Oversized extruder????
Oversized extruder????
(OP)
I want to trial a prototype extrusion from polyprop, I'm only semi familiar with the extrusion process and have never officially operated a machine. I'm currently building up a die and I have managed to pick up a hardly used extruder from a university for a song.
However I'm starting to be concerned that the extruder might be too big for my application and was wanting some thoughts The extruder is quite old, not really sure on specifics of it, I'd guess the screw is about one meter long, it only has two heat zones on the screw, however when it was used it had three other heat zones on the die area giving five zones - these three are going to be scrapped and I'll only have a third heat zone on the die. The machine has a 7.5kW (10hp) motor driving it.
From that I'm assuming it's capacity is around 25kg/hr based on hp specs from other machines I've seen. The parts of my die I've made so far look very petite when stuck on the end of the extruder and I'm assuming I'll only want a flow of around 500g/hr. Is this going to cause me a problem with plastic working, stagnant time etc? I should be able to slow the screw enough as I picked up a pretty flash VSD for a song also, can run down to 1Hz if I put a cooling fan on the motor.
Thanks for any heads up/advice in advance
However I'm starting to be concerned that the extruder might be too big for my application and was wanting some thoughts The extruder is quite old, not really sure on specifics of it, I'd guess the screw is about one meter long, it only has two heat zones on the screw, however when it was used it had three other heat zones on the die area giving five zones - these three are going to be scrapped and I'll only have a third heat zone on the die. The machine has a 7.5kW (10hp) motor driving it.
From that I'm assuming it's capacity is around 25kg/hr based on hp specs from other machines I've seen. The parts of my die I've made so far look very petite when stuck on the end of the extruder and I'm assuming I'll only want a flow of around 500g/hr. Is this going to cause me a problem with plastic working, stagnant time etc? I should be able to slow the screw enough as I picked up a pretty flash VSD for a song also, can run down to 1Hz if I put a cooling fan on the motor.
Thanks for any heads up/advice in advance






RE: Oversized extruder????
1 metre long is a very short screw.
Screw profile and temperature control in the barrel and the head and the die itself and the haul off are all important.
Regards
Pat
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RE: Oversized extruder????
RE: Oversized extruder????
Regards
Pat
See FAQ731-376: Eng-Tips.com Forum Policies for tips on use of eng-tips by professional engineers &
http://eng-tips.com/market.cfm
for site rules