Structure–property relationship of melt spinning polypropylene fibers containing inorganic particulate CaCO3 fillers

Abstract

Spinning technology using melt extrusion and spin-draw processes transforms polymeric materials into highly oriented, crystallized polymeric fibers. Thermoplastic isotactic polypropylene compound with ground CaCO3 (GCC) and precipitate CaCO3 (PCC) with stearic acid surface coating treatment was used in this study. This product was developed in masterbatch form, which contained 70% GCC in resin and 50% PCC in resin. The resulting (masterbatch pellets) polymer can be spun into fibers through a single-screw extruder. Surface and cross-sectional images of fibers were captured by optical microscopy and scanning electronic microscopy for identifying the organic/inorganic interface of fibers. The melt-spun fibers have a distinctive morphology, the particles impact on spinnability, and productivity in the spunbond will alter the mechanical property, thermal property and optical property of fiber-based products. Processing parameters, including spinning speed, throughput rate and take-up roll velocity, were systematically study to understand the structure formation. Meanwhile, different loading concentrations are applied for varied factor comparison of particle size and shape. The Weibull distribution model is applied for determining the tensile property of fibers containing high GCC dosages of 20–40%. Meanwhile, a few more steps of gauge length are utilized for studying the probability of a weak link in polymer materials. Through a systematic discussion of the GCC and PCC comparison study in changing fiber properties, the impact of the particle size on agglomeration formation is emphasized, as well as the breaking mechanism of fibers.