Cp, Cpk Improvement of Profile variation in Camber rolls

1. Cp, Cpk Improvement of Roll Crowning
Date:05.08.2016

2. Detail Of Roll Grinding Machine
Head Stock
Traverse
Cover
Camber
Mechanism
Wheel
Wheel
Motor
Carriage
Roll
Support
Roll

3. PROJECT SELECTION
Business Case
Problem Statement
Objective
Scope
Benefits
Process Overview

4. PROJECT CHARTER
General Information
Project Name:
Improvement in Cp, Cpk of Roll Crowning
Project No:
Project Location: Tribeni
Business Case: Reduction in variation of roll profile to avoid non uniform nip loading, nip width & mositure CD
profile in order to maintain product quality.
Project Details
Problem Statement: Profile variation of camber rolls leads to uneven Nip width of press/size rolls, which leads to moisture profile
variation in CD & paper break in the machine.
Goal/Objective: To improve roll crowning from existing level of 2.25 sigma rating (22.5% defects) to 2.65 sigma rating (12%
defects)
Project Scope:Paper Machine Roll
Project Constraints: Existing machine capability.

5. PROJECT CHARTER
Resources
Sr. No. Name Role in the Project Signature
1 Mohamed Tariq Aziz
Adherence to Timelines & DMAIC methodology and conducting regular meetings, analysis,
Idea generation
Technical inputs, statistical analysis of data, idea evaluation and implementation.
2 Navin Kumar
3 Abhi Ghosh
Baseline for Project
Project Metric(s)/ KPI name: Defects (Roll Profile Reading outside Acceptable range)
Project Metric(s)/ KPI Value at start: Present Defect-22.5%
Criteria for selecting Baseline value: Based on roll profile variation as per Last two years available data

6. PROJECT CHARTER
Benefits
Bottom line Savings Rs 153523 /- Per Year
Other benefits
1.Improvement in paper qualities
(Controlled Moisture In CD Profile)
2. Reduction in frequency of Roll
Changing

7. SIPOC Map
SUPPLIER CUSTOMERINPUT PROCESS OUTPUT
ROLL
GRINDING
CROWNED
ROLL
ROLL
Norton
Grindwell
PAPER
MACHINE
DOCUMENTS
PAPER
MACHINE
POWER
GRINDING WHEEL
BEARING
COOLANT
BEARING BRACKET
FIXTURES
FILTER PAPER
SKILL OF OPERATOR
DRIVE SYSTEM
ALIGNMENT
CAMBER MECHANISM
MEASURING INSTRUMENT

8. Roll Grinding process
Check surface of
bare roll
Changing
Grinding wheel
Bearing/bracket
fixing
Check limit
switches and
other parameters
Roll loading &
coupling in
Grinding m/c
To decide
Speed of Roll,
Wheel and
Traverse
direction
Required camber
setting
Roll face
alignment wrt
m/c bed
Roll surface
checking
before grinding
Feed cut &
Ammeter range
Repeat grinding
process
Reading of roll
surface with
regular
intervals
Dressing of
grinding wheel(if
required)
Final reading to
check with
allowable
tolerance
Unloading of
roll

9. PROJECT ANALYSIS
• Data Collection Plan
• Data Analysis
• Current Process Parameters Performance (Standard deviation,
Process capability, Sigma Rating)
• Measurement System Study (Gauge R & R)
• Cause & Effect Analysis (Scatter Plot)

