Coolant is a substance used to reduce, regulate, cool the temperature of substances or a system. It can be in form of liquid or gas.
MACHINE COOLANT
Machine coolant is primarily used for temperature control through cooling and lubrication of the workpiece. It works by extracting the heat from the working piece e.g cutting tool, to prevent the tool from over heating thereby wearing off easily. There is water coolant, water with oil coolant and chemical machine coolant which includes synthetic and semi-synthetic coolant.
WATER WITH OIL COOLANT FORMATION
Water and oil are used together as machine coolant. Water is a cooling agent, it is capable of cooling a substance 2.5 times faster and effectively than using oil. Oil serves as a very good lubrication but they are not good cooling agents like water. For highly effective result, water and oil is mixed. The oil used must be soluble in water and capable of preventing corrosion, e.g delox oil.
QUALITIES OF A GOOD COOLANT
SMELL: - Coolant is usually stored for a long period of time as it can be re-used, it must be free from offensive odor for proper management, use and disposal.
CLARITY: - Viscosity of the coolant is important so the work operation will not be obstructed. If the coolant has low viscosity, it will yield to suspension of dirt on the work piece which can limit work being carried on.
SAFETY: - Due to contact with the body while working, it is necessary for the coolant to be safe and not toxic while in contact with the body.
Misting: - The coolant should be incapable of misting to preventing being inhaled by machine operator and polluting the environment.
CORROSION: - A good coolant should inhibit corrosion.
FUNCTIONS OF COOLANT IN MACHINE
Coolant is necessary during machines working operation such as turning, facing, grinding, cutting, drilling, etc. Machines generate heat during operation and there is usually friction which could cause injury or damage to the work piece and tool used in operation.
TOOL LIFE EXTENSION: - The use of coolant extends tool life, there is less deformation and wear of the tool, leading to longer tool life.
REDUCTION OF FRICTION: - As the tool comes in contact with the work piece there is usually friction. The lubricant in the coolant reduces the external and internal friction.
REMOVAL OF HEAT: - Excess heat is generated during working operation, the heat is hot enough to burn ones skin and flying chios could get in contact with the eyes. Coolant reduces and removes heat from the tool, chip and work piece and prevents them from exceeding critical temperature range during operation.
REMOVAL OF PARTICLES: - Metal chips and cuttings from the tool are removed by the coolant, if they cluster around the tool and work piece it could mar and disrupt the finishing and quality of the work piece.
NOTE
Coolants can be excessively lost if mixed in wrong proportion, being too concentrated and is over used.
I am an Engineering student, I just completed my industrial training and wish to share what I learnt.
