Generally similar kind of thickener grease can be compatible. However, additives present in the grease may not be compatible. It is always advisable to perform a compatibility study and consult your lubricant supplier before proceeding for production.

Sudden hardening or softening of grease or drastic color change can be a good indicator to consider a check on grease. Observations can be confirmed with multiple tests to analyse the quality of the grease. A combination of following tests can help arrive at a conclusion.
a) Penetration test
b) Dropping Point Test
c) IR Test in comparison with fresh sample
d) Four ball anti-wear test
e) Wear Analysis

Low temperature greases produce very less torque and have excellent pumpability at lower temperatures. The pour point of the base oil along with the proprietary formulation are factors that determine low temperature properties of the grease. For example, pour point of the considered base oil should be around -50 ⁰C for the grease to be used at -40⁰C. Generally synthetic base oils such as PAO, Esters and Polyglycols are preferred for formulating low temperature greases. Flow pressure test and Low temperature torque test are typical test standards to measure the low temperature properties of the grease.

The measure of consistency is called penetration. Penetration depends on whether the consistency has been altered by working. Standard test procedures established by American Society for Testing and Materials International (ASTM) and accepted by industry are ASTM D 217 and D 1403, measure penetration of unworked and worked greases.

The NLGI has established consistency numbers ranging from 000 to 6, corresponding to specified ranges of penetration distance of the standard cone into the test grease. Table below lists the NLGI grease classifications along with a description of the consistency of each classification.

The most important feature of a grease is its consistency. A grease that is too stiff may not get pumped into areas requiring lubrication. While a grease that is too fluid may leak out. Grease consistency depends on the type and amount of thickener used and the viscosity of its base oil. A grease consistency is its resistance to deformation by an applied force.

Greases are made by mixing a solid material, called a thickener, with a base oil and property enhancing additives; but it’s the oil that forms the lubrication film. For better understanding, grease thickener can be thought of as a sponge saturated with oil. Moving parts squeeze the oil out of the sponge like thickener for forming the lubrication film. Typically, the base oil constitutes the largest proportion of grease weight at about 80-90%, followed by thickener at 10 to 20% and additives under 10%.

Dropping point of a lubricating grease is an indicator of the heat resistance of the grease. and is the temperature at which the grease is no more a thickened lubricating medium. The dropping point indicates the upper temperature limit at which a grease retains its structure, not the maximum temperature at which a grease may be used.

Few greases have the ability to regain their original structure after cooling down from the dropping point.

Viscosity: It is a measure of resistance to flow of a lubricating oil.

Viscosity index: It is defined as rate of change of viscosity with respect to temperature.

Significance:

• It is the most important property which determines the performance of lubricating oils under the influence of temperature
• A lubricating oil should have sufficient viscosity to retain a lubricating film on the surface
• On machine part moving at slow speeds under high pressures, a high viscous oil should be used as it better resists being squeezed out from between the rubbing parts.  Light oils can be used for lower pressures and high speeds.
• It is not possible to maintain a liquid oil film between two moving or sliding surfaces if the viscosity is too low and hence excessive wear will occur.

Unlike oils, greases can’t dissipate heat through convection which results in faster oxidation or carbonization. At high temperatures, regular grease can soften and bleed, form a crust or harden causing improper lubrication. High temperature greases can be recommended for processes that clock temperature above 1200C in the application.

Selection of high temperature grease for an application involves the following

1. Identification of temperature range
2. Lubrication intervals
3. Cooling cycles during operation
4. Spillage of lubricant on another component in process
5. Atmospheric contamination
6. Dropping point of the grease
7. Type of Base oil, its viscosity and viscosity index
8. Type of thickener
9. Composition of additives and its properties
10. Loading speed
11. Potential chances of atmospheric contamination

Energy, corrugated board and paper, mines, steel manufacturing, pellet plants, tire, hot rolling, automotive paint shops, ovens in food and pharma processing sectors are some industries that would typically require high temperature greases.

Separation of oil or puddling in the grease pails / containers are common occurrence in lubricants when exposed to heat for long or stored in a hot environments. The puddling can be mixed with the bulk of grease in the pail / container by safe stirring. Removing puddling can change the density of the grease. Follow standard procedures to mix the puddling with grease and ensure no external particles contaminate the grease. Oil separation will also occur when uneven top surface is formed after removal of grease from a container. Hence, it is suggested to level the top surface using a spatula. Consult with the lubricant manufacturer if you observe excessive oil separation.