10. DATA COLLECTION & STUDY
Current Process
Performance
Cause & Effect
Study
Measure
ment
System
Study

11. CURRENT PROCESS PERFORMANCE
Theoretical Camber value for Rolls- Cos 70 curve

12. CURRENT PROCESS PERFORMANCE
Existing Data Collection Sheet for Roll Grinding

13. CURRENT PROCESS PERFORMANCE
Modified Data Collection Sheet
S No Divison
Roll
Description
Theoretical Camber
value
Acceptable
Range
1 1
PM1MicroRock
0.00 1.5
2 2 0.00 1.5
3 3 0.00 1.5
4 4 0.00 1.5
5 5 0.00 1.5
6 6 0.00 1.5
7 7 0.00 1.5
8 8 0.00 1.5
9 9 0.00 1.5
10 10 0.00 1.5
11 M 0.00 1.5
12 10 0.00 1.5
13 9 0.00 1.5
14 8 0.00 1.5
15 7 0.00 1.5
16 6 0.00 1.5
17 5 0.00 1.5
18 4 0.00 1.5
19 3 0.00 1.5
20 2 0.00 1.5
21 1 0.00 1.5
S No Divison
Roll
Description
Therotical
Camber value
Acceptable
Range
1 1
SizePressMicromate(Swing)Roll(PM-1)
0 1.5
2 2 8.67 1.5
3 3 16.83 1.5
4 4 24.378 1.5
5 5 31.11 1.5
6 6 37.026 1.5
7 7 41.973 1.5
8 8 45.849 1.5
9 9 48.705 1.5
10 10 50.439 1.5
11 M 51 1.5
12 10 50.439 1.5
13 9 48.705 1.5
14 8 45.849 1.5
15 7 41.973 1.5
16 6 37.026 1.5
17 5 31.11 1.5
18 4 24.378 1.5
19 3 16.83 1.5
20 2 8.67 1.5
21 1 0 1.5

14. S No Division
Roll
Description Theoretical Camber value Variation Date- 21.2.16
Actual Reading Deviation
1 1
SizePressMicromateRoll(PM-3)
0 1.5 1 -1
2 2 7.14 1.5 6 1.14
3 3 13.86 1.5 11 2.86
4 4 20.076 1.5 17 3.076
5 5 25.62 1.5 23 2.62
6 6 30.492 1.5 29 1.492
7 7 34.566 1.5 33 1.566
8 8 37.758 1.5 36.5 1.258
9 9 40.11 1.5 40 0.11
10 10 41.538 1.5 41 0.538
11 M 42 1.5 42.5 -0.5
12 10 41.538 1.5 41 0.538
13 9 40.11 1.5 40 0.11
14 8 37.758 1.5 37.5 0.258
15 7 34.566 1.5 34 0.566
16 6 30.492 1.5 30 0.492
17 5 25.62 1.5 24 1.62
18 4 20.076 1.5 18 2.076
19 3 13.86 1.5 11 2.86
20 2 7.14 1.5 6 1.14
21 1 0 1.5 0 0
CURRENT PROCESS PERFORMANCE
Modified Data Collection Sheet

15. CURRENT PROCESS PERFORMANCE
Std Deviation , Sigma Rating, Process Capability
S No Profile Name Of Roll Cover Material Location SD Cp Sigma
Rating
1 Zero Micro rock Micro Rock PM1 0.922 0.542 2.76
2 Zero Marking Press Ventsura II PM1 1.034 0.322 2.06
3 Zero SCC Elaplast Neo Silk PM3 0.900 0.555 2.97
4 Zero Micro Rock(Post Rebuilt) Micro Rock PM3 0.567 0.880 3
5 Zero Elaplast Roll Neo Silk PM4 0.768 0.433 2.75
6 Camber Micro Rock(Pre Rebuilt) Micro Rock PM3 1.544 0.323 2.25
7 Camber Super Size XL PM3 1.521 0.328 2.16
8 Camber Micro mate Micro Mate PM3 1.521 0.328 1.93
9 Camber Micro Mate Micro Mate PM1 1.625 0.307 2.29
10 Camber 2nd Press Top Aquawell PM1 2.974 0.168 1.55
11 Camber 2nd Press Bottom Hard Rubber PM4 3.271 0.102 1.11
Crown:-Avg Cp -0.228 & Sigma Rating-1.9 Plain Roll:- Avg Cp- 0.559 & Sigma Rating-2.7

16. Measurement System Study
• Measuring Instrument Details :
• Caliper
• Water Level
• Dial Indicator
• Accuracy :0.01mm
• Model: Mitutoyo 2046S
Mitutoyo 2046S

17. Design of Measurement system Study
• Case 1:- Zero Camber Roll (PM#4 Granite Roll)
Total no of Parts (Divisions)- 21
No of Operators :-4
Total no of readings :- 2 set
• Case 1:- Camber Roll (PM#4 Second Press bottom Roll)
Total no of Parts (Divisions)- 21
No of Operators :-4
Total no of readings :- 2 set

