Effective Foam Control in Effective Foam Control in Metalworking Coolants & Industrial Metalworking Coolants & Industrial
FluidsFluids
Advantages of 3D Organo-Modified Siloxane Defoamers
Mary TaylorMünzing
KSTLE October 2, 2008
22
Presentation OverviewPresentation OverviewWhat is FoamWhy Control is necessaryMechanisms of Foam
StabilizationDe-Stabilization
Defoamer CompositionChoosing and Testing DefoamersAdvantages of 3D Organo-Modified Siloxane Defoamers
33
What isWhat is foam?foam?Basics
Simply StatedFoam is a (stable) dispersion of gas phase in a liquid system
(The Fundamentals)
44
Why is foam a problem?Why is foam a problem?The specifics are different for every industry
Use/Applications defectsMetalworking – insufficient lubricationPCB- Insufficient cleaningWood Preservatives- insufficient penetration into lumber
ProductionInsufficient fill of containersReduced speedVacuum and pump problems
SafetyTank overflow
77
Foam StabilizationFoam Stabilization
Electrostatic RepulsionSurface ViscosityGibbs ElasticityMarangoni Effect
88
Foam StabilizationFoam StabilizationElectrostatic repulsion
-When the cell wall of foam drains, the two air-liquid interfacesapproach. -Electrostatic repulsion from the adsorbed and orientedsurfactant prevents further drainage and cell rupture is prevented.
99
Marangoni Effect
• Stretching of the cell wall causes a surfactantdeficiency
• Unequal surface tensions • Migration of surfactant to achieve equal surface
tension restores or heals the cell wall (Marangonieffect)
Foam StabilizationFoam Stabilization
1010
Defoaming mechanismsDefoaming mechanisms
•Drainage due to gravity
•Defoamer Spreading
•Hydrophobic Dewetting
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Foam (De)StabilizationFoam (De)Stabilization
GAS DIFFUSION THROUGH THE LAMELLAE
DRAINAGE TO PLATEAU BORDERS
LESSERPRESSURE
GREATERPRESSURE
DRAINAGE DUE TO GRAVITY
Thinner Films
⎟⎟⎠
⎞⎜⎜⎝
⎛+=Δ
21 R1
R14γP
1313
Hydrophobic DewettingHydrophobic DewettingBridge Effects
Note:The defoaming active (whether a liquid droplet or solid particle) must have the correct size
lam
ella
Defoamers break the cell wall:
•bridging-dewetting•bridging-stretching•pin-effect
1414
What is a defoamer?What is a defoamer?
Defoamers must enter the cell wall and spread
Defoamer droplets need to have the right size to rupture the cell wall
Defoamers need to be incompatible with the system
However, too incampatible will lead to defects in the final application
Thus: defoamers must have the right balance between(in)compatibility and efficiency
1515
Defoamer ComponentsDefoamer Components
Adjust of viscosity, prevent separation, fouling,
Others
Adjust emulsifiability (compatibility) of defoamers in the systemEases spreading of the defoamer at the surface
Emulsifiers
Absorb surfactant molecules and enter into lamellae double layer
Hydrophobic ingredients
Transport of active ingredients to the surface, spread on the surface and prevent formation of a surfactant‘s layer
Carriers
1616
Defoamer compositionDefoamer composition
Biocides, thickeners, protective colloids
Surfactants
Waxes, hydrophobic silica, metal soaps, paraffines, amides, polyalkylene glycols, polyurethanes
Oils, water, solvents, modified Polyethersiloxanes, Oleo-ABCs
0 – 20%
0 – 5%
5 – 10%
75 – 90%
Others
Emulsifiers
Hydrophobicingredients
Carriers
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The key is the The key is the ““ Active particleActive particle””
Different active particles have different persistence strengths
3D Compounds: stable dropletSPE: semi-stable dropletGlycol emulsified: semi-stable dropletSilica: very hard particleStearate: Hard particleWax: soft particleOil emulsified: unstable droplet
For some particles, the process may “destroy” the particle or break it into smaller particles that are too small to effectively defoam
Note, the 3D siloxane compound is the ONLY truly stable particle
When effective, 3D compound is most effective.
