved in accordance with food safety standards and regulations.

Critical aspects for assessment and evidence required to demonstrate competency in this Unit

Evidence of ability to:

interpret mill flow diagrams and production requirements

set and monitor break and reduction system equipment

achieve flour recipes through correct use of grists and mill settings

adjust mill settings for breakdowns and other contingencies.

Context of and specific resources for assessment

Assessment must occur in a real or simulated workplace where the assessee has access to:

personal protective clothing and equipment

work procedures, including advice on safe work practices, food safety, quality and environmental requirements

equipment manuals including operating parameters

specifications, control points and processing parameters

break and reduction roll process and related equipment and services

conditioned grain suitable for the break and reduction roll process

sampling schedules and test procedures and equipment as required

documentation and recording requirements and procedures

cleaning procedures, materials and equipment as required.

Method of assessment

This Unit should be assessed together with core Units and other Units of Competency relevant to the function or work role.

Guidance information for assessment

To ensure consistency of performance, competency should be demonstrated on more than one occasion over a period of time in order to cover a variety of circumstances, cases and responsibilities, and where possible, over a number of assessment activities.

The range statement relates to the Unit of Competency as a whole. It allows for different work environments and situations that may affect performance. Bold italicised wording, if used in the performance criteria, is detailed below. Essential operating conditions that may be present with training and assessment (depending on the work situation, needs of the candidate, accessibility of the item, and local industry and regional contexts) may also be included.

Mill

The term mill is used to refer to the whole mill site including the actual milling equipment, equipment used for associated processes, and transport, warehouse, maintenance, testing and administration facilities.

Mill flow diagram

A mill flow diagram is a representation of the flow of products through the mill process.

Mill balance

Mill balance refers to achieving settings where each passage in the grain breaking and reduction process ensures that other passages and equipment operate on optimum quantity and quality of stock. It also refers to ensuring that the overall surface area (available contact area for product) is appropriate for that stage or passage and the mill as a whole.

Grain acceptance specifications may include:

weight

protein

moisture

odour

foreign object criteria

pests and pest treatment residues.

Grinding can refer to:

the break system which is the process of opening up the grain and scraping away the endosperm

the reduction system which is the process of reducing the endosperm until it can be classified as flour.

Extraction rate

The extraction rate is the number of parts by weight of flour obtained from a hundred parts of grain.

Optional equipment

Optional equipment is milling equipment not found in every mill. Examples include:

bran finishers/brushes

germ production machines

bran rolls

bran grinding rolls

micro-detachers.

Throughs

Stock which falls through apertures at each sifting or purifying stage.

Overtails

Stock left after throughs are collected and which depending on the stage may be:

endosperm particles with adhering bran

mainly bran

bran and endosperm requiring further treatment.

Wheatfeed

By product of the milling process including bran of varying sizes and varying amounts of attached endosperm.

Scalping

Scalping is the separation of coarse overtails after grinding

Roll adjustment

Adjustment of roll gaps may be done manually or through computerised.