Powder pressing technique in the fabrication of ceramic membranes: A review of influential factors and applications

The pressing technique is extensively used in the laboratory to fabricate ceramic membranes due to its efficiency and high production rate, as well as its ability to produce membranes with the required mechanical strength. This review presents a detailed evaluation of the pressing process, recognizing the complex interaction between important operational parameters such as applied pressure, the duration of pressure, and the inherent characteristics of the raw materials (e.g., particle size distribution). The role of additives (binders and pore formers) and heat-treatment parameters (heating rates and sintering temperatures) is discussed in detail. The findings highlight the decisive role of these factors in determining the final membrane's microstructural features (especially porosity and pore size distribution) and consequently its mechanical strength and permeability. Also, the industrial applications of ceramic membranes made by this technique are presented together with a critical discussion on their performance (flux, rejection rate, and long-term operational stability) and advantages (thermal, chemical, and mechanical stability) over the polymeric counterparts and potential. Despite widespread industrial deployment, challenges related to environmental and industrial sustainability (particularly the high energy consumption inherent in high-temperature sintering) persist, and innovative approaches are being pursued to mitigate these impacts.