INJECTION MOULDING
Veritable boom in microcellular foams / Focus at K 2004 exhibition / Saving cost and weight
Injection-moulded parts made completely from foam or at least with a foamed core have been around for many years. The advent of so-called microcellular foams is more recent. Aside from savings on cost and weight, they offer other compelling benefits, according to Messe Düsseldorf, organiser of the K 2004 international trade fair for plastics and rubber, to be held in the German city from 20-27 October (www.k-online.de).
Microcellular foams, which consist of bubbles or cells so tiny as to be measured in micrometres, are currently enjoying a veritable boom. Made by physical – as opposed to chemical – foaming, they have an average cell diametre of around 100 micrometres, and thus hover just above nanoscale. One foaming, or blowing, agent is carbon dioxide, also used in the conventional foaming of other polymers, including polyurethane (PU), polypropylene (PP) or polyethylene (PE).
One of the most popular microcellular foaming technologies is the “MuCell” process, patented by Trexel (Woburn, Massachusetts / USA; www.trexel.com). Machinery adapted for the process is offered by a number of internationally active manufacturers and can be operated with a licence from the US patent holder.
Alongside the diminished weight and reduced costs, another considerable advantage of microcellular foams touted by the US patent holder is the ability to use machines with a lower than usual clamping force. This is thanks to the lower pressure required in injection moulding with foaming agents. As the packing and holding phase required by conventional injection moulding also is eliminated, internal pressure in the mould is determined solely by the injection process.
A major user of the process is engineering plastics producer Ticona (D-65451 Kelsterbach; www.ticona.com). In August 2001, the subsidiary of chemicals group Celanese (D-65451 Kelsterbach; www.celanese.com) flipped the switches on a plant for the MuCell process from the Munich factory floor of Krauss-Maffei (KM, D-80997 München; www.krauss-maffei.de).
Tests performed at the Ticona technical centre confirmed the economies achieved by the microcellular foams. The process technology is, however, not without its challenges, and it is vital that the manufacturer take the initiative in gaining his own expertise, asserts Martin Witulski, managing director of Schröder Kunststofftechnik GmbH (D-58566 Kierspe; www.schroeder-kunststofftechnik.de). The German company was one of the first plastics processors to use microcellular foaming and has owned a MuCell-capable injection-moulding machine since mid 2003.
Microcellular foams, which consist of bubbles or cells so tiny as to be measured in micrometres, are currently enjoying a veritable boom. Made by physical – as opposed to chemical – foaming, they have an average cell diametre of around 100 micrometres, and thus hover just above nanoscale. One foaming, or blowing, agent is carbon dioxide, also used in the conventional foaming of other polymers, including polyurethane (PU), polypropylene (PP) or polyethylene (PE).
One of the most popular microcellular foaming technologies is the “MuCell” process, patented by Trexel (Woburn, Massachusetts / USA; www.trexel.com). Machinery adapted for the process is offered by a number of internationally active manufacturers and can be operated with a licence from the US patent holder.
Alongside the diminished weight and reduced costs, another considerable advantage of microcellular foams touted by the US patent holder is the ability to use machines with a lower than usual clamping force. This is thanks to the lower pressure required in injection moulding with foaming agents. As the packing and holding phase required by conventional injection moulding also is eliminated, internal pressure in the mould is determined solely by the injection process.
A major user of the process is engineering plastics producer Ticona (D-65451 Kelsterbach; www.ticona.com). In August 2001, the subsidiary of chemicals group Celanese (D-65451 Kelsterbach; www.celanese.com) flipped the switches on a plant for the MuCell process from the Munich factory floor of Krauss-Maffei (KM, D-80997 München; www.krauss-maffei.de).
Tests performed at the Ticona technical centre confirmed the economies achieved by the microcellular foams. The process technology is, however, not without its challenges, and it is vital that the manufacturer take the initiative in gaining his own expertise, asserts Martin Witulski, managing director of Schröder Kunststofftechnik GmbH (D-58566 Kierspe; www.schroeder-kunststofftechnik.de). The German company was one of the first plastics processors to use microcellular foaming and has owned a MuCell-capable injection-moulding machine since mid 2003.
16.09.2004 Plasteurope.com [200797]
Published on 16.09.2004