DuPont's Zenite liquid crystal polymer (LCP) is currently being used by
the Swiss electrical products manufacturer, Sonceboz, to manufacture very
thin-walled coil bobbins for its 4000 Series torque motor. Thanks to its
high thermal resistance and good melt-flow characteristics, Zenite fills
the tool cavities completely, even though the bobbins have a wall
thickness of just 0.30mm. Sonceboz uses a 30% glass fibre reinforced
Zenite for this application, enabling it to take the stresses of the
winding operation.
The material is also used to over-mould the wound coils, its low melt
viscosity preventing winding displacement during the injection process.
As the over-mould functions as a housing for the stator, it also serves
as a plastic bearing for the rotor shaft. Thanks to its good sliding
properties, Zenite LCP was used as a replacement for the separate
bearings of PEEK and bronze.