Sawing and cutting off developments update

To the naked eye, it looks easy enough. And yet there are enough variables to consider when performing sawing operations to make this a particularly unpleasant punch in the 'teeth' for even most canny of production engineers. Incorrect speeds and feeds, misalignment, worn blades, overheating, chatter and swarf accumulation are just a few of the potential problem areas here. However, with price such a big factor in securing hard-fought manufacturing contracts, the two unsurprising factors topping the wish list of almost all machine shops, when it comes to sawing technology, are productivity and waste (remnant) minimisation. Take Rotherham-based steel bar and tube supplier Staniforth-HKB Steel, for example. According to the stockholder's operations manager Dean Dainty, the company's new Kasto Performance Cutting (KPC) derivative of the Kasto TEC A5 bandsaw cuts hard materials in one-third of the time it took previously on the company's larger TEC A7 bandsaw, installed in 2005. Kasto (01908 571590) says that KPC technology gives attention to all aspects of the bandsawing process, including blade selection, guidance and monitoring, coolant delivery, and feeds and speeds. Specifically, it involves the innovative use of two spring-loaded 'tensioner' guides to suppress and manage blade vibration and harmonics. Image: Kasto technology in action at Staniforth So what can it achieve? Well, consider this. Staniforth-HKB cuts 410 mm diameter 817M40 high tensile steel in its annealed state into 31 mm thick slices to form blanks from which circular blades are produced for processing food. With a cermet-coated, tungsten carbide-tipped (TCT) blade on the TEC A5 with KPC switched on, material can be cut in nine minutes, some three minutes faster than when using an uncoated TCT blade with KPC switched off. On the older TEC A7, when processing material of the same specification and diameter using a bi-metal blade, between 25 and 30 minutes is needed to complete each cut, depending on the condition of the teeth – around three times longer than on the TEC A5 KPC. "Increasing business means that we are cutting-to-length larger volumes of material. Many of them are hard or tough, which is the higher added-value work we target," says Mr Dainty. The latest Kasto EC control with touch-screen on the TEC A5 contains optimised cutting data for a library of materials, cross sections and blade combinations, which are retrieved at the start of each job. Cut length and piece quantity are entered and the cycle runs automatically. Band speed and in-feed rate can be adjusted to optimise the process. As a point of note, when cutting circular bar, the control automatically slows band speed and in-feed during entry and exit to prevent undue blade wear. Mr Dainty says he plans to link the TEC A5 control directly to a PC in his office, so that programs can be transferred. The operator will then load the correct materials from hard copy cutting notes, after which sawing machine operation will be monitored remotely. Actual cutting data stored, including for overnight running, will be uploaded to allow machine and blade performances to be analysed. In another development, Kasto has also introduced optimisation capability in the CNC systems controlling its bandsaws, circular saws and automated storage systems. The software automatically minimises the number and length of bar remnants after a production run, even when both straight and mitre cuts are involved. Called KASTOoptisaw, the system assesses the stock situation, in terms of number of bars, their length, type of material and the number of rest pieces likely to result from processing an order. It then checks whether further orders in the control's memory can be fulfilled in whole or in part by the same piece(s) of material HEURISTICS FORETELL ALL By looking ahead at orders that have to be cut and combining them, built-in heuristic and evolutionary optimisation algorithms work out how best to use the available material, so that gaps between cuts and unused end lengths are minimised. The advantages are especially beneficial when expensive materials are processed. Returning to the productivity theme, Kaltenbach (01234 213201), the UK agent for Behringer, says that Behringer SC (Speed-Cutting) technology is now available across the entire range of HBM straight-cutting bandsaws as a factory-fitted, integrated SC Pack option. The addition of the SC Pack claims up to a further 30% performance gain over and above the existing claim of the industry's fastest straight-cutting bandsaws. TCT (tungsten carbide-tipped) blades are recommended to maximise the productivity gains on offer, although bi-metal blades can also be used with HBM saws, but with a reduction in performance. Image: Kaltenbach HBM SC Behringer SC technology was first introduced in 2010, with the HBM400 SC machine and which claimed, for example, to cut 150 mm diameter, 16MnCr5 material, in 21 seconds. Similar 'speed cutting' advanced features and benefits are now available for HBM 800, 540, 440 and 370 mm diameter capacity, straight-cutting bandsaws when specifying the SC Pack option. Satisfying ferrous and non-ferrous sawing, all HBM machines have an enclosed housing, which serves to attenuate process noise to very low levels and assist in swarf and coolant containment. Some would argue, however, that fast cutting doesn't necessarily lead to high productivity. While "How quickly can I cut this?" is the most common question presented to suppliers of sawing technology, Prosaw (01536 410999) suggests that, although machine/blade performance is important, it becomes irrelevant, if the cut component cannot be removed quickly. As a result, material handling (from basic input and output conveyors to fully automated handling systems) can be as critical as, or more critical than, the sawing process itself. Prosaw says production engineers should ask themselves two questions. First, after a stock bar has been processed, how long does it take to load and start processing the next stock bar? And, second, if it takes 30 minutes to saw a component, but the operator has to wait 10 minutes for a forklift/crane to remove it, is the process efficient? These are salutary points and ones with which Prosaw, as well as many other suppliers, will be pleased to help resolve. Ultimately, there's no longer any excuse for a bottleneck at the sawing machine. Class-leading machinery, coupled with expert technical support, can help provide genuine competitive gain. Box item High volume plate processing For high volume plate processing companies, Voortman has developed an innovative split configured system, based on two separate gantries. The V330S split plate processing system allows simultaneous drilling and cutting, which, according to Voortman, guarantees a 40% higher output, compared with other systems. Several machines have already been installed at large steel fabricators in Europe. It operates thus: once the drilling gantry has completed the required hole pattern, both gantries (equipped with magnetic lifts) start working together, bringing the plate to the cutting table. After releasing the plate, which can be up to 150 mm thick, the drilling gantry moves back to the drilling table, while the cutting gantry commences operation. During this dual operation of the gantries, a new raw plate can be loaded to the drilling table. Various solutions for automatic unloading, stocking and stacking for further processing can also be supplied. Availability in the UK is via Cutmaster Machines, Ireland (+353 (0)1 410 5555). (See video) First published in Machinery, January 2012