FIG. 2.

Representative outcome of the bonding of fluoropolymer films. (a)–(c) The outcomes of bonding were grouped into three categories: Imperfect bond (Condition A), Perfect bond (Condition B), and Deformation (Condition C). Optimization of the condition for the heat press: (d) Initially, the heat press was performed for a constant duration of time (30 min) with a variation of pressure (P) and temperature (T). This study suggested that the outcome was sensitive to the change in pressure. (e) Under the fixed pressure (P), the heat press was tested with a variation of time (t) and temperature (T). Overall, the condition of (P, T, t) = (1.7 MPa, 320 °C, 30 min) for the bonding of PTFE films.