HigherPersistence
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-a 3-dimensional crosslink siloxane
-presence of other components increases compatibility and washability
-very stable, very good persistence
Silicone, siloxane, SPE, Silicone, siloxane, SPE, …………SILOXANE (Si + O + CH3 + …)
SiliconeSPE
(Siloxane Polyether)3D Organo Modified Siloxane
“Silicone Fluid”“Silicone Oil”“PDMS”Polydimethylsiloxane
-very specific chemical structure:
-the “bad actor”-problems with washability-very hydrophobic:
-a good defoamer-but leads to defects
(CH3)3Si-O- -Si-O- -Si(CH3)3
CH3
CH3
x
(CH3)3Si-O- -Si-O- -Si(CH3)3
CH3
CH3
x
-a silicone backbone with polyether chains either (a) grafted on side or (b) incorporated into backbone
-PEG/PPG ratio in polyether will determine compatibility (including with water)
-the water affinity portions (i.e. the polyether portions) make this material “washable”
(CH3)3Si-O- -Si-O- - -Si-O- -Si(CH3)3
CH3
CH3
x
CH3
y
O C-CH2
OCH2CH2
OH
CH3H
m
n
(CH3)3Si-O- -Si-O- - -Si-O- -Si(CH3)3
CH3
CH3
x
CH3
y
O C-CH2
OCH2CH2
OH
CH3H
m
n
1919
3D 3D OrganoOrgano--Modified Modified SiloxaneSiloxane
Performance AdvantagesHigh Efficiency
Highly Surface ActiveHigh Persistence
High Surface AreaHigh washabilityExcellent Spreading & DispersabilityHigh Compatibility
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Defoamer Selection & testingDefoamer Selection & testing
Compatibility is the key to long term persistenceBalance between incompatibility & efficiency
Too compatible the carrier acts like a surfactant or oil Defoamer selection is primarily influenced by the chemistry of the Metalworking Fluid not the machining processOther influencers are water hardness & filtrationManufacturing process
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Compatibility EvaluationsCompatibility Evaluations
Oiling Out of Defoamer
Rating 1-5 (1=Best No Surface Defects)
2828
Defoamer PerformanceDefoamer PerformancePeristaltic Pump RecirculationPeristaltic Pump Recirculation
3535
Compatibility Compatibility vs.vs. EfficiencyEfficiencyExperimental
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
defoamer
air c
onte
nt (%
)
0
20
40
60
80
100
120
140
160
180
surf
ace
defe
cts
air content (%)
surface defects
E ( f
3636
Predicting defoamer behavior in any single metalworking fluid is difficult because of the complex interaction of multiple components.
There is no substitute for laboratory testing!
