Abstract
Recent development in farm machinery has produced another type of harvesting machine called the “Binder”, which can perform reaping and binding simultaneously. This machine, however, has some defects, especially in producing tight sheaf for threshing process after a certain period of drying.
In order to understand more about the problem, some experiments under various factors related to sheaf loosening have been conducted. For convenience, a criteria was established to express the tightness of binding by using the term ‘looseness’ as the magnitude of sheaf clearance with the binding rope under compressive force of 3kg. I. Looseness-sheaf condition
1. Looseness was linearly increased with the weight of sheaf. Magnitude measured at threshing was three times bigger than that of reaping time.
2. Looseness was linearly decreased with binding force. Influence of the force over the difference in magnitude at reaping and threshing time was not clear.
3. Smaller magnitude of looseness was observed when location of binding was higher than the standard height. This influence was also visible in magnitude difference at the two processing time.
II. Looseness-operation condition of the machine
1. The influence of binding materials tested over the magnitude of looseness is explained by the following relationship:
Jute<sisal<polypropylene blister<polypropylene rope
2. The time of reaping at harvest day was also affecting the looseness. This is thought as a results of water contents influence.
3. Looseness of big sheaf (1. 30kg.) at harvest time was larger than small sheaf of 1.09kg.
III. Looseness-planting method
1. Sheaf from plot planted by drill method showed a larger looseness than that from plot by transplanting method.
It is expected that this fact was due to the influence of straw-foliage ratio of the sheaf.
