RULER Dictionary

A B C D E F G H I J K L M N P Q R S T U V W X Y Z

Antioxidants

The oxidation reactions that occur in a lubricant at elevated temperatures in the presence of atmospheric oxygen lead to aging (or oxidation) of the oil. To protect the base oils throughout its service life, from this oxygen attack, oxidation inhibitors (or antioxidants) are added to the base oil. Antioxidants will slow down the rate of oxidation of an oil. During the use of lubricants they can both suffer from thermal and/or oxidative stresses, which will degrade the chemical composition of the lubricant's base stock and deplete the lubricant's additive package.

Biodegradable

Base oils (or organic material), which will be degradable by living organism. Base stocks can be vegetable oils (rapeseed and sunflower oils), synthetic esters (naturally based synthetic esters, or fully synthetic esters), or synthetics (polyalphaolefins, polyalkylenglycol, hydro cracked mineral oil), and have all their degree of environmental degradation. Biodegradable fluids can also be referred to environmental acceptable fluids.

Condition Monitoring

Any oil analysis program which consists of monitoring the main parameters of the lubricants in service, and trend the condition of the lubricant. As part of proactive maintenance programs, it will help to prevent equipment failures related to oil quality, and schedule oil changes, resulting in the maximization of lubricant, as well equipment life.

Degradation

Aging is the change in lubricating oils brought about by the action of atmospheric oxygen, heat, light and radiation. The main controlling function is the reaction with oxygen = oxidation. Any lubricant, in service or during storage, will suffer from degradation.

Electroanalysis

Extreme Pressure Additives

In order to achieve a high load-carrying capacity, and transmit strong forces, extreme-pressure (EP) additives are added to lubricants, like gear oils and hydraulic fluids. The phosphorus, sulfur and chlorine atoms of the EP additives enter into reaction with the metals at the conditions of friction/high load (temperature, pressure). EP-additives will form metal compounds on the surface of sliding metals, and prevent uncontrolled wear.

Friction

Friction is the force, which opposes the movement of one surface sliding or rolling over another with which it is in contact. Different research programs have proven that 1/3 of the world's energy production is consumed in overcoming friction. The primary function of a lubricant is to help overcome friction, which varies directly with load.

Grease

A lubricant composed of an oil (mineral or synthetic oils) thickened with a soap or a thickener, to achieve a semi-solid consistency. Greases are used for the lubrication of machine elements like plain bearings, gears, joints etc. where lubrication problems can not be solved by the use of lubricating oils for economical or technical reasons.

Hydrolysis

The degradation process of synthetic and natural esters due to the presence of water, to form corrosive weak acids. Hydrocarbon oils have excellent hydrolytic stability

Improvers

Viscosity Index improvers are used in a vast range of lubricants, and are additives which improve the viscosity-temperature characteristics of oils. In other words, it will help oil at cold starting temperatures (make oil thinner), as well as at higher temperatures (make oil more viscous).

Jet Engine Oils

These synthetic (mostly ester based) oils are used for the lubrication of the jet engines (both military as civil aircraft), which are operating at elevated temperatures and need a high oxidative and aging stability.

Ketones

Degradation products, resulting from oxidative degradation reaction.

Lubricant

A lubricant is a result of the blending between base stocks and additives, which will enhance specific aspects of an oils performance. All mechanical devices require lubrication to prevent over-heating and wear over solid surfaces in contact.

Mineral Oil

Mineral oils are derived from crude oil (naturally occurring mineral crude oils) by a series of refinery processes, in order to achieve desirable levels of organic molecules, as well to modify physical and chemical properties for different applications.

Neutralization number

As during oxidation organic acids are produced, these acids are detectable as a Total Acid Number, which quantifies acid concentration by measuring the volume of an alkaline (potassium hydroxide) reagent that is required to neutralize the acid in the oil. Total Acid Number will not differentiate acids constituents generated by oxidation, and those from ingested contaminants or some additives (like antiwear or rust inhibitors).

