Abstract: A mold assembly includes a top mold with a female mold and a lower mold with a male mold that is moved to match with the female mold. The female mold includes a first core received in a recess in an inner periphery of the female mold and a second core received in a recess of the first core. A plurality of paths is defined through the female mold and respectively communicates with escape notches defined in the first core and the second core. Gaps are defined between the female mold, the first core and the second core respectively and the escape notches are in communication with the gaps such that only annular flanges are formed at edges of the paper products that have smooth surfaces. Each of the female mold and the male mold has a heating device for dehydrating the paper products.