Constant Temperature Embossing of PEEK Films

A new variant of the hot embossing process has been conducted with amorphous PEEK films as a model material. Constant Temperature Embossing (CTE) utilizes the crystallizing nature of amorphous polymers such as poly (ether ether ketone) (PEEK), poly (ethylene terephthalate) (PET) and poly (ethylene naphthalate) (PEN) when heated above their glass transition temperature to eliminate the thermal cycling. The key process parameters such as embossing temperature and embossing time depend on the thermal behavior of the amorphous PEEK film. Embossing studies were conducted using silicon tools with microchannel arrays of different aspect ratios, and the films were characterized using scanning electron microscopy and optical profilometry. The process enables a simple isothermal embossing process for polymers that have a glass transition temperature well above the room temperature and also with a wide temperature gap between the glass transition temperature and melting point.