Elements and Performance Criteria

This competency applies to blown film line operations within the plastics and rubber industries. It includes the operation of all relevant additional equipment where that equipment is integral to the blown film process.

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

This competency includes tools and equipment such as:
extruder
die, air ring and blower
bubble guides and rollers
film rollers, slitting, trimming and winding gear
coolers, heaters and ancillary equipment
hand tools, knives, adjustment tools
relevant personal protective equipment.

Typical hazards include:
high air velocities
high voltage corona treatment systems
sharp knives
high towers
manual handling
fumes, humidity, air temperatures, radiant heat, hot dies
stationary and moving machinery, parts and components.

Respond to/rectify 'non-routine problems' means 'apply known solutions to a variety of predictable problems'.

Typical process and product problems include:
extruder control, temperature, pressures, screw speed
contamination
bubble control, size, stability
blemishes, voids, gels, die and weld lines, burn marks, poor surface finish, poor colour dispersion, partially decomposed products, uneven colour, contamination of colour
alignment and control of trimming and winding gear
materials variations
worn/damaged dies and extruder adjustments
raw material contamination, wrong grade, variations of polymer properties
hydraulic pressure variations, temperature variations, loss of power or drives
process sequencing problems
variations in component speeds.

Key variables to be monitored include:
extruder operating temperatures, melt temperatures, back pressures and current (amps)
nip and winding speeds, nip roller settings
corona treatment settings
winder settings, slitters, trimmers and die gap adjustments
colour
output rate
product thickness
product integrity and general conformance to specification/sample.

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 material and equipment conditions which may lead to out of specification production.
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:
products, materials and material characteristics
behaviour of materials in relation to heat, pressure and time
quality requirements at each production stage
function and operating principles of blown film equipment, machine components and ancillary equipment
impact of extruder speed, temperature, pressure on product quality and production output
impact of changes and adjustments to the winding gear on film properties
nature of mechanical, hydraulic, pneumatic, electrical and electronic principles which effect machine operation and product development
safety procedures and the use of PPE in relation to handling materials, equipment operation and clean up
the hierarchy of control including engineering controls
impact of variations in raw materials and equipment operation in relation to final product
changes to materials at various stages of production
waste management and importance of non-conforming materials
plan own work including predicting consequences and identifying improvements
interpret from production requests the correct selection and use of equipment, materials, processes and procedures
maintain output and product quality using appropriate instruments, controls, test information and readings
make adjustments to equipment operation to rectify variations in equipment operation or product quality
check blown film line for correct set-up to job specifications and implement adjustments or report deviations immediately
start up equipment and make appropriate adjustments to bring process on line
make measurements when required and identify product out of specification
safely shut down equipment in normal or abnormal circumstances
identify and describe own role and role of others involved directly in the film process
identify factors which may affect product quality or production output and appropriate remedies
identify when the operator is able to rectify faults and when assistance is required
identify hazards of the materials and process
implement appropriate procedures for hazard control
use PPE, safely handle products and materials, read relevant safety information and apply safety precautions appropriate to the task
distinguish between causes of faults such as:
materials
contaminants
equipment - adjustments/set-up
equipment - maintenance requirements.

Critical aspects
It is essential that competence is demonstrated in the ability to:
identify critical materials properties and blown film process characteristics in relation to the process requirements and the end product
plan own work process within workplace procedures and explain the reasons for the steps in the process
take appropriate action to observe equipment, materials and products for out of specification results, make adjustments and identify problems to be reported.

Consistent performance should be demonstrated. In particular look to see that:
production quality and output standards are met consistently
problems are anticipated from process observations
problems are efficiently resolved
the process runs consistently and smoothly.

Language, literacy and numeracy requirements
This unit requires the ability to read and interpret typical product specifications, job sheets and material labels as provided to operators.
Writing is required to the level of completing workplace forms and production reports.
Basic numeracy is required, e.g. to determine how many 2 kg, 3 kg and 5 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 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 that 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.