![]() ![]() The build-up of foam can severely impede the heat dispersion capacity of the cutting fluid. The problem here can be more insidious than mechanically caused foaming because the bubbles tend not to collapse over time, resulting in the formation of so-called stable foam. The second source of foaming has to do with the chemical make-up of the cutting fluid itself. If the bubbles collapse after a short while, the foaming is likely due to some air in the system. Bubbles caused by air entrainment will usually dissipate on their own, and a popular test suggests putting a sample in a jar and shaking it. If the problem persists, checking the entire circulation system for leaks can sometimes unearth the cause. Correcting for this situation is relatively straightforward by making sure the pump inlet is immersed in fluid throughout all the stages of the machining cycle. Similarly, leaks anywhere in the piping system can also suck in air and produce the same phenomenon. Improper sump levels, for instance, are thought to expose pump intakes to air that can be drawn in through the impellers and cause bubble formation. The first – mechanical – is caused by air being drawn into the system from somewhere. Specialists familiar with the peculiarities of cutting-fluid foaming generally attribute its existence to two sources. In some instances, these bubbles can impede the view of the operation and, worse, hamper the effectiveness of the fluid to carry off heat. Image credit: Dmitry Kalinovsky/ĭepending on the conditions of the system, the makeup of the cutting fluid, and the particulars of the machining process, bubbles can form in the fluid. Nozzles direct the cutting fluid into the work zone, after which it collects in a sump where it is filtered and pumped back up to the work area in a closed, continuous process. They serve to cool the work, extend the life of cutting tools, and remove swarf from the operating area. Cutting fluids used in CNC machining are often a mixture of water and water-miscible agents.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |