Unit of Competency Mapping – Information for Teachers/Assessors – Information for Learners

PMBPROD334A Mapping and Delivery Guide
Produce products using twin screw extruders

Version 1.0
Issue Date: April 2024


Qualification -
Unit of Competency PMBPROD334A - Produce products using twin screw extruders
Description This competency covers the operation and adjustment of twin screw extrusion equipment and extrusion processes and the solving of non-routine problems. It applies to extrusion processes for pipe, sheet, profile, film, cable and rod. It usually applies to products extruded from dry blend PVC powder/resin and other materials.
Employability Skills The required outcomes described in this unit contain applicable Employability Skills. The Employability Skills Summary of the qualification(s) in which this unit is packaged will assist in identifying Employability Skill requirements.
Learning Outcomes and Application Application of this unitThis competency is typically performed by technicians applying knowledge of materials, product purpose and processes to the operation of twin screw extrusion equipment to produce product conforming to requirements. It also requires using a range of well-developed skills requiring some discretion and judgement to recognise and solve a range of problems.The technician will:start up and shutdown the extrudercheck settings and adjustments of equipment monitor extruder operation make appropriate adjustments to correct materials, equipment or process variationssolve extruder, material and process problems, seeking guidance where necessary or appropriate. This unit does not include:operation, start up and shutdown of single screw extruders, see PMBPROD313C Produce extruded productsextrusion die changes - see PMBPREP305B Change extrusion die and calibration set-up.
Duration and Setting X weeks, nominally xx hours, delivered in a classroom/online/blended learning setting.
Prerequisites/co-requisites PrerequisitesThis unit of competency has no prerequisites.
Competency Field
Development and validation strategy and guide for assessors and learners Student Learning Resources Handouts
Activities 		Slides
PPT 		Assessment 1 Assessment 2 Assessment 3 Assessment 4
Elements of Competency Performance Criteria              
Element: Plan own work requirements.
  • Identify the most appropriate equipment to be used for production process, upstream and downstream operations from production plan or request.
  • Identify and check materials required, including additives and regrind and their amounts or percentages.
  • Implement measures to control identified hazards in line with procedures and duty of care.
  • Identify requirements for materials, quality, production and equipment checks.
       
Element: Start up twin screw extrusion process to procedures.
  • Identify process settings required for product.
  • Set process to required settings.
  • Check materials are correct.
  • Take appropriate action for non-conforming materials.
  • Set up date, batch and materials markings as required.
  • Complete pre-start checks.
  • Start up ancillary equipment as required.
  • Start up extrusion process.
  • Synchronise/balance system components as required.
       
Element: Operate and make adjustments to the twin screw extrusion process to procedures.
  • Operate extrusion process, noting key variables.
  • Monitor controls/displays/terminals for production and process data.
  • Take samples as required and identify product out of specification.
  • Monitor product/process quality.
  • Make adjustments to remedy faults and nonconformity as required.
  • Establish a stable compounding and extrusion process.
  • Adjust process to minimise scrap and trim.
  • Clean, adjust and lubricate equipment as required.
       
Element: Shut down twin screw extruder to procedures.
  • Determine type of shut down.
  • Select appropriate purging method.
  • Purge efficiently and adequately as required.
  • Leave machine in appropriate condition and with appropriate locks, tags or notices.
  • Complete relevant documentation.
  • Ensure area is clean and clear after the shutdown in readiness for the next start up.
       
Element: Anticipate and solve problems.
  • Recognise a problem or a potential problem.
  • Determine problems needing priority action.
  • Refer problems outside area of responsibility to appropriate person, with possible causes.
  • Seek information and assistance as required to solve problems.
  • Solve problems within area of responsibility.
  • Follow through items initiated until final resolution has occurred.
       


Evidence Required

List the assessment methods to be used and the context and resources required for assessment. Copy and paste the relevant sections from the evidence guide below and then re-write these in plain English.

The Evidence Guide provides advice on assessment and must be read in conjunction with the performance criteria, required skills and knowledge, the range statement and the assessment guidelines for this training package.

Overview of assessment

A holistic approach should be taken to the assessment.

Assessors must be satisfied that the person can consistently perform the unit as a whole, as defined by the Elements, Performance Criteria and skills and knowledge.

Where the assessee does not currently posses evidence of competency in PMBPROD213B Operate extruders, it may be co-assessed with this unit.

