A novel type of modified polyetheretherketone (PEEKWC) microcapsules was prepared using a procedure which combines membranes with the sol-gel phase inversion technique. An experimental and theoretical study was carried out to explore the fundamental aspects concerning the production of these polymeric capsules. By using a mono-pore polyethylene (PE) film with a pore diameter ranging from 300 to 1400 mm the formation of PEEKWC microcapsules with different morphologies was performed. The capsule morphology, its shape, and size can easily be adjusted with changing parameters such as polymer concentration, solvent, and nonsolvent involved phases. The mean diameter of the obtained microcapsules, with different morphology, ranged from 650 to 2200 mm. The capsules sizes, obtained experimentally were compared with the droplet diameter derived by a balance force analysis along the pore mouth. The theoretical analysis permitted to understand the droplet detachment mechanism, occurring during this process as a function of the membrane and process parameters involved. This study analyzed the different morphology and sizes of the capsules and clarified the mechanism by which the capsules are formed as a function of the parameters involved in the process.