News | April 18, 2006

New Blow Molding Machine Utilizing Parison Suction Technology For 3D Parts

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UMA 20.SH parison suction cuts energy and flash in blow molding long, 3D high-temp automotive and appliance parts

Tecumseh, MI — Uniloy Milacron's new UMA 20.SH blow-molding machine uses advanced parison suction technology to economically produce elongated and curved 3D shapes virtually flash-free from high-temp engineering resins. Particularly suited to automotive underhood components – air ducts, turbocharger pressure pipes, coolant lines, tank filler pipes, etc. – the innovative machine can also save production time and material waste for the appliance industry on high-temp lines and pipes for tumble dryers, laundry washers, and dish washers. Parison suction eliminates parting lines as weak points, while delivering superior wall-thickness uniformity. The UMA 20.SH machine can be equipped for sequential co-extrusion of two-material parisons, enabling molding of components with both stiff and flexible sections.

Modular machine design allows easy interchangeability between suction-blow and conventional blow-molding. This enables users to gain high flexibility and utilization from the accumulator head UMA 20.SH, especially in the early stages of developing suction-blow business. The machine's dimensions support processing of a wide range of products.

In parison suction, mold close comes first, then the parison is pushed out from the melt accumulator into the closed cavity. The parison floats on an air stream generated by a suction fan at the bottom of the cavity. The parison is drawn down through the mold contours, while support air is blown as needed inside the parison from the top to prevent parison collapse. When the mold is filled, sliders close off the top and bottom ends of the parison. The parison is inflated against the cavity walls via needles located at the parison ends. Additional needles can be used to enhance internal cooling/flushing air for reduced cycle times.

Parison suction permits exceptionally tall molds, enabling two or more parts to be molded end-to-end in one cycle, then separated afterwards.

The suction process eliminates flash along the length of components, in turn reducing trimming stations and waste handling. Parison suction leaves minimal flash material, just finishing of domes created by top and bottom close-off. The UMA 20.SH brings exceptional material utilization and process economies to blow-molding of HDPE, PP, high-temperature nylons, glass-filled resins, thermoplastic rubber, and engineered materials. The machine is engineered for 340°F (640°F) melt temperatures.

Parison suction allows a compact machine to produce parts of exceptional dimensions and geometries for significant investment and energy savings. The process enables a smaller head and extruder and lower clamp force than would be required for traditional blow molding of the same shapes.

The UMA 20.SH offers shot sizes up to 1.3 liter (1 kg of HDPE) with maximum output of 125 kg/hr HDPE. The adaptable machine accepts mold platens up to 700 x 650 mm (27.5" x 25.6") and provides 1000 mm opening daylight.

An open-access, tie-barless clamp unit, adapted from Uniloy shuttle machines, permits easy access to the mold from three sides. The 200 kN clamp unit (300 kN optional) enables traditional blow molding, along with suction blow.

A touch-screen machine interface provides 100-point process control, configuration of valve sequences, record of all modified variables, and remote tele-service access to machine screens and sequences. Control-based SPC/QC capability is available as an option. Ethernet communications allows easy networking and high-speed signal transmission.

Uniloy can supply the UMS 20.SH as a complete production system with downstream equipment for automated parts handling and finishing (cutting, milling, welding).

SOURCE: Unilow Milacron