1. Application of Failure Mode and Effect Analysis to the Powder Coat Process
Joan Burtner
Department of Mechanical and Industrial Engineering
Mercer University, Macon, GA

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

3. 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
Presenter: Dr. Joan Burtner, Mercer University

4. 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
Presenter: Dr. Joan Burtner, Mercer University

5. Powder Coat Facility Typical Spray Booth
Courtesy:
Accessed March 12, 2004
Presenter: Dr. Joan Burtner, Mercer University

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

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

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

9. 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, **Sample calculation 7*3+9*3+10*3=78
Presenter: Dr. Joan Burtner, Mercer University

10. 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
Presenter: Dr. Joan Burtner, Mercer University

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

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

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

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

15. 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)
Presenter: Dr. Joan Burtner, Mercer University

16. 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
Presenter: Dr. Joan Burtner, Mercer University

17. 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
Presenter: Dr. Joan Burtner, Mercer University

18. 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
Presenter: Dr. Joan Burtner, Mercer University

19. 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
Presenter: Dr. Joan Burtner, Mercer University

20. 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
Presenter: Dr. Joan Burtner, Mercer University

21. 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
Presenter: Dr. Joan Burtner, Mercer University

22. 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
Presenter: Dr. Joan Burtner, Mercer University