Grease that can be used for more than one application can be considered as multipurpose grease. Multipurpose grease is generally made of lithium soap with high quality paraffinic oil fortified with antiwear, EP, and antioxidant additives with corrosion protection. Multipurpose grease possess higher dropping point (about 1800c) and offer good resistance to oxidation and protection against rust and corrosion.

Additives such as sulphur, phosphorous, and zinc combinations generally give EP properties to the grease. Further, solid lubricants such as molybdenum disulphide and graphite can also be added to achieve certain EP properties.

EP additives can be classified in to temperature dependent and non-temperature dependent. Temperature dependent are activated when reacted with metal surface at elevated temperatures caused by extreme pressure. The non-temperature dependent additives contain colloidal carbonate salt dispersed within sulfonate. Colloidal carbonate forms a film and prevents contact between metal surfaces.

Environment in which the lubricant is stored plays a crucial role in lubricant performance. Lubricants stored for long under extreme environmental conditions such as high temperatures, higher temperature variations, severe humidity and corrosive environments can affect the lubricant performance based on the product category.

Oils stored improperly beyond storage life established by the supplier, can have issues such as oxidation, sedimentation build up and moisture absorption. For greases, oil separation from the grease would be the primary concern.
Ambient temperature, clean and dry atmosphere can ensure maximum storage life of a lubricant. A consultation with the lubricant manufacturer on the shelf life of the lubricant is recommended to ensure quality.

Discolouration of the oil during service is a part of the natural ageing process as it oxidises.  Generally higher operating temperatures lead to faster oxidation and shorter lubricant life. Sudden Oil discoloration can also indicate signs of oil contamination or degradation.

Additionally, additives as a part of the formulation may also change color during usage. However, this might not impact performance of the oil in any way. Hence, an oil analysis is suggested to check deterioration. The following tests can help arrive at a conclusion.

1. Viscosity test at 40⁰C and 100⁰C
2. Total Acid Number
3. IR Test in comparison with fresh sample
4. External contamination – Check on solid contaminants through filtration.

Consult your lubricant supplier to check the health of the oil

Keeping a tab on oil health through oil analysis is a great proactive practice. It helps to check for contaminants and machine wear. Abnormal analysis result indicates potential danger in the system. Oil analysis helps in identifying root cause and take corrective measures immediately. Issues such as metal wear, broken seals, improper filtration pose greater threat to machine and can lead to extended and expensive downtime.

Regular oil analysis enables finding the right lubricating interval and increases the life of equipment. It also enhances productivity by reducing unplanned downtime resulting in smoother business operations.

Environment in which the lubricant is stored plays a crucial role in lubricant performance. Lubricants stored for long under extreme environmental conditions such as high temperatures, higher temperature variations, severe humidity and corrosive environments can affect the lubricant performance based on the product category.

Oils stored improperly beyond storage life established by the supplier, can have issues such as oxidation, sedimentation build up and moisture absorption. For greases, oil separation from the grease would be the primary concern.
Ambient temperature, clean and dry atmosphere can ensure maximum storage life of a lubricant. A consultation with the lubricant manufacturer on the shelf life of the lubricant is recommended to ensure quality

The pour point of an oil is the minimum temperature at which the oil turns into semi solid and almost losses its flow characteristic. At low temperatures, the viscosity of the oil will be very high, causing the oil to resist flow. This is important in equipment that operates in a cold environment or handles cold fluids.

‘Oil into water’ or ‘oil in last (OIL)’ is a recommended practice for better solubility of the coolant in water. Water in oil would result in large size oil globules with the oil loving ‘oleopphilic’ ions of the emulsifier being ineffective. This would lead to a unstable oil water emulsion.

Emulsifiers help in increasing solubility of the cutting oil in water by breaking down the oil into smaller globules and thereby maintaining a stable and uniform emulsion. A stable emulsion provides longer tank life and also ensures lower carry over loss resulting in minimum top ups.

• Keep a regular check on the concentration of the emulsion, maintain recommended concentration
• Remove any tramp oil from the coolant tank thoroughly
• Measure pH regularly
• Avoid all sorts of dust near the tank, remove the machined debris from the tank regularly.
• Follow the prescribed procedure while changing the coolant.

