IE914556A1 - Method for processing waste paper - Google Patents

Abstract

The extraneous materials (30, 32/34, 36 and 24) arising in waste paper dissolution, with the exception of heavy materials which cannot be further utilised, are collected and fed to one (40) or two series-connected treatment devices (40, 56). The extraneous materials are subjected to a first comminution (42) rendering them uniform, in order to convert them into a state conveyable in suspension, are then predisintegrated (46) and freed of heavy dirt (48), in order to be ultimately fine-comminuted and disintegrated in a second comminution stage (52). The treatment device (56) serves essentially for upstream coarse comminution of the ragger rope (24) which may also be used. The suspension of extraneous material, obtained in the discharge shaft, is divided by sorting into a fibre material component and a residue component, of which the residue component is freed of fractions of higher density, and the substantially remaining thermoplastics are dried and granulated for re-use as semi-finished product in plastics processing. The long-fibre material component obtained is beaten and sorted in the conventional manner and, during beating, regenerated thermoplastic material in a finely divided form can be added to the fibre material for its later use in raw papers for corrugated board. <IMAGE>

Description

Method for processing waste paper Description The invention relates to a method for processing waste paper in which the waste paper is suspended in water and substantially defibrated under the action of agitating means, heavy trash collecting substantially in the pulping aggregate is separated and removed, socalled light trash separated from the fibrous suspension obtained in the pulping aggregate and/or in following sorting stages and the cleaned fibrous suspension used for paper making.

Waste paper is being increasingly recycled for paper making. The problem in waste paper processing resides in removing paper-foreign constituents and impurities from the raw material. For decades, the German paper industry has been processing a large proportion of socalled sorted waste paper which comes essentially from waste from the paperprocessing industry and pressed to form bales is used again as raw materia] for paper making. Admittedly, such waste paper also contains a certain amount of impurities, but the processing thereof is not very problematical. However, there is an increasing need to use lower quality waste paper grades, even including collected domestic refuse.

Such waste paper is preferably used for producing packing papers, in particular for producing papers from which corrugated board is made.

For processing conventional waste paper containing little or no domestic refuse at all, a type of processing plant has become established which is constituted essentially as follows : The waste paper is broken down or defibrated under the action of strong agitation in a disintegrating unit, a socalled pulper, which is especially equipped for processing waste paper. Heavy trash, such as stones, metal parts and the like, sink into a collecting space especially provided for them at the bottom of the pulper and from there are discharged through a lock from time to time. Foreign constituents such as fabric pieces, large-area foil pieces, ropes, cables, strings and the like spin themselves due to the agitation in the pulper to form a socalled tress or plait which is slowly withdrawn from the pulper and continuously grows by attachment of new plait-forming foreign constituents. A major part of foreign substances collecting in the waste paper pulping and having to be separated out, which cannot be directly broken down to individual fibres for recycling in paper making, consists of socalled light trash. This includes among other things plastic parts as well as pieces of undisintegratable paper coated on one or both sides with plastics. By a certain flow pattern in the pulper this light trash tends to collect at a predetermined point, for example in the vicinity of the pulper wall, from whence it can be continuously withdrawn to a certain extent.

The pulp or fibrous suspension withdrawn from the pulper via a sieve plate is generally conducted via one or more sorting stages in which further light trash usually collecting in smaller form is separated. In a typical plant the fibrous suspension is then divided by means of a sorter into a long-fibre component and a short-fibre component. The long-fibre component is for example concentrated by means of a belt pressure filter to a high substance density in order to be still further defibrated in a high-consistencv defibrator before use in the papermaking machine. After subsequent beating in a refiner at again reduced material density this long-fibre component is then generally used for making test liner, i.e. the paper which forms the top layer of a corrugated board and must have a high strength. The short-fibre component is used to make the centre ply for corrugated board, i.e. the paper which subsequently forms the corrugation in the corrugated board and is referred to as corrugated board raw paper.

The separated light trash collected in the waste paper preparation is possibly further subjected to a washing or sorting operation to free it from entrained fibrous material but then after draining it is supplied together with the heavy trash separated in the pulper to a container for depositing on a dump. When processing sorted waste paper the amount of heavy and light trash to be disposed with is within limits so that no special dumping problems are caused therebv.

