No abstract

A study of the cross-sections of single cotton fibers revealed that perimeter, cell-wall thickness, and cell-wall area are normally distributed, and that the parameters of the normal, or Gaussian, distribution can be used to describe these physical .

The fractured ends of single cotton fibers ruptured as a result of tensile strain, as well as cyclic bending fatigue, were examined in the scanning electron microscope. Interesting differences in fracture patterns were observed for fibers broken by the two methods. The study includes raw cotton as well as slack-mercerized fibers, and differences brought about as a result of swelling are described.

A study of the morphological features of cotton fibers and their relationship with tensile properties is described. An estimation of the magnitude of void space within the secondary wall on the basis of cell wall area and gravimetric fineness is made; the value of these voids seems to be quite high. The modifications brought about in both structural and mechan ical properties by swelling treatments using different swelling agents of appropriate concentration are given. Sodium hy droxide solution produces the maximum swelling in the cell wall, followed by ethylenediamine and zinc chloride. The reduction in strength at 0" gauge length due to swelling follows the same order.

An expression for the specific surface S0 of cotton has been derived in terms of gravimetric fineness H and a fundamental measure of maturity, namely, the degree of cell wall thickening θ. S02 has been shown to be a linear function of not only 1/θ H but also of 1/θ H2. This combined dependence, together with the fact that the apparent specific surface determined from airflow measurements depends upon the plug porosity, makes it possible to get reliable estimates of θ and H from measurements of airflow at two porosities. Analysis of data on a number of cottons has established that a single regression equation cannot cover all commercial cottons, but separate equations, depending on the flow rate, have to be used.