November / December 2016 NLGI Spokesman

Page 1

NLGI

SPOKESMAN

Serving the Grease Industry Since 1933 – VOL. 80, NO. 5, NOV/DEC 2016

In this issue . . . 4 President’s Podium 6 CALL FOR PAPERS 8 Industry Partner Spotlight 10 The Effects of Thickeners on the Low Temperature Properties of Open Gear Greases 14 The Effect of Polymer Additives on Grease Flow Properties 26 High Temperature Grease Utilizing New Silicone Based Fluids

NLGI wishes you all a warm

and peaceful holiday season that remains with you through 2017!


Lubricants formulated with additives from Vanderbilt Chemicals have “SUPERHERO” Performance.

ANTIOXIDANTS

VANLUBE® AZ - Zinc diamyldithiocarbamate. VANLUBE EZ - Zinc diamyldithiocarbamate and diamyl ammonium diamyldithiocarbamate. VANLUBE NA - Alkylated diphenylamine. VANLUBE RD - Polymerized TMQ. *VANLUBE 81 - Purified dioctyldiphenylamine. VANLUBE 887 - Ashless antioxidant synergist. *VANLUBE 961 - Octylated and butylated diphenylamine. VANLUBE 1202 - Alkylated PANA. *VANLUBE 7723 - Methylene-bis-dibutyldithiocarbamate. VANLUBE BHC - Phenolic antioxidant.

FRICTION REDUCERS/EP-ANTIWEAR AGENTS MOLYVAN® L - Molybdenum phosphorodithioate. MOLYVAN 822 - Molybdenum dithiocarbamate. **MOLYVAN 855 - Molybdenum friction reducer/no sulfur, no phosphorus. *VANLUBE 73 - Antimony dithiocarbamate. VANLUBE 73 Super Plus - Antimony dithiocarbamate & zinc diamyldithiocarbamate. *VANLUBE 829 - Dimercaptothiadiazole (DMTD) dimer. VANLUBE 869 - Synergistic zinc dithiocarbamate/ sulfurized olefin mixture. VANLUBE 871 - Ashless multifunctional dimercaptothiadiazole. VANLUBE 972M - Thiadiazole derivative in a butoxytriglycol polyethylene glycol blend. *VANLUBE 7611M - Ashless phosphorodithioate. VANLUBE 8610 - Synergistic antimony dithiocarbamate/sulfurized olefin mix. *VANLUBE 9123 - Amine phosphate.

METAL DEACTIVATORS *CUVAN® 303 - Benzotriazole derivative. CUVAN 826 - Dimercaptothiadiazole derivatives. NACAP® - Aqueous sodium mercaptobenzothiazole. VANCHEM® NATD - Aqueous disodium dimercaptothiadiazole. VANLUBE 601 - Heterocyclic sulfur-nitrogen compound. VANLUBE 601E - Heterocyclic sulfur-nitrogen compound. VANLUBE 704S - Barium sulfonate blend.

RUST INHIBITORS *VANLUBE RI-A - Dodecenylsuccinic acid derivative. VANLUBE RI-G - Fatty acid derivative of imidazoline. VANLUBE 8912E - Synthetic neutral calcium sulfonate.

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MOLYVAN 3000 - Molybdenum dithiocarbamate. MOLYVAN FEI Plus - Antioxidant, Antiwear, Friction Reducer Blend VANLUBE W324 - Dialkylammonium Tungstate in oil. TPS™ 20, 32 & 44 - Polysulfides used for EP applications. VANLUBE 289 - Borate Ester. VANLUBE 972 NT - Thiadiazole derivative in a polyalkylene glycol diluent blend, HAPs free. VANLUBE 996E - Methylene bis(dibutyldithiocarbamate) tolutriazole derivative. VANLUBE RI-BSN - Neutral Barium Dinonylnaphthalene Sulfonate. VANLUBE RI-CSN - Neutral Calcium Dinonylnaphthalene Sulfonate. VANLUBE RI-ZSN - Neutral Zinc Dinonylnaphthalene Sulfonate. VANLUBE 0902 - Multi functional S/P package. VANLUBE 407 - Antioxidant

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Registered and pending trademarks appearing in these materials are those of R.T. Vanderbilt Holding Company, Inc. or its respective wholly owned subsidiaries. For complete listings, please visit this location for trademarks, www.rtvanderbiltholding.com. NSF is a registered trademark of NSF International. UL is a registered trademark of UL LLC. TPS is a trademark of Arkema, Inc. Before using any of these products, read and comply with the information contained in the MSDS, label and other product literature.


PRESIDENT:

VICE PRESIDENT:

David Como Dow Corning Corp. P.O. Box 0994 Midland, MI 48686

Joe Kaperick Afton Chemical Corporation 500 Spring St. Richmond, VA 23218-2158

SECRETARY:

TREASURER:

Jim Hunt Tiarco Chemical 1300 Tiarco Drive Dalton, GA 30720

Dr. Anoop Kumar Royal Manufacturing Co., LP 516 S, 25th West Ave. Tulsa, Oklahoma 74127

PAST-PRES./ADVISORY:

EXECUTIVE DIRECTOR:

Chuck Coe Grease Technology Solutions LLC 7010 Bruin Ct. Manassas, VA 20111

Kimberly Hartley NLGI Inter­national Headquarters 249 SW Noel, Suite 249 Lee’s Summit, MO 64063

DIRECTORS Barbara Bellanti Battenfeld Grease & Oil Corp. of NY P.O. Box 728 • 1174 Erie Ave. N. Tonawanda, NY 14120-0728 Richard Burkhalter Covenant Engineering Services 140 Corporate Place Branson, MO 65616 Faith Corbo King Industries, Inc. Science Road Norwalk, CT 06852 Gary Dudley Exxon Mobil Corporation 3225 Gallows Road Room 7C1906 Fairfax, VA 22037 Gian L. Fagan Chevron Lubricants 100 Chevron Way Room 71-7338 Richmond, CA 94802-0627 Tyler Jark Lubricating Specialties Co. 8015 Paramount Blvd. Pico Rivera, CA 90660 Wayne Mackwood Chemtura 199 Benson Rd. Middlebury, CT 06749 Dwaine (Greg) Morris Shell Lubricants 526 S. Johnson Drive Odessa, MO 64076

Tom Schroeder Axel Americas, LLC P.O. Box 12337 Kansas City, MO 64116 Raj Shah Koehler Instrument Co. 85 Corporate Dr. Holtsville, NY 11716-1796 Dr. Huafeng “Bill” Shen Bel-Ray Co. P.O. Box 526 Farmingdale, NJ 07727 Terry Smith Lubrication Engineers, Inc. P.O. Box 16447 Wichita, KS 67216 Thomas W. Steib The Elco Corporation 1000 Belt Line Street Cleveland, OH 44109 Lisa Tocci Lubes ’n’ Greases 6105 Arlington Blvd., Suite G Falls Church, VA 22044 Mike Washington The Lubrizol ­Corpo­ration 29400 ­Lakeland Blvd. Mail Drop 051E Wickliffe, OH 44092 Ruiming “Ray” Zhang R.T. Vanderbilt Company, Inc. 30 Winfield St. Norwalk, CT 06855

NLGI

OFFICERS

SPOKESMAN

Serving the Grease Industry Since 1933 – VOL. 80, NO. 5, NOV/DEC 2016

4 President’s Podium 6 CALL FOR PAPERS 8 Where Were You in 1980?! 10 Industry Partner Spotlight 12 The Effects of Thickeners on the Low Temperature

Properties of Open Gear Greases, Raymond Drost, Donald Howard, Huafeng (Bill) Shen, PhD, Bel-Ray Company, LLC

16 The Effect of Polymer Additives on Grease Flow

Properties, Daniel M. Vargo and Brian M. Lipowski, Functional Products Inc.

