Selection Criteria for Plate Rolling Machines

Companies that employ plate metal in their fabricating processes are seeing their profit margins get squeezed due to falling factory orders and rising prices of labor and energy.

Manufacturers still need to spend money on new production equipment to be competitive, whether to upgrade from older models or to take advantage of emerging markets.

Manufacturers need to carefully evaluate the benefits and costs of investing in new plate-rolling equipment. Debt financing is still an option for buying new machinery, but without the equipment's ability to boost output, the loan repayments won't amount to much. When it comes to production quantities and tolerances, many buyers make the mistake of choosing equipment that is incapable of doing the job because they failed to fully investigate all of their possibilities.

Manufacturers can improve their plate rolling operations by keeping in mind the following five guidelines for selecting the best plate bending equipment:

The Qualities of the Material Being Rolled Must be Taken Into Account First

Despite the fact that the blueprints call for the same plate to be rolled down to the same dimensions, a far more powerful rolling machine will be needed for the stronger material. When these factors are ignored, the manufactured product may have flaws, and the producer may generate excessive scrap.

These days, you'd need a lot more muscle to bend steel because it's so much more robust. Steel comes in a dizzying array of types, from A36 and A516 grade 70 to Hardox 400/500 series and AR 200/300 series, all of which have been given precise designations according to the ASME. In addition, rolling pressure requirements for these various steels vary widely.

Matching the temper and yield strength of the metal to the customer's application is crucial for arriving at the right plate roller parameters. This is crucial in light of the fact that steel properties have shifted dramatically in the last few decades. You won't find any examples of "mild steel" nowadays.

Find a Dealer Who is Open to Discussing Your Unique Plate-Rolling Requirements

In order to get accurate responses, customers need to know what questions to ask. Every factory has its own set of problems, but a savvy salesperson may find out what tools will be most useful by asking a series of pointed questions.

To reach the widest possible audience, manufacturers must also carefully evaluate whether to roll conical or parabolic shapes. Due to the lack of surface scarring caused by hydraulically operated four-roll machines, less time is spent grinding the lamination (bullnosing) on the minor diameter edge of a cone.

When compared to electronic systems or proportional value systems, which just maintain a theoretical balance, features like torsion bar parallelism go a long way toward ensuring accurate conical rolling. It takes only five seconds to tilt the machine to its maximum conical position and then back to parallel, thanks to the machine's finite parallelism.

Inside diameters, materials, tolerances, and the final product form all need to be discussed with customers. Some items, such as those used in the pressure vessel sector, must have a diameter that is more than 1% out of round, or they will be rejected. Too much of a barrel effect from utilizing a plate roller with insufficient force can soon wipe out any profit you might have made off of the product.

It takes careful consideration to match plate-rolling machinery to a manufacturer's unique requirements. It's crucial that the dealer you choose is flexible enough to meet face-to-face to go through your business's unique requirements. A buying manager may not be able to anticipate all of the problems that may arise and need to be fixed.

Don't Deviate Too Far From the Machine's oOtimal Settings

Manufacturers should determine which substrates and gauges account for the majority of their output. Then (a company) can ship a machine that can camber to that specification, saving time and reducing waste.

Cambering quality in rolling machines typically occurs at 50% of the machine's full rated value. In order to roll a 1/2-inch plate with a nearly flawless edge, a 1-inch machine is cambered.

Ignoring this crucial detail can lead to a non-acceptable, out-of-spec product for the client. When rollers try to exceed the capabilities of their plate roll, issues typically develop. There will be some barrel effect if a plate that is 5/8 inch thick is rolled through a machine that is rated for 1 inch. The error margin here could be fine or it could be too high.

However, serious flaws can emerge as plate thickness reaches the machine's limit. It won't be marketable unless the gap is closed with a shim. However, the opposite is true: if thin material is rolled through a machine designed for thick plate, the result may be tighter in the middle than at the ends. Again, this "hourglass" effect requires laborious shimmying on the part of the user.

Consider the Sizes of the Bends You Intend to Make

A greater amount of pressure is needed to bend a smaller diameter. When rolling thick material into small IDs, the diameter of the top roll and the design of the machine are crucial factors in determining whether or not the cylinders will shut.

For the most part, the maximum thickness of plate that a machine can roll is 1.5 times the diameter of the upper roll. Therefore, interior diameters as small as 15 inches can be attained using a top roll with a diameter of 10 inches. However, new machines with planetary guides can maintain around 50 percent more plate surface under bend pressure during rolling, leading to ratios of 1.1 times the upper roll diameter. Because of this, we gain a 30% advantage on small diameters.

Even while operating at half capacity, all measuring devices maintain high levels of accuracy. Therefore, a 3/8-inch machine with a 10-inch top roller may reliably roll a 3/16-inch plate to an 11-inch ID without creating a barrel flaw, provided the roll geometry is 1.1.

Fifth, Make Use of Vertical and Lateral Supports to Prevent Sagging

The manufacturer of the plate rolling machine should provide specifications for both horizontal and vertical roller supports to ensure proper stability. Once a person has a job, plate rolling is no longer a two-person task. This frees up skilled workers who can be put to use in other areas.

When rolling a cylinder, the material's weight becomes sufficient to bend the cylinder as it moves away from the machine after the interior diameter is more than 200 times bigger than the thickness of the material. Unwanted radii form if there is insufficient support.

If you want to avoid this hassle, all you have to do is get a machine with roller supports on both the side and the top.

Some producers will try to save money by using a forklift or an overhead crane as "makeshift" support instead of spending the money on dedicated auxiliary machinery. While convenient, this workaround prevents the efficient use of resources. Unexpected kinks can still occur since it can't sustain the material well enough.