The big processor with a five-axis cutting head – the BLM LT 20 Jumbo – is able to cut large round, square and rectangular tubes and pipes, as well as non-tubular open structural sections such as beams, H, I, angle and channel in a heartbeat.

Largest machine of its kind to be installed in South Africa.

Fabricators use a variety of methods – sawing, lathe cutting, rotary cutting, supported shear cutting, dual-blade shear cutting, and laser cutting – to cut from mill lengths into shorter pieces for use in final fabrication of structural sections and components. No single method is optimal for cutting the broad range of materials and shapes produced by this industry. Which type of cutting machinery to use for an operation depends on the requirements. In addition, the expansive growth has required fabricators to increase production and automate cutting operations.

The new BLM LT 20 Jumbo, an automatic laser cutting system with a five-axis cutting head is able to cut large round, square and rectangular tubes and pipes, as well as non-tubular open structural sections such as beams, H, I, angle and channel in a heartbeat. The machine was supplied by First Cut

Lasers have been in use for industrial purposes for decades, and their capabilities continue to develop. These days many machines can cut sheet and tubular sections, and fabricators are finding that the laser’s programmability really broadens their capabilities. More recently, fibre laser cutting has opened up new possibilities. That said, many equipment manufacturers specialise in providing cutting equipment for tube, pipe and non-tubular open structural sections such as beams and several have rolled out new machines recently. However, it is in the area of processing large, big, hefty – call it what you want – material where there are a limited amount of machine manufacturers and as a result, processors or fabricators.

The continuing development of technology is expanding applications. Today’s high-production demands, and the need for higher-quality parts have led to a trend toward more automation. It may not be cost-effective anymore to cut parts on one machine and manually transfer them to a secondary operation. Automated material handling equipment handles material at high speeds, automatically loads into cutting or secondary operations, and stacks processed material into bins or bundles. Inline automation has also been developed to integrate primary machines with secondary operations.

Justin Cloete and Warne Rippon from Allied Steelrode

Processing is referred to as all done-in-one operation. This includes cutting to length, mitre, cope and shape, chamfer, drill (laser), slotted, cut or chamfer any shape, process with large-diameters and thick-wall material

In response to a growing demand for steel sheet that arrives flat and stays flat after laser, plasma or water-jet cutting, Allied Steelrode last year invested R150 million in a new 9 000m² facility in Midvaal, Gauteng, and a dedicated Red Bud Industries’ cut-to-length line with Suregrip® stretcher leveller technology incorporated. Users and distributors of flat steel now have access to significantly better flat steel, and new competitive advantages.

Structural processing
Now the company has invested in a BLM LT 20 Jumbo, an automatic laser cutting system designed to bring higher levels of precision to the laser cutting of large diameter, thick-walled material. The machine is equipped with a five-axis cutting head and is able to cut large round, square and rectangular tubes, as well as non-tubular open structural sections such as beams, H, I, angle and channel. The machine was supplied by First Cut.

The system can be used to cut round, square and rectangular tubes, plus non-tubular open structural sections, ranging in diameter from 75-508 mm and lengths up to 18 metres.

The versatile BLM LT 20 Jumbo can process mild, high strength, alloy and stainless steels and bevel edges, and also countersink holes.

Laser technology’s inherent flexibility is heightened by the fact that the BLM LT 20 Jumbo eliminates the need for special fixtures. This means that high volume production as well as low volume prototype work can both be processed easily, quickly and cost effectively.

Channel, tube, pipe cutting and hollow structural sections are some of the shapes of material that the BLM LT 20 Jumbo can process

A key aspect of the system is its high level of automation. All loading, cutting and unloading operations are controlled by CNC, and the system control software automatically selects the best cutting method. Because all machine operations are performed by programmed commands, no manual set ups or fixtures are required. Once material is placed on the loader, it is moved one by one into the feeding line with its automated chuck system.

First, the rear drive chuck grips the material and indexes it into a pair of working chucks and then into the cutting area. The rear chuck does not release the material until the entire part has been processed.

