Page 21 - MetalForming June 2012

Anatomy of a Laser-Cutting Automation System
A variety of fixed and scissor-lift loading tables and multiple shelf stocker configurations are available to store sheets and plates up to 1 in. thick.
Management line controllers execute the cutting schedule, manage raw material inventory, facilitate loading and unloading of individual machines and provide production data.
Traversers take material from
the storage location and loads
it to the appropriate laser-cutting machine.
Not shown are safety fencing and interlocks required to meet government regulations.
Laser automation systems are typically modular in design and permit the addition of new machines and other components to the system.
There are many offload configurations available,
including multiple tables that permit completed work to be seperated so specific workpieces can be pulled from the system and a variety of towers to store completed work.
Capacity Climbs
50 Percent or More
Automation systems allow capacity to flex through use of lights-out opera- tion without the burden of adding manpower. Automation also makes one-piece flow more practical, while producing short-run efficiencies that will reduce nonvalue-added fabricating time. The bottom line: Fabricators that automate their cutting machines typi- cally increase capacity by 50 percent or more compared to standalone machines, with significant reduction in lead times.
The key questions to consider when investing in cutting-machine automation:
1) Do you really need automation? 2) What type of automation is needed? 3) What should the initial machine
configuration look like?
4) What challenges lie ahead when
implementing an automation system?
1) Do You Really Need Automation?
The key benefits to automating the laser-cutting process are speed, con- sistency and capacity. An operator loading a machine manually will take about 35 percent longer than an auto- mated loader. The automatic loader does not get tired and does not take breaks—it always is available, and the amount of time between each cycle—
load/unload time—is consistent and predictable. Further, automation allows a fabricator to increase capacity with- out adding labor.
All three key benefits—speed, con- sistency and capacity—fit snuggly with- in a company’s lean-manufacturing scheme. They reduce rework and the need to build inventory, make workflow more consistent and help make pro- duction planning more predictable. The key deliverable: quality throughput.
To identify the specific benefits of automation and develop a cost-justifi- cation model, a fabricator must project near- and long-term production requirements. This can be done by selecting typical nests for common materials and thicknesses, and con- ducting time studies for cutting those nests. Keep in mind that there may be a significant difference in the process- ing time for older machines, as opposed to machines equipped with the latest technology.
Today’s leading-edge laser-cutting machines can automatically establish cutting parameters, and change nozzles and torches with lenses to accommo- date various material types and thick- nesses. Thus, these machines will run using optimal parameters, resulting in dramatically increased efficiency and throughput as compared to older machines.
Most laser-machine manufacturers can help fabricators forecast cut times. They also can help calculate and opti- mize cycle times and maintenance intervals, to better evaluate the net impact of automation on throughput. The comparative value of throughput calculated with standalone machines— including the possibility of adding an additional shift—and utilizing automa- tion will go a long way toward calcu- lating the return on investment (ROI) for implementing an automated sheet- handling system.
2) What Type of Automation?
Selecting an automated material- handling setup is not a one-size-fits-all proposition. Most automation systems use a modular or building-block approach that enables future growth. Key determining factors: desired throughput and the amount of varia- tion in workpiece material type and thickness.
Fabricators can select from three types of automation solutions: pallet changer (or shuttle table), load/unload system, or a flexible manufacturing system (FMS). A pallet changer installed on a standalone laser enables the oper- ator to stage one sheet of material while the laser cuts another sheet. While this basic type of automation is limited since it requires an operator to load
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