Thesis Details

Thesis Title: The effect of selected variables in pigment coloring on the carding characteristics and final fabric quality of polypropylene needlepunched nonwovens
Thesis Author: Karen L. Keane
Abstract: It is a well known fact that polypropylene cannot be dyed like other conventional fibers because it has no dye sites and no affinity for dye. The principal method to color the fib~rs is to introduce pigments into the melt before the fiber is extruded. When this is done, foreign material enters the melt, and the resulting fiber properties are affected. In needlepunch manufacturing, fiber property changes caused by pigments are realized most in the carding process. Unlike yarn manufacturing, in needlepunching, carding is the only opportunity to align the fiber and reduce weight variation. One of the greatest opportunities for improvement in this area is to determine why there is so much variation in processing performance among polypropylene fibers with various pigment colors. This was the basic opportunity upon which this research was designed. The bottom line conclusion is that different pigments do affect fiber cohesion and weight uniformity in needlepunch fabric formation. These changes are associated with the changes in fiber morphology, as found in this thesis. Based on this study, it is recommended to producers and users of pigmented polypropylene that each pigmented fiber be characterized, and appropriate adjustment in your process made to achieve maximum quality and efficiency.