Processability of t-die extrusion

Abstract

In achieving the high productivity or producing the thin film on the T-die extrusion, processability which includes instability and film failure is often a big problem. Processability was discussed by using the theoretical analysis previously reported. Instability was evaluated by dimensionless deformation rate which was suggested by Toriumi, and film failure was estimated by maximum stretching stress at the roll touch. Cooling air blowed off from an air knife which much influences processability made dimensionless deformation rate smaller, and it made stability better. As a result of the experiment in the various resins and process conditions, it was found that processability was dependent on dimensionless deformation rate and draw down ratio. Film failure was mainly influenced by maximum stretching stress. © 1986, The Society of Fiber Science and Technology, Japan. All rights reserved.