Self-cleaning filter ups machining performance

A new type of self cleaning disc filter has been developed that removes harmful metal chips from machine tool coolant more effectively than current alternatives. Dean Palmer reports

A new development in self-cleaning disc filter technology has opened up opportunities for removing harmful metal chips and fines from the coolant used in machining centres. Disc cleaning filters are well-established as a method of removing metal chips from coolant, but this latest development, the MCF unit from Axflow, features a permanent, self-cleaning slotted filter media. The unit incorporates a spring-loaded cleaning disc that continuously regenerates the open area of the filter media. According to Axflow, its MCF unit has a more efficient cleaning cycle and the purge frequency can be adjusted to meet the customer's needs. Extending the cycle times greatly increases the life of the moving parts and allows for greater concentration of chips to be discharged. Coolants are used on machining centres to lubricate, cool and flush contaminants away from the part and tool. Typically, the fluid is collected under the machining operation where it is routed through a set of weirs to separate out the large particulates. A pump then sends the fluid to a housing that contains cartridge filters, which are removed and replaced on a regular basis. The recurring costs of the cartridges, the cost of disposal, the labour for change out and machining downtime can become expensive. Other problems include tool life, the inability to separate harmful chips from the fluid, which can result in inferior quality parts, and safety concerns. The magnetically-coupled drive mechanism moves the self-cleaning disc, thereby eliminating the need for shaft or external drive seals. And, without the motors and actuators mounted on the lid of the filter unit, the filter chamber can be readily accessed for the rapid removal of the screen, optimising production uptime.