Product Description

The Nauta conical screw blender, marketed in the United States through Littleford Day and its predecessors, was a workhorse for dry powder blending in pharmaceuticals, pigments, resin masterbatches, and specialty chemicals. According to publicly filed asbestos litigation records, the orbital screw shaft seals allegedly used woven asbestos-fabric packing, and the top cone cover and discharge valve joints allegedly seated against compressed asbestos sheet gasket material.

Removing crusted product from the screw, replacing packing rings, and hand-cutting cover gaskets during cleanout allegedly released respirable asbestos fibers into the mixing bay.

Workers Exposed

  • Pharmaceutical plant blenders performing batch changeovers
  • Chemical process operators charging pigments and specialty chemicals
  • Plastics compounding operators handling resin masterbatches
  • Plant mechanics and millwrights servicing screw drives and seals