Arburg press boasts five injection units
An exotic ``two-component, four-color'' injection press built by Arburg GmbH + Co. KG has five injection units, to mold one of the original two-component products: toothbrushes with soft-touch handles.
The press was shipped to toothbrush maker Zahoransky Formenbau GmbH in Freiburg, Germany.
The five injection units on the Allrounder can produce four different two-component toothbrushes using a single mold. A horizontal unit injects plastic through the fixed platen in the conventional manner. The other four units come down vertically on a common base plate, which is mounted on the fixed platen.
All axes can be moved and programmed independently. Zahoransky Formenbau molds the toothbrush body from polypropylene, then molds four different colors of thermoplastic elastomer soft-touch components, in a single production step. An index platen, moved by an electric rotating unit made by Zahoransky, turns the eight-cavity mold insert through two injection stations, then passes finished toothbrushes to an Arburg Multilift robot.
Toothbrushes are sorted according to color. A conveyor belt moves them to downstream operations, such as insertion of the bristles and packaging.
Arburg said Zahoransky is considering a sixth injection unit, which would come in at a 45-degree angle through the fixed platen.
Arburg is based in Lossburg, Germany. Its U.S. unit, Arburg Inc., is in Newington, Conn.
Tel. (860) 667-6500, fax (860) 667-6522, e-mail [email protected]
Solvay SA's process can strengthen parts
An injection molding process patented by Solvay SA injects the melt onto a rotating core, improving the strength and dimensional stability of cylindrical or conical parts - such as an automotive throttle body.
Improved burst strength is reached because the process produces a preferred orientation in the polymer. The polymer chains become arranged around the circumference of a cylindrical or conical part, rather than along the flow path of the plastic. Solvay compares that orientation to the reinforcing belts under the tread of a radial tire.
Rotating the core during injection also reduces knit lines, or where the flow fronts meet.
Solvay Advanced Polymers LLC in Alpharetta, Ga., is studying additional benefits of the technology, especially in improved dimensional stability over a range of temperatures and humidity. In the throttle-body example, there is a tight tolerance between the dimensions of the air-regulating valve and the core - and it should not change with fluctuations in under-the-hood conditions.
Beyond automotive, other applications could include plumbing fittings and thrust washers.
Tel. (770) 772-8200, fax (770) 772-8454, e-mail [email protected]
Nitrogen gas system reduces cycle time
Munich, Germany-based Linde AG supplies nitrogen gas for gas-assisted injection molding. The company has developed a way to reduce cooling time, cutting cycle time by as much as 30 percent.
The patented process is suitable mainly for parts with pipe-shaped gas channels, Linde said. After the normal gas injection, the feed of nitrogen to the primary injector is interrupted. The pressure and flow regulation system opens the injector to the atmosphere, then the gas flow is reversed. Additional nitrogen flows through a second injector placed at the end of the gas channel, opposite the primary injector, which now functions as a gas outlet.
The high-pressure nitrogen flowing through the part cools the inner side of the gas channel and removes heat.
Also new from the Linde Gas Division: a cryogenic deflashing machine that uses liquid nitrogen.
Tel. +49 (89) 126-6690, fax +49 (89) 126-6 6915.