A differentiated approach to the mechanical finishing of "POLAR FLEECE" type pile knitted fabric

Abstract

Purpose. Justification and development of an energy-efficient technological cycle for the mechanical finishing of "Polar fleece" pile knitted fabric, which ensures compliance with the regulatory requirements of the technical specifications of the Ministry of Defense of Ukraine (TS MODU) in terms of thickness and air permeability without the use of specialized combing machines. Methodology. The study employs a comprehensive approach that includes experimental research on the influence of the parameters of a 6-stage differentiated raising on the fabric's surface texture using double-drum equipment. Laboratory tests of physical and mechanical indicators were conducted in accordance with DSTU ISO 5084:2004, DSTU ISO 9237:2003, and DSTU ISO 12945-2:2005. The theoretical analysis of thermophysical properties is based on thermal resistance models, as specified in ISO 11092. Results: It was established that the classical "Raising – Combing" finishing scheme used in imported analogs results in excessive structural consolidation of the pile, reducing air permeability below 600 dm³/(m²s) and decreasing thickness. It was proven that the application of the proposed 6-stage cycle "raising – felting – imitative combing" on universal raising machines enables achieving a normative thickness of 5.0 mm and an air permeability exceeding 600 dm³/(m²s).
Scientific novelty: For the first time, the possibility of imitating the anti-pilling combing process on universal raising equipment was substantiated through the precision control of the speed modes of the "pile and counter-pile" rollers at the final finishing stage, which ensures the preservation of the material's capillary-porous structure (Loft effect). Practical significance: A technological cycle for finishing "Polar fleece" pile knitted fabric was developed and implemented, providing high thermophysical characteristics compared to foreign analogs without additional capital investments in specialized equipment.