Retrofit and ready for better bending
A refrigeration systems manufacturer shrinks cycle time with new press brake tooling
Kysor/Warren, Columbus, Ga., cutomizes the refrigerated display cases and refrigeration systems for its customers. Unfortunately, it didn't have a very efficient bending operation to keep up with the production demands related to its diverse product line. To remedy the situation, the company purchased Wila precision ground tooling and installed hydraulic clamping systems on its press brakes.
Kysor/Warren knows a thing or two about efficiency. The company knows production efficiency.
It has been manufac-turing commercial refrigeration equipment for more than 125 years. Today the maker of refrigerated display cases and refrigeration systems for supermarkets has more than 500,000 square feet of manufacturing space in Columbus, Ga. In addition, it has 100,000 sq. ft. to store purchased parts, and 140,000 sq. ft. dedicated to finished-goods storage. With its manufacturing expertise honed over the years, the company knows how to transform its retail customers‘ refrigeration visions into sheet metal realities in a matter of weeks.
The company knows energy efficiency. Realizing that on average 60 percent of supermarket retailers’ operating expenses are tied to running refrigeration systems, Kysor/Warren is committed to sustainable production practices and developing environmentally responsible refrigeration technologies.
An example of the latter is the STRATUS line of merchandise display cases (see Figure 1), launched in May 2009. The new line features a modular design and a sleek appearance, but more important it has glass doors that provide ample room for product display and help to keep the chilled air from escaping. The company believes the product line will be very popular as retailers look to upgrade their commercial refrigeration offerings.
Another example of the company’s energy efficiency is the introduction of a carbon dioxide (CO2) refrigeration system in 2009. Relying on naturally occurring CO2 instead of a man-made refrigerant, the system reduces the equipment’s global warming potential by as much as 50 percent when compared to similarly sized, more traditional systems, according to Kysor/Warren. The Environmental Protection Agency has recognized Kysor/Warren’s efforts with a GreenChill Distinguished Partner Award.
The company knows supply chain efficiency. In January 2011 it became a part of Heatcraft Worldwide Refrigeration, located in Stone Mountain, Ga. The new combination creates a single source for all of the grocery store retailers’ refrigeration needs, from display cases to commercial condensers and evaporators.
“Kysor/Warren is very good at designing and manu- facturing products that meet maintenance goals and that of reconstruction, store designers, merchandisers, equipment buyers, and store owners,” said Mechelle Clark, the company’s marketing manager.
A lot of that feedback from customers results in requests for customized products. And as any job shop will tell you, an increase in special orders creates scheduling and production challenges on the shop floor.
To meet the requirements of all of its customers yet maintain its own corporate goals regarding product development, Kysor/Warren needed a more efficient means of producing the metal parts for its diverse product line. More specifically, it needed to upgrade its bending operations.
Kysor/Warren has a total of 20 press brakes, mostly Cincinnati and LVD machines, ranging in size from 55 to 230 tons. Most of the press brakes were purchased in the early to mid-1990s, but a couple were purchased within the last year.
Press brake operators typically work with galvanized and stainless steel blanks that can be as large as 150 by 48 inches. Material thicknesses are from 0.016 to 0.099 in.
The operators form a variety of angles, including hems and offsets, for the many different shapes and sizes of commercial refrigeration units, according to Derek Burgess, a CNC programmer with Kysor/Warren. Unfortunately, most of the press brake bending had been done with worn tooling that threatened the quality of bends and made setups more difficult and time-consuming than they should have been.
“We were also looking for reliability because in the past the tooling had relatively poor life. We needed to improve productivity with precision- ground tooling and increase brake capacity to meet peak season requirements,” Burgess added.
Toward the end of 2010, Kysor/Warren invested in Wila USA press brake tooling. It also had the press brake tooling and accessory manufacturer retrofit the press brakes with hydraulic clamping systems and Dutch hydraulic hemming tables, which act as die holders for both standard dies and hemming dies.
The Kysor/Warren manufacturing team first placed the new tooling, clamping system, and hemming table on one press brake and let the operators try out the new setup.
“After seeing the results, we had operators asking when their machines would receive the tooling upgrades. Not only did it make their jobs safer, but it made setups much easier,” Burgess said.
Soon after the tooling was rolled out to the press brakes and the more than 50 press brake operators were trained to use the new tooling, the bending department began to show production improvements (see Figure 2). Even with large parts (see Figure 3), bending consistency and quality improved; it was also much safer for the press brake operators because the large tooling that they previously used could be as long as 13 ft., occasionally requiring a forklift for loading.
Burgess said perhaps the best example of how bending efficiency has improved is the hemming operation. Before the retrofits, only one press brake had the tooling necessary to perform hemming. So the operators had to move their parts to that one machine to make hems.
“Once we purchased the hydraulic hemming toolholder, we were able to perform all the steps required to complete the part in one setup at one machine. This increased our throughput dramatically,” Burgess said.
The same could be said for all press brake operations. Burgess estimated that bending productivity has increased between 25 and 50 percent for those brakes with the new tooling upgrades. The biggest impact has been in the area of setups for short-run jobs, he said, because operators now require only one to five minutes to prepare a press brake for a run, rather than the 15 to 30 minutes of downtime that was once the norm. Quality also has improved for parts of all sizes because of the upgrades (see Figure 4), he added.
The only challenge for press brake operators occurred when some of them simply forgot to lock their tools into the beam (see Figure 5) before attempting to form a part. To resolve that issue, the maintenance department installed a safety point that won’t allow the ram to move unless the tools are locked into their holders.
Kysor/Warren now knows new efficiencies in its bending department. The precision-ground tooling provides better bending accuracy, even across the very long parts, and setup and changeover time has been reduced greatly because of the flexible tooling design and the ease of changeout associated with the hydraulic clamping system.
“We strive to be a world-class leader in the development of new products and use world-class manufacturing technology to manufacture them,” Burgess said.
Kysor/Warren’s new press brake upgrades put it in a position to do just that, even as it continues on a never-ending journey to seek out further efficiencies.
The FABRICATOR is North America's leading magazine for the metal forming and fabricating industry. The magazine delivers the news, technical articles, and case histories that enable fabricators to do their jobs more efficiently. The FABRICATOR has served the industry since 1971.