An oriented nylon 6 monofilament of uniform cross-section as shown in FIG. 9 with dimension D 0.100 inches was moved to between an arrangement of gears such as depicted in FIG. 2. Deformations of approximately 0.003 inches were uniformly spaced along the length of the monofilament of 0.090 inch intervals. Fibrils formed while trimming vegetation averaged less than 0.015 inches in length.