28 High Temperature Grease Utilizing New Silicone

Based Fluids, Dr. Manfred Jungk and Aleksandra Nevskaya, Dow

Corning GmbH

Dennis Parks Texas Refinery Corp. One Refinery Place Ft. Worth, TX 76101

TECHNICAL COMMITTEE CO-CHAIRS:

CHAIR, SESSION PLANNING:

Chad Chichester Dow Corning Corporation 2200 W. Salzburg Rd., C40C00 Midland, MI 48686

Wayne Mackwood Chemtura 199 Benson Rd. Middlebury, CT 06749

David Turner CITGO 1293 Eldridge Parkway Houston, TX 77077

SERVICE INDUSTRY ASSISTANCE COMMITTEE CHAIR: J im Hunt Tiarco Chemical 1300 Tiarco Drive Dalton, GA 30720

EDITORIAL REVIEW COMMITTEE CHAIR: Joe Kaperick Afton Chemical Corporation 500 Spring St. Richmond, VA 23218-2158

NOTE: Due to various personal issues, Kim Smallwood of CITGO, has resigned from the NLGI Board of Directors. NLGI wishes him well.

35 Advertiser’s Index 36 Ask the Expert 38 Industry Calendar of Events ON THE COVER HAPPY HOLIDAYS from NLGI! Published bi-monthly by NLGI. (ISSN 0027-6782) KIMBERLY HARTLEY, Editor NLGI International Headquarters 249 SW Noel, Suite 249, Lee’s Summit, MO 64063 USA Phone (816) 524-2500, FAX: (816) 524-2504 Web site:  http://www.nlgi.org — E-mail:  nlgi@nlgi.org One-year subscriptions: U.S.A. $65.00; Canada $80.00; International $109.00; Airmail $147.00. Claims for missing issues must be made within six months for foreign subscribers and three months for domestic. Periodicals postage paid at Kansas City, MO. The NLGI Spokesman is indexed by INIST for the PASCAL database, plus by Engineering Index and Chemical Abstracts Service. Microfilm copies are available through University Microfilms, Ann Arbor, MI. The NLGI assumes no responsibility for the statements and opinions advanced by contributors to its publications. Views expressed in the editorials are those of the editors and do not n­ ecessarily represent the official position of NLGI. Copyright 2015, NLGI. Postmaster: Send address corrections to the above address.


PRESIDENT’S PODIUM DECEMBER 2016

Kimberly Hartley NLGI Executive Director

Well, another year has passed by in the blink of an eye it seems. I think I say that every year! 2016 brought a great deal of change in our industry, and as a result NLGI is also changing to provide more services to you, our Members. Dealing with change is challenging but also a chance to improve and grow, and perhaps head in a different direction than you ever thought of. There were some sad times this past year, particularly the passing of Ralph Beard. I miss him both personally and professionally, and sure missed seeing him at the Annual Meeting this past June. Additionally, Marilyn Brohm chose to resign her position with NLGI at our September Board meeting. We wish her the best. On a very positive note, there were many wonderful accomplishments by the Board of Directors and home office in 2016. A large portion of the Board met in January with a Strategic Planning Consultant. We were able to define future goals for NLGI and plan of action to obtain them. The first effort was to update our Constitution & By-Laws. This proved to be quite a process! But we are now in the final stages of completing the new Constitution & Policy Manual (rather than By-Laws,

a Policy Manual is a more fluid document as policies and procedures change over time). This will be going out via email for our full membership to vote on in the coming weeks. Please cast your vote! I know it’s been a rough election year, but I assure you this vote will be far less volatile! We are also in the final stages of formalizing all NLGI Committees, re-defining and updating descriptions, appointing chairs and updating our Organizational Chart. This, as well as the above mentioned Constitution, will be available in the Members Only area of our website. NLGI exists because of YOU, our Members, so get involved! You do not have to be on the Board to serve on a Committee. Speaking of the NLGI website, we are currently in the middle of a complete redesign. You’ll find navigation much easier, a cleaner look and a more streamlined registration process. We hope to roll this out in early 2017! I am very excited about our 2017 Annual Meeting location, the Resort at Squaw Creek, June 10-13, “Home of the 1960 Winter Olympic Games”. I had the opportunity to spend a week there this past summer,

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part vacation and part planning our meeting. The venue and scenery is spectacular, and it was wonderfully cool, even at the end of July! Here are some helpful tips when budgeting your attendance:

• Registration Fees: Will remain the same in 2017 ($625.00 Members/$900.00 NonMembers) • Room rate: $179.00 Single/Double ($197.00 incl. 10.065% tax) • (Upgrade to a Fireplace Suite for $199.00) • Location: 42 miles from Reno-Tahoe International Airport (RNO), contact concierge for options (530-583-6300) • Parking: Self complimentary/Valet $35.00 • Education Courses: Two offered; Basic and Advanced • Registration will open mid-March. I hope the holidays are relaxing, peaceful and the feelings they bring stay with you through the coming year. Sincerely,

Kimberly Hartley Executive Director

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CALL FOR PAPERS – NLGI 84th Annual Meeting

Going for Gold ~ ‘The Science Behind Superior Grease Technology’ Squaw Creek, CA

A call is hereby issued for technical papers for presentation at the NLGI 84th Annual Meeting, which will be held at The Resort at Squaw Creek, Olympic Valley, CA, USA from June 10th -13th, 2017. You do not need to be an NLGI member in order to present a technical paper at our Annual Meeting.

Submission deadline is January 15, 2017. We are seeking papers that define breakthroughs in the lubricating grease industry:

• Grease formulations to solve industry challenges

• New additives and fluids, or unique use of current systems, to enhance grease performance

• Test method development or improvement to better evaluate grease performance

• Reducing environmental impact of lubrication through technology and chemistry

• Improved grease manufacturing techniques

• Adapting technology to meet changing regulatory environments

Papers covering any other success stories of superior application, or improvement of technology are also welcomed. Technical papers approved for presentation at the Annual Meeting may be published in the NLGI Spokesman, after evaluation by the NLGI Editorial Review Committee.

COMMERCIAL PAPERS:

NLGI will also accept up to 4 papers of a commercial nature which will be offered at the beginning of each of our 4 Technical Sessions, therefore will not conflict with any other presentations or events. Acceptance on a first come, first served basis. (A fee of $1,000 will be charged for all commercial papers accepted for presentation.) You may download the Author Information and Author Instructions/Deadlines forms for your technical presentation, as well as the Commercial Presentation Application form, on our website: https://www.nlgi.org/call-for-papers If you are interested in submitting a technical or commercial paper for presentation, please send your name, contact information and abstract to:

NLGI

nlgi@nlgi.org

NLGI INTERNATIONAL OFFICE 249 SW Noel St. Suite 249 Lee’s Summit, MO 64063 USA

Phone 816-524-2500 • FAX 816-524-2504


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IS S V R E E O X R F O S D B N E R E V A M RO GE E I S PP ER D A W N O E N L F

INTRODUCING

GEAR

RUST, DUST, DEBRIS - WHEN LUBRICANT FILM FAILS, METAL TOUCHES METAL, BEARINGS SCRATCH, GEAR TEETH SCORE AND GEARBOXES DIE. IN A WORLD WHERE INDUSTRIAL GEAR BOXES ARE INCREASING IN POWER DENSITY, PROTECTION TECHNOLOGY IS CRUCIAL FOR EXTENDING GEARBOX LIFE AND OIL DRAIN INTERVALS WHILE REDUCING OPERATING COSTS. INDUSTRIAL GEAR MICROBOTZ™ DEFEND GEARBOXES WITH A PROTECTIVE SHIELD. AND, AS OEMS INTRODUCE NEW, MORE DEMANDING SPECIFICATIONS, AFTON’S GEAR TECHNOLOGIES RISE TO THE CHALLENGE. HITEC® 307 AND HITEC® 352 PERFORMANCE ADDITIVES DELIVER EXCELLENT CLEAN GEAR PERFORMANCE; SUPERIOR COMPATIBILITY WITH PAINTS & SEALS AND OUTSTANDING BEARING WEAR PROTECTION - BUT NOW THEY HAVE ANOTHER ACCOLADE: THEY ARE BOTH SIEMENS REVISION 15 APPROVED FOR FLENDER GEARBOXES! AS THE WORKING ENVIRONMENT GETS TOUGHER, THE INDUSTRIAL MICROBOTZ™ GEAR UP FOR PROTECTION

www.aftonmicrobotz.com

© 2016. Afton Chemical Corporation is a wholly owned subsidiary of NewMarket Corporation (NYSE:NEU). AFTON®, HiTEC®, MicrobotzTM and Passion for Solutions® are trademarks owned by Afton Chemical Corporation. Passion for Solutions® is a registered trademark in the United States.


