Green machining creates features before final firing and therefore requires shrinkage compensation. Fired machining works on the final hard ceramic and can achieve tighter critical dimensions, but usually needs diamond tooling and higher cost.

Extrusion suits continuous profiles and many tower-packing or honeycomb shapes; pressing offers repeatability for molded components; casting supports other complex forms. Ceramic product design should match the forming route rather than treating ceramic like machined metal.

Ceramic components can crack before firing when moisture gradients cause uneven drying shrinkage. Thin walls, thick junctions and complex geometry require controlled drying conditions to prevent hidden defects that may later open during firing or service.

Raw-material particle size distribution influences industrial ceramic porosity, shrinkage, dimensional consistency and mechanical strength. It is usually controlled by the manufacturer rather than specified by the tower-packing buyer, but it is an important hidden driver of batch quality.

Ceramic packing has substantial thermal mass, so a packed bed does not heat or cool instantly. Thermal conductivity, heat capacity, bed weight and gas-liquid heat transfer determine temperature gradients and therefore influence startup time and thermal-shock risk.