Defoamer Selection Defoamer Selection --TestingTesting
Why not let us work for you
3737
Performance Advantages Performance Advantages
Münzing 3D Organo-modified Siloxane Defomoamers Formulated for:
CompatibilityHigh Efficiency (Speed to Knock Down)High Persistence (Time of control)Dispersability & Washability
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Value of 3D OrganoValue of 3D Organo--Modified Modified Siloxanes & Technical SupportSiloxanes & Technical Support
Study A – Customer Submitted 5 SystemsCustom formulated 3D Organo-modified siloxane defoamer improved compatibility & efficiency over current competitive product
Customer consolidated from 3 defoamers to 1Study B-Post Add Recirculation Test
Persistence-Up to 2 X more persistent over PDMS or Oil/Wax EmulsionEfficiency-Up to 4 X reduction in additions over PDMS or Oil/Wax Emulsion
Study C-Post Add Recirculation Test Competitive SPE vs. 3D Siloxane comparison
3 Hours Recirculation at Time Zero 16.5% Improvement1 Minute off system recovery 86% improvement5 Minutes off system recovery 86% improvement
Study D-Post Add Recirculation TestCompetitive SPE vs. 3D Siloxane comparison
With 100 ppm water & filtration Minimum 40% improvement
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Compatibility Rating 5 Differnt Metalworking fluids
0
1
2
3
4
5
6
7
8
Semi 206 Semi C804 Semi M203 Semi 3030 Semi 500
Ratin
g 1-
15 (l
owes
t val
ue b
est)
Competitve3D Siloxane
Study A- Product Consolidation
4040
Study A- Product Consolidation
Hand Shake Data, Time to Zero
0
10
20
30
40
50
60
70
Semi 206 Semi C804 Semi M203 Semi 3030 Semi 500
Seco
nds
Competitve 3D Siloxane
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Burrell Wrist Action Shaker, Time to Zero
0
10
20
30
40
50
60
70
Semi 206 Semi C804 Semi M203 Semi 3030 Semi 500
Seco
nds
Competitve 3D Siloxane
Study A- Product Consolidation
4242
Peristaltic Recirculation Semi 206
0
200
400
600
800
1000
1200
0 5 15 30 60 120 180 240 241 245
Time, minutes
Foam
Hei
ght,
mls
Competitive control 3D Siloxane
Pump Turned Off
Study A- Product Consolidation
4343
Peristaltic Recirculation Semi C840
0
100200
300400
500
600700
800
0 5 15 30 60 120 180 240 241 245
Time, minutes
Foam
Hei
ght,
mls
Competitive control 3D Siloxane
Pump Turned Off
Study A- Product Consolidation
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Peristaltic Recirculation Semi M203
0100200300400500600700800900
0 5 15 30 60 120 180 240 241 245
Time, minutes
Foam
Hei
ght,
mls
Competitive control 3D Siloxane
Pump Turned Off
Study A- Product Consolidation
4545
Peristaltic Recirculation Semi 3030
0
200
400
600
800
1000
1200
0 5 15 30 60 120 180 240 241 245
Time, minutes
Foam
Hei
ght,
mls
Competitive control 3D Siloxane
Pump Turned Off
Study A- Product Consolidation
4646
Peristaltic Recirculation Semi 500
0
200
400
600
800
1000
1200
0 5 15 30 60 120 180 240 241 245
Time, minutes
Foam
Hei
ght,
mls
Competitive control 3D Siloxane
Pump Turned Off
Study A- Product Consolidation
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Post Add Recirculation Tank Side Defoaming StudyFoam Height Equivalent Additions
0
500
1000
1500
2000
2500
3000
3500
3D Organo Modified Siloxane SPE Competitor Oil Wax Defoamer 10% Siliconeemulsion
Ave
rage
Foa
m H
eigh
tStudy BStudy B-- Post Add RecirculationPost Add Recirculation
High Efficiency
4848
Study BStudy B-- Post Add RecirculationPost Add RecirculationHigh Persistence
Post Add Recirculation Tank Side Defoaming Study Foam Height 1 minute after pump shut down
0
50
100
150
200
250
300
350
400
3D Organo Modified Siloxane SPE Competitor Oil Wax Defoamer 10% Siliconeemulsion
Foam
Hei
ght,
cm
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Average Foam Height 18 different systems After 3Hours time 0 1minute pump off 5 minutes pump off
0
100
200
300
400
500
600
700
0 1 5
Foam
Hei
ght,
ml
Study CStudy C-- Post Add Post Add RecirculationRecirculation
SPE Competitive
3D Siloxane Defaomer
5050
Foam Height after pump shutdown
0
200
400
600
800
1000
1200
DI 100ppm DI+Filter 100ppm Filter
Foam
Hei
ght,
ml
SPE Competitor
3D Siloxane
Study DStudy D-- Post Add Post Add RecirculationRecirculation
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Representation
Production Site
R&D or Tech. ServiceCenters
Regional Management
Headquarters
Munzing: Organization - Locations
Heilbronn, GermanyBloomfield, NJ
Clover SC
Shanghai, China