Elements and Performance Criteria

This competency applies mainly to the rubber industry, but may also be relevant in the plastics industry. It includes the operation of all additional equipment where that equipment is integral to the mill blending process.

This competency would typically apply to the mixing of rubbers or plastics, but may be applied to other materials mixed on an open mill blender.

Procedures means all relevant workplace procedures, work instructions, temporary instructions and relevant industry and government codes and standards.

This is an inherently hazardous operation, and hazards should be identified from observation of the mill itself, the blender feed and product delivery equipment, and from workplace reference materials including materials safety data sheets and equipment instructions.

This competency includes equipment and tools such as:
mill knifes
nip adjusting bars
bale hooks
relevant personal protective equipment.

Typical hazards include:
cuts
nip hazards
material hazards
burn hazards
manual handling hazards.

'Rectify routine problems' means 'apply known solutions to a limited range of predictable problems'.

Typical process problems include:
power failures
incorrect machine adjustments
incorrect quantities of materials
incorrect blending times
equipment breakdowns
short scorch products
forming the initial band
adjusting bank size for efficient mixing.

Typical product problems include:
variations in materials
contamination of materials
lack of a homogeneous product.

All operations are performed in accordance with procedures.

Essential knowledge and enterprise requirements
Application of knowledge of the materials, equipment and process sufficient to recognise out of specification products, process problems and materials faults.
Knowledge of the enterprise's procedures and relevant regulatory requirements along with the ability to implement them within appropriate time constraints and work standards.

Competence includes the ability for the practical completion of the job to:
apply and/or explain:
the nature of the principles which influence the open mill blender equipment operation and product blending
the impact that chemical reactions/mechanical processes have on changing the state, form and condition of the materials
purpose of developing elasticity and controlling temperatures
effects of mastication, differential speed, overheating
production workflow schedule requirements
focus of operation of work systems and equipment
correct use of equipment, processes and procedures
planning own work including predicting consequences and identifying improvements
identify the function of open mill blender equipment, machine components and the materials used
describe changes to materials at the stages of production conducted by the employee
explain the impact of open mill blender machine speed, pressure, time and temperature on finished product quality, production process and output
identify the role friction plays in the blending of product
describe causes and effects of variations in blended batches
identify and describe own role and the roles of others involved in the open mill blender process and in delivery within the workplace of raw and blended materials
explain the effect of unauthorised or emergency shutdown of equipment on the open mill blender process
operate the open mill blender in accordance with the organisation's procedures
plan own work sequence including identification of key checkpoints for equipment monitoring, product quality checks and monitoring of supplies and downstream operations
monitor equipment operation and product quality
identify factors which may influence product quality and production output, and appropriate remedies
make appropriate alterations to own work plan and equipment to maintain both product quality and required production output
locate, interpret and apply relevant information and maintain workplace records
identify and safely handle products and materials, read relevant safety information and apply safety precautions appropriate to the task.

Critical aspects
It is essential that competence is demonstrated in the ability to:
understand the importance of critical material properties and quantities
recognise potential situations requiring action and then implement appropriate action.

Consistent performance should be demonstrated. In particular look to see that:
production standards are met consistently.
blending results in materials of the right consistency and specification
upstream and downstream communication is timely and effective
common production faults and equipment malfunctions are identified/anticipated and appropriate action is taken (ie the fault fixed or reported)
non-routine problems are identified and reported to appropriate personnel
all safety procedures are adhered to.

Language, literacy and numeracy requirements
This unit requires the ability to read and interpret typical product specifications, job sheets, procedures, material labels and safety information as provided to operators.
Writing is required to the level of completing workplace forms.
Basic numeracy is required, e.g. to determine that two 25 kg bags are needed to make up a requirement for 50 kg.

Assessment method and context
Competence in this unit may be assessed:
on an operating plant allowing for operation under all normal and a range of abnormal conditions
by use of a suitable simulation and/or a range of case studies/scenarios
by a combination of these techniques.

In all cases it is expected that practical assessment will be combined with targeted questioning to assess the underpinning knowledge and that the theoretical assessment will be combined with appropriate practical/simulation or similar assessment.

Resource implications
This section should be read in conjunction with the range of variables for this unit of competency. Resources required include suitable access to an operating plant or equipment that allows for appropriate and realistic simulation. A bank of case studies/scenarios and questions will also be required to the extent they form part of the assessment method. Questioning may take place either in the workplace, or in an adjacent, quiet facility such as an office or lunchroom. No other special resources are required.