Abstract: A fiber suspension is produced from waste paper by first filling a pulper with a batch of the waste paper. The pulper is operated to partly defibrate the batch of waste paper substantially without disintegrating coarse imputities into finer impurities. The partly defibrated batch of waste paper is separated into a coarse reject fraction and an initial fiber suspension containing some waste paper fragments and fine impurities. The initial fiber suspension is pumped through a rotary screen apparatus provided with a tubulat fine screen and a pulper type impeller rotating coaxial with the tubular screen, but devoid of any impeller co-operant extraction plate, to defibrate waste paper fragments remaining in the initial fiber suspension and to separate the initial fiber suspension by means of the tubular fine screen into a fine reject fraction containing fine inpurities and a complete fiber suspension substantially free from impurities.

Abstract: A pulper for producing paper pulp from waste paper containing undesired scrap particles includes a container (1) forming a chamber (4) defined by a bottom wall (5) and a cylindrical circumferential wall (6). A paper tearing member (7) is arranged in the chamber closed to the bottom wall and is rotatable in a horizontal direction of rotation about the centre axis of the cylindrical wall. The bottom wall and the circumferential wall forms a substantially circular peripheral reject chute (11) situated under the paper tearing member for collecting reject including undesired scrap particles. The reject chute extends helically in the direction of rotation of the paper tearing member from an upper end (12) of the reject chute downwardly to a lower end (13) of the reject chute. The circumferential wall (6) has a substantially cylindrical shape and extends vertically to the reject chute (11). A discharge element (2) is adapted to discharge reject in batches from the reject chute.

Abstract: A halogen-containing polyester resin composition having an improved stable flexibility and flame retardency which comprises a bislactam compound and a flame-resisting aromatic polyester copolymers containing halogen at a ratio of 0.5 to 30% by weight, said copolymers being by the poly-condensation of(A) aromatic dicarboxylic acids or ester-forming derivatives thereof;(B) aliphatic glycols or ester-forming derivatives thereof; and(C) halogen-containing ester-forming compounds, said bislactam compound being present in a ratio of 0.1 to 10% by weight based on the total quantity of the composite.