1980

Where were you in 1980?! If you were at the NLGI 48th Annual Meeting at the Royal Sonesta Hotel in New Orleans, November 5, you would have witnessed Mr. J.W. Lane with Total C.F.R. receive the first NLGI Meritorious Service Award. In 2004, with the passing of Mr. John Bellanti, Battenfeld Oil & Grease, the award was renamed the John A. Bellanti Sr. Memorial Meritorious Service Award and was awarded to Mr. Thomas Pane, King Industries, Inc. To this day, this award remains one of NLGI’s most coveted honors. The award acknowledges meritorious service to the industry, on a Technical Committee, or on the NLGI Board. Join us for the 84th NLGI Annual Meeting, Resort at Squaw Creek, Olympic Valley, CA, USA, June 10-13, 2017, where NLGI will honor the next recipient of this most prestigious award, as well as several other significant NLGI Awards.

Have someone in mind? Let us know! You could be responsible for that someone special being honored. For a nomination form click here. Please email the form to Kim Hartley - kim@nlgi.org Other award descriptions you may wish to nominate someone for are listed on the next page.

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INDUSTRY PARTNER

SPOTLIGHT

ILMA’s 68th Annual Meeting: Partner. Collaborate. Engage!

The beautiful desert venue of the Fairmont Scottsdale Princess was the setting for the Independent Lubricant Manufacturers Association’s (ILMA) 68th Annual Meeting, Partner. Collaborate. Engage! The attendance was another huge success with 1,078 members, prospective members and guests. This number was the second all-time best, coming close to last year’s all-time high of 1,096. General Session Keynote Speaker Mark King was funny and engaging. The former TaylorMade Golf/ adidas CEO shared his remarkable corporate turnaround story that saw the company grow from $300 million to nearly $2 billion in sales in a 13-year period, at a time when the customer base was flat and the world economy challenging. King’s story of building a corporate culture that fosters innovation and excellence was inspiring.

Numerous Networking Opportunities

As always, the networking opportunities could not

be beat, with several receptions, the “Breakfast of Champions” highlighting Sunday’s sports tournaments and a special lunch session featuring American Fuel & Petrochemical Manufacturers’ (AFPM) president, Chet Thompson. Thompson held more than 200 members spellbound as he shared his challenges leading AFPM in the current political environment which favors (not to mention


in the Global REACH Landscape: Asia-Pacific and Beyond;” “The Evolving Business Dynamics of the Lubes Industry;” “Understand the Economics of Pouches and Global Trends;” and, “U.S. Base Oil Pricing Mechanisms in a Global Base Oil World.” Andrew Keyt, executive director of the Loyola University Chicago Family Business Center, gave a superb presentation for the Family Business Session about “Myths & Mortals: Family Business Leadership and Succession Planning.”

In Closing – A New President!

Frank H. Hamilton III, ILMA’s 2015-2016 president handed over the gavel to 2016-2017 president Beth Ann Jones at the closing President’s Dinner. Jones was happy to continue a family tradition — her sister Leslie had been ILMA’s 1999-2000 president! And she is eager to work on moving ILMA’s new strategic plan forward and continuing the great success earned by Hamilton and his predecessors.

subsidizes) “renewable” energy sources and almost has contempt for traditional energy providers. Some ILMA members wanted to commit on the spot toward his initiative to change the dialogue on the role of American oil and gas companies in the economy and in creating a better standard of living in our country and around the world.

Family Business and Industry Sessions

This year’s industry sessions were particularly impressive and included a panel discussion on “Obsolete Oils and Multivehicle Transmission Fluid: Headed to Extinction?” Also on the program: “New Developments

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The Effects of Thickeners on the Low Temperature Properties of Open Gear Greases Raymond Drost, Donald Howard, Huafeng (Bill) Shen, PhD Bel-Ray Company, LLC Abstract

Open gears operate under severe conditions, often at their design limits. Severe conditions include extreme pressures, varying speed and contamination. Possibly the most important aspect of open gear lubricant selection is low temperature pumpability and the ability of the lubricant to be applied through a centralized lubrication system at the lowest anticipated ambient temperature. Considering the cost of downtime of an electric rope shovel or walking dragline in a mining operation, choosing the correct open gear lubricant for the application is critical. When it comes to selection, open gear greases using various thickeners are available and their low temperature performance needs to be examined. While keeping the additive system constant, lab samples of an open gear grease were blended with four thickener types; Aluminum Complex, Lithium Complex, Calcium Sulfonate Complex and Organo-clay. The open gear lubricants’ low temperature properties were evaluated using standard tests to determine the effects of the thickener type on their low temperature properties.

Keywords

Open gear lubricant; Thickener; Ventmeter; Grease Low Temperature Properties.

Introduction

The earliest open gears have been used since the beginning of rotational machinery and were made using wood with cylindrical pegs and lubricated with animal fat. Engineers developed metal gears during the British industrial revolution in the mid-18th century. It was not until a century later that open gears and the way they were lubricated were modernized. Large heavy-duty

open gears are a very common method of transmitting power. In addition, they are the most economical type of gear drive where high load-carrying capacity is required under severe shock load conditions for extended periods of time. Typically, there are two varieties of gear systems; Type 1 and Type 2. For the extent of this paper, only Type 1 gear systems will be discussed. Type 1 open gear systems consist of a motor, typically an actuator and a rack system on machinery such as the hoist and drag drives of mining shovels and draglines. The main difference between Type 1 and Type 2 gear systems is the operation. During operation, Type 1 systems change speeds and are bi-directional, whereas Type 2 systems operate at constant speeds and in the same direction. Due to the nature of Type 1 systems, different physical and performance properties need to be examined in order to properly lubricate these systems with maximum efficiency for reduced cost of operation and down time of the equipment. Variable speed and directional changes under heavy loads could pose the toughest conditions the lubricant can handle. For this reason, EP properties to protect against friction and wear, tackiness for adhesion to the gears, corrosion resistance and the ease of pumpability are all important factors in choosing the correct open gear lubricant for the application. Several industry standards have been established for performance properties as well as another important factor; base-fluid viscosity. As aforementioned, open gear lubricants encounter some of the harshest conditions a lubricant can face. Therefore, a proper film thickness of the lubricant is critical in ensuring optimal performance

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of the machinery. In addition, due to the continuous speed and directional changes of Type 1 gear systems, open gear lubricants face boundary, mixed and hydrodynamic lubrication. Heavy base-fluids are crucial in keeping the proper film thickness of the lubricant. However, this also creates the challenge of pumpability. With regards to lubrication, it is not only the additive system or film thickness that can affect the performance of the product. Thickener type can also effect physical and performance properties of open gear lubricants. As it is widely known in the industry, there are various types of thickeners available all with their advantages and disadvantages for each type of application. This paper will focus on and offer an explanation on the effects of thickener type on the performance properties of open gear greases; specifically on the low temperature properties. Before discussing the preparation of the samples used for testing, it is important to note the test methods used in evaluating the open gear greases:

Grease Sample Preparation

For the scope of this paper, four thickener types were examined: Aluminum Complex, Lithium Complex, Calcium Sulfonate Complex and Organo-Clay. All samples were prepared using the same proprietary base oil and additive system consisting of EP additives, corrosion inhibitors, antioxidants, mineral oils and high viscosity synthetic oils. To make the comparison, the samples were each blended by mixing the components mentioned above in a Kitchen Aid mixer with each respective thickener to make a total of four blends. In order to achieve the same consistency, a different amount of each thickener was needed. The thickener content needed to achieve an unworked penetration of an NLGI Grade 0 grease is shown below in Table 2. To evaluate the performance of each thickener, preliminary testing was conducted on the samples prepared to ensure consistent results for each sample. A dropping point and unworked penetration were tested. As a note, for the extent of this research, only the unworked penetration was tested for consistency according to ASTM D217.

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Results and Discussion

There were multiple tests conducted in order to determine the low temperature properties of each of the formulas. The test conditions are inclusive of 2 temperature parameters, 0°C and 25°C. To obtain a base line for comparison, all of the tests considered necessary in measuring low temperature properties were performed at 25°C first.

The samples were then evaluated at 0°C on each test performed above to determine the values.