It has however been found that with increasing processing of refuse waste paper in a plant of the aforementioned type the light trash proportion increases considerably. This is due to the fact that refuse waste paper contains to a greater degree also packing materials of plastic, in particular however plastic-coated papers, which cannot be broken down in a conventional waste paper processing plant and thus collect as light trash. An analysis of the light trash with greater use of refuse waste paper has shown that this light trash does indeed contain a high proportion of substances which by their nature could also be recycled.

The invention is therefore based on the problem of providing a method with which it is possible to process to the greatest possible extent to recyclable raw material or half stuff primarily the light trash collecting in a conventional waste paper processing plant with increased use of refuse waste paper, but possibly also the plait material, depending on the composition thereof. Light trash and plait material will be referred to hereinafter as foreign material.

This problem is solved according to the invention by the following method steps: a) comminution of the foreign material in a first comminuting stage to homogenized sheet portions which are conveyable in aqueous suspension, b) further comminution of the homogenized sheet portions in a second comminuting stage to small sheet pieces in aqueous suspension, c) disintegration of the small sheet pieces in aqueous suspension , d) separation of the suspension into a fraction containing essentially fibrous material and a fraction containing essentially non-disintegratable residual material, and e) processing of the residual material fraction for collecting and reusing thermoplasts contained therein.

When reference is made within the scope of this description to disintegration or defibration in conjunction with the processing of waste paper and light trash, this means on raw material consisting of paper pulp and on the other hand the detachment of the fibrous material from the non-fibrous material or vice-versa. The plastic sheet components mainly contained in the foreign material or in the light trash are for example not defibrated but at the most comminuted. For indicating the suspension concentrations, hereinafter the usual units percent abs. dry usual in the paper industry will be employed, relating to the percentage of the solid imagined to be absolutely dry in the suspension .

The precomminution of the foreign material is carried out possibly with addition of water in a cutting or tearing mill suitable for this purpose into sheet pieces as far as possible of less than 40 mm diameter. The foreign material collecting as light trash is then preferably comminuted into sheet pieces of the order of magnitude of 2 to 15 mm and particularly preferably into sheet pieces in the range of 6 mm to 12 mm diameter. The foreign material of course also already contains from the start particles having a size which is substantiallv smaller.

To preserve the precomminuting tools in the first stage it may be desirable to sift the foreign material again for heavy trash constituents, such as small stones or metal parts. This is expediently done in the aqueous slurry itself by suitable sedimentation means. However, providing an adequately robust comminuting aggregate is used for the first comminuting stage it may be expedient to perform a further heavy trash separation only between the first and the second comminuting stages because under certain circumstances further additional heavy trash might be exposed by the first comminution. The finely comminuting and disintegrating comminuting aggregate for the second stage is however generally sensitive to heavy trash so that the additional heavy trash separation should take place at the latest before the second comminuting stage. Suitable tools for the comminuting aggregates will be discussed within the scope of the description of the drawings.

In a preferred embodiment the first method steps are carried out in an aggregate which is especially combined for that purpose and which comprises essentially means for the first comminuting stage in which operations can be carried out with and without addition of liquid, furthermore an intermediate trough with agitating means which is additionally provided with a heavy trash collecting chamber and a heavy trash discharge lock means, and means for the second comminuting stage.

The method steps described above are suitable and also adequate for initiating the processing of the light trash collected from a waste paper pulping plant. Additional steps may be necessary if within the scope of the foreign material processing the plait from the pulper is also to be processed. Whether or not this is expedient will depend on the particular conditions. Since the plait or tress contains essentially large-area foreign constituents, they may well include large-area packing foils of polyethylene and relatively large pieces of foil-coated paper, for the disintegration of which the breaking down work done in the pulper is not sufficient. If these constituents form a high fraction of the plait the co-processing thereof according to the method of the invention may be worthwhile.

If the plait is also to be processed, it is expedient to divide said plait in such a manner that it reaches the first comminuting stage in substantially the same state as the remaining light trash. For this reason, according to the invention before its material reaches the first comminuting stage the plait is subjected to a one or twostage coarse comminution, the first coarse comminuting stage of the plait consisting simply in a cutting of the plait into smaller portions and the further coarse comminution consisting of the dividing of said portions into a form which is suitable for the first comminuting stage according to the invention. For the coarse preparation of the plait, here a combined aggregate can be used similar to that preferably proposed for the first and second comminuting stage, said aggregate simply being equipped with different tools for the different use.

Before conducting the separation into its fractions, the finely comminuted and essentially disintegrated suspension leaving the second comminuting stage according to claim 1 can be stored for after-disintegration in an intermediate vat which is equipped with a correspondingly powerful agitating mechanism which promotes an additional disintegration or defibration of the material. The material densities to be expediently adjusted for such a step are to be chosen by the person skilled in the art depending upon the requirements.