The combined action of the two working chucks and drive chuck move and position the material under the five-axis cutting head according to the programme parameters. The interpolation of the cutting head in combination with the material movement allow for processing anywhere along the length. The machine can cut in front of the main chuck, between the working chucks, or behind the main chuck. The design provides maximum flexibility and access with little or no scrap.

The system can be used to cut round, square and rectangular tubes, plus non-tubular open structural sections, ranging in diameter from 75-508 mm and lengths up to 18 metres. The versatile BLM LT 20 Jumbo can process mild, high strength, alloy and stainless steels and bevel edges, and also countersink holes

After being laser cut, each finished part is unloaded to a specific programmed position according to length. Parts up to three metres in length can be unloaded onto the short part unload conveyor and longer parts, up to a maximum of 18 metes, will be sent to the long part unloader.

Processing is referred to as all done-in-one operation. This includes:

• Cutting to length
• Mitre, cope and shape
• Chamfer
• Drill (laser)
• Slotted
• Cut or chamfer any shape
• Process with large-diameters and,
• Thick-wall material

The automatic laser cutting system is designed to bring higher levels of precision to the laser cutting of large diameter, thick-walled tubes, along with the heightened efficiency and productivity needed to compete with the plasma systems commonly used to cut this class of material.

The structural challenge in the construction industry
Allied Steelrode says that with this investment it will open up a wealth of opportunities for their customers, not just in the extra operations and capacity they provide, but also in the speed of response they can offer.

“The BLM LT 20 Jumbo will also increase our capabilities for the newer and growing requirements in the construction industry and other markets where high volumes of large sections and components are required, often to tight deadlines,” said Allied Steelrode’s Warne Rippon.

The BLM LT 20 Jumbo is the largest machine of its kind to be installed in South Africa by BLM and First Cut

“From a purely physics perspective, hollow structural sections have numerous advantages, one being strength. By moving the material away from the center of the section (as with a typical hot-rolled beam) toward the periphery, hollow structural sections have a high strength-to-weight ratio.”

“But from an engineering perspective, wide-flange beams have had one main advantage, they’re easy to connect. To assemble angles and beams, an erector simply bolts through two adjacent flanges, or he bolts through a clip into a web section.”

“Do that, and you get the slip-critical connection everybody wants. But connecting hollow structural sections can be challenging. How do you attach a nut? If you try to fabricate connection points out of pieces of plate, then you’re going back more than a century, back before the wide-flange beam was in common use, when individual plates were riveted together to make structural beams.”

After being laser cut, each finished part is unloaded to a specific programmed position according to length. Parts up to three metres in length can be unloaded onto the short part unload conveyor and longer parts, up to a maximum of 18 metes, will be sent to the long part unloader

“This is where steel cast connections fill the need. Technology has advanced so much that this is now a real solution. It is now up to us to educate structural and design engineers in South Africa that hollow structural sections, besides having greater strength in true weight to loading, are straighter and lighter and, as a result, are cheaper for use in structural construction. We have to educate them to design in tube as it gives you unrestricted capabilities. Aesthetically it gives them a new vision and variability.”

“Instead of constructing pods and sliding them into a frame built on-site, when using hollow structural sections, the steel frame itself is broken up into a chassis, or cubical (or rectangular prism) steel frames. That can then be fabricated in the controlled shop environment allowing each chassis to then be outfitted into a complete module with flooring, electrical, HVAC, sprinkler systems, tiles, and even drywall and the building façade.”

“Very real time and cost savings can be realised as a result.”

Any form or shape of tube and pipe can now be processed by Allied Steelrode

The new BLM LT 20 Jumbo laser processing machine has been installed in a renovated
17 500m² facility that the company owns, and is situated adjacent to its main processing facility in Alrode, Gauteng. The facility consists of eight bays, all under crane, that will house and process all of its long hollow structural sections and beams.

“Crucially, these computer controlled operations allow us to guarantee repeatability in terms of accuracy, tolerances and finish. These enhanced strengths also mean that customers can now order stock and tube and beam cutting from one source.”

For any enquiries please contact Allied Steelrode on TEL: 0861 777 777, email info@alliedsteelrode.co.za or visit www.alliedsteelrode.co.za