Effective Foam Control in Metalworking Coolants & Industrial Fluids Advantages of 3D Organo-Modified Siloxane Defoamers Mary Taylor Münzing KSTLE October 2, 2008
Presentation Overview What is Foam Why Control is necessary Mechanisms of Foam Stabilization De-Stabilization Defoamer Composition Choosing and Testing Defoamers Advantages of 3D Organo-Modified Siloxane Defoamers 2 2
What is foam? Basics (The Fundamentals) Simply Stated Foam is a (stable) dispersion of gas phase in a liquid system 3 3
Why is foam a problem? The specifics are different for every industry Use/Applications defects Metalworking insufficient lubrication PCB- Insufficient cleaning Wood Preservatives- insufficient penetration into lumber Production Insufficient fill of containers Reduced speed Vacuum and pump problems Safety Tank overflow 4 4
Why is foam a problem? 5 5
Foam Stabilization Cohesive strength pure water surfactant system 6 6
Foam Stabilization Electrostatic Repulsion Surface Viscosity Gibbs Elasticity Marangoni Effect 7 7
Foam Stabilization Electrostatic repulsion -When the cell wall of foam drains, the two air-liquid interfaces approach. -Electrostatic repulsion from the adsorbed and oriented surfactant prevents further drainage and cell rupture is prevented. 8 8
Foam Stabilization Marangoni Effect Stretching of the cell wall causes a surfactant deficiency Unequal surface tensions Migration of surfactant to achieve equal surface tension restores or heals the cell wall (Marangoni 9 effect) 9
Defoaming mechanisms Drainage due to gravity Defoamer Spreading Hydrophobic Dewetting 10 10
Foam (De)Stabilization Thinner Films DRAINAGE DUE TO GRAVITY GAS DIFFUSION THROUGH THE LAMELLAE LESSER PRESSURE GREATER PRESSURE 1 ΔP = 4γ R + 1 1 R 2 DRAINAGE TO PLATEAU BORDERS 11 11
Defoamer Spreading 12 12
Hydrophobic Dewetting Bridge Effects Defoamers break the cell wall: lamella bridging-dewetting bridging-stretching pin-effect Note: The defoaming active (whether a liquid droplet or solid particle) must have the correct size 13 13
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 14 14
Defoamer Components Carriers Hydrophobic ingredients Emulsifiers Others Transport of active ingredients to the surface, spread on the surface and prevent formation of a surfactant s layer Absorb surfactant molecules and enter into lamellae double layer Adjust emulsifiability (compatibility) of defoamers in the system Eases spreading of the defoamer at the surface Adjust of viscosity, prevent separation, fouling, 15 15
Defoamer composition Carriers Oils, water, solvents, modified Polyethersiloxanes, Oleo-ABCs 75 90% Hydrophobic ingredients Emulsifiers Waxes, hydrophobic silica, metal soaps, paraffines, amides, polyalkylene glycols, polyurethanes Surfactants 5 10% 0 5% Others Biocides, thickeners, protective colloids 0 20% 16 16
The key is the Active particle Different active particles have different persistence strengths 3D Compounds: stable droplet SPE: semi-stable droplet Glycol emulsified: semi-stable droplet Silica: very hard particle Stearate: Hard particle Wax: soft particle Oil emulsified: unstable droplet Higher Persistence 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. 17 17
Silicone, siloxane, SPE, SILOXANE (Si + O + CH3 + ) Silicone Silicone Fluid Silicone Oil PDMS Polydimethylsiloxane -very specific chemical structure: CH3 (CH 3 ) 3 Si-O- -Si-O- -Si(CH 3 ) 3 CH3 x -the bad actor -problems with washability -very hydrophobic: -a good defoamer -but leads to defects SPE (Siloxane Polyether) -a silicone backbone with polyether chains either (a) grafted on side or (b) incorporated into backbone (CH 3 ) 3 Si-O- -Si-O- - -Si-O- -Si(CH 3 ) 3 -PEG/PPG ratio in polyether will determine compatibility (including with water) -the water affinity portions (i.e. the polyether portions) make this material 18 washable CH3 CH3 x CH3 O H C- CH 3 CH 2 O CH 2 CH 2 OH 18 m n y 3D Organo Modified Siloxane -a 3-dimensional crosslink siloxane -presence of other components increases compatibility and washability -very stable, very good persistence
3D Organo-Modified Siloxane Performance Advantages High Efficiency Highly Surface Active High Persistence High Surface Area High washability Excellent Spreading & Dispersability High Compatibility 19 19
Defoamer Selection & Testing
Defoamer Selection & testing Compatibility is the key to long term persistence Balance 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 process Other influencers are water hardness & filtration Manufacturing process 21 21
Testing Procedures INOCULATION OF CONCENTRATE 22 22
Compatibility Evaluations Oiling Out of Defoamer Rating 1-5 (1=Best No Surface Defects) 23 23
Compatibility Evaluations Precipitation In Concentrate Rating 1-5 (1=Best No PPT) 24 24
