Polymer Concentration-Driven Morphological and Mechanical Variations in Flash-Spun High-Density Polyethylene Fibers

Area of Science:

• Materials Science
• Polymer Science
• Textile Engineering

Background:

• Flash-spun filaments (FSFs) from high-density polyethylene (HDPE) are crucial for industrial nonwovens due to their robust morphology and mechanical strength.
• Understanding the influence of processing parameters on FSF properties is vital for optimizing nonwoven performance.

Purpose of the Study:

• To investigate the impact of polymer concentration on the formation and properties of HDPE FSFs.
• To elucidate the relationship between polymer concentration, solvent evaporation, phase separation, and FSF characteristics.

Main Methods:

• Laboratory-scale flash-spinning under supercritical conditions.
• Morphological, mechanical, and crystallographic analyses (including X-ray diffraction).
• Systematic variation of polymer concentration from 5 to 15 wt%.

Main Results:

• Increasing polymer concentration (up to 12 wt%) enhanced filament thickness, crystallinity, and mechanical strength, with optimal modulus at 270.77 cN/tex.
• At 15 wt%, mechanical properties degraded due to hindered solvent evaporation, disrupting polymer alignment.
• X-ray diffraction showed consistent small crystal sizes (6.4-6.9 nm), indicating concentration affects domain number, not size.

Conclusions:

• Polymer concentration critically influences FSF morphology, orientation, and mechanical stability.
• Solvent evaporation dynamics and phase separation are key factors in FSF structure development.
• Precise control over polymer concentration is essential for designing high-performance flash-spun nonwovens.