Abstract: Filter cake produced from a slurry is compressed in an enclosure (6) having a pair of opposed flexible walls (5) at least one of which is constituted by a filter and drainage medium. The filter cake is cyclically deformed while under compression with the filter cake supported at least one position (14, 52) within its periphery whereby the unsupported parts of the filter cake are cyclically deformed about the periphery and the position or positions of support. All parts of the filter cake are thus subjected to substantially uniform bending whereby drying of the filter cake is improved.