Modern Lubricants for Tube Bending Christopher Fletcher, ChE Tower Oil & Technology Co.
Outline Selecting Lubricants Why? Tools Chemistry Steps Today s Choices Lubricants Substrates & Sizes Wear Tooling Application
Do I Have To? Not Always. However
Why Lubrication? Photos courtesy of thefabricator.com
Why Lubrication? F f = μ N where F f = frictional force μ = coefficient of friction N = normal force Lower μ is desirable
Tools Twist Compression Test (TCT) Scientific Bench Test Very High Interface Pressures Variable Test Materials Lubricant Starvation Low Speed
TCT
TCT
TCT 0.5 100 0.45 90 0.4 80 Coefficient of Friction 0.35 0.3 0.25 0.2 0.15 10,000 psi 1650 W-4177 70 60 50 40 30 0.1 20 0.05 10 0 0 5 10 15 Time (s) 0 1 2 3 Interface Stress (MPa)
TCT Comparing Two Gel Products
Chemistry Viscosity or Thick Film www.stle.org
Chemistry Boundary www.stle.org Create space to keep asperites from touching
Chemistry Extreme Pressure (EP) Use iron in metal to form chemical reaction Cl = Iron Chloride S = Iron Sulfide P = Iron Phosphate
Key Steps Health & Safety Considerations Chemical Content or Restrictions Waste Disposal Application
Key Steps Desired Residue Secondary Operation Compatibility No Adverse Effects on Material, Tooling, or Equipment Quality Parts & Acceptable Tool Life
Today s choices
Preferred Lubricants Synthetic Chemical Solutions Seed Oil Compounds Renewal Resource Soluble Oils Gels Pastes Compounded Oils
Synthetic Chemical Solutions Varying viscosities Dilutable Easy to wash Weld over lube residue True solutions or dispersions Lube does not drip out in paint oven Use when welding and/or painting are required Can be viscosity, boundary, and EP
Seed Oil Compounds Vegetable and/or renewable Minimal lubricant required (MQL) Lost lubricant theory No oily mess at machines No parts washing Weld over lube residue No waste disposal Usually viscosity and boundary
Soluble Oil Very Versatile Lube All Metal Safe Use neat or diluted Mix with water Easy to clean Can be viscosity, boundary, and EP
Emulsions Oil In Water Water in Oil
Gels http://powerlisting.wikia.com/wiki/file:gel_ojos.jpg Contain no mineral oil Very clean High water content Good weld through Mostly viscosity and barrier Not all work on aluminum Need controlled application
Necessary Gel Features Does not harden in drum or mandrel No slumping on mandrel under heat Does not drip out of tubes in-process Pump-able from drums/pails Come with drums liners
Paste Contain mineral oil and water Form an invert emulsion to thicken Typically blended with lubricity and/or EP or solid film lubricants for tougher applications Modern high quality pastes do not harden like a rock Can be cleaned and conducive to secondary processing
Compounded Oils Wide range of viscosities Typically used for extreme pressure lubrication Easy to pump or apply Additives to improve cleaning
So much to choose from There are many products within each family of lubricants. The individual products range from Light Duty to Medium Duty to Heavy Duty and in some cases Extreme Duty.