18. Measurement System Study-Data Collection
Name:- KD1
DS Actual Reading NDS
1 2 3 4 5 6 7 8 9 10 M 10 9 8 7 6 5 4 3 2 1
Theoritical
Value 0.00 14.96 29.04 42.06 53.68 63.89 72.42 79.11 84.04 87.03 88.00 87.03 84.04 79.11 72.42 63.89 53.68 42.06 29.04 14.96 0.00
Actual Value 0.00 14.75 28.00 41.00 51.75 61.00 70.00 76.00 81.00 84.00 85.00 84.00 80.50 75.50 69.00 61.00 51.25 41.00 30.00 16.00 0.50
Variation 0.00 0.21 1.04 1.06 1.93 2.89 2.42 3.11 3.04 3.03 3.00 3.03 3.54 3.61 3.42 2.89 2.43 1.06 -0.96 -1.04 -0.50
Name:- SC1
DS Actual Reading NDS
1 2 3 4 5 6 7 8 9 10 M 10 9 8 7 6 5 4 3 2 1
Theoritical
Value 0.00 14.96 29.04 42.06 53.68 63.89 72.42 79.11 84.04 87.03 88.00 87.03 84.04 79.11 72.42 63.89 53.68 42.06 29.04 14.96 0.00
Actual Value 0.00 15.00 27.00 39.00 50.50 60.00 68.00 75.00 80.00 82.50 83.50 82.00 79.00 74.00 67.50 59.50 51.00 40.00 29.00 15.00 0.00
Variation 0.00 -0.04 2.04 3.06 3.18 3.89 4.42 4.11 4.04 4.53 4.50 5.03 5.04 5.11 4.92 4.39 2.68 2.06 0.04 -0.04 0.00
Name:- MG1
DS Actual Reading NDS
1 2 3 4 5 6 7 8 9 10 M 10 9 8 7 6 5 4 3 2 1
Theoritical
Value 0.00 14.96 29.04 42.06 53.68 63.89 72.42 79.11 84.04 87.03 88.00 87.03 84.04 79.11 72.42 63.89 53.68 42.06 29.04 14.96 0.00
Actual Value 0.00 15.00 28.00 40.25 51.00 62.00 70.00 76.00 81.00 83.00 83.50 82.00 78.00 72.00 65.00 56.00 47.00 36.00 23.00 11.00 -1.00
Variation 0.00 -0.04 1.04 1.81 2.68 1.89 2.42 3.11 3.04 4.03 4.50 5.03 6.04 7.11 7.42 7.89 6.68 6.06 6.04 3.96 1.00
Name:- SD1
DS Actual Reading NDS
1 2 3 4 5 6 7 8 9 10 M 10 9 8 7 6 5 4 3 2 1
Theoritical
Value 0.00 14.96 29.04 42.06 53.68 63.89 72.42 79.11 84.04 87.03 88.00 87.03 84.04 79.11 72.42 63.89 53.68 42.06 29.04 14.96 0.00
Actual Value 0.00 15.00 28.00 40.00 51.00 61.00 69.00 75.00 80.50 83.00 83.75 82.25 82.25 73.50 67.50 60.00 50.00 40.50 26.00 11.00 0.00
Variation 0.00 -0.04 1.04 2.06 2.68 2.89 3.42 4.11 3.54 4.03 4.25 4.78 1.79 5.61 4.92 3.89 3.68 1.56 3.04 3.96 0.00

19. Gauge R & R Result for Zero Camber Rolls

20. Gauge R & R Result for Zero Camber Rolls

21. Gauge R & R Result for Camber Rolls

22. Gauge R & R Result for Camber Rolls

23. CAUSE & Effect Study
Moisture CD profile V/s Roll Profile
S No 2 PM#1 Size Press Micromate
Roll Changing
Date
02.11.15
Roll Division 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 M 10.00 9.00 8.00 7.00 6.00 5.00 4.00 3.00 2.00 1.00
Roll Profile
Theoritical
0.00 8.67 16.83 24.38 31.11 37.03 41.97 45.85 48.71 50.44 51.00 50.44 48.71 45.85 41.97 37.03 31.11 24.38 16.83 8.67 0.00
Roll Profile
Before(9.11.15)
3.00 5.00 15.00 25.00 30.00 35.00 40.00 45.00 45.00 50.00 53.00 55.00 50.00 45.00 42.00 40.00 30.00 25.00 15.00 10.00 0.00
Roll Profile
After(16.9.15)
0.50 8.00 15.00 22.00 29.50 35.00 41.00 45.00 47.00 49.00 51.00 49.50 47.00 45.00 40.00 35.00 30.00 23.00 15.00 8.00 0.00
Variation before -3.00 3.67 1.83 -0.62 1.11 2.03 1.97 0.85 3.71 0.44 -2.00 -4.56 -1.30 0.85 -0.03 -2.97 1.11 -0.62 1.83 -1.33 0.00
Variation After -0.50 0.67 1.83 2.38 1.61 2.03 0.97 0.85 1.71 1.44 0.00 0.94 1.71 0.85 1.97 2.03 1.11 1.38 1.83 0.67 0.00
Moisture CD
Before
0.22 0.21 0.22 0.22 0.21 0.20 0.20 0.19 0.20 0.20 0.18 0.18 0.21 0.21 0.20 0.20 0.22 0.23 0.24 0.23 0.23
Moisture Profile
After
0.15 0.15 0.14 0.14 0.13 0.13 0.13 0.13 0.14 0.14 0.14 0.13 0.18 0.17 0.15
Moisture
CD
Roll
Profile
SD before 0.0242 2.1499
SD After 0.0150 0.7620

