2Session aimTo improve the delegates understanding of quality issues, relating to injection moulding and how the process can be optimised and monitored.
3Session objectives By the end of the session you will be able to: State 3 Quality Improvement tools.Explain how weight can be used to monitorthe process.Calculate Cm and Cmk values.
4Quality control - Detection systems The manufacturing processMethodsPeopleMaterialOutputInformation on qualityDecisions takenEnvironmentEquipmentSmed,DOE,FMEA,JIT,SPC where do they fit in ?
5Quality assurance - Prevention systems The manufacturing processMethodPeopleMaterialOutputDecisions takenEnvironmentEquipmentSmed,DOE,FMEA,JIT,SPC where do they fit in ?SPCInformation on qualityImproveDesignsFMEAUpdatePerformanceDoE
6Quality tools DoE (Design of Experiments) A combination of trials to identify optimumprocess conditions. e.g. L8 – 7 variables with 2 levels.DoE (Design of Experiments)Step-by-step approach to identify all possible failures in a design, manufacturing or assembly process.FMEA (Failure Mode & Effects Analysis)Explain how weight can be used to monitor the process.SPC (Statistical Process Control)A mathematical technique to measure andimprove performance.
7Failure Mode & Effects Analysis 1. Process function – Capability study on m/c.2. Potential failure modes – Zero cushion position3. Potential effects of the failure – High scrap rate4. Potential causes of the failure – Worn/damaged check ring5. Current process controls – None6. Recommended actions – a) Barrel tolerances +/- 100C b) Monitor cushion positionc) Visual check every 6 months (Abrasive polymers)PC & GF grades
8SPC - More detail Statistical ProcessControlCollecting, representing and analysing data,developing and understanding patterns.A sequence of operations, not only themachine cycle.Explain how weight can be used to monitor the process.Measuring performance, taking action onthe data.
9x x x x xx x x x x x Terminology Total Tolerance Top Limit Bottom Limitx x xx x x x x xTarget
10x x x Case study Target piston diameter = 60 mm (+/- 1mm) 58.8 59.0 Total ToleranceTotal Variation in SampleTargetxxx58.859.059.259.459.659.860.060.260.460.660.861.061.2Measured sizes