The influence of processing parameters on the structural and mechanical properties of drawn polypropylene fibres: A factorial design approach

Abstract

This article reports a study of multi-stage polypropylene fiber drawing (stretching) as a continuous, but independent stage of the overall fiber-forming process. The fibers were drawn according to a factorial experimental design, once appropriate spinning conditions had been devised. The structures of the drawn fibers were studied using wide-angle X-ray diffraction and birefringence measurements. In addition, the fibers were characterized with respect to filament tenacity, elongation to break, specific secant modulus, and extent of shrinkage at 130 C. All these properties were quantitatively assessed as responses to nine specially selected process control parameters in the drawing equipment. For every property analyzed, the temperatures of the hot plates in the draw frame were found to exert no significant influence, whereas the temperatures of the initial rollers were in most cases significant. Furthermore, the speed of the final roller also played an influential role, and a number of interactions between process parameters were identified as significant. Explanations are advanced for the parts played by significant process parameters on the properties of the drawn fibers. The article also demonstrates the advantages of factorial experimental design in determining correct settings for process parameters to give drawn fibers with the properties desired.

Experimental Investigation of Polypropylene Composite Drawn Fibers with Talc, Wollastonite, Attapulgite and Single-Wall Carbon Nanotubes

“…This sample was used for spectroscopic measurements. 3 T m : melting point, 4 D 50 : mass-median-diameter, 5 MFI of the PP used for the preparation of the masterbatch and not the MFI of masterbatch itself.…”

“…Depending on drawing parameters, e.g., draw ratio and temperature, the increase in tensile strength and elastic modulus of PP fibers may be significant, i.e., from 2 to 10 times higher [2,3]. In this direction, the drawing of PP fibers has been extensively studied in terms of fiber production and drawing methods, including the use of melt spinning/drawing [4][5][6], ecologically friendly isothermal bath [7], laser-assisted drawing [8,9], temperature gradient multiple stage drawing [10,11], and overdrawing [12]. However, the drawing of polymer matrices and the subsequent improvement of properties present limitations, such as the difficultly in processing low molecular weight polymers and the shrinkage of drawn materials with aging.…”

Predicting the physical properties of drawn Nylon-6 fibers using an artificial-neural-network model

“…Moreover, the risk of excessive downtime for trials is reduced [2][3][4][5] . Due to their simplicity, regression-based models and statistical analyses were extensively used to solve textile technological problems [2][3][4][6][7][8][9] . However, they have certain limitations as they require a specialized knowledge of both the statistical methods and techniques of experimental design.…”

Use of D‐optimal design to model and the analysis of the effect of the draw ratio on some physical properties of hot multistage drawn nylon 6 fibers

“…A better control and understanding of synthetic fiber processing are essential requirements for obtaining a desired range of mechanical and physical properties. In this regard, the statistical approach is well suited for the development of the synthetic fiber process technology; it efficiently leads to more reliable and accurate results in a small number of experiments …”