PKSC 4300: Cast Extrusion exam
1. Define drawdown: - when the melt velocity at the die exits is slower than the speed of the chill roll
- results in edge beading
2. drawdown ratio equation: DDR = speed of the casting drum/ speed of the melt at the die
3. How is the thickness of a cast die changed?: use beta gauges to measure the film thickness to
then send electrical signals to an electronic bolt
4. What are the parts of a cast film line?: 1) extruder
2) chill roll
3) stripper roll
4) edge trim slitter
5) thickness scanning system
6) winder
5. What are some important cast film properties?: 1) Thickness and basis weight
2)Tensile properties
3) Crystallinity
1/2
1. Define drawdown: - when the melt velocity at the die exits is slower than the speed of the chill roll
- results in edge beading
2. drawdown ratio equation: DDR = speed of the casting drum/ speed of the melt at the die
3. How is the thickness of a cast die changed?: use beta gauges to measure the film thickness to
then send electrical signals to an electronic bolt
4. What are the parts of a cast film line?: 1) extruder
2) chill roll
3) stripper roll
4) edge trim slitter
5) thickness scanning system
6) winder
5. What are some important cast film properties?: 1) Thickness and basis weight
2)Tensile properties
3) Crystallinity
1/2