Before going into the further processing of the fractions obtained from the foreign material suspension after separation, the essence of the method according to the invention will again be clarified: The comminuting steps carried out according to the invention have a fundamentally different action to the conventional pulper for waste paper pulping. In the pulper the operation is carried out only with agitation effects and suspension shearing forces which admittedly permit the separation of such paper pulp structures which are not fixedly held together by plastics or other means; however, the pulper is not able to divide plastic-containing sheet pieces and expose fibres connected thereto and for this & reason such elements must be separated in the pulper itself or in the following sorting of the pulp suspension.

The essence of the steps according to the invention is therefore a genuine comminution. The first comminuting stage is intended to effect that the foreign materials are reduced to a size of the order of magnitude in which they are conveyable in aqueous suspension by conventional suspension conveying means, such as agitating mechanisms and suspension-suitable pumps. The second comminuting step into relatively small sheet pieces having a size which is controlled by the passability through a predetermined sieve is intended to transform the suspension into a state in which optimum suitability for the separation of the small area pieces into fibrous material and non-defibratable constituents is present. It has for example been observed that with plastic-coated packing papers and cartons the pi astic layer can be detached from the substrate under the action of energy if the sheet pieces concerned have sufficient smallness. Consequently, the extent to which the comminution is actually carried out is firstly a question of the separability of fibrous material and plastics and secondly a question of retaining a desired strength of the fibrous material. By greater comminution more fibres in the material are of course severed so that the average fibre length of the exposed fibrous material is reduced by a high previous comminution. In these cases, the person skilled in the art must determine an optimum treatment procedure depending upon the starting material and the objectives.

The separation of the foreign material suspension obtained after the second comminuting stage into its fractions can be done with ordinary commercial apparatuses, for example a turbowasher of the Voith company in Heidenheim. Since when processing the foreign material alone, in contrast to the processing of for example complete foil-coated packing cartons, the fibrous proportion is the smaller component, a single-stage washing will generally be sufficient as regards the residual material. Moreover, for reasons which will be described later it may even be desirable for a certain amount of fibres to remain in the residual material.

The components to be recovered from the residual material are essentially the thermoplasts which make up a high proportion thereof. Generally, however, the residual material contains to a smaller extent other plastics as well, usually with higher specific weight, such as PVC and the like. These heavy plastics are preferably separated from the residual material suspension in a one or two-stage cyclone apparatus. The accept material from this cyclone sorting apparatus is then expediently coarsely dewatered on a vibrating sieve in order for example to be subsequently predrained in a centrifuge. The filtrate collecting here can be reemployed for suspension dilution in a preceding stage .

After the centrifuge draining the residual material is then dried and can be intermediately stored in a silo. Fundamentally, the residual material consisting almost exclusively of thermoplasts can already be handled or filled into containers in this form in order to be recycled as raw material in a further processing. However, expediently, the drying of the residual material will be followed by a pelletizing.

Tests have shown that the thermoplast granulate thus obtained can be further processed in plastic extruders for making a great variety of articles. The fibrous material content of about 5 % still contained in the granulate even has a positive influence on various strength properties of the plastic which are retained providing that the plastic processing does not take place at temperatures at which the fibrous material breaks down.

The fibrous component obtained on separation of the foreign material suspension is expediently concentrated to a higher material density in order to subject it to the usual beating operation for paper making.

It has been found that the fibrous component recovered from the foreign material is a long-fibre material of high value from the points of view of paper making. However, to avoid making the cleaning requirements too demanding, it is preferably added in the production of corrugated board raw papers to the short-fibre material resulting from the waste paper processing described above in order to increase the strength .

Within the scope of the invention a particular step has been developed for finishing this long-fibre component in a manner which is specially suitable and enhances the quality for producing corrugated board raw paper. For it has been found that in the beating operation of the pulp in a refiner, which for this purpose should be provided as far as possible with stone fittings, finely divided thermoplast material can be fixed to the fibres and remains unchanged during the paper making but in the corrugated board production under elevated temperatures acts on the corrugation to increase the stiffness thereof. A particular feature of the method described here resides in that part of the dried or also already granulated residual material regenerate from the foreign material processing is finely ground in a mill to grain sizes of 0.6 mm and added to the fibrous or pulp material in the refiner beating.

