Abstract
The mechanical properties of lint were daily measured in relation to the development of the micro-structure of primary and secondary cell wall during the growing process of cotton fiber. The cotton variety used for this research was “Rikuchimen Kan-no No.I”, a sort of upland cotton.
The strength increases and the elongation decreases linearly with age of fiber, from the beginning of wall thickening until when wall thickening is just completed, and thereafter both strength and elongation show constant value until when boll opening just finishes. (strength 5.9g/lint, elongation 9.8%, after boll opening.) On the other hand, the strength per unit section area of lint begins its increase early in the growing process of elongation and attains a constant value (about 25kg/mm2) already at the day when wall thickening just begins.
The contribution of the primary cell wall to mechanical strength per unit section area is less than that of the secondary cell wall. The increase of the mechanical strength in the secondary cell wall is directly proportional to the increase of net area.