Compatibility Evaluations Rating 1-5 (1=Best No Haze) Loss Of Clarity 25 25
Defoamer Performance Handshake Test 26 26
Defoamer Performance Burrell Wrist Action Shaker 27 27
Defoamer Performance Peristaltic Pump Recirculation 28 28
Recirculation with Filtration 29 29
CNOMO Tester 30 30
Defoamer Performance Silverson Mixer 31 31
Defoamer Performance 32 32
Defoamer Performance Filtration Recirculation 33 33
Defoamer Performance ASTM D892 34 34
Compatibility vs. Efficiency Experimental 16.0 14.0 12.0 air content (%) surface defects E ( f 180 160 140 air content (%) 10.0 8.0 6.0 4.0 120 100 80 60 40 surface defects 2.0 20 0.0 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 35 35 0
Defoamer Selection -Testing 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! Why not let us work for you 36 36
Performance Advantages Münzing 3D Organo-modified Siloxane Defomoamers Formulated for: Compatibility High Efficiency (Speed to Knock Down) High Persistence (Time of control) Dispersability & Washability 37 37
Value of 3D Organo-Modified Siloxanes & Technical Support Study A Customer Submitted 5 Systems Custom formulated 3D Organo-modified siloxane defoamer improved compatibility & efficiency over current competitive product Customer consolidated from 3 defoamers to 1 Study B-Post Add Recirculation Test Persistence-Up to 2 X more persistent over PDMS or Oil/Wax Emulsion Efficiency-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% Improvement 1 Minute off system recovery 86% improvement 5 Minutes off system recovery 86% improvement Study D-Post Add Recirculation Test Competitive SPE vs. 3D Siloxane comparison With 100 ppm water & filtration Minimum 40% improvement 38 38
Study A- Product Consolidation Compatibility Rating 5 Differnt Metalworking fluids 8 Rating 1-15 (lowest value best) 7 6 5 4 3 2 1 Competitve 3D Siloxane 0 Semi 206 Semi C804 Semi M203 Semi 3030 Semi 500 39 39
Study A- Product Consolidation Hand Shake Data, Time to Zero 70 60 50 Seconds 40 30 20 10 0 Semi 206 Semi C804 Semi M203 Semi 3030 Semi 500 Competitve 40 3D Siloxane 40
Study A- Product Consolidation Burrell Wrist Action Shaker, Time to Zero 70 60 50 Seconds 40 30 20 10 0 Semi 206 Semi C804 Semi M203 Semi 3030 Semi 500 Competitve 41 3D Siloxane 41
Study A- Product Consolidation 1200 Peristaltic Recirculation Semi 206 Pump Turned Off Foam Height, mls 1000 800 600 400 200 0 0 5 15 30 60 120 180 240 241 245 Time, minutes Competitive control 42 42 3D Siloxane
Study A- Product Consolidation Peristaltic Recirculation Semi C840 Foam Height, mls 800 700 600 500 400 300 200 100 0 0 5 15 30 60 120 180 240 241 245 Time, minutes Competitive control 3D Siloxane Pump Turned Off 43 43
Study A- Product Consolidation Peristaltic Recirculation Semi M203 Pump Turned Off 900 800 Foam Height, mls 700 600 500 400 300 200 100 0 0 5 15 30 60 120 180 240 241 245 Time, minutes Competitive control 3D Siloxane 44 44
Study A- Product Consolidation Peristaltic Recirculation Semi 3030 Pump Turned Off 1200 Foam Height, mls 1000 800 600 400 200 0 0 5 15 30 60 120 180 240 241 245 Time, minutes Competitive control 45 45 3D Siloxane
Study A- Product Consolidation Foam Height, mls 1200 1000 800 600 400 200 Peristaltic Recirculation Semi 500 Pump Turned Off 0 0 5 15 30 60 120 180 240 241 245 Time, minutes Competitive control 46 46 3D Siloxane
Study B-B Post Add Recirculation Post Add Recirculation Tank Side Defoaming Study Foam Height Equivalent Additions 3500 High Efficiency 3000 Average Foam Height 2500 2000 1500 1000 500 0 3D Organo Modified Siloxane SPE Competitor Oil Wax Defoamer 10% Silicone emulsion 47 47
Study B-B Post Add Recirculation High Persistence Post Add Recirculation Tank Side Defoaming Study Foam Height 1 minute after pump shut down 400 350 Foam Height, cm 300 250 200 150 100 50 0 3D Organo Modified Siloxane SPE Competitor Oil Wax Defoamer 10% Silicone emulsion 48 48
Study C-C Post Add Recirculation 700 Average Foam Height 18 different systems After 3Hours time 0 1minute pump off 5 minutes pump off 600 Foam Height, ml 500 400 300 3D Siloxane Defaomer SPE Competitive 200 100 0 0 1 5 49 49
Study D-D Post Add Recirculation 1200 Foam Height after pump shutdown 1000 800 Foam Height, ml 600 400 SPE Competitor 3D Siloxane 200 0 DI 100ppm DI+Filter 100ppm Filter 50 50
Munzing: Organization - Locations Bloomfield, NJ Heilbronn, Germany Representation Production Site Shanghai, China R&D or Tech. Service Centers Regional Management Headquarters Clover SC 51 51
Committed to Technical Support and Innovation Chemical Technologies Oil and Fat Chemicals- Sulfonation Esterification Amidation Phosphation Chlorination Polymer Chemicals Polymerisation Polycondensation Polyaddition Compounding/Formulating 52 52