* Cone & Plate test was run using CPE-52 Spindle @ 2.5 rpm ** Brookfield viscosity was run using a T-Bar Spindle (T-C) and Helipath stand @ 30 rpm *** Brookfield viscosity was run using a T-Bar Spindle (T-F) and Helipath stand @ 30 rpm In order to correctly evaluate the low temperature properties of each thickener, it is necessary to determine which test results directly correlate to the performance in the application of the open gear lubricants. Two tests that that are relevant but do not necessarily correlate to the application were run for data; Brookfield viscosity and the Cone and Plate test. Both of these tests are rotational viscometers that measure the viscosity by the torque required to rotate an object in a fluid at a constant speed. A contributing factor in the difference in rheological properties of each thickener can be due to the size of thickener fibers and its gel structure. Although the exact

size of the thickener fibers were not determined, the structure can affect the low temperature properties of open gear greases. As previously mentioned, the “ease of pumpability” of the lubricant is very important. The first test that was conducted which corresponds to this is the Lincoln ventmeter test. The Lincoln ventmeter test effectively measures the temperature flow limits of a grease. It determines the greases yield stress and shear thinning index to approximate the apparent viscosity at a given temperature. In a paper by Conley and Shah1, the significance of this test is described: “By measuring the flow properties of grease, a lubricant designer or an application engineer or technician can select the pump and line size to ensure good performance of the centralized grease lubrication system, or select an appropriate lubricant for an existing system. The Ventmeter provides this information.”

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After evaluating the results for the Lincoln Ventmeter test at 0°C, the Aluminum Complex formula performed best. The table below shows the percent increase in venting pressure of each sample when compared to the Aluminum Complex formula:

The second test that is important in determining low temperature performance in open gear greases is the Grease Mobility test. According to the U.S. Steel method using S.O.D. cylinder and capillary tube2 “Grease Mobility is a measure of resistance to flow under prescribed conditions”. Open gear greases can face sub-zero temperatures for extended periods of time. This makes grease mobility very important, especially in centralized lubricating systems. With regards to this test, a larger grease flow rate (g/min) indicates better mobility.

Conclusion

After evaluating the low temperature performance of open gear lubricants using various thickeners, it was determined that using Aluminum Complex as the thickener is the preferred choice. This conclusion is supported by the Lincoln Ventmeter and Grease Mobility test data. The data also shows that, although the performance is not quite as good as Aluminum Complex, Calcium Sulfonate Complex performed significantly better than Lithium Complex and Organo-Clay thickeners. This data also shows how the thickener type has a significant impact on the low temperature properties of open gear greases. Since choosing the correct open gear grease is critical in optimizing the performance of the applied machinery, thickener type needs to be carefully considered.

References

1. Conley, P., Shah, R. “Ventmeter Aids Selection of Greases for Centralized Lubrication Systems”. Machinery Lubrication. (January 2004) 2. The Lubrication Engineers Manual. 2nd ed. Pittsburgh, PA. Association of Iron and Steel Engineers, 1996. (p.154)

Acknowledgments

The authors would like the thank Calumet Specialty Products Partners, L.P. for the support on conducting research on the effects of thickeners on low temperature properties of open gear greases. The authors would also like to thank our colleagues in the R&D lab for evaluating physical properties of open gear greases and sample preparation for this study.

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The Effect of Polymer Additives on Grease Flow Properties Daniel M. Vargo and Brian M. Lipowski Functional Products Inc.

Abstract

Grease used in centralized lubrication systems must have proper flow characteristics under operating conditions. The Lincoln ventmeter was developed as a method to determine if a particular grease is suitable for a centralized grease distribution system. The additives used in the grease may affect their suitability. A range of polymeric additives were added to lithium complex and calcium sulfonate base greases to determine their effect on grease flow properties at ambient temperatures and at -1°C. At low temperatures the effect seems to be polymer dependent. It has been shown that many types of polymers do not adversely affect the flow properties of lithium complex grease as measured by the Lincoln ventmeter. The flow properties of calcium sulfonate grease are negatively impacted by addition of polymer.

Introduction

Lubricating grease comprises two phases and three components: base fluid, thickener, and other performance additives. The liquid phase is primarily formed by the base fluid and the solid phase is formed by a network of soap molecules or a dispersion of solid particles such as inorganic clays or other fillers.1 The solid phase thickener can consist of soap molecules with or without added polymer. The base oil solubilizes polymers and performance additives and is immobilized by the soap molecule network structure, resulting in a semi-solid to solid appearance.2 Lubricating grease used in centralized distribution systems must have proper flow properties in order to perform efficiently and effectively. These properties are influenced by the selection of base oil, thickener and other additives.

The purpose of this paper is not to determine whether certain polymers can or cannot be used in a centralized grease distribution system but is only to examine the flow properties of a grease containing various polymer structures using the Lincoln ventmeter as a tool. Generally, the soap thickener is a metallic salt of a long-chain fatty acid, e.g. lithium 12-hydroxy stearate, which can assemble into a network structure in solution. Polymers incorporated into the grease can be used to enhance the properties of the grease such as consistency, shear stability, water resistance, adhesion, tackiness, and soap yield.3,4 Polymers such as polyethylene, polypropylene, polyisobutylene, halogenated polyethylene, polymethacrylate and polyurea are reported to improve the properties of greases.1,5,6 Olefin copolymers (OCPs), styrene-ethylene-butylene (SEBS) and OCP-anhydride (OCP-A) were studied. The type and structure of polymer selected has significant impact on grease properties including low temperature flow, thickening efficiency and shear stability.7 The shape of the polymer molecule is defined by its structure. Polymers with a variety of structures can be synthesized depending on the polymerization technique and catalysts used. Figure 1 shows several polymer structures that may be obtained. Linear polymers are those with repeat units connected in a single long chain. Branched polymers or comb polymers are comprised of structures with a long backbone and multiple side chains.

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Star polymers and dendrimers have repeat units arranged radially.8 The polymers studied in this paper have linear or branched structures.

Base greases

The selection of the base fluid used to make the grease has a large impact on the low temperature properties. At low temperatures, paraffinic oils containing significant portions of saturated hydrocarbons generally crystallize which impedes flow.9 Certain pour points depressants are effective at disrupting these wax crystal structures and can improve flow at low temperatures.10 Unlike paraffinic oils, naphthenic oils generally do not contain high levels of molecules that can crystallize at low temperature. The viscosity increase at low temperature is generally due to purely thickening effects as described by the viscosity index. Naphthenic oils are generally preferred over paraffinic oils for low temperature use.10,11 More recently, synthetics including polyalphaolefins and esters have been used as base fluids in greases for use at low temperature.10,12 Similar to paraffinic oils, polyalphaolefins may contain components that crystalize at low temperature. Esters may also exhibit poor low temperature properties if, during use, cleavage of the esters into alcohols occurs.

The selection of the thickener also has an impact on the performance of grease used at low temperature. As machine design evolves operating conditions that the grease must endure has become more severe. Also, the expectation is increased machine productivity and less downtime. This has made it difficult for lithium greases to satisfactorily fulfill these requirements. The National Lubricating Grease Institute (NLGI) GC-LB specification requires greases to surpass simple lithium 12-hydroxystearate greases. These requirements can be met by more efficient high performance greases like lithium complex, calcium sulfonate (sometimes calcium sulfonate complex), aluminum complex, polyurea and clay based greases. However, because of their compatibility with most widely used simple lithium greases, lithium complex and calcium sulfonate greases appear to be the best candidates of these high performance greases.13 Table 1 compares the typical properties of lithium complex greases to calcium sulfonate greases.