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

It is essential that competence is demonstrated in the knowledge and skills defined in this unit. These may include the ability to:

identify critical materials properties and extrusion process characteristics in relation to the process requirements and the end product

make adjustments to the process as required

identify and take appropriate action on problems and potential problems.

Consistent performance should be demonstrated. For example, look to see that:

extrusion production quality and output standards are met consistently the process runs consistently and smoothly, with the minimum need for human intervention

all safety procedures are adhered to.

Assessment method and context

It is preferred that assessment takes place on an industrial extruder in a work-like environment.

Competence in this unit may be assessed:

by using an appropriate, industrial twin screw extrusion system requiring demonstration of start-up, operation and shutdown procedures

in a situation allowing for the generation of evidence of the ability to recognise, anticipate and respond to problems

by using a suitable simulation and/or a range of case studies/scenarios

through 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 Statement 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.

Submission Requirements

List each assessment task's title, type (eg project, observation/demonstration, essay, assignment, checklist) and due date here

Assessment task 1: [title]      Due date:

(add new lines for each of the assessment tasks)

Assessment Tasks

Copy and paste from the following data to produce each assessment task. Write these in plain English and spell out how, when and where the task is to be carried out, under what conditions, and what resources are needed. Include guidelines about how well the candidate has to perform a task for it to be judged satisfactory.

This describes the essential skills and knowledge and their level required for this unit.

Application of knowledge of the materials, equipment and process sufficient to recognise material and equipment conditions which may lead to out of specification production. For example foreign material in the polymer feed leading to black spots in the product.

Knowledge of organization procedures, quality requirements at each production stage and relevant regulatory requirements along with the ability to implement them within appropriate time constraints and work standards.

Application of the knowledge of managing risks using the hierarchy of controls applied to the extrusion process. Application of approved hazard control, safety procedures, the use of PPE in relation to handling materials, equipment operation and cleanup.

Knowledge as a basis for solving processing and material problems, including:

characteristics of materials and behaviour in relation to heat, pressure, flow rate and time

function and operating principles of twin screw extruder equipment, machine components and ancillary equipment (eg stackers, haul off, saw/cutter, printing, embossing, coil winder, packaging)

requirements for compounding within the extruder

critical process variables such as temperature, torque, power

impact of extruder machine speed, torque, temperature, pressure, time, haul-off speed, on product quality and production output

operation and adjustment of vacuum system and the venting of volatiles

the relationship between the type of extruder and the materials being extruded

nature of mechanical, hydraulic, pneumatic, electrical and electronic principles which affect machine operation and product development

processing behaviours of the materials extruded in the workplace

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.

Competence also includes the ability to:

plan own work, including predicting consequences and identifying improvements

maintain output and product quality using appropriate instruments, controls, test information and readings

identify and describe own role and role of others involved directly in the extrusion process

identify factors which may affect product quality or production output and appropriate remedies

identify when assistance is required to solve problems.

Distinguish between causes of faults such as:

routine product extrusion faults - burn marks, flow marks, poor surface finish, poor colour dispersion, blistering, colour contamination, black spots

incorrect quantity of materials

contaminated materials/additives

equipment faults.

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, eg to determine how many 2 kg, 3 kg and 5 kg bags are needed to make up a requirement for 50 kg.

The range statement relates to the unit of competency as a whole. It allows for different work environments and situations that may affect performance. Add any 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.

Where reference is made to industry codes of practice and/or Australian/international standards, the latest version must be used.

Context

This competency applies to all work environments and sectors within the plastics, rubber and cablemaking industry. It includes the operation of all relevant ancillary equipment where that equipment is integral to the extrusion process.

Procedures

All operations are performed in accordance with procedures.

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

Tools and equipment

This competency includes use of equipment and tools such as:

twin screw extruder equipment and components (such as main drive, gear box, thrust assembly, adapter, gate, breaker plate, screen pack, doser, screw/s, barrel, heaters, thermocouples)

vacuum pump, vacuum system

extrusion dies (eg rod, sheet, pipe, profile and cable)

twin screw extruders, including those with parallel, tapered or other screw configurations

auxiliary equipment (eg water pump, feeders, hopper loader, pelletiser, dehumidifiers)

tools for taking samples

relevant personal protective equipment

Materials

This unit applies primarily to dry blended PVC powder, where the materials are 'compounded' within the extruder. For other materials, refer to PMBPROD313C Produce products using single screw extruders.

