Roll Forming Processes
* All Products are produced to order. No Stock Products.
Inline Press Fabrication for Roll Forming: Johnson Bros. Metal Forming Co. has modernized its equipment and tooling to be able to offer Roll Forming Services with the latest automated technology in Pre-Notching, Pre-Punching, Cut-to-length, and Post-Fabricating combined with the cut-to-length operation. These roll forming operations are all done Inline with presses during the production of the Roll Formed Sections on a roll forming machine, which uses Roll Dies to bend the metal into shape. Pre-Punch dies & Pre-Notch dies are used between the entry side of the Roll Forming machine and the coil reel that holds the continuous raw coil stock that is fed into the machine. Cutoff dies, Cutoff dies that also perform other fabrications, and Post-Punch dies, are used on the finished sections, in presses at the exit side of the Roll Forming machine, as the sections exit the machine.
In rare cases with high volumes, precut strips may be fabricated and used or Pre-Cut and fabricated by a Pre-Notch press. Pre-Cut strips are not advisable due to excessive distortion and end flair that can occur on the ends of the profile. Special guides are required to help reduce this. The latest automated technology in press design and controls, and die design, is used by Johnson Bros. to perform as many roll formed operations as possible to provide a completed part without the need for secondary fabricating as was the case many years ago. In order to do this Johnson Bros has replaced most of its Inline Presses with accurate, fast acting, Pneumatic and Hydraulic Presses. Some mechanical presses are still needed for special roll formed applications. The installation of sophisticated, computer controllers, with length encoders, operate Accelerators with servo drives and Die Boosts. This provides high accuracy and multiple operation capability in one die or many dies used in the presses. Gag punching is a technique to accomplish many operations in the same press die and is only possible with the latest controls technology. It may be used in Pre-Notch or Cutoff Dies. In many cases Pre-Notch dies are not needed when using Gagging operations in the Cutoff die and Tolerances can be improved by avoiding the stretch that can occur on a roll formed section in the roll dies. There are some applications when Pre-Notching is the only method possible. Additional presses can be added to the entry and/or exit ends of the Roll Forming machine, when Gag Punching is not possible, or the best method.
Inline press operations for roll forming: The Inline press operations that Johnson Bros. Metal Forming Co. performs for roll forming are as follows: Holes, Slots, Notches, Perforating, Cut-to-Length, End Fabricating, Cutouts, Miters, K/O`s, Shear Forms, Embossing, Depressions, Part Identification, Tabs, Break Away Grooves, Expansions, and many other operations. In addition, Tubing may also be: Swaged, Crimp Cut, Staked End Cut, Flattened with Hole punching, and many other styles of inline fabricating. On Lock Seam & Split Seam tubing, Clean End Cuts can be provided, using a Pre-Notch operation. Holes placed on this tubing in the cutoff operation will be embossed. Many of these same operations can be performed inline on rings as well as the inline bending of the Roll Formed Shape into Ring Form. Inline bending into Ring Form is accomplished with bend rolls and or blocks on an adjustable, straightening, and fixture at the exit end of the Roll Former.
Cutting to Length is an Inline process that can be performed with two different die designs. One is a Crop Cut which is made of a stationary blade and a moving blade. This design will give good cuts with the least die building and maintenance expense as it lasts longer between sharpenings. It can be used for less end cut burr than other die designs. It also makes Gag Punching in the cutoff easier. However, this process of roll forming can leave more end flare that can be worse on some part designs such as thinner, larger parts. It may also not be possible for parts that are very narrow or are tubular in shape. The alternative Cutoff die method is for a Slug Removal Blade that moves between two stationary jaws called a Slug Cut. This Slug Cut process in roll forming is used to reduce or reverse end flare but can be much more expensive to build and requires more frequent sharpening to avoid burrs on the ends of the parts. Carbide can be used on the blade to reduce this maintenance. Some Inline operations done in the cutting die are done more simply with a Slug Cut die. Examples of this may be Holes at each end or the end of the part requiring a cutout pattern, not as a square end cut. Roll Forming from Precut strips can cause severe end flare and distortion. That is why it is usually avoided. Short lengths can be made as long lengths with Break Off Grooves to allow the end user to break off the longer parts into shorter parts. This process is done in the Pre-Notch press but can leave burrs where the break-off takes place. No matter what method is used, End Flare distortion is an important concern when parts are cut to finished lengths. Proper Roll Die design can keep the flare to a minimum. Other important concerns about end cutting are tolerances on length and for tubing whether the part needs to be clean cut or can be dimple cut. It is critical to our roll forming process that you discuss these issues with our contact personnel. On longer standard length sizes, to give the best price on parts possible, it is important for us to know if you can take a random length or need an end, cut to the finished length it will be used at.