- 17 NLGI SPOKESMAN, NOVEMBER/DECEMBER 2016


Lithium Complex vs. Calcium Sulfonate

Lithium complex greases generally possess good mechanical stability, high temperature degradation resistance and water resistance properties.14 Other performance requirements like, antiwear, extreme pressure, rust and corrosion can further be improved by adding suitable additives. These greases, when properly formulated, meet NLGI’s GC-LB specification requirements.14 A comparison between lithium complex and calcium sulfonate greases reveals that calcium sulfonate greases possess intrinsically better performance aspects is shown in Table 1. An important difference between these two types of greases is that calcium sulfonate greases do not typically need additives to meet certain performance requirements like lithium complex greases do. The reason for this is that the calcium sulfonate thickener in the greases is generally overbased to a high total base number (TBN). The active chemistry in addition to the calcium sulfonate matrix is amorphous, oil soluble calcium carbonate.15 Other benefits of calcium sulfonate greases include superior mechanical and roll stability compared to lithium complex greases. This can be attributed to lower leakage and run out during operation. These greases also have higher dropping points and may be used at higher temperatures than lithium complex greases.15 Calcium sulfonate thickeners have inherent extreme pressure, antiwear properties and are known to be natural rust inhibitors. Many of these thickeners provide

excellent water-resistance and do not break down in the presence of water. Lithium complex greases usually require tackifiers to improve their water-resistance properties.15 Calcium sulfonate greases are also compatible with lithium and lithium complex greases. However, calcium sulfonate greases suffer from inferior pumpability and high cost when compared to lithium complex greases.13

Grease Flow

Grease flow is a complex phenomenon determined by many factors. The most important factor is temperature. As the temperature decreases a grease will have poorer mobility. Other factors include thickener type and amount, base oil properties and other mobility improvers. The most readily pumpable or dispensable greases are made from lithium complex or aluminum complex soaps. Less readily pumpable greases are based on calcium complex and calcium sulfonate type soaps. Calcium sulfonate greases contain a higher level of soap to attain a particular NLGI grade compared to lithium complex greases. This accounts for the decreased flow rate of calcium sulfonate greases. The base oil accounts for 80 to 90% of a typical grease. Therefore, its properties strongly influence grease flow. High viscosity base oils result in lower mobility greases; however, in machinery operation these greases provide better lubricity through increased film thickness. Base oils with low viscosity indexes generally have poorer

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mobility at lower temperatures. Higher base oil pour points indicate the presence of waxy components, which restrict mobility as they crystallize at low temperature. Mobility improvers are generally low pour point, low viscosity oils or solvents. These can include synthetic esters and polyalphaolefins.16

Current Test Methods

A property that is often associated with low temperature performance is the consistency of the grease. There are several methods used to attempt to adequately describe the consistency and flow characteristics of the grease. The NLGI grade of a grease as measured by cone penetration (ASTM D217) is a simple method of numerically describing the consistency of a particular grease at a given temperature.17 Cone penetration values at one temperature have not been shown to be particularly good predictors of values at another temperature or indication of flow properties at low temperatures. The apparent viscosity of a grease may also be determined using a rheometer, commonly set up as a plate-plate system.10 The amount of torque required to turn one plate may be recorded at several temperatures. An increase in the torque required implies that the grease has a higher viscosity and will therefore flow less well. A series of capillary rheometer runs can also be used such as in the ASTM D1092 Apparent Viscosity test.18,19

The ventmeter test was developed by Lincoln St. Louis to evaluate the compatibility of different greases with their SL-1 and SL-11 injector systems at various temperatures.21 Today, it is primarily used to evaluate the low temperature flow performance of a grease in a centralized lubrication system. The ventmeter contains 25 feet of coiled 1/4 inch diameter steel tubing. Inlet (valve #1) and outlet (valve #2) valves are attached at each end of the coiled tubing.19,21 Figure 2 shows the internal design of the ventmeter. The data collected with the apparatus can be used to calculate an approximate yield stress.22 This parameter is important in the design of a centralized lubrication system.19 A standard grease gun is filled with test grease and is attached to the ventmeter through a hydraulic grease fitting. The ventmeter is then filled with grease by pumping the grease gun handle. All air is expelled in the charging process.19

The two tests most frequently used to determine the pumpability or dispensability of a lubricant are the U.S. Steel mobility test and the Lincoln ventmeter test. The U.S. Steel mobility test determines the resistance of lubricating grease to flow at a given temperature and pressure. Mobility is determined by the flow rate of the grease through a pressure viscometer.20 Typically the pressure viscometer is constructed of stainless steel and is fitted with a No. 1 (40:1 ratio) capillary. With the sample at the test temperature, the flow of grease is started under the selected pressure using a nitrogen tank and regulator. Typical test pressure is 150 psi and temperatures of ambient, 32째F, 20째F, 10째F, and 0째F. Flow rate, usually measured in grams per second, is determined by collecting the grease for a specified period.

A pressure gauge is located at the outlet side of the ventmeter Valves 1 and 2 are both closed and additional grease is pumped into the instrument to develop a pressure of 1800 psi. Valve 1 is opened for 30 seconds and the vent pressure is recorded. To measure grease flow

- 19 NLGI SPOKESMAN, NOVEMBER/DECEMBER 2016


at temperatures other than ambient, the filled ventmeter and grease gun assembly are placed into a freezer and allowed to equilibrate to the test temperature for a minimum of 3½ hours.

Materials

The base greases used were a Lithium Complex Grade #2 grease containing 10% soap without any additional additives and a calcium sulfonate base grease containing 26% of 400 TBN calcium sulfonate. The base oil viscosity was 73 cSt at 40°C, and was a blend of 100N and 500N Paraffinic Group I base oils.

Figure 3: Types of polymers used in this study, their abbreviations and structures. Polymers were incorporated into the base grease by mixing in a Hobart mixer at 80°C. The polymer additives used in this study were in powder, liquid or pellet form and are shown above in Figure 3. Polymers were added and mixed for 3 hours to ensure complete solubilization of the polymer. For reference, the base grease was heated and stirred using the same process as the samples containing the powdered polymers.

Experimental Methods

A Lincoln ventmeter was used to determine the flow properties of greases. A manual grease pump was bulk-loaded and used to fill the ventmeter. After filling the ventmeter the outlet valve was closed and pressure was applied using the grease pump up to 1800 psi. The test valve was then opened for thirty seconds and the pressure was recorded. The final pressure reading was recorded from these values. Final pressure values were normalized to an initial pressure of 1800 psi to account for small variations between runs. Measurements were performed at ambient temperature and -1°C (30°F).

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Results and Discussion Lithium Complex Greases

At ambient temperature there are no significant differences in the final ventmeter pressure reading of the greases when compared to each other or the base grease, as shown in Figure 4. This indicates that adding polymer to improve other characteristics of the grease such as water spray-off or grease consistency does not have an impact on the flow properties of these greases.

At -1°C, there are generally no significant differences in the final pressures recorded when compared to each other or the base grease, as shown above in Figure 4. However, greases containing 0.5 or 1 wt% of SEBS show a significant increase in final pressure reading. This increase corresponds to decreased flow at -1°C. SEBS has a negative impact on flow at low temperature when used in this lithium complex base grease. This may be due to the styrene content of this polymer additive. At low temperatures the styrene is less soluble and can form large domains of styrene. These domains can aggregate and result in the formation of a strong network that will resist flow. As a result of this strong network, the SEBS forms the stiffest greases measured by cone penetration measurements. Decreasing the temperature will drive more styrene into these domains further increasing the strength of the network and thus the stiffness of the grease. The grease flow as measured with the ventmeter at ambient temperature or -1°C does not seem to show any dependence on the stiffness of the grease as measured using cone penetration, as shown in Figure 5. There is also no dependence on the water spray-off values, as shown in Figure 6. No correlation between water spray-off and flow properties would be expected.

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Calcium Sulfonate Greases

In the case of calcium sulfonate greases, adding polymer significantly decreases flow at both ambient temperature and -1°C when compared to the base grease, as shown in Figure 7. Unlike the case of lithium complex greases, there is little significant difference in flow properties when the type of polymer is taken into consideration. The final ventmeter pressure reading is similar for each type of polymer included. It seems that the addition of any additional network to the grease is enough to substantially impact flow regardless of how relatively weak or strong the polymer network is. As in the case of lithium complex grease, there does not seem to be a dependence of flow properties on either the cone penetration or the water spray off values, as shown in Figure 8 and Figure 9, respectively. The base grease is clearly shown to have a lower final pressure than those greases containing polymer.

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Conclusion

Adding polymer to grease does not affect lithium complex grease flow at ambient temperature or -1°C as compared to the base grease without polymer, with the exception of the styrene containing SEBS which forms a relatively stiff network at -1°C and adversely affects flow. Adding 4% OCP-M to a lithium complex base grease represents the best compromise between water spray-off performance and low temperature flow properties. Any polymer significantly decreases flow in calcium sulfonate greases. If a polymer must be added, selecting 1% OCP for use in a calcium sulfonate base grease seems to be the best compromise between good water spray-off and flow properties. These issues may be overcome using pour point depressants or other mobility improvers in fully formulated low temperature greases. A similar study could be performed using aluminum complex and clay thickened greases containing various polymer additives.

