Ice provides the natural fixturing choice
Ice provides the natural fixturing choice An ice cube tray stuck in the freezer or frost holding wipers to windshields on a winter morning are nature’s way of showing the strong adhesive power of ice. A world leader in the use of this technology, French company AMCC uses the concept to develop its GF Series of icing plates. These plates use the power of ice to hold parts for milling, turning or grinding. This new clamping system is rigid and does not induce stress into the part. It holds parts on a single face, is fast and easy to use and can firmly hold limitless shapes and materials. Tamworth-based Leader Chuck Systems is the exclusive UK agent for this impressive and unusual technology. Managing director, Mark Jones, says: “Icing plates are particularly effective for machining sintered materials, unfired ‘green’ ceramic, ferrite, graphite, and much more. Ice is an excellent adhesive that can grip almost any material, rigid parts made of metal or plastic, and flexible parts made from rubber, neoprene and even textile.” On metals, ice has a tensile strength of 1.48 N/mm2, compared to magnets at 1.17 N/mm2or a vacuum at just 0.09 N/mm2. Using icing plates removes the need for costly bespoke fixturing assemblies. And, there is no distortion and breakage due to clamping and/or unclamping. Whatever the shape, fragile parts are held firmly in place and without stress. With the parts held on one face the machine tool can access the other five faces. For plastics, freezing increases its rigidity, and therefore improves surface condition. Plate cooling is achieved by means of a patented compressed-air heat exchanger. On some models, the assembly is driven by a temperature-controlled pneumatic system. By using the thermal inertia of the icing plate, this control system also conserves compressed air. Thanks to its compact mono-block design, the GF icing plates are quick to install. Simply connect to the compressed air system, spray water onto the icing plate, and position the part to be machined. Then activate the temperature control button. Within seconds the water freezes and the part is clamped. Unclamping is done just as fast by reversing the freeze/thaw valve. What's more, the Z-axis repeatability is maintained as there is no water film under the part. The plate also removes the heat generated by the machining process, negating the need for any lubrication. Mark Jones concludes: “Originally designed to meet the rigorous demands of the space industry, AMCC's icing plates have since found suitable applications in a diverse range of manufacturing applications which feature delicate parts, including medical, electronics, watch-making, jewellery, and so on. With the benefits it offers the technology will be of significant interest to companies machining composite parts. AMCC has several models of GF Series icing plates available, according to use, and can customise a solution based on specific customer needs.”