Clean-cut benefits from latest sawing technology

More frequently in the modern manufacturing era, criteria such as speed, accuracy and quality are considered as 'given' when it comes to the latest sawing equipment. Production engineers require greater throughput for competitive gain, and better accuracy and finish to avoid or reduce subsequent facing (machining) operations. Along with high levels of flexibility and a keen budget, these are the factors that determine machine selection. SPECIAL-PURPOSE TREND It may come as little surprise, then, that Prosaw (01536 410999) says it has seen a big increase in sales of special-purpose machines over the past two years. A recent case in point saw an enquiry arrive from Saudi Arabia for a massive bandsaw to cut 3,000 mm diameter heat exchangers. As a result, Prosaw was able to offer a bespoke bandsaw to suit the customer's exact requirements – designed and built in the UK. While the customer's existing saw used three expensive bandsaw blades to complete each cut, with the cut time taking 11 hours, the Prosaw sawing machine achieves the same cut in 1 hour and 45 minutes, with bandsaw blades typically lasting 30 cuts. So impressed is the customer that the company is now also ordering blades from Prosaw. It's no secret that a large target market for sawing technology is material stockholders. However, one notable trend in this area is that stockholders are now processing far more exotic materials than 10, or even five, years ago, and this makes sawing machine selection all the more critical. A clear example can be seen at INTOCO UK, based near Gloucester, which has recently taken delivery of an Amada PCSAW330 pulse-cutting bandsaw supplied by Birkett Cutmaster (01274 870311) to process materials such as 400, K500, 600, 601, 625, 718 and 825 nickel alloys. Other materials cut include H13 and H11 tool steels, as well as stainless steels such as Super Duplex, martensitic 440c and 17-4PH (precipitation hardening). Image: Fast sawing within minimum wastage, that's what Amada technology offers INTOCO UK "The machine is fast and, in addition to economy of cut, provides an accurate high quality finish and consistency throughout the cutting cycle," says INTOCO's special steels and alloys manager, Les Preece. "What is, perhaps, just as important to our operation, however, is the machine's ability to provide extended blade life when using Amada's Smartcut bi-metal blades, which are 0.5 mm thinner than standard M42 blades. The use of thinner blades – allowed by the pulse-cutting action of the saw – also reduces the wastage of high value materials, and helps us control and reduce production costs even further." SECOND INSTALLATION The INTOCO installation is the second PCSAW330 supplied by Birkett Cutmaster to the UK market. The first was installed at the Halesowen distribution centre of Sandvik Materials Technology UK, where it has improved the cutting service and tolerances provided for customers. The pulsed operation of the incision (thrust force) made by the PCSAW is achieved by controlling the motion of the blade's tooth tips. Conventional bandsaw tooth tips move downwards towards the material in the direction of the incision, while the pulse-cutting machine's blade tips instantaneously move away from the material and then rapidly down again – repeating these movements while making the incision. Cutting resistance, chatter oscillations and noise levels are reduced to a 'friendly hum', even when cutting large diameter hard steel bars, says Birkett Cutmaster. To give an indication of capability (using an Amada carbide blade), the machine can cut a 400 mm diameter bar of H13 tool steel in 5 minutes and a 304 stainless steel bar of 400 mm diameter in 8.5 minutes. Another material stockholder, Barrett Steel Group, has opened a separate facility for exotic materials in Rotherham to help break into the oil and gas market. Under the name Barrett Nickel Alloys, the company installed four Kasto (01908 571590) bandsaws to aid cutting the new materials. The latest model, a KASTOtec AC5 automatic bandsaw, can process stock up to 530 mm diameter or wide using tungsten carbide tipped (TCT) blades. Image: Four Kasto bandsaws underpin Barrett Nickel Alloys venture into the oil and gas market The machine has a steel/mineral cast composite construction that is six to eight times more vibration-absorbing than cast iron, and a main drive through a rigid, play-free, spur bevel gear, delivering 98% of the available power directly to the drive wheels. Double bearings on both the driven and idle blade wheels promotes stable, even, power flow and allows band tension to be raised, which translates into higher accuracy cutting. Precision is aided further by having blade guides as close as possible to the stock on both sides and linear guides for the hydraulic in-feed. Other functions of KASTOtec AC machines include automatic slowing of band speed and feed rate during entry and when exiting the cut to prolong blade life, while a patented feature involving retraction of the stock and blade on completion of a cut avoids marking the face of the workpiece and eliminates the risk of damaging teeth. Kasto has also had recent success with circular saw technology as part of a turnkey solution for a bearing manufacturer. The machine is being used for cutting off short lengths of stock from thick-walled 100Cr6 steel tube (677 N/mm² tensile strength) to produce bearing race blanks. MASS PRODUCTION Mass production circular saw KASTOgripspeed is the machine chosen to fulfil the task. The saw blade is fed into the tube on linear guides at an angle of 25°, which offers best performance, in terms of burr-free cutting, regardless of material cross section. The saw blade itself is guided by three pairs of large carbide plates. Other features are a frequency-controlled 11 kW drive, play-free gears, a material magazine and a ballscrew-driven gripper to ensure accurate positioning of the material. Due to the interrupted cutting conditions experienced by the saw teeth as they enter the bore of the tubes, the sawn faces are prone to picking up vibration marks and blades tend to wear faster than when processing solid bar. To minimise these effects by avoiding chips collecting inside the tube, Kasto installed a system to vacuum the swarf continuously from the bore. This also has the effect of reducing the noise generated by sawing. Box item Sawing product and supplier news Kaltenbach made a significant number of new 'world-first' advanced machine efficiency claims at the 'International Partners in Steel' event, held at its headquarters in Lorrach, Germany, recently. Among the new saws launched was the KBS1051 mitring, structural steel bandsaw. Claimed by Kaltenbach to be the world's fastest bandsaw, demonstrations at the event saw it cut an HEM400 beam in 83 seconds. Kaltenbach also unveiled a new design of the KKS 463 NA universal, automatic mitring, up-stroking circular saw, the KKS 463 NA, again claimed to be the world's fastest. Also re-engineered, and similarly claiming to be the quickest in its technology area, is the range of high speed sawing systems from Ficep (01924 223530), offering width capacities of 600 to 2,000 mm. Bandsaws are traditionally built using a ballscrew set-up for the saw blade feed, which can become less efficient over time, so a new hydraulic system and gearbox improvement has been developed by Ficep to circumnavigate this issue. Image: Ficep's technology - claimed to be the quickest in its technology area In other news, Prosaw is the new UK agent for Geka, the Spanish manufacturer of products that include automatic shearing lines. First published in Machinery, October 2011