Acknowledgements

Functional Products Inc. would like to thank Mark Adams and Justin Thompson of Tribology Testing Labs for allowing us the use of their Lincoln ventmeter. We would also like to thank Tony Wenzler and Rob Haak of Battenfeld Grease and Oil Corp. of NY for supplying the lithium complex base grease and Vittoria Lopopolo, Martin Keenan and Doug Irvine of Petro-Canada Lubricants Inc. for supplying the calcium sulfonate base grease.

References

(1) In A Comprehensive Review of Lubricant Chemistry, Technology, Selection, and Design; Rizvi, S. Q. A., Ed.; ASTM International, 2009; pp. 443–496. (2) Silverstein, S.; Rudnick, L. R. In Lubricant Additives Chemistry and Applications; Rudnick, L. R., Ed.; CRC Press: New York, 2009; p. 586. (3) Larson, B. K.; Mroczek, W. In NLGI Annual Meeting; 2009. (4) Vargo, D. M. In NLGI 81st Annual Meeting; Palm Beach Gardens, FL, 2014. (5) Scharf, C. R.; George, H. F. NLGI Spokesm. 1996, 59, 4–16. (6) Levin, V. NLGI Spokesm. 2004, 68, 25–32.

(7) Fish, G.; Ward, W. C. In ELGI 25th Annual Meeting; Amsterdam, 2013. (8) Feldman, D.; Barbalata, A. Synthetic Polymers: Technology, Properties, Application; 1996. (9) Baczek, S. K.; Chamberlin, W. B. In Encyclopedia of Polymer Science and Engineering; John Wiley & Sons, 1988; p. 22. (10) Denis, R. A.; Sivik, M. R.; George, H. F. In NLGI 69th Annual Meeting; Coronado, CA, 2002. (11) Rizvi, S. Q. A. In A Comprehensive Review of Lubricant Chemistry, Technology, Selection, and Design; Rizvi, S. Q. A., Ed.; ASTM International, 2009; p. 38. (12) Coffin, R. In STLE 2013 Annual Meeting Education Course: Synthetic Lubricants 203-NonPetroleum Fluids & their Uses; STLE: Detroit, 2013; p. 70. (13) Kumar, A. Machinery Lubrication. February 2004,. (14) Pirro, D. M.; Wessol, A. A. Lubrication Fundamenals; 2nd ed.; Marcel Dekker, Inc.: New York, 2001; pp. 73–75. (15) Authier, D.; Herman, A.; Muntada, L.; Ortega, E.; Vivier, H.; Ribera, L.; Saillant, B. In 25th ELGI Annual General Meeting; Amsterdam, 2013. (16) Fish, G.; Ward, W. C. In STLE 2012 Annual Meeting; STLE: St. Louis, MO, 2012. (17) ASTM D217-97: Standard Test Methods for Cone Penetration of Lubricating Grease; 1997. (18) ASTM D1092-99: Standard Test Method for Measuring Apparent Viscosity of Lubricating Greases; 1999. (19) Conley, P.; He, C.; Shah, R. In NLGI 73rd Annual Meeting; Lake Buena Vista, FL, 2006. (20) Conley, P.; Shah, R. In NLGI 70th Annual Meeting; Hilton Head, SC, 2003. (21) Rotter, L. C.; Wegman, J. NLGI Spokesm. 1965. (22) Michell, R.; Chan, Y. N. In NLGI 80th Annual Meeting; Tucson, AZ, 2013.

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Appendix

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- 27 NLGI SPOKESMAN, NOVEMBER/DECEMBER 2016


High Temperature Grease Utilizing New Silicone Based Fluids Dr. Manfred Jungk and Aleksandra Nevskaya Dow Corning GmbH

Introduction

Silicone, or as per IUPAC nomenclature Polysiloxane, represents a wide variety of polymeric chains and networks constructed around a backbone of Si-O-Si atoms. The Si-O bonds of silicones are >30% stronger than C-C bonds of hydrocarbons. The Si-O-Si angle is wider compared to C-C-C; this gives to the molecule great flexibility. The strength, length, and flexibility of silicone bonds impart many unique properties, including low melting temperature, fluidity, low glass transition temperature, and increased compactness. For the use as lubricating base fluid their exceptional oxidative stability and temperature-viscosity indices stand out. Their synthesis and manufacturing process is complex, starting from the reduction of Quartz with Carbon to yield elemental Silicon. Then using a fluid bed reaction process Silicon and Methylchloride form a mixture of Chlorosilanes with the majority being Dichlorodimethylsilane. Hydrolysis of distilled Chlorosilanes and subsequent polymerization result in Polysiloxanes. The most common silicone structure is polydimethylsiloxane (see Figure 1) which is used in many applications including lubricants as well but has limited wear resistance. Polydimethylsiloxane based greases and compounds find use as O-ring and Valve lubricant, Damping grease, Plastic Gear lubricant or Brake Caliper grease. Phenyl groups on the silicone molecule provide additional thermal and oxidation resistance but do not improve lubricity. Polyphenylmethylsiloxane based greases are used in Metal-to-metal applications requiring high temperatures such as Clutch Release bearings or requiring slip prevention such as Overrunning Clutches. Trifluoropropyl substituted siloxanes exhibit reasonable wear protection and load carrying capacity, though their oxidation stability is not as good as that of the above mentioned Phenyl substituted materials. Typical applications of Polytrifluoropropylmethylsiloxanes - 28 VOLUME 80, NUMBER 5


are for pumps, mixers or valves in the chemical industry and Circuit Breakers. This paper describes the development of a model to predict tribological properties of above mentioned as well as newly synthesized Silicones. Some examples of the new fluids will be compared with Hydrocarbon based fluids.

New Silicone structures

In order to characterize a Silicone where Methyl groups have been substituted we use a nomenclature as described in Figure 2, where J stands for the type of substitution, L for the length in Carbon atoms of an alkyl chain substitution, Q for the percentage of Silicon atoms of the Siloxane polymer chain where methyl groups have been substituted by J and Z the number of Silicon Atoms in the Siloxane polymer chain. In addition the commonly used Polydimethylsiloxanes, Polyphenylmethylsiloxanes and Polytrifluoropropylmethylsiloxanes new Polycyclohexylmethylsiloxanes, Polyalkylmethylsiloxanes, and Polyphenylalkylmethylsiloxanes were synthesized either by Hydrosilation reaction with a respective Olefin or through Hydration of Phenyl substituted Silcones. Table 1 lists the fluids that have been measured for the development of the model with its designated nomenclature to describe its molecular structure. Specific Volume and viscosity measurements were determined in the temperature range from 25 to 125 oC. Pressure viscosity indices were taken from high-pressure viscometric literature data and compared to calculated values from film thickness measurements. Generally spoken the literature data fit reasonably well into the range of calculated data at different - 29 NLGI SPOKESMAN, NOVEMBER/DECEMBER 2016


test temperatures. Elastohydrodynamic film thickness was measured at temperature range from 30 to 125 oC using a PCS thin-film tribometer at a maximum Hertzian pressure of 0.54 GPa, while speed was incrementally decreased from 4.35 to 0.020 m/s under nominally pure rolling conditions. Friction measurements were made at disk speeds from 5.00 to 0.025 m/s with the ball attached to a motor-driven shaft to vary the slide-to-roll ratio at a maxi-mum Hertzian pressure of 0.82 GPa. Boundary friction data were obtained using a ball (dia. 3/8”: Steel HRC~60 ) on disc (52100: Steel HRC~35) tribometer in fully flooded condition at 5kg Load, Disc Speed of 50mm/s with Entrainment Speed of 25mm/s for a total 1000 Revolutions. Table 2 gives a snapshot of some of the experimental data for illustration purposes. Silicones are well-known for their temperature resistance and high Viscosity index. The data show that film formation capabilities of silicones are comparable with PAO and much more stable at higher temperatures. But boundary friction and wear values are higher compared to Polyalphaolefine (PAO) base oils. However, we have identified alkyfunctional silicone structures (A100-8, A100-12, A30-16, A100-8/12) showing low friction and good wear resistance. Two substances (A8-8 and PCMS 90) have high EHL friction values for potential use in traction fluid application.