Inline horizontal deburring of coil edges is accomplished using edge rolls that are mounted on fixtures connected to the Roll Forming machine or the prepunch press. Rolls for deburring coil edges vertically can also be used. These rolls are mounted on a set of shafts in the roll forming machine that are normally used to mount our roller dies. The combination of these two can remove coil slitting burr on the raw material and can either coin or give a thicker metal a rounded edge.
Parts that require water soluble coolant to form properly, can be dried inline, when necessary, after the straightener fixture, at the exit end of the roll former, using Air Knives. Wipers can also be used made of various high tech materials, rubber or cloth.
A separate department for Secondary Press Fabrication is also provided for less cost on lower volume or when the design of the part makes some inline press fabricating impossible. All inline operations can be performed as secondary operations. For example, Rings may be cut in a secondary operation press, for lower volume orders, from a coiled helex. Holes, Shear Forms, Tabs and other operations can be added to the rings in that same cutoff die to reduce costs. Slots, not possible to put in the legs of channels due to distortion during roll forming, may be done as a secondary press operation. Some assembly can also be performed in this department.
Application of materials in roll formed parts: Application of many different materials onto, or in Roll Formed Parts, can be performed Inline during the roll forming process with special feed units. These feed units are designed and built specifically for the type of application operation needed. A few examples of this operation are: Specially designed Double Sided Adhesive Tape applied to Lock Seam Roller Tubes and Control Joint Mouldings, Seamless Plastic Tubing with lubricity that is slit and applied as a cladding onto a mating surface of a roll formed track, A coil of thin decorative stainless that is rolled as a Cladding over thicker raw steel to make an Open Seam Tube Railing. There are many other application operations. Materials that have been applied generally are needed in coil form and are cut to length where the Roll Formed Part is cut, at the same time.
Insertion of materials during roll forming process: Many types of materials can be Inserted Inline into a Roll Formed Part during the Roll Forming process. Special feed units are also designed and built for this process. One example of this is for rubber and flexible plastic Moldings, Extrusions, or Felt material, inserted into Roll Formed Metal Mouldings, Channels, and Profiles to serve as Wipers, Weather Strips, Gaskets, and other uses. Another example is round Wire inserted into a rounded groove formed into a Lock Seam Tube or Wire inserted into the inside of a round Split Seam Tube. Paper Rope can be placed in Special Shaped Profiles and used as a gasket for a lid frame in the Metal Container industry. These operations use materials that generally come in coil form and are cut in the same place at the same time as the Roll Formed Part. Examples of other insertion applications, with materials, not from coil stock, is the insertion of wood parts into the inside of Roll Formed parts such as C-Channels or Frame Mouldings, or large multiple thickness Paper Strips placed in U-Channels with holes punched through the paper strip and the Channel at the same time during the Roll Forming process. In some cases, these operations may be performed between two Roll Forming machines or between the roll former and the cutoff press with special fixtures to close and crimp the Profile tightly around the insert before its cut to length. Gaps may be left in the part that are removed as a slug from the cutoff blade.
Johnson Brothers Metal Forming Co. is a roll forming Chicago based company providing quality, custom metal forming services for the upper Midwest and Canada. Contact us for more information regarding our green energy products and green manufacturing principles.