24. S No Roll Description Roll Changing Date Std Dev Value Moisture CD Roll Profile
1 PM#1 Size Press Micromate 28.07.15
Std Dev Before 0.072723 2.114474
Std Dev After 0.071951 0.881909
2 PM#1 Size Press Micromate 02.11.16
Std Dev Before 0.024157 2.149887
Std Dev After 0.014960 0.762012
3 PM#1 Size Press Micromate 06.02.16
Std Dev Before 0.385506 3.975730
Std Dev After 0.039402 0.524308
4 PM#3 Super size XL 20.12.15
Std Dev Before 0.151711 7.275876
Std Dev After 0.113490 1.115663
CAUSE & Effect Study
Moisture CD profile V/s Roll Profile

25. • Average Sigma level after Apr-2016 = 3.23(Average of 6 rolls of
different machine)

26. 876543210
0.4
0.3
0.2
0.1
0.0
Roll Profile
MoistureCD
Scatterplot of Moisture CD vs Roll Profile
Scatter Plot
CAUSE & Effect Study
Moisture CD profile V/s Roll Profile

27. • Based on Collected Data Analysis
• Target Setting
• Action Plan
IMPROVEMENT PLAN

28. PROPOSED ACTION PLAN
• Modified Check list
• Changing Measuring Instrument
• Workforce Training
• Machine Overhauling

29. Modified Checklist
S No Divison Roll Description Therotical Camber value Acceptable Range Date:-3.6.16
Divisons Actual Reading Deviation
1 1
PM#12ndPressTopRoll
0 1.5 1 1.00
2 2 28.05 29 0.95
3 3 54.45 55 0.55
4 4 78.87 78 -0.87
5 5 100.65 100 -0.65
6 6 119.79 119 -0.79
7 7 135.795 135 -0.79
8 8 148.335 148 -0.34
9 9 157.575 157 -0.57
10 10 163.185 163 -0.19
11 M 165 166 1.00
12 10 163.185 163 -0.19
13 9 157.575 157 -0.57
14 8 148.335 148 -0.34
15 7 135.795 135 -0.79
16 6 119.79 119 -0.79
17 5 100.65 100 -0.65
18 4 78.87 78 -0.87
19 3 54.45 54 -0.45
20 2 28.05 28 -0.05
21 1 0 0 0.00
Variance 0.44
Std Dev 0.66
Var 0.44
SD 0.66
Cp 0.75
DPMO 0
Sigma Rating 3

31. Changing Measuring Instrument
Measuring Instrument Details :
Caliper
Water Level
Dial Indicator
Accuracy :0.001mm
Model: Mitutoyo 2109S-10

32. IMPLEMENTED ACTION PLAN
• Modified Check list
• Changing Measuring Instrument
• Machine Overhauling
Bed Alignment
Grinding Wheel bearing changing
Carriage needle roller bearing changing

33. PROCESS PERFORMANCE AFTER
IMPROVEMENT ACTION
Crown:-Avg Cp -0.53 & Sigma Rating-2.57 Plain Roll:- Avg Cp- 0.68 & Sigma Rating-2.7
S No Profile Name Of Roll Cover Material Location SD Cp Sigma
Rating
1 Zero SCC Elaplast CI PM4 0.900 0.35 2.97
2 Zero Elaplast Roll Neo Silk PM4 0.25 1.33 4
3 Zero Micro Rock Micro Rock PM3 1.37 0.36 2.01
4 Camber 2nd Press Top Aquawell PM1 0.94 0.53 2.57