Model from Molecule to Friction

A model to predict the tribological performance of a silicone fluid from its chemical structure was recently developed in cooperation with Northwestern University. Figure 3 shows schematically the calculation method to start from individual atoms building a polymer molecule to derive at the rheological data of the polymers with its shear, temperature and pressure dependency. Knowing the molecular structure from Nuclear Magnetic Resonance (NMR) spectroscopy and Gel Permeation Chromatography (GPC – giving the molecular length and its distribution by the polydisperity) the Molecular Weight Mw and Van der Waals Volume (using the Van der Waals Radii of each atom) νw can be easily calculated.

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The Molecular Packing Factor (MPF) is the quotient of Specific Van der Waals Volume over measured Specific Volume v0. The Specific Volume at room temperature and atmospheric pressure ν0 can be calculated using Molecular Packing Factor. The viscosity (η0) can be calculated using the structure-viscosity equation of Berry and Fox which includes the parameters of Radius of Gyration and Monomeric Friction. The Tait Equation of State (v(T, P)) describes the pressure and temperature dependence of the Specific Volume and The Tait Doolittle equation (η (T, P)) which is used to calculate the temperature and pressure dependence of the Viscosity. In the next step of the model we have identified the Total Friction Coefficient from Rheological parameters as calculated above. Total Friction is the sum asperity and film friction. The Hamrock Dowson equation is often used to calculate film thickness of elastohydrodynamic lubrication. But rather than going through the complex equation we will look qualitatively at the influencing parameters. When speed increases, film thickness increases. If contact loading increases, film thickness goes down. The contact load depends on the applied load. The materials tendency to expand when compressed hence the Poisson ratio and the materials elasticity hence the Young’s modulus. Rougher surfaces lead to lower film thickness, while the curvature of the non-conformal moving bodies impacts the contact load. The film thickness to composite surface roughness ratio determines if the load is carried by a mixture of asperity and fluid film (boundary and mixed lubrication) or totally by the fluid film (full film lubrication). Greenwood/Trip and Patir/Cheng used Greenwod/Williamson model along with simplifying assumptions based on engineering surfaces to calculate the contact pressure as a function of separation distance. The friction in unlubricated contact arises from metal to metal contact and was measured at μdry=0.3. Thus the asperity friction is derived by multiplying that value with the quotient of above calculated pressure over the pressure at zero film thickness. Fluid film friction is the quotient of mean shear stress over mean pressure. Mean pressure in the interface is computed by integration over the contact surface area while the shear stress distribution over the range of shear rates (depending on velocities) and viscosities is determined by a modified version of the Carreau model. The total friction is the addition of asperity friction and film friction at same loading. On the right hand side of Figure 4 the graphical user interface for the algorithm to calculate the tribological data from a molecular structure of a Silicone is shown. The Molecular structure such as the species (J), branch length (L), branch content (Q), polymer length (Z) and the polydisperity need to be entered together with application conditions as temperature, speed, loading and slide-to-roll ratio. Interface geometry such as radius and surface finish of the 2 bodies as well as the Young’s modulus and the Poisson ratio can be varied to be consistent with a tribological contact in question.

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Comparison to Carbon based Fluids

Parallel to the development of the model larger quantities of Polyoctylmetylsiloxanes with varying branch percentage and molecular length were synthesized to evaluate their properties for use as lubricating base fluid in comparison to hydrocarbon based materials. Table 3 shows the Load carrying capacity as per SRV method, the Wear behavior according to 4-Ball test, oxidative stability according to the Oxidative Onset Temperature per Differential Scanning Calorimetric measurements in air, the viscosities and respective Viscosity Index. The data for the Polyoctylmetylsiloxane shows the minimum and maximum values of a series of more than 25 different fluids. From the fluids shown for comparison the data for Polyalphaolefine (PAO 6), Polydimethylsiloxane (PDMS) and Fluorosilicone fit well in the range of those of the Octylmethyl fluids. The Perfluoropolyther’s data fit also in the range except their outstanding oxidative stability. Another example of a newly synthesized Siloxane that was developed parallel to the model is a fluid for potential use as lubricant at high temperatures. Table 4 shows results from the new fluid compared to known Silicone and Hydrocarbon based fluids. While Fluorosilicones have reasonable 4-ball wear performance their high temperature capability is not as good as that of Phenyl Silicones as can be seen from the oxidative onset temperature of Differential Scanning Calorimetric measurements in air. The new Siloxane high temperature fluid exhibits overall good performance with respect to Viscosity Index, 4-Ball wear and Oxidative stability. - 32 VOLUME 80, NUMBER 5


Greases formulated with the new new Siloxane show also 4-ball wear results comparable or better than other high temperature greases based on Perfluoropolyethers. Furthermore bearing tests using the FAG Fe9 Test show better performance at 220oC as compared to currently used high temperature greases.

Outlook

Besides the Polyoctymethyl- and the New High TemperatureSiloxanes developed in parallel, the model in form of the graphical user interface and its algorithm can be used to optimize the chemical structure for a specific tribological need. The plot of film thickness versus entrainment speed for Polyphenylmethylsiloxane (PPMS 90) and Polyalkylmethylsiloxane (A100-12) at different temperatures show that ring branches show nearly Newtonian behavior. High monomeric friction allows a relatively low molecular mass (Mw=1990 g/ mol for PPMS 90) to build viscosity, so shear thinning is low. For alkylfunctional fluids we see different behavior where low monomeric friction requires a relatively high molecular mass (Mw=29900 g/mol for A100-12) to build viscosity and shear thinning is high, thus linear branches may exhibit temporary shear-thinning. The plot of coefficient of friction versus film thickness at two different temperatures for cyclohexylmethylsiloxane PCMS 50, phenylmethylsiloxane PPMS 50 and standard polydimethylsiloxane PDMS shows that for PCMS the coefficient of friction does not change much by temperature. In case of PPMS and PDMS coefficient of friction drops down at higher temperatures. This means that Cyclohexyl siloxanes have greater thermal stability in the fluid film region. That indicates siloxanes are adaptable to diverse application, e.g. cycloalkysiloxanes as traction fluid or alkylsiloxanes as energy efficiency lubricants.

besides Silicones, explore the impact of mixtures and additives to the model or introduce functional groups (S, N, P) to the side groups.

References

1. Zolper, T.J., Li, Z., Chen, C., Jungk, M., Marks, T.J., Chung, Y.-W., Wang, Q.: Lubrication properties of poly-alpha-olefin and polysiloxane lubricants: molecular structure-tribology relationships. Tribol. Lett. 48, 355–365 (2012) 2. Zolper, T.J., Li, Z., Jungk, M., Stammer, A., Stoegbauer, H.,Marks, T.J., Chung, Y.-W., Wang, Q.: Traction characteristics of siloxanes with aryl and cyclohexyl branches. Tribol. Lett 49, 301–311 (2013) 3. Zolper, T.J., Seyam, A.M., Chen, C., Jungk, M., Stammer, A., Stoegbauer, H., Marks, T.J., Chung, Y.-W., Wang, Q.: Energy efficient siloxane lubricants utilizing temporary shear-thinning. Tribol. Lett. 49, 525–538 (2013) 4. Zolper, T.J., Seyam, A.M., Chen C., Jungk, M., Stammer, A., Chung, Y.-W., Wang, Q.: Friction and Wear Protection Performance of Synthetic Siloxane Lubricants. Tribol. Lett. 51, 365–376 (2013) 5. Zolper, T.J., Jungk, M., Marks, T.J., Chung, Y.-W., Wang, Q.: Modeling polysiloxane volume and viscosity variations with molecular structure and thermodynamic state. Journal of Tribology 136(1), 011801/1-011801/12 (2014).

Besides tailoring siloxane fluids for specific tribological challenges as described above, the researcher could extend model to other types of chemical structures - 33 NLGI SPOKESMAN, NOVEMBER/DECEMBER 2016


STRATCO HOSTS RIBBON CUTTING AT NEW WORLD HEADQUARTERS, WITH SCOTTSDALE MAYOR JIM LANE & INTERNATIONAL GUESTS

SCOTTSDALE, AZ -- STRATCO, Inc. celebrated its new world headquarters Open House with a special event that coincided with the Independent Lubricant Manufacturers Association (ILMA) Annual Meeting, Oct. 15-18, 2016. This event was highlighted by a ribbon cutting ceremony and champagne toast with Scottsdale Mayor, Jim Lane. The annual meeting is an international draw, and over 100 people attended the event at STRATCO in the Scottsdale Airpark district. “As a supporter of ILMA and the National Lubricating Grease Institute (NLGI), I was thrilled to host this event and share our facility - including our new lab, featuring the Pilot Contactor™ Reactor - with other industry professionals,” said Diane Graham, STRATCO CEO. “We were happy to see our friends and colleagues enjoying themselves and our beautiful Arizona weather.” STRATCO has been involved in NLGI since its inception in 1933, and the European Lubricating Grease Institute (ELGI) since its inception 25 years ago.