Order Light Duty Diluted Synthetics & Soluble Oils Seed Oil and Renewable Resource Gels Medium Duty Synthetics Seed Oil & Renewable Resource Soluble Oils Gels & Pastes
Order Heavy Duty Synthetics & Soluble Oils with EP Seed Oil and Renewable Resource with Boundary and/or EP Thicker Gels and Pastes with Boundary or EP Compounded Oils Extreme Duty High viscosity Soluble Oils with EP High viscosity Gels & Pastes with EP High viscosity Compounded Oils with EP
Lubricant Performance Variables Degree of Bending Diameter of Tube Substrate Material Thickness Tooling
D of Bend Use the degree of bend (D) to help determine how heavy duty the lubricant needs to be Photo courtesy of Tools for Bending D of Bend = CLR OD Example: 4 CLR 2 OD = 2 D
Rule of Thumb To help select bending lubricants, use the following rules of thumb 3 OD and < 2 D Bend: Use Heavy Duty Lube 3 OD and 2 D Bend: Use Light or Medium Duty Lube
Rule of Thumb > 3 OD and < 2 D Bend: Use Heavy or Extreme Duty Lube > 3 OD and 2 D Bend: Use Medium or Heavy Duty Lube Use heavier duty lubricant as: OD increases Thickness increases
Substrates Steel Seed Oils & Renewable Resource Gels Pastes Compounded Oils Aluminum Gels Pastes Renewable Resources
Substrates Stainless 4xx Series Seed Oils & Renewable Resource Gels 3xx Series Seed Oils & Renewable Resource Pastes Compounded Oils Aluminized Stainless Same as above only more paste
Substrates Copper/Brass/Softer Metals Seed Oils & Renewable Resource Synthetic (compatible) Soluble Oils Inconel/Titanium Pastes Compounded Oil
Tooling Mandrel AMPCO Bronze 18, 21, M4 are most common Soft = wears quickly Used on steel, stainless New coatings extending life Photo courtesy of Omni-X All lubricants
Tooling Mandrel Steel Harder Chromed; Other coatings Longer life but more wear on tube Photo courtesy of Omni-X Use on steel, stainless, aluminum, aluminized, and softer metals Higher end lubricants
Tooling Mandrel Plastic Becoming more useful Soft = wears quickly Used on helix, continuous, short run large Light lubricant
Tooling Mandrel New Material Longer life Acts like coating Light lubricant Photo courtesy of Tools for Bending
Tooling Wiper AMPCO Bronze Flexible Steel D2, S7, H13 Photo courtesy of Omni-X Some coatings on both, but cannot be brittle
Tooling Cutoff Knives High Speed Steel TiN Coating
Application Synthetic Chemical Solutions, Soluble Oils & Compounded Oils Basic fluid pump Bender turns on and off Air/electrical operated 1:1-5:1 ratio
Application Synthetic Chemical Solutions, Soluble Oils & Compounded Oils Air over lube tank with solenoid Electrical operated Bender sends signal but PLC can manipulate Photo courtesy of Industrial Innovations All can be sprayed or injected into locations depending on viscosity
Application Seed Oil Compounds & Renewable Resource Micro-mist Air or electrically operated Bender controls frequency
Application Gels & Pastes Air operated drum/pail pump Depends on viscosity Light = 5:1 ratio fluid pump Heavy = 15:1-50:1 grease pump; follower plate Metering system For < 4 OD Valves or metering pumps Bender controlled for each lube point
Matrix Substrate Thickness OD Typical Mandrel Material Bronze Mandrel Lube Synthetic Seed Oil Soluble Oil Gel Application Micro Mister Drum pump Drum pump/metering system Can be very large Generalities Rules of thumb Locked variables Narrows down quickly Multiple parts per bender Carbon Steel Thin Heavy < 3" > 3" < 3" Steel Chromed Bronze Steel Chromed Bronze Steel Chromed Bronze Paste Compounded Oil Synthetic Seed Oil Soluble Oil Gel Paste Compounded Oil Synthetic Seed Oil Soluble Oil Gel Paste Compounded Oil Synthetic Seed Oil Soluble Oil Gel Paste Compounded Oil Synthetic Seed Oil Soluble Oil Gel Paste Compounded Oil Synthetic Seed Oil Soluble Oil Gel Paste Compounded Oil Synthetic Seed Oil Soluble Oil Gel Drum pump Drum pump/metering system Micro Mister Drum pump Drum pump/metering system Drum pump Drum pump/metering system Micro Mister Drum pump Drum pump/metering system Drum pump Drum pump/metering system Micro Mister Drum pump Drum pump/metering system Drum pump Drum pump/metering system Micro Mister Drum pump Drum pump/metering system Drum pump Drum pump/metering system Micro Mister Drum pump Drum pump/metering system Drum pump Drum pump/metering system Micro Mister Drum pump Drum pump/metering system > 3" Steel Chromed Paste Compounded Oil Synthetic Seed Oil Soluble Oil Gel Paste Compounded Oil Drum pump Drum pump/metering system Micro Mister Drum pump Drum pump/metering system Drum pump Drum pump/metering system
Conclusion Method to the madness Run through selection steps Gather data Key in on performance, then optimize Consider application methods Consult lube and tooling suppliers
Sources Grinelli, Tony. "When a Good Tube Bends Bad - Part II." TheFabricator.com. N.p., 11 Apr. 2006. Web. 28 Sept. 2013. Tools for Bending Bend Tooling OMNI-X www.thefabricator.com www.stle.org www.industrialinnovations.com www.unist.com www.ampcometal.com www.toweroil.com
Thank You Christopher Fletcher, ChE Tower Oil & Technology chris@toweroil.com 248-838-8884