Influence of Process Temperatures on Blister Creation in Micro Film Insert Molding of a Dual Layer Membrane

In this work the suitability of a dual layer membrane, consisting of a non-woven Polypropylene (PP) support and a membrane layer made out of Polyethylene Terephthalate (PET) for Micro Film Insert Molding (μFIM) was investigated. The emergence of blisters at the surface of the PET-membrane layer was observed for some combinations of the process parameters used in this investigation.

Since these blisters are not only an optical issue but can also deteriorate the functionality of the membrane, a blister free over moulding of the membrane is required. In particular the mold and the barrel temperature were found to influence this blister creation. The influence of these two parameters on the amount of blisters and the blister height, characterized by the a real surface topography parameters peak material portion (Smr1) and reduced peak height (Spk), is presented in this paper.