Including the effectiveness of ‘cutting fluid’, tool life is impacted by a host of other parameters including cutting speed, feed rate, depth of cut, tool and work material, nature of cut and machine rigidity. Cutting fluids with high amount of EP additives would insulate the tool from frictional wear and ensure longer life. Studies have shown that with all other parameters remaining the same, cutting fluids with good EP properties can increase tool life by 20 to 40%.

Aluminum alloys which contain Copper and Zinc as alloying elements are susceptible to chemical reaction (black stains) with cutting fluids that contain Amines as ingredient. For machining such Aluminum alloys, amine free cutting fluids are recommended

Colour change of the emulsion is notable during machining of Cast Iron with the Fe ions dissolving with the emulsion. However with all other parameters such as pH, conductivity, concentration and microbial behaviour remaining within the specified limits, colour change does not impact performance of the emulsion.

Operators handling components with bare hands and in constant touch with the emulsion could feel irritation and itchiness or develop rashes as well. As sensitivity of the skin is subjective, operators need to handle machined components with proper gloves and other protective gear with the objective of avoiding direct contact with the emulsion. Barrier creams could also be considered where direct contact is unavoidable.

Ensuring a stable emulsion with regular check on pH levels and microbial growth by removing chips, swarf and tramp oil from the tank will also help in reducing possibilities of such concerns. Encourage operators to maintain good personal hygiene, recommend regular laundry of their work dress, avoiding wet rags into pockets, usage of mild soaps etc.

Operators handling components with bare hands and in constant touch with the emulsion could feel irritation and itchiness or develop rashes as well. As sensitivity of the skin is subjective, operators need to handle machined components with proper gloves and other protective gear with the objective of avoiding direct contact with the emulsion. Barrier creams could also be considered where direct contact is unavoidable.

Ensuring a stable emulsion with regular check on pH levels and microbial growth by removing chips, swarf and tramp oil from the tank will also help in reducing possibilities of such concerns. Encourage operators to maintain good personal hygiene, recommend regular laundry of their work dress, avoiding wet rags into pockets, usage of mild soaps etc.

It is recommended to use de-mineralised water for all cleaning cycles. Water quality is an important and complex issue which requires attention in nearly every industrial cleaning process

The four basic variables that, combined, establish the success rate of any cleaning cycle are time, temperature, chemistry and mechanical action

Offending spots are usually created when water evaporates leaving behind a solid residue. The resulting residues or spots are unacceptable and may interfere with the function of the part itself. The best way to prevent drying spots is to use demineralised water for the final rinse prior to drying.

A grease with low base oil viscosity (between 15 cst to 20 cst) and effectively controlled solid particle size plays a major role in reduction of operating temperatures of top roll end bushes, especially at high drawing speeds of over 500 metres per minute.

A grease with low base oil viscosity (between 15 cst to 20 cst) and effectively controlled solid particle size plays a major role in reduction of operating temperatures of top roll end bushes, especially at high drawing speeds of over 500 metres per minute.

In lubrication engineering, the base oil viscosity should be lower with increasing speeds. Jockey pulley bearings fall under high speed category (6500 rpm to 7500 rpm for a spindle speed of 19,500 rpm to 22,500 rpm). The base oil viscosity of regular greases typically used in the Spinning industry varies between 120 cst to 160 cst for the application. Considering the high speed of bearings, the viscosity is excessive for the application and the primary reason for power surge after the re-greasing process.

BECHEM recommends a low base oil viscosity grease (between 15 cst to 25 cst) in minimizing the internal friction whilst maintaining the desired lubricant film and thereby eliminating the power surge after re-greasing process.

Journal bearings at cane crusher mills operate in boundary and mixed lubrication regime due to slow speeds and heavy loads. Traditional lubrication approach has been to continuously pump the conventional lubricant to avoid metal to metal contact between the frictional surfaces and thereby undesired wear. Additionally water is continuously pumped to reduce bearing temperatures. This approach however results in significant lubricant consumption as well as a messy shop floor.

To provide effective lubrication and thereby reduce consumption, a lubricant with high base oil viscosity that can form thick film between the shaft and sleeve and thereby reduce metal to metal contact is required.

