Medical manufacturers count on filtering chip conveyors for precise product finish
Flotec is a company that makes regulators and other essential components of medical equipment used by hospitals, neonatal ICUs and EMS services. These components address respiratory failure, stroke, mass casualty, cardiac arrest and other critical events.
The company provides parts for both OEMs and end users around the globe, and these products are virtually all custom created. At last count, the regulator line alone boasted over 4 trillion unique items.
Headquartered in Indianapolis, the privately held company began life in 1983 as an offshoot of a fluid power distributor. Their major customer required respiratory equipment that could not be found anywhere. In response, Flotec was created to manufacture custom respiratory products, a unique niche they still occupy.
COVID-19 increased production demands
As the Covid-19 pandemic spread, the demand for Flotec’s products pushed the company to maximize its output and rely even more heavily on lights-out production. As is often the case, successful overnight production required that every part of the manufacturing process be trouble-free. When inefficient chip management caused interruptions, Flotec brought in LNS to help solve the problem.
As part of its ongoing program to continuously improve production, the company had recently installed a Star SK-51 CNC lathe with 2 turrets and 2 spindles. Each turret operates in the X, Y & Z axes making it an 8-axis machine. This was the workhorse Flotec needed for lights-out operations.
The CNC machine came equipped with a standard belt-type chip conveyor that may have been adequate in some services. But, Flotec's production primarily relies on milling 6061 and T651 aluminum, some 350 brass alloy and 303 stainless steel. The process created very fine chips that passed through the chip conveyor and into the recovered coolant. The fine chips then flowed into the coolant tank filtering system.
The SK-51 has 4 high-pressure filter baskets and an additional basket that catches the fines before they get into the coolant pumps. These chips filled the filtering baskets causing lower coolant levels. Meanwhile, chips accumulated in the coolant tank, thus displacing coolant volume. This loss of volume set off low coolant alarms that reduced coolant flow through the high-pressure delivery system. As a result, the part being machined and the cutting tool were insufficiently cooled. Therefore, leading to shorter tool life and, more importantly, degraded part finishes.
Filtering chip conveyors contribute to meeting production demands
The LNS solution was to replace the existing conventional hinge-belt chip conveyor with the LNS Turbo MH 250 filtering chip management system. A unique, self-cleaning filter box design enables MH 250 filtering chip conveyors to remove virtually all sizes and types of chips. For example, fine aluminum and brass such as those produced by Flotec’s milling process, while filtering coolant to 250 microns. Other MH models filter coolant to as little as 50 microns.
According to Flotec President Brian Davidson, “Before replacing the original chip conveyor with the LNS filtering model we were getting about 75 units of production during the day and 40 when running lights-out overnight. We now produce 75 units per 9-hour day and 125 units of production from 5:30 PM when we turn off the lights until 8:30 the next morning.
We set up for lights-out at end of the workday and the machine is still making parts when the staff arrives the following morning. As a result, we’ve more than doubled the output of this CNC machine from approximately 2875 production units per month to 6000 units per month. We were able to achieve production efficiency simply by replacing the original chip conveyor with the LNS MH 250 filtering chip conveyer.
There is also less maintenance. We now clean out the coolant tank only once per month. Before switching to the filtering chip conveyor, we were cleaning out the 2 SK-51 filter baskets 3 to 4 times per day. Now we only clean them twice weekly. Likewise, we’ve reduced the high-pressure filter baskets (2 + 2) cleanout from daily to once per week.”
Flotec also found that without the fines displacing and degrading coolant, the high-pressure system is able to perform properly. Therefore, protects critical part finishes, reduces tool wear and extends coolant life.
Meeting customer expectations
“Product finish is very important to our customers. We have multiple ISO certifications. In addition to making parts for the U.S., we produce products to the British National Standard, Japanese standards, Scandinavian SSI standard, Deutsche Industrial Norms and about 13 other international standards. We’re able to manage this diverse workload by programming macros into our machines. In this case, we can make parts to the various standards in a single production run without changing machines.
LNS was very helpful and easy to work with on this project. We already had non-filtering LNS chip conveyors on a few of our other machines, so we had confidence in their products. Based on our experience with the MH 250, we plan to replace a number of our other chip conveyors with LNS filtering chip conveyors.
You can’t get the best production out of a CNC machine if there is a weakness in the overall setup. This is particularly important when it comes to lights-out production which is critical in a high-demand environment. After all, you don’t put an in-line 4-cylinder engine in a Ferrari and expect to win the race.”