What are the uses of emulsifiable cutting fluids? Uses of emulsifiable cutting fluids can be classified in three groups: Lubrication Refrigeration Removing shavings Large quantities of friction occur during cultivating process of metal and too much force is needed to defeat this friction.
If a fluid is used during the process, it lubricates forming a pellicle between the geartip and the item and allows the same work to be done by less force. This also minimizes gear detritions by reducing the friction between gearshaving and gearitem and provides a smooth surface. Emulsifiable cutting fluid minimizes deformation by controlling heat of gear and item. Removing shavings from the system by its detergent feature, it provides better surface smoothness.
Do all emulsifiable cutting fluids have the same features? Can we categorize them? Emulsifiable cutting fluids are formulized with different features in order to obtain intended performance. These products have a wide range of application fields. In some cases lubrication is most important, in some cases refrigeration is important and during operations where thin shavings form, detergency feature is important. In order to answer various needs emulsifiable fluids are produced in various groups such as neat oils, emulsions (boron oils), Semi-Synthetic products and synthetical products. NEAT CUTTING OILS These oils are used free of water in applications where lubrication necessity is greater than refrigeration necessity. They consist of either one or more compounds of fossil, animal, sea or vegetable oils. It is the predominantly used oil in formulating mineral cutting oils. On the other hand application field of pure mineral oils is limited to highly workable metals (e.g. aluminum, brass, magnesium) and a few processes of steel. Pure usage of mineral oil provides only hydrodynamic lubrication. On the other hand when polar additives are used with mineral oils polar lubrication of the oil improves and it can be used in harder operations. The same way, to operate under even harder conditions extreme pressure (EP) additives can be blended into the formulation of these oils. EMULSIONS (BORON OILS) These products contain over 60 percent mineral oils. Emulsion is a compound that is formed by oil granules hanging in water as a result of mixing emulsion constructive agents and other additives with oil. Supplementing animal or vegetable oils or esters improves the lubrication quality of emulsions. Supplementing with sulphide, chloride and phosphorous additives provides the emulsions with high lubrication and extreme pressure (EP) features. Water is the most efficient refrigeration medium with its high specific heat, high thermal conductivity and high vaporization heat. In emulsions, perfect refrigeration features of water are combined with lubricant additives. SYNTHETIC PRODUCTS Those kind of products form semitransparent or transparent solutions contrary to emulsions which form milky appearance when diluted with water and they are preferred in applications where refrigeration is more needed than lubrication. These products do not contain mineral oils but contain lubrication improvement and rust prevention additives based on usage objectives. HALFSYNTHETIC PRODUCTS Those kinds of oils contain less mineral oil in comparison with emulsions. Extreme pressure (EP) additives, rust prevention additives, bacteria spread preventing additives can be added to their formulations according to their usage objectives. They are most commonly used products as they combine lubrication features of emulsions and refrigeration features of synthetical products.
What is lubrication, hoe does lubrication mechanism work in metallic emulsifiable cutting fluids? Lubrication is facilitating motion and preventing surfaces in relative motion from deformation by forming a pellicle between two surfaces in relative motion and decreasing friction parameter. LUBRICATION MECHANISM Either one or simultaneously more of the following lubrication mechanisms can be applied to emulsifiable cutting products used in metal processing operations in respect to operation conditions. HYDRODYNAMIC LUBRICATION In that kind of lubrication, lubricant prevents two surfaces from contact and thereby friction forming a pellicle between surfaces only because of its viscosity. Pellicle which forms in this lubrication is extremely thin and can easily deform. Therefore this kind of lubrication is used where minimal lubrication is needed. POLAR (BOUNDRY) LUBRICATION This kind of lubrication occurs with the polar additives the fluid contains. Polar additives in fluid accumulate on the surface of metal and they push each other as a result of their polarity and lubricate and minimize friction by preventing metal surfaces from contact.
