Industrial Machinery News

Archive for January, 2010

Automated metal forming has become an integrated part of our construction and production units. We use their service for erecting high rise buildings, constructing our homes and offices and making cars. The roll forming machines have a say everywhere. Manufacturer using roll forming machines can see the advantage of investing in a cold forming or metal forming machine. With a roll forming machine you can make corrugated metal roofing, which is in huge demand nowadays. Didn't you notice the new stainless steel roofing in your neighboring area? The offices today are planning to reconstruct their roof with galvanized steel as it is rust free and more durable than the traditional roof.

To cut down the cost of making cars and trucks, the automotive suppliers are using metal stamping and metal shapes for making auto parts like chassis and press brake. Steel bending with cold forming machines has helped them decrease the number of defective parts produced. This in turn has significantly reduced the per part cost. When everyone is using roll forming machines then how can the construction industry remain untouched? In construction industry, steel bending machines are used for making purlins. Purlins are used for supporting tall walls, floor structures and large ridge beams. Purlin bridges the gap in the construction process. Looking at the huge role that roll forming machines play in our life, it is prudent for manufacturers to switch over to roll forming and give a tough competition to their counterparts. 

Steel purlin provides an excellent choice for tall walls, floor structures and floor structures. Made from hot-dip galvanized steel and produced on roll forming machines, purlins contain high load bearing capacity and are free from mold and damp. With light weight, purlins are convenient to transport and easy to assemble. Purlins are used in structural and engineered buildings. Z purlin and c purlin have a special role to play in construction. With the support of rafters and building walls, z purlin and c purlin easily hold the load for the roof deck and sheathing. It is the steel purlin, which is used to bridge a gap in the construction process. 

Advent of roll forming machines has made it much easier for manufacturers to produce purlin rails and other purlin products. Purlin is made by bending cold formed steel into Cee and Zee sections. In terminology, the Cee and Zee purlins are called girts. With a quick change over process, the manufacturer even produces both the profiles on the same roll forming machine. It helps the manufacturer in saving a lot of time and labor. But switching between two very different profiles need prudence because even a slight negligence can lead to poor quality produce, which is of no use for either party. Roll forming machines are not only used in making purlins but they are also used for punching holes in purlins. Sometimes roll forming machines have to be carried to the construction site for much accurate hole-punching in purlins.   

Corrugated metal roofing produced by cold forming machine has become the first choice of home owners and entrepreneurs alike. The strength and toughness provided to the metals with a roll former makes a metal roof durable and reliable. Use of corrugated roofing machine has made it easier for manufacturers to produce metal roofs in large quantity. Cold forming is used in bending and squeezing the plain metal sheets into various profiles. A roll former can make corrugated roofs in any style or shape. A corrugated roofing machine produces less scrap and so contributes to its master's profit. Today it is possible to make metal roof of a particular thickness or hardness to suit various needs. The most common profile used today is Trapezoidal or box profile.

Steel is the most trusted metal used for producing corrugated metal roofs. Steel comes in galvanized and stainless steel form. The galvanized steel has a zinc coating that makes it free from rust for ever. It is relatively inexpensive and also contains excellent physical properties. But corrugated galvanized steel roof has its drawback as well. The roof made of galvanized steel has a tendency to change in appearance when it comes in contact with oxygen. You may feel that your corrugated galvanized roof looks odd after a few years. Stainless steel is slightly weaker than the galvanized steel but it can retain its beauty and charm for decades. If you are looking for durability, you can choose galvanized steel roof. However, if look matters most to you then go for stainless steel roof.    

The most commonly used lubricant to aid the roll-forming of building panels is vanishing oil. This product provides the necessary lubrication for the forming process and also has the advantage of evaporating over time to permit ease of handling and installation at the construction site. However, the vanishing oil or other lubricant should contain at least 95% solvents or be a water-based lubricant that leaves minimal residue. Care should be taken to allow the roll formed panels to be completely dried prior to shipment. No lubricants should be used on either acrylic coated GALVALUME or Galvanized steel that U. S. Steel identifies as ACRYLUME2 or ACRYZINC3, respectively.

Inadequate lubrication can cause problems with the roll former operation and/or in the finished panel. A common problem within the roll former is the bonding (welding or fusion) of coil coated products to the roll tooling. This is time consuming to remove. Some companies have had some success by mounting SCOTCH-BRIGHTTM rolls4 on the tooling to continuously remove coating build-up or by polishing the rolls while in operation. Problems can also extend to the finished panel. Part configuration, forming issues, oil canning, twist, bow, and improper finished dimensions can all result from inadequate lubrication.

Tooling is generally designed to form panels from the center of the strip outwards. When threading a strip into the line, it is recommended to cut a bevel on each side of the incoming strip. This enables the strip to feed through the line on the center.

Many operators thread material into the line with a square cut edge. Although this can be successful, it often leads to problems in the later stands. If the strip moves even slightly off center in the early stands, the problem will be magnified in the later stands. When this occurs, the operator may have to cut a portion of the strip from the line, which will not feed through the balance of the line due to jams or wrinkles. When this type of problem is encountered, often simply cutting a bevel on the incoming strip will eliminate threading issues.

Mill alignment is critical. Since tooling is designed to specific tolerances, the forming rolls and their components must be aligned to each other both horizontally and vertically. The rolls must be aligned both side-to-side and pass-to-pass. Forming material with the gauge either lighter or heavier than that for which the tooling is designed can result in problems indicative of mill misalignment.