STRATCO’s new location provides a more functional space for its Pilot Plant that is used for Research & Development, as well as for laboratory services for Customers in the development of lubricating grease formulations and the investigating of new product lines. These new facilities will bring benefit to STRATCO’s Customers in the Lubricating Grease industry and other industries where reacting, mixing and blending technologies are needed. Since 1928, STRATCO has been known for the supply of the highest quality equipment available, including the STRATCO® Contactor™ reactor and Skid Mounted Pilot Plants. STRATCO is now expanding and upgrading its Grease Kettle designs. STRATCO’s Customers are located in 63 countries on six continents. Originally based in Kansas City, MO, STRATCO, Inc. is a privately-held firm headquartered in Scottsdale, AZ. The company provides engineering and equipment manufacturing solutions to customers worldwide in the lubricating grease, modified asphalt and petrochemical industries. STRATCO, Inc. is a member of the STRATCO GLOBAL family of companies, which includes ECOPATH™, formed in 2004 to provide technology solutions to the modified asphalt industries.

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Advertiser’s Index Afton Chemical, page 7 Biederman Enterprises Ltd., page 5 Covenant Engineering, page 35 Lubes ‘n’ Greases, page 41 Lubrizol Corporation, back cover OilDoc, page 35 Patterson Industries Canada, A Division of All-Weld, Co. Ltd, page 37 Stratco, page 34 Vanderbilt Chemicals, LLC, inside front cover

More than First class speaker line-up. International Exhibition. Excellent networking. More than90 85high-class high-classpresentations. presentations. First class speaker line-up. International Exhibition. Excellent networking.  Condition Monitoring – Online, On-Site, Offline  Lubricants – Design to Application velopments  Fluid Management – Innovative & Sustainable  Metal working and forming lubrication all recent de and risks Get to know portunities  op re t  Lubricants – Latest developments ared for futu at one even  Lubrication in Special Environments ep s rt pr pe Be ex y  ke ternational workshops in d e an th t es ee iti M  Tribology – Research targeting Experience  Functional fluids – Everything but lubrication portun  tworking op  Excellentcialneevents and little Oktoberkfeanstd Salzburg  Top so km from Munich, Innsbruc  Just 50 international airports

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the Expert Q:

Can you confirm that there are no greases with a NLGI consistency number with a “Grade N2” designation?

A:

We can confirm that there is no NLGI consistency grade designated N2. Please visit the NLGI website for a complete listing of all NLGI Certified greases with the consistency grade included.

Q:

We are trying to qualify a grease for an NLGI classification - what needs to happen get this done? We will be performing D217 Cone Penetration on their grease - would you accept our results to qualify the grease?

A:

The requirements for qualifying a grease against the NLGI GC or LB service categories are detailed in ASTM D4950. All tests listed must be performed to qualify a grease against either of the categories. A D217 Penetration test performed as prescribed in the test method is considered to be suitable to be part of the data used to qualify the grease.

Q:

My company has a standard grease we¹re currently using. But it is causing us some problems so we are looking at alternatives. I am trying to find a list of grease manufacturers that have a significant international presence. If I find the perfect grease in USA and it isn¹t available in China, Brazil, etc. it does me no good. Is that something your organization can help with?

A:

NLGI cannot recommend a grease manufacturer, as there are many that make up NLGI’s membership. However, there are many grease manufacturers with an Internet presence or that can be found in trade magazines, journals, and periodicals. Most multinational oil companies produce lubricants and greases and most of them have presence in major industrial markets such as the USA, Europe, Japan, China, Brazil, etc. Attending NLGI’s annual meeting is an opportunity to network with many grease manufactures.

- 36 VOLUME 80, NUMBER 5


Q:

Would you please advise me if greases in different consistency could be mixed? For example, could grease with NLGI 2 replace by grease with higher or lower NLGI, e.g. NLGI 1 or 3 and 4?

A:

Greases of different NLGI consistency grades can be mixed. The mixture typically has a consistency intermediate to the two products that were mixed. Generally, a product with a given consistency grade (i.e. 1, 2, 3, etc.) is specified by the equipment or bearing manufacturer for a given set of operating conditions (operating temperature, bearing type and size, speed, and load). That grease should be used in the application, and greases of different consistency generally should not be mixed with the specified grease. In some cases, grease consistency is changed with the seasons (i.e. NLGI 2 in summer and NLGI 1 or 0 in winter) in equipment that is exposed to outdoor temperatures. In places with a consistent year-round climate, such as Singapore, a single consistency grade product would be preferred. The above assumes that the two products being mixed are compatible, and mixing them would not result in incompatibility of the thickeners in the greases. Incompatibility often results in the mixture of greases becoming soft, even fluid, and not staying in the application. In some cases the mixture becomes stiffer, resulting in difficult poor performance in the application and relubrication. A mixture of greases becoming either fluid or extra stiff can result in poor lubrication and premature equipment failure. Mixing of greases should be investigated in the laboratory prior to mixing the greases in an application.


Industry Calendar of Events Please contact Kim if there are meetings/conventions you’d like to add to our Industry Calendar. kim@nlgi.org (Your company does not have to be an NLGI member to post calendar items.)

November 30 – December 2, 2016 12th ICIS Pan American Base Oils & Lubricants Conference Hyatt Regency Jersey City, USA http://www.icisbaseoils.com/panambaseoils2016

February 15-17, 2017 21st ICIS World Base Oils & Lubricants Conference Park Plaza Westminster Bridge, London, UK http://www.icisconference.com/worldbaseoils2017

March 7 – 10, 2017 F+L Week 2017 Four Seasons Hotel, Singapore Call for Papers until Sept. 9, 2016 submit to: conference@fuelsandlubes.com More Information: http://fuelsandlubes.com/

April 5 & 6, 2017 5th ICIS Indian Base Oils & Lubricants Conference Mumbai, India http://www.icisconference.com/indianbaseoils2017

April 20-22, 2017 ILMA Management Forum Park Hyatt Aviara Carlsbad, CA

May 6-9, 2017 29th ELGI AGM Hilton Kalastajatorppa Helsinki, Finland Visit Website

May 21-25, 2017 72nd STLE Annual Meeting & Exhibition Hyatt Regency Atlanta, Georgia (USA) More Information - 38 VOLUME 80, NUMBER 5


June 10th – 13th, 2017 NLGI 84th Annual Meeting Olympic Valley, CA Resort at Squaw Creek

June 9 – 12, 2018 NLGI 85th Annual Meeting The Coeur d’Alene Resort Coeur d’Alene, ID

October 10 – 14, 2017 CLGI Biannual National Conference China Location and more information to come

October 14-17, 2017 ILMA Annual Meeting Hyatt Regency Grand Cypress Orlando, FL

October 31 – November 2, 2017 2017 Chem Show The Event for Processing Technology Javits Center New York City, New York www.chemshow.com

October 6-9, 2018 ILMA Annual Meeting JW Marriott Desert Springs Resort & Spa Palm Desert, CA

June 8 – 11, 2019 NLGI 86th Annual Meeting JW Marriott Las Vegas Resort Las Vegas, NV

April 19-21, 2018 ILMA Management Forum Fort Lauderdale Marriott Harbor Beach Resort & Spa Fort Lauderdale, FL

- 39 NLGI SPOKESMAN, NOVEMBER/DECEMBER 2016


NLGI SPOKESMAN Be featured in NLGI Member Spotlight!

All NLGI members may take advantage of this opportunity to highlight your company’s history, global reach, vision, employees or whatever you’d like our readership to know about your company. You may talk about products & services, however, no competitor trade names may be used, nor mention of product pricing. There is no limit on words and we welcome many photos of your headquarters, offices, plant & employee photos. We will accept articles for publication on a first received, first published basis. Contact Kim Hartley kim@nlgi.org at NLGI if you would like to submit an article for possible publication in an upcoming issue. There is absolutely no charge to have your article appear in the NLGI Member Spotlight


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- 41 NLGI SPOKESMAN, NOVEMBER/DECEMBER 2016


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