posted May 30, 2007 08:43 AM            

I am having some process problems in monolayer blown film plant. Plant specifications are as under.

Film width - 800mm
Die dia- 90mm die and 75 mm die
Die gap - 0.8 mm gap
Extruder - 45mm dia with grooved feed

I have run the HDPE ( Stavrolen - grade- PE 4FE 69. ) its density is 0.949 and Melt Flow Index is 7 to 11 g/10min at 190 deg.C /21.6 kg. 90% + LDPE 0.3 MFI 10 %

I have faced the problem of bubble instability and gauge variation in 10 micron film. First i kept a temperature range 185 to 200. then I kept 200 to 220.

I am getting the wrinkles in both ends of films, it is becuase of bubble is slightly moving ( Bubble instability )

Please let me know sir, what can be reason behind this. and how can i get better bubble stability without wrinkles on 10 micron film.
and can improve gauge variation in film.

thanking you in advance with best regards,

Mitul R. Chavda.