Using material thinner than the designed gauge can result in manufactured panels with finished radii greater than the intended design. This is usually offset by over-tightening the rolls, which causes a deterioration of tool life. Processing heavier gauge material than intended can also lead to larger radii than designed. When running thicker material, the tooling will make contact on the side of the tool radii leaving no center contact with the tooling. Since the material is not in proper contact with the tooling, gap differences from side to side become more critical. Small side-to-side roll gap differences can result in twist, bow or sweep problems.

Metal forming has opened the door to many manufacturers around the globe.  Having the ability to bend and form steel plate in to complex shapes and profiles has allowed engineers to design and create new and exciting products. 

The tools (also called tooling) have evolved over the years and are now a highly integral part of the overall design of roll forming systems.  The roll tools are what form the shapes made by rollforming equipment. 

It seems that everywhere we turn we see objects formed by bending steel plate in to the final profile. In the home building industry we find many products made by these industrial level machines. 

You will find corner beads used to finish the ‘corners’ of walls.  The corner bead comes in various shapes and profiles such as square, rounded, perforated and so on.  Like the corner bead you will find expanded metal products used in drywall applications.  Another common steel formed product found on profitable construction sites is the steel stud.  This product has many benefits over the traditional wooden studs.  First steel framing is resistant to mold and mildew, fire resistant, and easier to build with.  Other steel products found on the job site include steel purlins, zee, cee and sigma.   Many buildings are manufactured using steel siding or steel corrugated roofing.  Both provide installers and home owners many advantages.

Many other process could be used to form metal in to these complex shapes.  Metal pressing or stamping, hydroforming are just but a few ways to form metal.  However, roll forming machines provide a highly cost effective and high quality product unlike it’s competitors. 

Here is some more information on Roll Forming Equipment.

• Roll forming is a common and useful method for forming objects from sheet metal.
• Roll forming is a very precise process and a special type of machine is used to roll form metal.
• These roll forming machines have several rolls that are placed one after another and they are divided into sets called 'stands'.
• Each stand bends the metal only a little. So the metal can be passed multiple stands to reach the desired curvature.
• Roll forming is ideal for making parts, which are very long. 
• Roll forming machines bend the metal into predetermined shapes. The shape would be a desired cross-section profile, meaning it will look like it was cut out from a complete shape like a cylinder for example. The cross-section profile is simply what the required end result of the bending is.
• Every shape needs its own unique set of rollers. That means that one roll forming machine can only make one shape.

Roll forming equipment has been around for many years.  The use of them is wide and varied through modern manufacturing.  A leader in this industry is Samco Machinery.  They have lead through carious innovative products focused on providing high quality machines to metal manufacturers.

You can see more of their machines at (http://www.samco-machinery.com)

Thermo Goring Kerr AuditCheck is an optional system that, if not installed at the factory, can be easily installed in your DSP3. It is an automatic means of checking the calibration of both sensitivity and phase angle. It is used to check the phase and sensitivity calibration of the DSP3. AuditCheck simulates the presence of a metal contaminant in the product by “firing” a metal ball through the search head coinciding with a product passing. The metal ball does not come into contact with the product. It is fired through part of the search head that is segregated from the main aperture.

Excerpt from Thermo Goring Kerr DSP 3 Auditcheck manual

Theory of Operation

To understand the benefits of AuditCheck it is necessary to determine what is meant by sensitivity of a metal detector head. As an example a common head sensitivity of 1mm ferrous and 1.2mm non-ferrous indicates the head is capable of detecting spherical piece

of ferrous material with a diameter of 1.0mm or a spherical piece of non-ferrous material with a diameter of 1.2mm All products have their own effect on a metal detector. In some cases, this effect is small (such as products referred to as “dry” products). Other products have a much larger effect (such as products referred to as “wet” products). Any metal detector must be capable of correctly compensating for such product effects so uncontaminated product is not rejected. The AuditCheck system is a true quantitative measurement of sensitivity since it actually passes a test piece through the head magnetic field and measures the resultant head signal in the presence of product.

The AuditCheck system has been designed to provide the ideal automatic sensitivity test for metal detectors. AuditCheck takes advantage of the fact there is a fixed relationship between the sensitivity at each point in a metal detector field and by firing the ball through the same magnetic field as the product, AuditCheck produces the same effect as if a metal contaminate were in the product. Figure 1 illustrates the essential elements of AuditCheck. A tube is inserted into the metal detector case along the line “AB” that is

within the active magnetic-field area of the head. A test piece (molded into a plastic shuttle) is able to travel along the line of the conveyor or pipeline from “A” to “B” and return from “B” to “A”. As part of the automatic setup and calibration the test piece, under the control of the central processing unit (CPU), is fired from “A” to “B” simultaneously with the product. The resultant metal detection signal can then be measured in the presence of the product.

The test piece returns under the control of the CPU from “B” to “A”.

 The TEK 21 metal detector operates on the balance coil full loop detection system. Three equally spaced coils surround the aperture or opening through which the product to be inspected passes. The center coil is connected to an oscillator circuit to produce an electromagnetic field. This signal is received by two coils on either side of the oscillator coil.

These are the receiving or input coils

Since the receiving coils are equally spaced from the oscillator, they receive equal mounts of signal. The coils are wound in such a way that their signals oppose each other; therefore, the net signal across the coil is zero.

When a piece of metal enters within the electromagnetic field, it alters the field strength around it. As this metal passes through the aperture, it changes the balance of the receiving coils so that the net signal is no longer zero. This error is then greatly amplified, compared in phase to the original oscillator signal and passed to the timing circuits. Eventually, it operates the reject relay. 

A metal detector is a high performance measuring instrument; the search head being the transducer. The quality of the installation will have a direct effect upon performance and reliability.  For more information and the complete Goring Kerr Tek 21 manual download today here.