How to solve the surface residue problem of metalworking fluid?
January 21, 2022
One of the primary functions of metalworking fluids is to provide parts with inter-process rust resistance, which is accomplished by leaving a rust-resistant film on the metal surface. So, the discussion here is not whether metalworking fluids leave residues, but whether residues are left on purpose. The residue of metalworking fluid on the parts will affect the amount of metalworking fluid taken away, the function of use, the filtration, the cleanliness of the machine tool and parts, and the replacement of the grinding wheel of the grinding machine. The residues on the surface of the metalworking fluid machine tool may stick to iron filings and grinding wheel ash. When they are stuck by the residue, the iron filings and grinding wheel ash will act like scrapers and abrasives, resulting in seals, guide rails, and abrasives of the machine tool. Wear on sliders, cams, tappets, etc. Therefore, the residue should be removed during machine maintenance.
1. Residues can be easily and effectively observed by the following methods
Fill a glass dish with 5 ml of cutting fluid concentrate and let it expose to ambient atmospheric conditions for a month or more.
In general, the longer the exposure time to the atmosphere, the better to see the result of oxidation of the cutting fluid. A properly formulated cutting fluid is antioxidant. This experiment can also be carried out by adding different machine tool oil spill contaminants and minerals in the water at the same time.
2. Classify the results of the residue experiments Sort by appearance | Residue Type | Influence Situation |
| Liquid Residue | Optimal residue morphology, especially on machine tools, also relies on lubricant splash, which is acceptable. |
| Soft Form | Residues of this form generally do not affect the function of the machine tool, but can stick to iron filings and grinding wheel dust. |
| Hard Residue Form | This residue can cause problems for damage to the machine, and it can make the limit switches of the machine inoperable. These hard residues become hard with prolonged exposure to air. |
| Gel State | This configuration can cause the machine to have problems with sliding. |
| Crystal Form | As long as the crystalline residue is easily re-dissolved in water, this residue is not a problem for most machine tools, but it is a hindrance for machines that use grating scales for positioning. |
| Mixed Form | Residues are common. Due to the many ingredients in the formula, various chemical components can produce residues in different forms. It is very important to check the residue to make sure it keeps the machine tool running properly. |
Classified by solubility
| Soluble Substances | Influence Situation |
| Water | Any residue that is soluble in water is also soluble in the working fluid, and the residue will be easily washed away by the working fluid. |
| Working Fluid | Ideally, all residues left on or around the machine will be easily or with minimal labor Aid in redissolving in the working fluid. |
| Solvent | It is impractical to use solvent cleaning machine tools to keep machine tools clean, increases cost and lacks the operability of regular cleaning. |
These classifications will have a certain degree of partiality, but when used for comparison of cutting fluids, they still have certain reference significance. Through the classification of these residues, we can see that if the residues of the machining fluid have affected the production process, the The machine tool has had an adverse effect on the workpiece, etc., and it is difficult to fundamentally solve the problem through simple maintenance.
Carryover can be minimized by: 1. Select the appropriate processing fluid so that the residue is acceptable in your application, and its functions in other aspects are also more in line with your requirements 2. Run the machining fluid at the proper concentration. If you use a working fluid at twice the minimum concentration required for the job, you will also get twice the residue 3. Use high-quality water mixing fluid as much as possible. "Hard water" is one of the main sources of cations, which can react with components in the machining fluid to form water-insoluble residues 4. Remove residue and metal chips from the tank in time. They may also be a source of cations 5. Periodically "flush" the machine with machining fluid. Redissolves residues formed by water evaporation. This also reduces the amount of make-up fluid. In conclusion, regular cleaning makes it easy to keep the machine clean 6. If there is a more difficult residue on the machine tool. Lightly spraying or brushing a compatible surfactant on the machine surface to allow it to penetrate into the residue before cleaning can be very helpful.
