Posts: 4
From:pune,maharastra,INDIA.
Registered: Jan 2005

posted January 25, 2005 01:27 AM               

---

I WORK WITH TWINS SCREW PARALLEL COUNTER ROTATING EXTRUDER.AT THE TIME OF PROCESSING PVC RIGID SHEETS WHEN WE GO FROM LOWER THICKNESS TO HIGHER THICKNESS i.e FROM 8mm to 10mm or 5mm to 8mm, SURGING USE TO OCCURE WE CONTROL IT BY INCREASING CALENDER ROLLS SPEED AND REDUCING BARREL TEMPERATURE BUT DOING SO,WE MISS THE REQUIRED THICKNESS AND SURFACE,RESULTS IN SCRAP. IS THERE ANY OTHER METHOD BY WHICH WE CAN AVOID SURGING?
THANKS

IP: Logged

Posts: 339
From:McHenry, IL USA
Registered: Nov 2002

posted January 29, 2005 07:45 AM               

---

Sounds to me like a feeding issue. If your not feeding the correct amount needed to fill the screw, you'll surge. Other factors can cause this too. Hook up a chart recorder to your pressure transducer, then when you see surging occur, work backwards. Start at the winder or puller.

IP: Logged

All times are ET (US)