and the clear filtrate shown less than 100 ppm average suspended solids measured on paper filter black label the pulp is then brought to ph 6 and sent to a buffer chest having 8 hours total retention time from this point it is then pumped to the mixing chest of the paper machine at controlled flow rates according to the paper grade actually produced and in function of the mean composition of the secondary pulp the clear filtrate from the polydisk filter is then totally recycled in order to dilute the stock ahead of the third washing stage and make up is provided by fresh industrial water which does not contain aluminium ions the application of such a process in a paper mill having one single paper machine offers the following advantages a possibility to maintain constant freeness and ash content during a grade run independently from the incoming waste paper characteristics thus allowing the paper machine to run at maximum speed and efficiency b possibility to achieve very quick grade change exactly as whenusing virgin pulp and fillers without the need to intervene a long time before in the waste paper plant thus permitting an easier and more constant operation of that plant c possibility to always use the highest possible quantity of recycled fibers in the paper by the free disposal of each one of the two fractions and their use in the optimum way d possibility to produce totally cleaned pulps having the same standards of cleanliness than virgin pulps and thus offering the highest possible runability in the paper machine room particularly being free of any 34 sticky 34 or 34 hot melt 34 or ink vehicle free particle the raw material is a.