POLAR (BOUNDRY) LUBRICATION This kind of lubrication occurs with the polar additives the fluid contains. Polar additives in fluid accumulate on the surface of metal and they push each other as a result of their polarity and lubricate and minimize friction by preventing metal surfaces from contact. Lubrication is higher than hydrodynamical lubrication. Type and amount of the chosen polarizers also affect the lubrication extent. This lubrication may not achieve intended objectives under extreme pressures since polarity of additives are decreased. EXTREME PRESSURE LUBRICATION This kind of lubrication is provided with supplementing of EP additives in formulation. EP additives form a heavyduty pellicle as a result of chemical reaction with metal surfaces and these pellicles sustains its lubrication and prevent friction without deteriorating under toughest conditions, such as heat reaching 800900° C.
Points to consider while preparing a new emulsion? Following points should be considered while preparing emulsions: PREPARATION OF EMULSIONS Before preparing emulsion it must be guaranteed that emulsion tank and machinery are cleaned physically and biologically. 95 percent of the necessary amount of water should be placed in the emulsion tank and 5 percent should be kept aside for later concentration adjustment and mixing the product in another container. Oil amount necessary to obtain the concentration required for the operation must be perfectly stirred in another container and supplemented with water. In the course of mixture oil must be added to water, not water to oil. Stirring should be carried over during supplementation. Water temperature should be about 20°C for easier stirring. When oil supplementing is over, concentration must be checked up and if needed concentration should be adjusted for the intended degree with the previously kept water. Stirring should be carried over for 10 minutes before starting the process just to be sure the emulsion is homogeneous. Preparation date of emulsion should be recorded, specimen should be taken, analyzed and filed for later mixtures.
How should the system be cleaned on the condition that a spoiled emulsion is to be thrown and a new one to be prepared? On the condition that a spoiled emulsion is to be thrown and a new one to be prepared, to get the maximum performance and effective life span from the new emulsion, system must be perfectly cleaned. Before placing the new emulsion in the system, emulsion tank, machinery and duct circuits must be perfectly cleaned. The physical cleaning of the system is cleaning the emulsion tank, machinery and duct circuits from shaving residues, mud, and all kinds of dirt and filth and in need any kind of detergent is usable. To get maximum performance and effective life span from the emulsion, physical cleaning of the system must be performed every three months. Emulsion should be taken to another container for this operation and replaced back after cleaning is over. Biological cleaning of emulsion is removing all kinds of bacteria from the system and it is good to apply a disinfectant to every point emulsion can contact. As described below more particularly, this process is performed by circulation of a disinfectant added to emulsion along with it. Tarmond suggests the system to be disinfected with the product named TAC 131 as stated below: 1 percent of TAC 131 is added to the emulsion to be replaced. (Supplementing should not be more than 1 percent as it can cause corrosion) Machine goes on regular operation for 6 hours thus disinfectant reaches every point emulsion contacts. (This process does not cause any time loss as the machine goes on its regular operation) At the end of 6 hours emulsion is thrown away. Physical cleaning of emulsion tank, machinery and duct circuits is performed. Tank is rinsed out with water. DISINFECTION OF SYSTEM WITH TAC 131 IN EVERY EMULSION REPLACEMENT PROVIDES 50 PERCENT OF IMPROVEMENT IN EMULSION PERFORMANCE AND EFFECTIVE LIFE SPAN.
