25 MICRO-LAYER BLOWN FILM COEXTRUSION DIE

摘要

An 18" modular disk blown film die was designed from a 2x scale up of a smaller laboratory die using a client's specifications to make a 25 micro-layer film containing alternating micro-layers of one material of no more than 25% of the total layered material. The finished 18" modular disk die was assembled in the client's plant and attached to 2-65 mm extruders delivering the 75% material and a third 50 mm extruder to deliver the 25% material. After initial alignment of the .090" exit die gap, the first melt issued uniformly around the die annulus and a bubble was blown. There were no issues such as melt leaks and film thickness uniformity. The 25 micro-layer film product that was made tested satisfactorily in all respects. Production of the film began shortly at 640 Ibs/hr mainly in 12 hour shifts but also around the clock in some cases for about 150 days while product and variations of it were made for large market evaluations. After this production run and with other product development experiments completed, a series of die evaluation tests were conducted with the die making quality film up to 800 Ibs/hr.