METHOD, PROGRAM, AND APPARATUS OF DESIGNING DIE FOR STRAND MANUFACTURING, DIE AND METHOD FOR STRAND MANUFACTURING

摘要

PROBLEM TO BE SOLVED: To enable design of a die for strand manufacturing that is appropriate for a desired supply flow rate.SOLUTION: A method contains: a preparation step to prepare a given relation investigated by using a nozzle for investigation and a channel for investigation that communicates to the nozzle for the investigation; a first calculating step; a second calculating step; and a step to decide the die channel. A prepared given relation is the relation of a nozzle part shear rate and a channel passage required time that shows a boundary whether strand curling phenomenon occurs. In the first calculating step, the shear rate of the thermoplastic material in a die nozzle in the given flow rate is calculated. In the second calculating step, time not to cause a strand curling phenomenon by the calculated shear rate is calculated based on the above relation. In the step to decide a die channel, the shape and the size of the die channel are decided so that the thermoplastic material passes through the die channel, spending time more than the time calculated by the second step.