How should maintenance be for maximum performance and long life span during operation of emulsions? In order to get maximum performance and long effective life span from emulsifiable cutting fluids during operation they have to be renewed regularly. Concentration and pH rates of emulsions should be daily checked and recorded. PH measurement can be done by pH papers and digital pH meters. PH paper is proper for daily pH measurements but a calibrated electronic meter should be used for more definite results in detailed monthly tests. Daily concentration tests can be easily done by refractometer. On the other hand emulsions get contaminated with foreign substances and this causes lapses in refractometer measures. Thus, concentration test should be applied with acid extrication method at least once a month. Any user can easily make daily pH and concentration tests. But those tests are not sufficient for testing stability and operationality of emulsion and at least once a month specimen should be taken and particularly tested in manufacturer laboratory, results should be considered with ideals and if needed mandatory interventions to emulsion should be made. Tarmond regularly takes specimens from products used by customers and records the progress of emulsions as seen in the report in appendix. Each report is given a lot number and registered in computer and is also saved in customer file to keep tabs on the progress of emulsions from the date they are first used. Besides daily pH and concentration tests, at least once a month emulsion conductivity, rust, bacteria, frothiness and smell tests should be made and favorable ones should be selected according to results and mandatory interventions should be made if needed. As usage performance and effective life spans of emulsions are directly affected by water used, water should also be tested regularly.
What is the importance of concentration control is emulsion, what are disadvantages of operating under low or high concentration? There are ideal applications concentrations of emulsions for the operations they are used and maximum performance can be obtained within these limits. Going beyond these limits may cause problems. Thus, concentration should be checked up daily. The easiest way of concentration checkup is using the portable refractometer. If concentration is high; Sticky deposits form on the item surface and workbench. There is smoke in emulsifying zone.
If concentration is high; Sticky deposits form on the item surface and workbench. There is smoke in emulsifying zone. Irritation may occur on operator’s hands (Especially with synthetic products). If concentration is low; Oxidation problems may be seen on items and workbench. Due to decrease of lubrication, sharpening period of cutting equipments shorten, intended surface smoothness quality cannot be obtained. Emulsion is less protective against bacteria propagation.
What does the conductivity rate of emulsions measure and how does it affect emulsion’s performance? Conductivity is an indicator of accumulated salts, different anions and cations in emulsion and those demolish the most basic, rust prevention and emulsifieing additives of the emulsion and prevent them from operating. As conductivity rate increases those additives may be totally deactivated and in this condition emulsion is no more usable. Conductivity increase in emulsions is a result of water supplementing. For this reason, water used in preparation of emulsions should be chosen meticulously. Conductivity can be easily measured by conductivity meter which also has portable types. Conductivity rate for effective operation of emulsions without problems is 60007000 microsiemens /cm. Beyond those rates various problems may occur with emulsions; Emulsion stability deteriorates Some oil may separate from the emulsion, creamatization occurs and while emulsion is circulated in the system it can leave sticky remainders in machinery and items. Emulsion causes oxidation problems. Conductivity of emulsion is directly related to the conductivity of the water used. If conductivity of the water is high conductivity of emulsion also increases in an instance and emulsion completes its effective life span in a much shorter period. Emulsion should be replaced when conductivity rate outreaches 7000 microsiemens/cm for a safe and nonproblematic operation.
What are the effects of foreign oils mixed in an emulsion? Way oils, hydraulic oils and any other kind of oils mixed into emulsion for some reason are called foreign oils and their entrance to system is an undesirable situation. Foreign oil rate in the system should not outreach 3 percent. On the contrary; They accumulate over the emulsion and cause it to suffocate and thus anaerobic bacteria propagate in emulsion causing it to cause molds It makes up proper nutrition conditions for anaerobic bacteria and causes them to propagate and cause molds Smoke occurs in emulsifying zone Emulsion stability deteriorates Detergency feature of the emulsion decreases Lubrication and refrigeration features of emulsion decreases It is circulated in the system with emulsion and leaves sticky remainders in machinery and items. When system is not operating, removing foreign oils accumulating in emulsion has prior importance for preventing the harmful effects stated above.
Why do emulsions get moldy, how can it be prevented? Main cause of molding in emulsions is bacteria propagation. And the main cause of bacteria propagation is foreign oils mixing in the system. Those oils accumulate over the surface and cause anaerobic bacteria and provide proper nutrition conditions for them in the lower parts and those bacteria cause molding. To prevent this, TARMOND TECHNICAL SUPPORT suggests; To use Tarmond’s extra bacteria propagation resistant scf Series and biostable products, To use Tarmond’s TARBIS K Series deep drawing and hydraulic system oils compatible with emulsions To regularly remove foreign oils mixed with emulsions, To circulate emulsion in certain times and ventilate it when machine is off.
