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 Extrusion, Twin Screw
 new to PVC PIPE manufacturing help me ?
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| Author | Topic: new to PVC PIPE manufacturing help me ? |
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Kvs Member Posts: 3 |
posted June 04, 2004 09:39 AM
   
would like to know the points to look while buying a new extruder for PVC pipe and difference between single screw barell and twin screw barell ? please help me IP: Logged |
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jonathan lapointe Member Posts: 1 |
posted July 15, 2004 11:30 AM
well for me i think the price of twin screw extruder is really high and take a lot of maintenance.i work with both single and twin screw extruder and can not see a really big difference between.but every one have is opinion! IP: Logged |
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2beeps Moderator Posts: 74 |
posted August 02, 2004 10:29 AM
I'd guess that over 90% of PVC pipe worldwide is produced on counter-rotating twin screw extruders--either conical or parallel.This "battle"(single vs.twin) was fought-and won- back in the late 60's and early 70's. Despite the higher initial cost, a twin screw will more than pay for itself due to several factors: 1) Less overweight to maintain minimum wall thickness (5-6% vs. 8-10% for single screws). This is material GIVEN away, since pipe is sold by the length.Twins deliver a much more even melt flow to the die,since they essentially act as positive displacement gear pumps. 2) Lower power requirement for a given output rate, and generally higher outputs for similar sized extruders. 3) Lower formulation costs--lower shear twins need less stabilizer in their formulations. 4) Lower exit melt temp.--easier sizing. Cheers, Skip IP: Logged |
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