Low-cost apparatus for measuring undispersed particles in extruded plastic ribbon

An apparatus was designed and constructed that quantitatively measures the number and size of poorly dispersed particles ( >3 μ m diameter) that protrude above the surface of an extruded plastic ribbon ( 0.10–0.15 mm thick). Major components of the apparatus include a set of in-house fabricated dispensing and take-up wheels for guiding the ribbon’s path, a commercially available variable differential transducer, and custom-designed software based on National Instruments’ LABVIEW platform. The reproducibility and repeatability of the technique are presented, along with data comparing this approach to more conventional, albeit labor-intensive manual approaches.