Why do emulsions cause oxidation, how can it be prevented? Normally emulsions are formulated to prevent operating machines from rusting. If there is oxidation it is because: Concentration is low, There are inorganic salts in the system (causing high conductivity), Too much chlorinated water is used in concentration, Bacteria propagation in emulsion, Emulsion has fulfilled its effective life span and decomposition has started. If emulsion is causing rust it has to be replaced immediately. On the contrary irreparable oxidation problems may occur in the machinery and items. TARMOND TECHNICAL SUPPORT SUPPORTS YOU IN ANY OXIDATION PROBLEM, OFFERING YOU QUALIFIED PRODUCTS.
What should be the features of water used in preparing emulsions? Mineral oil based and halfsynthetical products form emulsions with water and synthetical products form the solution. Both oil based ones and synthetical ones are used in approximately 5 percent (38 percent) concentrations. This means there is 5 kilos of metal process fluid and 95 kilos of water in 100 kilos of emulsion. Thus, in order to operate emulsion free of problems and to get long effective life span, water to be added to emulsion should be chosen meticulously. For those kinds of applications water conductivity, permanent hardness and pH degrees should be between certain limits in general. Both oil based ones and synthetical ones are used in approximately 5 percent (38 percent) concentrations. This means there is 5 kilos of metal process fluid and 95 kilos of water in 100 kilos of emulsion. Thus, in order to operate emulsion free of problems and to get long effective life span, water to be added to emulsion should be chosen meticulously. For those kinds of applications water conductivity, permanent hardness and pH degrees should be between certain limits in general.
What are the effects of conductivity of water on the emulsion prepared? Conductivity of water is stated as microsiemens/cm and it expresses ionics in water such as calcium, magnesium, sulphate, chlorine, potassium. Water is as conductive as those ionics exist in water. When used for preparing emulsion these ionics dilute the effects of rust, preventing and emulsion producing additives in the formulation of product added to water. For this reason, ionics in water used for preparing emulsion should not exceed certain limitations, namely conductivity rate should not be over 500 microsiemens/cm. On the other hand, emulsion fulfills its effective life span when conductivity rate is 60007000 microsiemens/cm. Creamatization and oxidation problems occur in emulsions. Under normal circumstances, emerging emulsion’s conductivity is about 10002000 microsiemens/cm when prepared with water having 500 microsiemens/cm conductivity and emulsion supplementations prepared with that water reaches 60007000 microsiemens/cm at least within 68 months. On the other hand, conductivity of an emulsion prepared with high conductivity water is 30004000 microsiemens/cm from the beginning and it reaches 60007000 microsiemens/cm in a short while and emulsion fulfills its life span in a short while.
What does it mean that water is hard and how does it affect the emulsion prepared? Minerals like calcium and magnesium in water dilute the effects of emulsion producing additives in metal process fluids and prevent the fluid from emulsifying with water. In emulsions prepared with such water some oil separate from emulsion and float on the surface. Thus, lubrication, rust preventing and refrigeration features of water are diluted. By the way, minerals like calcium and magnesium in water are such a good nutrition for bacteria and bacteria propagate in emulsions prepared with such water in a short while. Bacteria cause molds as well as dilution of the effects of rust preventing additives in emulsion and oxidation problems occur. For those reasons, hardness of water used in emulsion preparation should not exceed 20 French Hardness in order to operate emulsions free of problems and to get long effective life span. WHATEVER SOURCE IT HAS (DRAW WELL, CITY WATER. ETC.) WATER QUALITY IS INCONSISTENT. TARMOND TECHNICAL SUPPORT SUPPORTS YOU BY TESTING YOUR WATER REGULARLY AND OFFERING ADVICE.
