Observations of soiling of nylon 66 carpet fibers

Soiling of nylon 66 carpets was studied to investigate the effect of spin finishes with and without fluorocarbons finishes; and, in addition, the use of a secondary extraction process was examined to determine the effect of removing residual spin finish oils. Two types of residential carpet of intimate blend trilobal fibers with two modification ratios were evaluated: one had fluorcarbons in the spin finish with an additional topical mill-applied fluorocarbon. The second carpet had no fluorocarbons in the spin finish, but had a topical mill-applied fluorocarbon finish so that both carpets had a target of 250 to 300 ppm fluorine. Ace-tone extraction was used to remove the spin finishes from the carpets. Both carpets with and without extraction were soiled with particulate soil in the laboratory. Visual ratings and color difference measurements indicated more soiling on the carpets that had been extracted. Fluorine analysis showed that fluorcarbons were removed from both carpet types with the acetone extraction. Electron microscopy indicated the deposition of soil in the V-groove of the filaments with the higher modification ratio. Furthermore, fiber surfaces near the face of the carpet exhibited higher levels of soil than surfaces located near the carpet backing.