Thesis Details


Thesis Title: The effects of fiber properties and web uniformity on nonwoven polypropylene needlepunched fabrics
Thesis Author: Rotricia Smith
Abstract: Fiber characteristics greatly influence the level of fiber openness, the uniformity of the carded web, and ultimately the quality of the nonwoven needlepunched fabric. With technological advancements in nonwoven manufacturing, production speeds of nonwoven machinery are increasing, and the control of the web weight for web uniformity becomes more challenging. Manufacturers are faced with higher raw material costs to achieve desirable web properties. Optimization of fiber properties will reduce the need to use additional raw materials to compensate for the strength of nonwoven fabrics due to nonuniform webs. The purpose of this thesis was to study the effects of fiber openness, chip content, finish level, and crimps per inch on web uniformity and fabric strength, elongation, weight, and air permeability. The results indicated that bale conditions with a higher finish, chip content, and crimp level produced lower openness values. The poorest web uniformity was found for the high chip, high crimp, and medium finish bale conditions. The nonwoven fabric strength increased with increasing crimps per inch up to an optimal level, beyond which the strength decreased. Low chip content bale conditions produced a high fabric elongation with increasing crimps per inch as compared to high chip content conditions. Heavier fabric was produced for medium crimp, high chip, and low bale openness conditions. Results for air permeability were found to be inconclusive, with no practical significance.