Todd Hockenberry and Dave Sweet
Whirlpool boosts laser marking performance by giving PCs the boot
As a manufacturer of home appliances, Whirlpool had discovered the many advantages of laser marking at its more than 70 manufacturing and technology research centers around the world. With the right partner, however, Whirlpool was able to take laser marking to new levels of productivity and cost-efficiency.
Among the many applications for laser marking, Whirlpool used lasers to mark its logo and dial indicators on custom grills and stovetops. While the results were impressive, the process for getting the marks there was not. In fact, the legacy CO2 system that controlled the company’s lasers caused several expensive and time-consuming problems. For example, the system was PC-controlled and prey to common PC-related issues. In addition, the company had to physically attach the PC to the laser marking system on the manufacturing floor during operation.
While common in manufacturing environments, PC-controlled equipment also can be troublesome. Whirlpool’s PCs were no exception, and problems frequently disrupted production. For example, temperature fluctuations and other aspects of the industrial environment often affected performance and produced system glitches that halted line production. Raymond Kielhorn, lead Whirlpool project engineer, recalls, “We had computer-based problems regularly with our laser marking system. The slow cycle time of the marker we had in-house and the unreliability of the system forced us to go outside for our laser marking.” Other PC problems, such as disk failures and reboots, provided their fair share of headaches, too.
Although Whirlpool appreciated the benefits of laser marking in-house, the costs associated with persistent maintenance and downtime issues were unacceptable. “Whirlpool was spending up to $10 per part to have them marked by an outside vendor. Our laser-marked part volume is at least 1000 parts per week, so our cost to do the marking at a contract marking company was more than $10,000 per week,” states Kielhorn.
Because laser marking is highly valuable to Whirlpool for parts marking, traceability, and branding purposes, a different controlling system seemed to be the answer. Whirlpool turned to MECCO Marking and Traceability to design and create a new system that would be more reliable and versatile and free from the physical constraints imposed by the old system.
Ethernet advantages
MECCO’s project leader for Whirlpool visited the company’s production facilities and conferred with Kielhorn. At that point, LanMark Controls (Boxborough, MA, USA; www.lanmarkcontrols.com) was contracted to develop a fiber-laser marking-system design with an embedded control card. The laser marking system is designed to incorporate embedded controller technology to allow the laser to be LAN-operated. This solution provides the flexibility of several different modes of operation and features three configurations for maximum operational versatility.
One configuration of the system allows the PC to continue to communicate with the laser. However, instead of using an industry-standard PC-based or USB connection, this system features an Ethernet solution. The advantage of the Ethernet connectivity is that Whirlpool is no longer limited by the distance between the computer and the laser marker. The controlling computer can be located anywhere in the facility, from a central computer room to an engineer’s desk. Users now have the flexibility to operate the system, for example, to load jobs to the laser marker, remotely. In this mode, however, a one-to-one relationship from the laser to the computer still somewhat limits overall system functionality and versatility.
This one-to-one limitation was addressed by engineering a second configuration-networking mode. The system’s Ethernet-based connectivity allows Whirlpool to network a computer system to control a group of laser markers. By providing each laser marker with its own IP address, each marker is now a node out on the network. Whirlpool can control each laser from one central computer. By using the Ethernet connection, the central computer and other associated desktops/laptops can be located anywhere off the factory floor and still control the system-from cubicles to central control rooms. The difference in this networking configuration, however, is that the relationship from computer to laser is now one to many.
A third configuration, known as the embedded mode, was created. In this configuration, a job is stored locally to memory on a laser control card with an on-board processor. The advantage of this mode is that the control card is mounted in the laser control box, not in the computer. The operator can load jobs to the card using either a laptop or a memory stick. In both cases, the job is stored to the memory on the card, and then the operator can use either a handheld pendant to load the job or a programmable logic controller (PLC)-a commonly used device in the automation world to control multiple operations and/or equipment. The PLC can use the API command set on the embedded controller, the LEC-1, to load and execute jobs.
Whirlpool uses the system in the third, embedded-mode, configuration. Now, its operators create a job on a remote PC and save that job to a memory stick. They then go to the laser marking system on the factory floor where they use the hand pendant to load the job from the memory stick. Once the job is loaded, they use a PLC to operate the laser.
This Ethernet-based, embedded-card system totally eliminates the need for Whirlpool to attach or connect a PC to control the laser marker on the manufacturing floor. More important, this laser marking system delivers several critical benefits. The system has virtually eliminated production line downtime caused by computer malfunctions. In addition, it has decreased lifetime laser-marking-system costs by reducing maintenance. Better yet, it has increased productivity through its remote-control capabilities. A critical added benefit is that the fiber-laser system has enabled Whirlpool to mark parts at a much higher rate, up to four times faster than the previous system according to Kielhorn, and with a better quality than it could get from the CO2 marking system.
Todd Hockenberry (todd.hockenberry@ meccomark.com), vice president sales & marketing, and Dave Sweet, vice president operations, are with MECCO Marking & Traceability (Cranberry Township, PA; www.mecco.com).