Fine bubbles improve machinability and also prevent the water-soluble cutting fluid from spoilage and purify it.
Major achievements related to machine tools
● Improvement of grindability machinability
● Separation of lubricating oil and cutting oil
● Cleaning and purification of coolant tank
● Purification of cutting fluid and spoilage prevention
Application examples of fine bubbles related to machine tools
The number of inquiries about the use of fine bubbles for machine tools has been increasing since last year. There have been remarkable effects in aluminum processing and grinding. We will show you the current application example here.
Aluminum built-up edge peeling effect
Fine bubbles can peel off the built-up edge accumulated against cutting tool during aluminum processing and thus improve the surface roughness of aluminum products and lower the defect rate.
The mechanism of peeling is considered to be due to the force and shock waves when the fine bubbles burst. Since the cutting edge at the time of cutting becomes close to 800 °C, fine bubbles peel off the built-up edge due to the rapid thermal expansion and rupture. It is also possible that the heat radiation effect of fine bubbles makes it difficult to form the built-up edge. Furthermore, it is also possible that the fine bubbles are thermally expanded, creating a condition (space) in which it is difficult to generate a built-up edge against the cutting edge. It will be all clarified in the future research.
In the automobile industry, aluminum parts are increasing due to the weight reduction of automobiles. In the future, it is expected that fine bubble generating nozzles will be permanently installed in machine tools in order to reduce the defective rate of aluminum products.
Coolant tank cleaning
Fine bubbles can inhibit the generation of biofilm generated on the inner surface of the water-soluble coolant tank. Fine bubbles are also used in aluminum processing plants for automobile parts to remove fine powder caused by aluminum processing that adheres to the inner wall of the coolant tank together with biofilm.
Hence, these will lead to the inner surface of the coolant tank cleaning and coolant liquid purification.
Mirror polishing of silicon wafer
Fine bubbles improve the surface roughness by always securing the cutting edge of the grinding wheel. OK Nozzles are used in various machining processes of silicon wafers. PTFE OK Nozzles are used in processes not suitable for using metal ions. Please see the processing example shown below.
Shortening the polishing time for small metal molds
The depth of cut can be increased from 4 μm to 7 μm by polishing the terminal metal mold. It is considered that this is because the fine bubbles remove the chips and the cutting edge is always secured. There is a possibility that the machining time can be significantly shortened by devising the conditions of generating fine bubbles and also of grinding.
Floating separation of lubricating oil
If lubricating oil is mixed in the coolant, it can be removed by floating separation using fine bubbles.
Spoilage prevention and malodor suppression of water-soluble coolant
Fine bubbles prevent spoilage by activating aerobic microorganisms in the tank. At the same time, you can suppress bad odors. The above effects can be easily obtained by installing a fine bubble generation nozzle in the coolant tank or in the middle of piping to generate fine bubbles.
Comment from the developer Mr. Matsunaga
I am deeply moved as I have been involved in the design of exclusive machine tools for 40 years. Started researching fine bubbles in 2000 and became a regular member of the Japanese Society for Multiphase Flow and of FBIA (Fine Bubble Industry Association) from the beginning of its establishment. During this period, I have seen the research flow of fine bubbles and the development of generators, the progress in the development of fine bubble measurement technology and measurement equipment. Also, as an FBIA member, I have experienced the international standardization of fine bubbles.
Loop flow fine bubble generation OK Nozzles have been researched and developed, and the generation efficiency has become one of the highest in the world. The amount of ultra-fine-bubbles (nano bubbles) generation is 400 million pieces/mL. Peak diameter : around 110nm. These invisible ultra-fine-bubbles are thought to be playing a major role in peeling and preventing formation of the built-up edges and improving grindability and machinability.
Fine bubble has been popular in the field of machine tools for about 6 years, and I am very much looking forward to the breakthrough in the near future and the permanent installation of fine bubble generating nozzles in machine tools. It is multiple effective for energy saving Improving grindability and machinability and reducing fraction defective using fine bubbles have multiple effects that save energy in their own use
Using fine bubbles will result in multifaceted effects that save energy by improving grindability and machinability and reducing the defective rate.