methods and apparatus for rapidly drying and compacting wet fiber mats are disclosed . rapid drying is produced by heating the wet fiber mats with a combination of radiowave energy and conductive heating . as the fiber mats are heated , three - dimensional compacting forces are applied by pressing the fiber mats between a flat surface press and a porous support on which is mounted a resilient mold insert . at high radio frequencies in the microwave range , power is transmitted from a multimode cavity through the porous support and resilient mold insert to the fiber mat . at low radio frequencies , differential radio - frequency voltages are applied directly to metal press plates which contain and compact the fiber mat . methods and apparatus can be adapted to conveyorized or multi - opening press operations . objects suitable for use with the invention are most commonly characterized by having a flat face surface on one side and webs or other features which may extend normal or generally normal to the flat surface .