Specially developed for high load applications, Berulit SM Super has high base oil viscosity of 2500 cSt which enables it to form a thick film between the contacting surfaces and thereby significantly minimizing wear rate of journal bearings.

Multiple field trials have proven reduction in consumption by 8 to 10 times when compared to conventional bituminous oils and by approximately 30% against low viscosity greases and high viscous oils.

Due to inherent properties of this special grease, minimal lubrication is sufficient to maintain the ideal bearing temperature. This also eliminates the need for external cooling of bearing and also reduces loads on ETP.

Due to the nature of operation, shock loads on mill bearings are unavoidable in the crushing area. Conventional lubricants that are unable to withstand such extreme pressures, ooze out under these conditions allowing the contact surfaces to absorb the impact. Repeated impact of such loads might result in burn marks and cracks in the bearing. Lubricants with good EP properties can help mitigate the affect of shock loads on the bearings.

The special additive package along with high base oil viscosity, equips Berulit SM Super with a high load carrying capacity of over 8000 N. Additionally solid lubricants as additives, provide emergency lubrication properties and thereby guards bearing from critical loading conditions.

Conventional greases are thick and have a tendency to hold onto contaminants during regular crushing operations leading to abrasive wear on the shaft and sleeve. An ideal lubricant for the crushing mill application should not only be able with withstand high loads but also possess good flushing and pumping properties.

Berulit SM Super is a fluid grease with excellent flushing property. Additionally, the fluid grease based on special metal soap thickener that has superior pumping properties in comparison to other thickeners has excellent flow-ability and pump-ability. This avoids choking of lubrication lines and points and any undesired damage to bearing by line choking and lubricant run-out.

Mixing incompatible lubricants can have dire consequences.

Food grade certification ( For Example, NSF, Halal) for grease lubricants require stringent restrictions on the type and quantity of additives that can be used in the grease formulation. Non food certified greases can contain additives like sulphur and phosphorous which are restricted materials. Hence it is always advised to clean up the bearing or the mechanical application in concern, free of old grease residues with a food grade certified degreaser/cleaner, before switching to Bechem’s food grade range.
Subsequently if possible, initiate a run-in process of the changeover food grade grease to eliminate any residues and further reduce chances of contamination.The application is now ready for a fresh grease fill and equipped to achieve the desired performance.
It is recommended to connect with your lubrication supplier for grease compatibility during a grease changeover process. To connect with a nearby BECHEM specialist, drop in a message.

Food grade white mineral oils are highly refined premium quality mineral oil, extracted from petroleum base oils and are generally composed of saturated aliphatic and alicyclic non-polar hydrocarbons. These ultra-refined food grade oils undergo severe hydrogeneration process and are almost free from paraffin wax, aromatic agents and other compounds containing oxygen, nitrogen and sulphur.
It is termed as ‘white mineral oil’ due to its transparent and colourless structure. Their odourless, tasteless and non-staining nature makes it perfect for the formulation of food grade grease and oil.
As per international standards, white mineral oils are categorized under Group III on the basis of its refining standard. Typically, they have a viscosity index above 120 and greater than 90% saturates.

Modern day food processing involves sophisticated machineries operating continuously to mass produce food items of the highest quality with the right nutritional value. The equipment require lubrication for its seamless operation and maintenance. However even with the best shop floor practices, the possibility of contamination from a conveyor chain or vapours from non food grade greases / oils applied in high temperature applications can impart specific odour to the food being processed. Also, possibilities of carry-over from oil particles in compressors and other machineries cannot be ruled out. This poses a risk for contamination and rejection of the batch or potential safety concerns if undetected.
Additionally, the risk of lubricant mix-up by the operator, accidentally picking a non-food grade lubricant for a food critical application is certainly a possibility.
Hence, to eliminate the risk of possible contamination even in a well-maintained setup, it is recommended to use food grade lubricants for all applications and equipment in the facility.

Food grade lubricants like food grade oil and food grade grease are developed from highly refined white oil extracted from natural petroleum sources. However, they are also formulated on synthetic base oil artificially made from chemical compounds like PAOs (polyalphaolephins), PAGs (polyalkalene glycols) and silicones.
Additionally, food grade lubricants are also developed from vegetable oils extracted from castor, palm, soybean, canola (rapeseed),sunflower etc.