Uncoiler 101

by Marcy Marro | October 3, 2022 12:00 am

While the rollformer, punching, stamping or slitting lines may do the hard work of creating the metal panel and trim pieces, it’s the uncoiler that does all of the heavy lifting. Uncoilers, or decoilers, are necessary for any machine where the metal coil needs to be unrolled for the process. There are a variety of different types of uncoilers, so it’s important to be sure you have one that does everything you need it to.

Uncoiler Basics

In its basic form, an uncoiler holds a large roll of aluminum, steel or other metal, and feeds it into a rollforming or other type of machine. Coils of metal, rather than flat sheets, allow fabricators to store a lot of linear footage in a compact space where they can have the flexibility to determine the length of the panel or product they are making.

Ben Schmidt, industry sales manager–metal buildings, trim and decking at The Bradbury Co. Inc.[1], Moundridge, Kan., notes that a coil of steel arrives from the supplier wrapped with many layers. For example, he says, a 9,000-pound coil can contain thousands of lineal feet. “The uncoiler function is to safely unwrap the single layers of steel,” he says.

“Uncoilers basically pay off the material into a press, rollforming line, or other types of processing lines you have,” adds Thomas Schwarzer, regional sales manager Northeast U.S. and Canada, and marketing manager at ASC Machine Tools Inc.[2], Spokane Valley, Wash. “The coils can be very narrow or they can be very wide. We build uncoilers for coils from 4 inches to 72-inch-wide coils.”

The use of uncoilers allow fabricators to dictate how long of a piece of metal they need. “You can pay off thousands of linear feet of a coil, and you are free to choose any part length you need to produce,” explains Schwarzer. “It can be very short parts; it can be very long parts. The coil is a continuous strip of metal and its linear footage depends on the material thickness and coil weight.”

For material thickness or gauge, there’s typically two kinds of uncoilers: one is a power payoff, and the other is a drag brake. Uncoilers designed for material thickness greater than 18 gauge typically include a nip arm to help control the spring back or clock spring of the material. Spring back occurs after the bands are broken on the coil. “Uncoilers designed for greater than 18 gauge typically include a drag brake which prevents the coil from unwinding,” Schmidt explains, “while uncoilers designed for less than 18 gauge typically have a powered mandrel to payoff material and create a loop for material to accumulate before feeding through a line.”

Coil Cars

Along with the uncoiler, most fabricators have coil cars to place and remove the coils onto the uncoil. “A coil car will receive a coil from an overhead crane or fork truck, traverse the coil laterally, raise the coil to the uncoiler mandrel height and slide the coil onto the mandrel,” explains Schmidt. “Coil cars repeat the process in reverse to remove a coil from the uncoiler mandrel during coil changeover.”

There are two kinds of coil cars, Schwarzer says. “Non-rotating coil cars simply move in and out on a track, and lift the coil up to load it onto the mandrel. And the other one is a rotating coil car, which has a saddle that can rotate by 90 degrees. Rotating coil cars allow to load the coil in direction of flow of the rollforming line. It makes way easier to load coil when floor space is tight.”

Double- versus Single-Arm Uncoiler

Every time a coil of metal needs to be changed, the production line can go down for anywhere between 10 to 15 minutes, depending on the type of coils. “With a single-arm uncoiler, every time you need to change a coil, you need to stop the whole line, rewind the coil, take it off, and put a new one on,” Schwarzer says.

Double-arm uncoiler have mandrels that rotate by 180 degrees. “While one mandrel is paying material into the rollforming line, the other mandrel can be unloaded and reloaded,” Schwarzer explains. “This helps to reduce coil change over times by five to 10 minutes.”

Determining Factors

There are many factors what determine the best type of uncoiler. Schwarzer recommends always calling the manufacturer and explain what you want to do and what kind of rollforming machine you have. And, as Schmidt notes, “If speed of coil changeover is most important, then a double-mandrel uncoiler is required. If changeovers are not as important, then increasing the weight capacity of the uncoiler may provide more benefit. The heavier the coil, the more footage and finished product can be produced without changing coils. Crane or forklift capacity is also important to determine the capacity of the uncoiler.”

Source URL: https://www.metalarchitecture.com/articles/uncoiler-101/

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