Cutting fluids are created for metalworking and machine work. They can be categorized into soluble oils, straight oils, synthetic oils and semi-synthetic oils. These cutting fluids are usually made out of petroleum derivatives, plant oils or animal fats. The main objective is to ensure that a work-piece maintains a consistent temperature; they serve as coolants. In addition, they help to reduce the friction of cutting tools and thus prolong their life span. Though cutting fluids serves various purposes there are problems are associated with them which need solutions for optimal results. Here, we look at some of the common problems of cutting fluid and their solutions.
Foam is one of the most common problems of cutting fluids. It is usually created as a result of entrainment of air in a fluid through chemical or mechanical process. You cannot solve foam cutting problem before establishing the process which caused the problem. It is recommended that you put enough fluid in a covered container and then shake the fluid vigorously for few seconds. If after shaking the form dissipates quickly then the cause is mechanical and on the other hand if the foam does not dissipate rapidly then the issue is chemical. To solve a foam problem caused by mechanical process, sufficiently cover the pump intake with fluid as well as fill the reservoir to normal operating level. In addition, ensure that there is no leak or crack in the pump’s housing. This will ultimately eliminate the foam issue.
Alternatively, if the cause of the problem is chemical, the first thing that you need to rectify this problem is to evaluate the source of water utilized in diluting the cutting fluid. Soft water increases the potential for foaming with some cutting fluid. If the issue is the softness of water, then you can either change the cutting fluid used or the quality of water to eliminate the foaming problem. If the quality of water is okay then the concentration of the cutting fluid might be the cause of foaming. High concentrations of cutting fluid tend to increase the propensity to foam. If concentration of the cutting is the issue then dilute by adding some water to the system.
It is worth noting that eliminating foam problems in cutting fluids will result to increased performance of the machine tool as well as higher throughput.
Rust or Corrosion
Corrosion is another common problem of cutting fluids. It is caused by an electrochemical reaction between metal surface that is susceptible to rust and its environment (oxygen and water). Corrosion results in reduced machine tool longevity and poor performance of the machine tool. This will ultimately lead to ruined customer relations and lost sales. Metalworking fluids offers corrosion protection by blocking moisture or oxygen from the metal surface. However, if corrosion occurs you need to find a way of addressing the situation by analyzing a plethora of factors to establish the root cause of the problem. If the concentration of the cutting fluid is lower than 4% then corrosion protection components are inadequate to prevent corrosion of the metal surface. If the concentration is above 4% then pitting might be the cause of rusting. This is when the cutting fluid contains excess ions and minerals. Other things that can cause corrosion are too low PH levels, fluid reservoir full of swarf and chips and inappropriate machine tool grounding. To deal with the problem of corrosion, establish the cause so that you can solve the problem permanently. Replacing cutting fluid on a regular basis only solves corrosion issues in the short run but to have a permanent solution deal with the problem.
Residues are another common cutting fluid problem. They can be divided into product residues and insoluble deposits. If a cutting fluid picks up contaminants or undergoes chemical changes then insoluble deposits residue problem is likely to occur. These deposits usually interfere with the performance of the cutting fluid. Product concentration, water hardness, low humidity and oil contamination are major causes of product residues. To resolve the issue of residues, you can use deionized water to minimize the building up of mineral salts that significantly contribute to residue formation. You can also use premix eliminate residues left on the machines. Residues contain highly concentrated contaminants and fluids which can cause dermatitis (skin irritation). Ensure that you wash off residues on a regular basis to avoid accumulation of the same since it can cause severe harm even to your body.