By Aaron Hand, Managing Editor
For one reason or another, machine builders might find that their application is not best served by an off-the-shelf enclosure. They could be constrained by temperature, space, or any number of particular needs.
"By the time they get to us, they've found they need something special," says Mark Lovell, team leader in the proposal department at Pepperl+Fuchs (www.pepperl-fuchs.us). They have tried standard enclosures, and find that there's too much work to complete on their end, whether trimming the size or punching more holes in the structure. "Any time you cut holes or add welded parts, you're going to add cost."
In one case, a company that makes the machines that prints and folds the papers typically found in a prescription box found that it needed several different enclosure sizes to house the controls on the machine, says Tom Moran, president and owner of Midwest Plastic Fabricators (MBF, www.midwestplasticfabricators.com). "They had cobbled together a variety of standard enclosures," he says, with different sizes coming from different manufacturers. "They all looked a little different, and then they still had to put holes in them. They tried to adapt to what was available."
Instead, MBF was able to make a variety of enclosures that looked like they belonged to the same family. All the necessary holes are done online as the enclosure is made, which is much less challenging than doing it after the fact, Moran adds.
Washdown situations always have a need for custom enclosures, Lovell notes. "We see a lot more requests in the stainless variety vs. painted steel," he adds, pointing to petrochemical, chemical and pharmaceutical industries, where materials tend to melt paints, and there's more need for corrosion-resistant materials.
Although stainless steel has been a popular standby for washdown environments, non-metallic enclosures are an excellent substitute, Moran says. Enclosures built with PVC or polycarbonate, for example, are non-conductive, non-corrosive, easier to work with, and are lightweight.
Moran describes one application in the meat-processing field, in which a hog carcass hangs from a hook and moves along on a chain conveyor while a skill saw runs up and down vertically to split the carcass in half. The machine controls are in a large enclosure that's mounted on a swivel; the operator swivels the controls over to do the programming, then pushes it out of the way again. "It used to be stainless steel, which is really heavy," Moran says. "We make them out of polycarbonate, which gives them the ability to be hosed down, to wash up the mess."
MPF has patented a process that makes plastic enclosures less expensive to make as well, forming them in much the same way that steel enclosures are formed and doing away with traditional tooling costs. CNC equipment allows easy customization, and Moran has been able to apply that technology to processing and forming non-metallic enclosures. "Traditional non-metallics are made with molds, so you can only make one shape," he adds.
Sometimes getting a custom enclosure means more than just getting the box made the way you need it, but also having it come complete with some of the components that you'd rather not have to design in—perhaps an HMI or purge system. Many companies these days are trying to do more with less, Lovell says. "They look for somebody to offer more with the piece, so they don't have to figure it out themselves," he says.
For Pepperl+Fuchs, a custom enclosure typically involves added components inside the box, so that customers don't have to integrate those components themselves. "If they have an application, and they need something done to make it happen, we find ways to get them to where they have the least amount of resistance," Lovell says.
It's all about going to specialists to get a job done more effectively than you might be able to do it yourself. "Everybody is trying to trim costs," Moran says, noting that a machine builder might job out enclosure customization. "But then the specialist is also looking to cut costs. The machinery guy will specify to a subcontractor, who looks for somebody to provide the components."
Everything that can be done upfront could help reduce costs and headaches in the long run.