Studies on Harvesting Machines (25)

Compressibility of Sheaves of Barley, Wheat and Rice

Abstract

This paper presents the experimental results of the compressibility of green or dry sheaves, using some binding materials on variable tightening forces. We have got some results, that is:
1. The relation between the rate of shrinkage of sheaves and the tightening force of binding material is represented by the experimental equation: E=a+mlogW
where, E: rate of shrinkage (%)
W: tightening force (kg)
a, m: coefficients
2. The rate of shrinkage of sheaves does not depend upon the kind of binding materials, but it diminishes as the diameter of binding material becomes larger.
3. The sheaves of green barley and wheat shrink easier than green rice sheaves, but there is little difference of shrinkage in dry sheaves.
4. We could not find out the difference in the characteristic of shrinkage between before and after the ripening season. The rate of shrinkage of the sheaves of green stalks is smaller than that of dry sheaves.
5. If the binding force is released, the sheave can not regain its original volume. We call this phenomenon residual shrinkage. The rate of residual shrinkage changes in obedience to the rate of shrinkage.
6. When the sheaves are binded by uniform force, the quantity of shrinkage, of sheaves is larger in accordance with the volume of sheaves, while the rate of shrinkage is smaller.
7. In this test, we come to the conclusion that nearly 50%-shrinkage of sheaves is enough for small binder, and that the standard tightening force for small sheaves is 10-15kg.