The blocking can be reduced by applying Only necessary pressure at the pinch rollers, by cooling the film as much as possible before pinching it, reducing the line speed if necessary to enhance cooling of the bubble.
Insert air into the tube before pinch rollers of the winder and after it passes the winder introduce side slitter to slit the tube into two sheets to be rolled seperatelly. If seperating the sheet is difficult use two strips of adhesive tapes and pull it out to insert it onto the slitter. Provide a continuous stream of air through the slitter to keep the sheets seperated.
Use of antistatic unit also helps in reducing blocking.
I hope this helps.