Molded thermoplastic filter plate

A generally square molded polypropylene recessed filter plate for use in a filter press of the type used for separating solids from a liquid wherein a plurality of filter plates are brought together in abutting relationship and filtration is accomplished by passing a liquid through filter cloths disposed between adjacent filter plates, comprising:

• a. a peripheral rim extending completely about the perimeter of and integral with a recessed inner web such that inner recessed drainage faces are formed on each side of said filter plate, each side of said filter plate being divided into four triangular sectors, the boundary of each sector lying generally along a line extending from the center of said inner drainage face to a corner of said peripheral rim of said filter plate, from said corner along the outer edge of said peripheral rim to an adjacent corner of said peripheral rim and from said adjacent corner back to the center of said inner drainage face such that each of said sectors includes a corresponding side of said peripheral rim;
• and
• b. a plurality of discontinuous raised drainage ribs molded on said inner drainage face in each of said sectors of said filter plate such that a majority of said ribs of a particular sector are parallel to the corresponding side of said peripheral rim in that particular sector.