Behavior And Mathematical Model Of Fuzzing And Pilling Of Wool Fabrics

Martindale tester was adopted to measure the mass of fuzz fibers on the surface of knittedfabric with100%wool. The number and mass of pills on the surface of the fabric and worn-offwere measured and their differences among morphology, mass and density in the platform regionwere also obtained.Experimental results showed that the effect between the mass of fuzz fibers on the surface offabrics and pilling was obvious. Both had two linear regions with different slope and their turningpoints at the same rubs. In the pilling region, the increase of fuzz fibers which could entangle intopills made contributions to the linear increasing of the total number of pills. On one hand, thedecrease of fuzz fibers resulted in slowly rising of the total number of pills. On the other hand, theexistence and growth of pills limited appearance of hairiness, especially these which couldentangle into pills.The curve of pills on the surface of fabric could be divided into three regions, which were thestage of pilling which was linearly going up, approximately exponential decay of worn-off zoneand platform region. The curve of pills worn-off consisted of quickly worn-off region in an “S”shape, whose rate distribution was corresponded to normal distribution and slowly and linearlyincreased area. The curve of the total number of pills included two linear regions with differentslope. So, The process of fuzzing and pilling had obvious periodic characteristics and could bedivided into three stages, which were stages of “pilling”,“worn-off” and platform region. Fuzzfibers entangling into pills and the number of pills going up mainly took place in the stage ofpilling. The growth of pills and pull-out or break-off of pills mainly occurred in the stage of“worn-off”. Pull-out of anchor fibers and twist of large pills mainly happened in the platformregion.The number of pills on the surface of fabric was constant in the platform region. Thephenomenon of “Occupying” happened. That’s to say that new pills formed until the existing pillsat the same position broke off or pulled out. That was also the essential reason of slowly rising ofthe total number of pills. In the platform region, pills on the surface of fabric tended topull out and twist and became longer and denser, whose height, mass and densityincreased with various degree and diameter and volume had different degrees ofdecline. All of these of pills worn-off went down and were less than that of pills onthe surface.The feature points on the curves of the mass of fuzz fibers and the number of pills, such asthe point T, P or A and B, had greater practical significance. The essential reason of or wasthe increase of fuzz fibers which could entangle into pills and the number of pills in unit areareached the saturation. That large pills were difficult to wear off and new pills were too weak tobreak off resulted in the appearance of the point in the platform region. The value of point isthe number of pills in unit area which was constant. These feature points will be the best conditions to conduct post-treatment. Two ways to achieve practical and ideal anti-pilling wereobtained according to the maximum number of pills on the surface of fabric and the point B andrubs getting to these two points.The development tendency of the mass of pills was consistent with that of the number of pills.Both firstly rise and then went down. The mass of pills was just rising slower than the number ofpills and also very much slower to reach the maximum points. The development tendency of themass of pills worn-off was strikingly similar to that of the number of pills worn-off: rapidly rosefirstly in an “S” shape and then slowly and linearly decreased. The total number of pills firstlylinearly went up and the slowly continued to rise. While the total mass of pills firstly rose in a “S”shape and later slowly increased.The process of fuzzing and pilling was self-limited. In the platform region, the mass of fuzzfibers gradually decreased and the number of pills in unit area was constant and the number andmass of the total pills slowly increased.The models of fiber entanglement, pills worn-off and the mass of pills were proposedaccording to the obviously periodic characteristics in the process of fuzzing and pilling and theirmain development and effects. The results achieved through these models were roughly the sameas the experimental results.