Mechanical Properties of Feather and Down Fibers

Abstract

The elastic moduli of European goose feather barbs and down filaments have been measured at 70° F. and at 65% RH and various pressures of dry air. These latter meas urements at various dry-air pressures have been made to estimate the effects of air- damping on vibroscopic determinations of several fiber properties, have indicated the air-damping effects to be significant but relatively small, and are described in detail in Part II of these papers [6]. A detailed series of measurements has been made at 65% RH and 70° F. of the extensional properties, the bending modulus, and the torsional modulus. The breaking extension is about the same for all the different materials studied, but for the other extensional properties—such as elastic modulus—the properties of the feather barbs are greater than those of the down filaments, and generally the properties of the vane barbs (straight) are greater than those of the fluff barbs (curly). A similar finding holds for the corresponding cross-sectional areas. As in the case of the exten sional properties, the bending and torsional moduli of the feather barbs are greater than those of the down filaments, and vane feather barbs exhibit larger moduli than do fluff barbs. The significance and limitations of these measurements are discussed.