Blocking is a common phenomenon encountered in plastic film rolls, one common reason for film blocking is winder tension, which may be overlooked unless the core cannot be removed from the journal. Conversely, if the tension is too loose the film may telescope off the core making further conversion impossible.
Seasonal changes are an acute problem in most extrusion plants. The weather change, particularly from cold to hot and back to cold require a re-learning process that does not seem to be understood. The ambient temperature in a plant affects the sensitive nature of frost line height. The hotter the higher, the colder the lower. This height affects every film property and the rate of the line. Chillers, IBC systems and higher towers can gain back some of the rate loss and ease blocking but attention to detail is equally necessary. Another significant cause of blocking is incorrect resin selection or additive package. The resins are specifically designed and loaded with proper type of anti-block additives these anti-block additives have the ability to ooze on the surface of the plastic film and hence disengage the contact between the film layers and hence avoids blocking between the layers of the plastic film. Thus even in roll winding does not cause the blocking of plastic in the roll.
Seasonal changes are an acute problem in most extrusion plants. The weather change, particularly from cold to hot and back to cold require a re-learning process that does not seem to be understood. The ambient temperature in a plant affects the sensitive nature of frost line height. The hotter the higher, the colder the lower. This height affects every film property and the rate of the line. Chillers, IBC systems and higher towers can gain back some of the rate loss and ease blocking but attention to detail is equally necessary. Another significant cause of blocking is incorrect resin selection or additive package. The resins are specifically designed and loaded with proper type of anti-block additives these anti-block additives have the ability to ooze on the surface of the plastic film and hence disengage the contact between the film layers and hence avoids blocking between the layers of the plastic film. Thus even in roll winding does not cause the blocking of plastic in the roll.
