Owing to aluminium’s special characteristics, the rules for sawing it differ from those for other materials such as steel. Cutting speeds must be higher and cutting forces lower. To ensure clean, exact cuts, it is especially important to have an optimum cutting geometry along with good lubrication and cooling. Chips can readily cause problems owing to the high speeds and must be removed in an effective manner. Users who saw aluminium on a regular basis are therefore advised to purchase a machine that is specially designed for this purpose.
The Kasto portfolio includes a wide selection of machines in all sizes, from semi-automatic floor-standing circular saws for workshops to gantry-type band sawing machines for aluminium mills. Kasto, based in Achern-Gamshurst, Germany, is a company that provides solutions for sawing tubes, profiles and solid materials as well as sheets, plates, ingots and castings. The range includes versatile multipurpose saws for various materials, plus saws that are optimised for machining aluminium.
The Kastoalu range comprises a number of floor-standing circular saws for use in workshops. They are especially suitable for aluminium, other light metals and plastics. Their high-performance carbide saw blades have trapezoidal flat teeth with a positive cutting angle, ensuring perfect results even at low cutting pressures. Users have a choice of saw blades with different numbers of teeth depending on the panel and plate thickness. This allows the creation of reproducibly precise, burr-free cut parts. Less work is required for reworking, and the parts can be further processed or installed right away.
Figure 1: There are semi-automatic mitre-cutting circular sawing machines in the Kastoalu U line are
especially good for cutting tubes and profiles to length.
Figure 2: The Kastospeed M line was developed for low-cost, high-volume cutting of aluminium, copper and brass.
The range includes the semi-automatic models E 12 / U 12, U 14 and U 20, which cover a cutting range from 100 to 200 millimetres (for tubes and profiles), as well as the fully automatic, numerically controlled Kastoalu A 13 with a cutting range of 100 millimetres (likewise for tubes and profiles). The semi-automatic saws are capable of straight and mitre cuts, with an increment-free mitre angle between ±45° and ±90° depending on the machine. There are models which, in contrast, are suitable only for straight cuts. All the models have a hydropneumatic, infinitely adjustable saw feed plus pneumatic horizontal and vertical clamping elements. An efficient micro-spray lubrication system and an integrated air gun come as standard, and a connecting sleeve for installing a chip suction unit is standard as well. Various roller tracks and measuring systems are available as optional accessories.
The company also produces as separate line for low-cost, high-volume cutting of aluminium, copper and brass. This circular saw is available in two versions, with a cutting range of up to 90 millimetres or up to 152 millimetres (round stock). The robust machine construction with an obliquely meshing spur gear mechanism, combined with a hydraulically damped measuring stop and a bar pusher that can be moved rapidly into position, ensures precision cutting and very high output. Depending on the application, high-speed steel, carbide tipped or PCD saw blades are used. Material feeding and sorting can be adapted to the customer’s requirements by means of a well-designed modular system.
Figure 3: There are band saw options for all common aluminium materials up to a diameter of 830 millimetres like the Kastotec M bandsaws.
The company also has a series that provide a quick, economical solution for all common aluminium materials up to a diameter of 830 millimetres (round). A spindle-driven material advance slide exactly positions the material to be sawn. Precision-balanced drive elements permit very high cutting speeds in combination with smooth running that is kind to the tools. Specially designed blade guides support the tool and form short chips that are easy to dispose of. It also has a self-explanatory control system with a clearly structured interface that makes operation much easier and reduces set-up times.
The company also offers solutions for efficient sawing of small aluminium ingots, plates, castings and test strips with a maximum height of 600 millimetres and a length of up to 1,250 millimetres. A moveable material support table ensures quick, safe handling of stock. Precision-balanced drive elements and specially designed blade guides permit cutting speeds of up to 100 meters per minute and high cutting performance while ensuring a smooth sawing process with minimal tool wear and an optimal operational lifetime. Technologies include a bandwheel housing is designed to optimise the path of flying chips to a suction device. The cutting speed and feed rate are continuously adjustable.
Figure 4: There are also options for efficient sawing of small aluminium ingots, plates, castings and test strips.
For material with large dimensions, there are also options for users like the Kastomaxcut. The gantry-type band sawing machine is suitable for fully automatic sawing of aluminium plates with a thickness of six to 2,000 millimetres. Depending on the version, there are bandsaws can handle ingots with cross-sections of up to 2,200 x 850 millimetres and lengths of up to 4,100 millimetres. Its heavy-duty design makes it suitable for medium-scale to very-large-scale production. The cutting speed is continuously variable from 300 to 3,000 metres per minute. Even so, the saw runs very quietly and without vibration. The machine can be operated with both bimetallic and carbide blades.
This heavy-duty machine is used in aluminium mills and other facilities. For example, Gleich Aluminiumwerke GmbH & Co. KG in Kaltenkirchen, Germany, uses the saw to manufacture aluminium plates from ingots measuring 2,000 x 4,000 x 800 millimetres. The company supplies customers in the mechanical engineering, tool-making, aerospace, automotive and construction industries. The machine has significantly increased saw blade lives and reduced downtimes. Moreover, thanks to fully automatic operation the company was able to increase its production while maintaining consistently high quality. The machine is equipped with strong roller tracks and transverse conveyors plus a vacuum transfer unit to handle the ingots, which can weigh up to 15 tonnes.
