LOOP STRENGTH OF SPUN COLLAGEN-FIBERS

The effects of gultaraldehyde (GA) crosslinking, basic chromium sulfat e (Cr) tanning, and thermal treatments on the loop strength of spun co llagen fibers were studied. The loop test have been carried out using a piano wire as a model loop. The promotion of GA crosslinking led a s ignificant decrease of the strength and elongation at break. On the ot her hand, the promotion of Cr tanning gave no change. These properties decreased with an increasing shear stress at bending region of loop. The improvement of these mechanical properties were realized by therma l treatments of both GA crosslinked and Cr tanned fibers. The thermal treatment temperature showed the maximum effect at 100 degrees C. Howe ver, there was no effect of thermal treatment for the noncrosslinked f ibers. The fracture morphology of Cr tanned fibers is characterized by longitudinal splitting along the fiber axis in the bending region, al though the fracture morphology of noncrosslinked and GA crosslinked fi bers can be characterized by transverse fracture. (C) 1996 John Wiley & Sons, Inc.