Archive for Prosinec 9th, 2011

Conductive plastics stop toys from interfering

A five-strong team at AIJU, based in the Spanish toy industry center of Ibi, is undertaking a two year research and development project to tackle the interference problem. They are combining carbon nanofibers with polyethylene and polypropylene, polymers commonly used in toy production, to assist electrostatic dissipation, electrostatic painting and electromagnetic outer screening.

To achieve the aims of the program, it was essential the resulting materials were lightweight, capable of being extruded and injection molded and able to resist a magnetic and electrical field, as well as being cost competitive.

During the first year of AIJU’s EMIToy project, which saw investment of around 95,000 euros, the materials specialists achieved encouraging results. Tests incorporating carbon nanofibers and carbon black in a composite material significantly reduced the levels of electromagnetic percolation to below 2 percent, according to project manager Ana Ibá?ez.

“Immediately, the degree of resistance is in the region of 1,000 ohm cm. Probably, with 8 percent concentration of [carbon] nanofibers and 12 percent of carbon black we could reach effective electromagnetic screening,” she told European Plastics News.

In the second year of the EMIToy project, the Spanish team has been working with a base PP matrix incorporating an 8 percent carbon black content, prepared in a twin-screw co-rotating extruder. This formed the base material for trials with varying quantities of carbon nanofibers: 2 percent, 4 percent and 6 percent. Similar tests are being carried out with a high density polyethylene substrate.

Once the team from AIJU’s Product Engineering Laboratory has determined the optimum percentage content and type of nanofibers, it will design a suitable plastic housing component for the chosen electronic toy using the best conductive material.

Already, a number of companies in the Spanish toy industry and from other sectors have expressed interest in the results of the project, which is due to be completed by the end of this year, Ibá?ez says.