Question

define die swell in extrusion

Answer 1

Die swell is very common process use in polymer processing by extrusion process. in this process

a stream of polymer material is forced through a die of very specific internal shape , size and geometry. the die swell phenonmenon is the instance where polymer stream is compressed by entrance of die into the die and once polymer comes out of die , the sudden pressure release causes the polymer chain to relax and tries to gain its former shape.

this partial recovery or swell back to the former shape and volume of polymer after exiting the die is termed as Die Swell phenonmenon.