Oxidation

The oxidation reactions that occur in a lubricant at elevated temperatures in the presence of atmospheric oxygen lead to aging of the oil. Oxidation of hydrocarbons is sometimes referred to " combustion or burning", and will result in the cleavage of the lubricant chain where the oxidation takes place. Significant changes (viscosity, TAN, RUL%) can be observed once the oxidation reactions has occurred to a large extend of the oil base stock. Increasing of the viscosity, as a direct result of oxidation, is due to the polymerization process between oxidation products (radicals and peroxides) and the base stock.

PAO

Polyalphaolefins is an accepted general appellation for synthetic (hydrocarbon) manufactured lubricants, through the polymerization reaction from alfa-olefins. PAO have been commercially developed as lubricants and high-performance functional fluids, with highly desirable properties like there are: excellent thermal and oxidative stability, as well hydrolytic stability, low toxicity, high viscosity index, and are frequently used for long service life.

Phenol

Organic antioxidant frequently used in turbine, and hydraulic oil formulations. Usually the phenols are hindered phenols, and they have the ability to trap peroxy radicals (oxidation products).

Remaining Useful Life

The Remaining Useful Life of a lubricant is the length of engine operating time from when a lubricant is sampled, until the antioxidants are depleted. This results in large changes in the basestock's physical properties, and formation of insoluble gums or sludge.

Synthetic Oil

A lubricant produced by synthesis rather than by extraction or refinement, and as a result of the synthesis, the molecular structure can be precisely arranged to meet the manufacturers' criteria for high performance engines. Synthetic lubricants are manufactured from a number of differing chemical bases, and several classes of compounds have been developed to provide base stocks for commercial synthetic fluids. Synthetic fluids are knows a Polyalfaolefins (PAO), poly esters, poly alkaline glycols (PAG), silicones, silicate esters, phosphate esters, fluoro carbons, etc. Synthetics lubricants frequently satisfy special requirements such as non-flammability, thermal stability, resistance to oxidation and radiation much better than mineral oil products. Also the urgency to the concept of environmental responsibility has led to the increased development and need for functional fluids that are both biodegradable and low in toxicity. A mixture of mineral and synthetic base fluids is often used to formulate high performance lubricants.

Thermal Degradation

In addition to oxidative degradation, hydrocarbons are subject to thermal cracking at elevated temperatures, and forming unstable compounds. These unstable compounds are prone to oxidation, and will polymerize to form resins, waxes and sludge (coke formation). Also the high temperatures will affect the antioxidant package.

University of Dayton Research Institute:

Our partner at Fluitec International, who is providing us with research in existing application, as well research for on-line applications.

Viscosity

All liquids have viscosity. The term viscosity describes a liquid's rate of flow, or resistance to flow. Oils have different viscosities, in function of the type of application, and temperature will affect the viscosity of oil. High temperatures will make the oil more liquid, resulting in a lower liquid. When cooled, an oil becomes thicker.

Voltammetry

The technique behind the RULER technology is linear sweep voltammetry. Voltammetric analysis method is an electrochemical method, which directly extracts the antioxidants out of the base oil into a working solution. By applying a controlled voltage ramp through the electrode inserted into the diluted grease sample, a current to flow will peak at the oxidation potential of the antioxidant. The height of the peak is related to the concentration of the additive in the solution.

Wear

Wear is a mechanism which will occur in any application were 2 surfaces are coming in contact, and most wear phenomena are the result of friction. In most of the industrial applications a certain (controlled) degree of wear is accepted. Different degrees of wear can be identified: Abrasive wear: removal materials from surfaces in relative motion by cutting or abrasive action of a hard particle (usually a contaminant) Adhesive wear (scuffing): removal of materials from surfaces in relative motion as a result of surface contact. Corrosion wear: removal of materials by chemical action. Anti-wear additives will be added to fluids to protect the rubbing surfaces against wear.