Abstract
In this report, an analysis of breakage effect of cylinder type- and beater-type machines, which are used in breakage of cotton tufts, was performed by a digital simulation.
As cylinder type machine, double Crighton Opener and Superio Cleaner, and also as beater type machine, Double Scutcher were used.
On cylinder type machine, the size distribution obtained experimentally agreed with that obtained by the simulation which was made under the assumption that the ratio of a tuft affected by breakage action is propotional to its weight (called size) and the break part was distributed uniformly on tuft.
Superio Cleaner
It was considered from size distributions by experiment and simulation that breakage of tuft in Superio cleaner is saturated at break stage of S-4 or S-3. Good results were obtained when a by-pass effect that only the tufts with the sizes larger than the max-size estimated from size distribution are broken was introduced into the simulaton model of Superio Cleaner.
Crighton Opener
A difference of simulation model between Superio Cleaner and Crighton Opener concerned with the transfer of tuft in the breakage zone and it was supposed in the simulation model that transfer condition of a tuft passing through the breakage zone was propotional to the size.
Then, using the transfer condition weighed by a factor decided from the relation between max. length of tuft and size, good results were obtained.
In the simulation model of beater type machine, it was assumed in beating zone of Scutcher that the size distribution of tufts cut by beater is exponential and the distance from the beating point to the nip point of a tuft (effective beater guage) was about 30-45mm.
The size distributions of the simulaton of beater type machine agreed with experimental results under the above assumptions and the relation between size of a tuft and its max. length.
As input data to these simulation models, the size distributions obtained experimentally were used.
