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AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Green Sand Control
Best Practices
Al JacobsonGrede LLC
St Cloud, MN
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Al Jacobson – Background
Worked for Grede since May, 1989
Grede – Reedsburg, WI (7 years)
• Industrial Engineer
• Method Engr./Quality Circle Facilitator
• Mold/Core Supervisor
Grede – St. Cloud, MN (18 years)
• Mold/Core Superintendent
• Process Quality Engineer (last 13 years)
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
North America Footprint
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Green Sand Control
Best Practices
Green Sand Control is
Variation Reduction on Key Variables
We all make “good” sand at times.
We all make “bad” sand at times.
Successful Foundries make “good” sand most of the time
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Green Sand Control
Best Practices
Grede St. Cloud Sand Systems:
BMD Simpson 6G Batch Muller
System: Simpson MC-100 Multi-Cooler
Hartley Compactability Tester
Disa Simpson 23G-250 Cont. Muller
System: Simpson MC-250 Multi-Cooler
3818 Cont. Compactability Tester
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Green Sand Control
Best Practices
Roadmap to Variation Reduction
• Determine Key Independent Variables
• Find a Method to Quantify Current
Variation
• Implement Improvements to Reduce
Variation and Monitor Results
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Green Sand Control
Best Practices
Key Independent Variable #1:
Compactability: Measures the relationship of water absorbing material (ie: clays) and amount of moisture.
Typical ways to test:
1. 3-ram or squeezer method(manual tester)
2. Automatic tester (ie: Hartley style)
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Green Sand Control
Best PracticesHow to quantify current variation
• Define with standard deviation
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Green Sand Control
Best Practices• Other methods to fit your equipment
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Green Sand Control
Best Practices• Percentage of reading within stated control
limits (typical Hartley Tester method)
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Green Sand Control
Best Practices
Key Independent Variable #2:
Methylene Blue Clay Test: measures
the amount of live clay present in
sand
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Green Sand Control
Best PracticesHow to quantify current variation
• Define with standard deviation
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Green Sand Control
Best PracticesHow to quantify current variation
• Define with standard deviation
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Green Sand Control
Best PracticesKey Independent Variable #3:
Size Distribution of Washed Green Sand
Ways to express this:
1. AFS Grain Fineness Number (GFN)
2. Surface Area
3. Percent Fines
4. Individual Screens
5. Permeability (be careful)
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Green Sand Control
Best Practices
Disa Surface Area:
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Green Sand Control
Best PracticesDisa Percent Fines:
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Green Sand Control
Best Practices
Comparison of GFN to Surface Area:
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Green Sand Control
Best PracticesIdeas to improve variation for key variables:
Compactability – reduce variation of incoming sand
• Reduce variation of incoming sand
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Green Sand Control
Best PracticesIdeas to improve variation of your key variables:MB Clay– make pre-emptive clay add changes (mass
balance)
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Green Sand Control
Best PracticesIdeas to improve variation of your key variables:
Size Distribution of Washed Green Sand
1. Regular differential checks of dust collection systems
(I do quarterly). Also gives you a good reason to go
through and see what needs repair.
2. Identify key collection points and document blast gate
locations. Adjust as needed based on washed green
sand results and appearance of castings.
3. As work mix changes you may have to adjust grade or
amount of direct sand additions to green sand system.
Core sand grade adjustment have more pitfalls.
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Green Sand Control
Best Practices
In Closing
In Green Sand Systems :
Variation is your Enemy
My Recommendation
Get to know your Enemy, then by
reducing variation make it a Friend
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
www.grede.com
MOVING INDUSTRY FORWARD