MuCell® MICROCELLULAR FOAM TECHNOLOGY
NEGRI BOSSI IN COLLABORATION WITH TREXEL, INC.
Trexel, Inc. has led the development of the MuCell® microcellular foam injection moulding technology and has pioneered many plastic processing solutions. The MuCell® technology provides unique design flexibility and cost savings opportunities by allowing plastic part design with material wall thickness optimised for functionality and not for the injection moulding process. The combination of density reduction and design for functionality often results in material and weight savings of more than 20%. The numerous cost and processing advantages have led to rapid global deployment of the MuCell® process in automotive, consumer electronics, medical, packaging and consumer goods applications.
Negri Bossi, in collaboration with Trexel, is able to offer a machine that is suitably equipped to perform the MuCell® microcellular foaming process.
Trexel offer full product design consultation and will provide the technology license, SCF metering system, injector and special screw assembly. Negri Bossi equips the host machine with special software, special barrel, and the required hydraulic modifications.
Some elements of the MuCell® injection moulding equipment are sourced directly from Trexel, but Negri Bossi takes responsibility for the coordination of the assembly and interface of the different system elements with the injection moulding machine. In this way, the customer gets the best possible advice from the experts at Trexel, but can be sure that the system is properly integrated by Negri Bossi, the primary injection moulding machine supplier.
The MuCell® Process
THE MuCell® PROCESS
MuCell® microcellular foam technology for injection moulding is achieved in four distinct steps in the moulding process.
|1. During plasticization, precisely metered amounts of supercritical fluid (SCF), typically Nitrogen or CO2, are introduced into the polymer through injectors mounted on the plasticizing barrel.|
|2. Homogeneous mixing and dispersing of the supercritical fluid (SCF) into the polymer through the specially designed mixing section of the plasticizing barrel, creates a single phase solution of SCF and molten polymer.|
|3. Injection of polymer into mould cavities. Cells start to nucleate once exposed to lower pressure in the mould cavity. Molecular dispersion of SCF provides for homogeneous closed cell structure with a solid skin layer.|
|4. Low pressure filling of mould cavities. Pack and hold phase is replaced by controlled cell growth, which ceases once the mould cavity is filled. Cell growth results in a uniform pack pressure throughout the mould cavity.|
The following is a visual representation of the various equipment provided as part of a MuCell® injection moulding system.