Application of Failure Mode and Effect Analysis to the Powder Coat Process Dr. Joan Burtner Chair, Department of Industrial Engineering and Industrial Management Mercer University School of Engineering, Macon, GA

Paint Cell Project Interdisciplinary team Industrial management Industrial engineering Technical advisor - Joan Burtner External client Georgia manufacturer Practices Six Sigma philosophy ISE426ETM528 Spring2018 Presenter: Dr. Joan Burtner, Mercer University

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 ISE426ETM528 Spring2018 Presenter: Dr. Joan Burtner, Mercer University

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 ISE426ETM528 Spring2018 Presenter: Dr. Joan Burtner, Mercer University

Courtesy: www.thefabricator.com Powder Coat Facility Typical Spray Booth Courtesy: www.thefabricator.com Accessed March 12, 2004 ISE426ETM528 Spring2018 Presenter: Dr. Joan Burtner, Mercer University

Quality Issues Surface preparation Operators Coverage Color change Training Skill Coverage Color change Cleanliness/ contamination ISE426ETM528 Spring2018 Presenter: Dr. Joan Burtner, Mercer University

Preliminary Process Map Load Wash Dry Paint Cure Rework Accept Unload ISE426ETM528 Spring2018 Presenter: Dr. Joan Burtner, Mercer University

Key Customer Requirements Minimal paint thickness Even coverage Scratch-free parts ISE426ETM528 Spring2018 Presenter: Dr. Joan Burtner, Mercer University

Cause and Effect Matrix # Process Step Process Input Paint Thickness Even Coverage Damage Free Total Customer Imp 7 Customer Imp 9 Customer Imp 10 1 Load Hook 3* 3 78** 2 Conveyor 78 Spray Gun 9 154 4 Cure Temp 58 * Correlation values 0, 1, 3, 9 **Sample calculation 7*3+9*3+10*3=78 ISE426ETM528 Spring2018 Presenter: Dr. Joan Burtner, Mercer University

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 ISE426ETM528 Spring2018 Presenter: Dr. Joan Burtner, Mercer University

Control Charting Locations Factor - paint thickness 5 locations Repeated measures 25 samples for baseline chart North West Middle East South ISE426ETM528 Spring2018 Presenter: Dr. Joan Burtner, Mercer University

Control Charting Sample Preliminary Range not in control ISE426ETM528 Spring2018 Presenter: Dr. Joan Burtner, Mercer University

Control Charting Sample Results - Revised Range in control Xbar not in control ISE426ETM528 Spring2018 Presenter: Dr. Joan Burtner, Mercer University

Designed Experiments Dependent variable - paint thickness Factor 1 - location Factor 2 - shift Statistical software package - Minitab ISE426ETM528 Spring2018 Presenter: Dr. Joan Burtner, Mercer University

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) ISE426ETM528 Spring2018 Presenter: Dr. Joan Burtner, Mercer University

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 ISE426ETM528 Spring2018 Presenter: Dr. Joan Burtner, Mercer University

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 ISE426ETM528 Spring2018 Presenter: Dr. Joan Burtner, Mercer University

Failure Modes and Effects Analysis - Category Ratings 3 Ability to Detect (10-1) Cannot detect 10 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 1 ISE426ETM528 Spring2018 Presenter: Dr. Joan Burtner, Mercer University

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 ISE426ETM528 Spring2018 Presenter: Dr. Joan Burtner, Mercer University

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 ISE426ETM528 Spring2018 Presenter: Dr. Joan Burtner, Mercer University

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 ISE426ETM528 Spring2018 Presenter: Dr. Joan Burtner, Mercer University

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 ISE426ETM528 Spring2018 Presenter: Dr. Joan Burtner, Mercer University