Hazards

Typical hazards include:

spills

dusts/vapours

slip and fall (eg due to spilt granules)

temperature (eg due to heated barrel, head and die)

volatiles vented from the extruder

hazardous materials, including decomposing polymer during start up and shut down

moving equipment (eg moving moulds, robots and ancillary equipment)

manual handling hazards

equipment operations.

Problems

'Anticipate and solve problems' means resolve a wide range of routine and non-routine problems, using product and process knowledge to develop solutions to problems which do not have a known solution/a solution recorded in the procedures.

Typical routine faults include:

burn marks

flow marks

poor surface finish

poor colour dispersion

blistering

colour contamination

black spots

dimensional changes

high reversion

ovality

bowing.

Non-routine faults, which may have multiple causes include:

product distortion

plateout

residual stresses

intermittent faults.

Typical process and product problems may include:

die/tooling problems such as damage or build-up

equipment malfunction

variations in temperatures, pressures, torque, speeds and times

vacuum performance and volatile venting rates

variations in material properties and/or contamination of materials

variation in material flow rates

processing problems.

Appropriate action for problems outside of area of responsibility may be reporting to an appropriate person.

Appropriate action for solving problems within area of responsibility includes asking questions and seeking assistance from appropriate persons/sources.

Variables

Key variables to be monitored include:

differences between actual and set temperatures

speeds, including screw speed and haul-off

colour and uniformity

surface finish and appearance

product finished thickness

output rate

product integrity and general conformance to specification/sample.

Copy and paste from the following performance criteria to create an observation checklist for each task. When you have finished writing your assessment tool every one of these must have been addressed, preferably several times in a variety of contexts. To ensure this occurs download the assessment matrix for the unit; enter each assessment task as a column header and place check marks against each performance criteria that task addresses.

Observation Checklist

Tasks to be observed according to workplace/college/TAFE policy and procedures, relevant legislation and Codes of Practice Yes No Comments/feedback
Identify the most appropriate equipment to be used for production process, upstream and downstream operations from production plan or request. 
Identify and check materials required, including additives and regrind and their amounts or percentages. 
Implement measures to control identified hazards in line with procedures and duty of care. 
Identify requirements for materials, quality, production and equipment checks. 
Identify process settings required for product. 
Set process to required settings. 
Check materials are correct. 
Take appropriate action for non-conforming materials. 
Set up date, batch and materials markings as required. 
Complete pre-start checks. 
Start up ancillary equipment as required. 
Start up extrusion process. 
Synchronise/balance system components as required. 
Operate extrusion process, noting key variables. 
Monitor controls/displays/terminals for production and process data. 
Take samples as required and identify product out of specification. 
Monitor product/process quality. 
Make adjustments to remedy faults and nonconformity as required. 
Establish a stable compounding and extrusion process. 
Adjust process to minimise scrap and trim. 
Clean, adjust and lubricate equipment as required. 
Determine type of shut down. 
Select appropriate purging method. 
Purge efficiently and adequately as required. 
Leave machine in appropriate condition and with appropriate locks, tags or notices. 
Complete relevant documentation. 
Ensure area is clean and clear after the shutdown in readiness for the next start up. 
Recognise a problem or a potential problem. 
Determine problems needing priority action. 
Refer problems outside area of responsibility to appropriate person, with possible causes. 
Seek information and assistance as required to solve problems. 
Solve problems within area of responsibility. 
Follow through items initiated until final resolution has occurred. 

Forms

Assessment Cover Sheet

PMBPROD334A - Produce products using twin screw extruders
Assessment task 1: [title]

Student name:

Student ID:

I declare that the assessment tasks submitted for this unit are my own work.

Student signature:

Result: Competent Not yet competent

Feedback to student

 

 

 

 

 

 

 

 

Assessor name:

Signature:

Date:

Assessment Record Sheet

PMBPROD334A - Produce products using twin screw extruders

Student name:

Student ID:

Assessment task 1: [title] Result: Competent Not yet competent

(add lines for each task)

Feedback to student:

 

 

 

 

 

 

 

 

Overall assessment result: Competent Not yet competent

Assessor name:

Signature:

Date:

Student signature:

Date: