Application of Quality Improvement Techniques to the Powder Coat Process Joan Burtner, Chris Durre & Nikki Smith Department of Mechanical and Industrial Engineering Mercer University, Macon, GA

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University2 The Six Sigma Approach in the Business Community  Six Sigma - a comprehensive system for achieving, sustaining and maximizing business success  Drivers  a close understanding of customer needs,  disciplined use of facts, data, and statistical analysis  diligent attention to managing, improving, and reinventing the business process

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University3 Benefits of the Six Sigma Approach  cost reduction  productivity improvement  market-share growth  customer retention  cycle-time reduction  defect reduction  culture change  product/service development

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University4 The Six Sigma Philosophy  Designed to foster data-driven management decisions  The Three C’s  common metrics  “constant” communication  culture change

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University5 Selection Criteria for Six Sigma Improvement Projects  There is a gap between current and desired/needed performance.  The cause of the problem is not clearly understood.  The solution isn’t predetermined, nor is the optimal solution apparent.

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University6 School of Engineering Senior Design Course  Two semester course required for graduation with a bachelor’s degree in engineering or industrial management  Student Teams  Two or three students  Often interdisciplinary  Management  Senior design course instructor  Departmental technical advisor  Client – internal or external

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University7 Paint Cell Project  Interdisciplinary team  Industrial management  Industrial engineering  Technical advisor - Joan Burtner  External client  Georgia manufacturer  Practices Six Sigma philosophy

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University8 Powder Coat Process Overview  Material - powdered paint  Two basic application methods  Part is lowered into a fluidized bed of the powder, which is electrostatically charged  Powdered paint is electrostatically charged and sprayed onto the part  Curing  Part placed in an oven - powder particles melt and form a continuous film

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University9 Powder Coat Equipment  Spray Gun  Corona charging guns -electric power used to generate the electrostatic charge  Tribot charging guns - electrostatic charge generated by friction between the powder and the gun barrel  “Bell” charging guns -powder charged by being "flung" from the perimeter of the "bell

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University10 Powder Coat Facility Typical Spray Booth Courtesy: Accessed March 12, 2004

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University11 Quality Issues  Surface preparation  Operators  Training  Skill  Coverage  Color change  Cleanliness/ contamination

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University12 Six Sigma Methodology  Define  Measure  Analyze  Improve  Control  Project Scope D-M-A

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University13 Preliminary Process Map Load Wash Unload Paint Cure Dry ReworkAccept

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University14 Process Step #InputMeasure System C/U Type OutputMeasure System Load4 Wash4 Dry2 Drying ovenVisual inspection CDry panelVisual inspection Paint6 Cure2 Unload1 Rework2 Paint Cell Process Matrix

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University15 Key Customer Requirements  Minimal paint thickness  Even coverage  Scratch-free parts

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University16 Preliminary Data Collection  Student teams  Observer  Recorder  Random sampling  75 observations for control charts  Collection sheet variables determined by client

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University17 Revised Data Collection  Student teams  Observer – voltage, temperature, etc  Thickness gauge operator  Thickness gauge recorder  Revised data collection form  Limited variables – panel, color, hook, 5 locations  Larger cells for recording data

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University18 #Process Step Process Input Paint Thickness Even Coverage Damage Free Total Customer Imp 7 Customer Imp 9 Customer Imp 10 1Load Hook 3*33 78** 2Load Conveyor Paint Spray Gun Cure Temp Cause and Effect Matrix * Correlation values 0, 1, 3, 9 **Sample calculation 7*3+9*3+10*3=78

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University19 Control Charting Deliverables  Target Factor - paint thickness  Data collection plan  Documentation of plan as standard operating procedure  Control chart training materials  Control charts of baseline data

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University20 Control Charting Locations  Factor - paint thickness  5 locations  Repeated measures  25 samples for baseline chart North West Middle East South

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University21 Control Charting Sample Preliminary  Range not in control

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University22 Control Charting Sample Results - Revised  Range in control Xbar not in control

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University23 Designed Experiments  Dependent variable - paint thickness  Factor 1 - location  Factor 2 - shift  Statistical software package - Minitab

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University24 Failure Modes and Effects Analysis (FMEA) Techniques  48 process steps selected for investigation  4 experts polled  Operators  Management  Ratings entered into basic FMEA worksheet  RPNs calculated  Process steps ranked by RPN (high to low)

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University25 Failure Modes and Effects Analysis - Category Ratings 1  Severity of Effect (10-1)  Hazardous without warning  Hazardous with warning  Loss of primary function  Reduced primary function performance  Loss of secondary function  Reduced secondary function performance  Minor defect noticed by most customers  Minor defect noticed by some customers  Minor defect noticed by discriminating customers  No effect

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University26 Failure Modes and Effects Analysis - Category Ratings 2  Likelihood of Occurrence  9 Very High: Almost inevitable  7 High: repeated failures  4 Moderate: Occasional failures  2 Low: Relatively few failures  1 Remote: Failure is unlikely

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University27 Failure Modes and Effects Analysis - Category Ratings 3  Ability to Detect (10-1)  Cannot detect  Very remote chance of detection  Remote chance of detection  Very low chance of detection  Low chance of detection  Moderately high chance of detection  High chance of detection  Very high chance of detection  Almost certain detection

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University28 Risk Priority Number Example Calculations  Paint Material – accident or transport failure  Potential Failure Effect  Lack of paint consistency  Severity of Effect rating 4  Potential Cause  Dropped powder  Likelihood of Occurrence rating 3  Current Control  Lifting procedures  Ability to Detect rating 3  Severity*Likelihood*Detection = 36 = RPN

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University29 Failure Modes and Effects Analysis Results  Ratings ranged from 300s to 20s  Uncontrolled process steps eliminated  Critical controlled process steps  Powder application - operator  Cure process  Powder application - spray gun  Loading  Unloading

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University30 Control Plan Worksheet  Critical to Quality (CTQs) factors listed according to RPN ranking  Process step as listed in process map  Inputs/outputs  Process specifications  Measurement system  Current control plan  Control method  Who  Where  When  Reaction plan

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University31 Control Plan Follow-up  Revision of current standard operating procedures (SOP)  Establishment of standard operating procedures for CTQs that do not already have an SOP  Periodic review

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University32 Future Work  Phase 1  Development of plan for constant metrics  Implementation of new SOPs  Phase 2  Periodic process review  Implementation of new metrics as needed  Phase 3  Project closure  Implementation of related Six Sigma projects

IIE Annual Conference May 2004Presenter: Dr. Joan Burtner, Mercer University33 Contact Information   Room 105D, School of Engineering  Phone (478)  Fax (478)