Thus, within the scope of the foreign material reprocessing described two half stuffs with particularly advantageous properties are obtained, that is firstly a thermoplast material still having a certain fibrous content and secondly a fibrous material with attached thermoplast material.

Tests have shown that within the scope of the foreign material processing according to the invention described above from one ton of precomminuted light trash about 20 % fibres and 50 % thermoplasts can be recycled for further use. This means that about 70 % of the light trash can be processed to a recyclable raw material whilst the light trash within the scope of a conventional waste paper processing plant all had to be dumped.

DESCRIPTION OF THE DRAWINGS Hereinafter the method according to the invention for processing waste paper will be explained in detail with the aid of a preferred method sequence in so far as the preparation of interest here of the foreign materials separated in the paper disintegration is concerned. In the drawings : Figure 1 is a method scheme for the apparatus region around a conventional waste paper pulper with collection of the foreign materials accruing in this region and separated from the waste paper suspension, as well as the comminution thereof and transformation to a sortable suspension, and Figure 2 shows a method scheme for the apparatus region in which the foreign material suspension is separated into its components and these components are reprocessed to half stuffs which can be used again.

Since in the waste paper processing field certain basic operations are familiar to the person skilled in the art and readily apparent from the method schemes, in the following description only the essential method elements will be discussed.

The central aggregate of a waste paper processing plant as the one shown in Figure 1 is a waste paper disintegrator or pulper designated by 2. As shown in the method scheme, via a conveyor belt 4 commercial waste paper in the form of bales is supplied to the pulper 2 whilst via a further conveyor belt 6 in addition waste paper in loose form to a certain extent is supplied as unsorted domestic refuse. Furthermore, via a conduit 8 the pulper receives returned intercepted materials from the following paper works and via a conduit 10 water for the pulping. The fibrous or pulp suspension resulting on disintegration of the waste paper is continuously withdrawn from the pulper in the vicinity of the pulping impeller 14 via sieve plates and supplied to a first socalled A sorting stage 18. The accept material from this sorting passes to a vat 20 and from there onto a B sorting (not illustrated).

Via a plait tube 22 a plait 24 is slowly continuously withdrawn from the pulper 2 and forms in the turbulence of the pulper from spinning foreign substances such as strings, wires, or also large-area plastic sheets and foils, rags and the like. Beneath the plait tube 22 a light trash component is withdrawn continuously or intermittently from the pulper and in the separating means 26 is freed from entrained heavy trash and then supplied to a draining sieve drum 28. A first light trash component 30 leaves the sieve drum 28 as substantially drained foreign material. The reject material collecting at 32 from the first sorting stage 18 of the fibrous material is generally sorted again and the reject material from this afterIE 914556 sorting collects as second light trash component 34. Finally, from the (not shown) B sorting another reject fraction collects and forms a third light trash component 36.

It can be seen from the method scheme of Figure 1 that all the light trash components, i.e. the components 30, 34 and 36 are supplied to the feed hopper 28 of a processing apparatus 40. This apparatus comprises a first comminuting unit 42 in which the foreign material is homogenized as regards its area and length distribution and thus converted into a state which can be conveyed without any problems in aqueous suspension. From the first comminuting aggregate the previously comminuted material in the apparatus 40 passes to a trough-like collecting chamber 44 which is provided with an agitating mechanism 46. In addition, the apparatus 40 also comprises a heavy trash collecting chamber 48 in which any remaining heavy trash which has been exposed additionally by the precomminuting is separated and from time to time discharged through lock means. The agitating mechanism 46 conveys the material transformed to suspension and possibly already predisintegrated to an exit well 50 in which a second comminuting aggregate 52 is disposed for performing a second comminuting step. A sieve 54 is located at the exit of the second comminuting aggregate 52. Said sieve has in the example of embodiment a mesh width of 8 mm so that the finely comminuted material can pass this sieve only if it has been brought to the necessary fineness in the second comminuting aggregate 52. At the same time the material is disintegrated and defibrated in the second comminuting aggregate 52 by crushing tool action. The comminuted and disintegrated material from the apparatus 40 then passes into the plant section of Figure 2 for further processing.

The tools provided for the first comminuting aggregate 40 may be a cutting arid a tearing tool which consists essentially of parallel rotatably driven tool carrier shafts which are equipped alternately with interengaging cutting, chopping or tearing blades. Since, seen from above, the shafts rotate towards each other, they form a drawing-in nip into which the material to be comminuted is automatically pulled.

As suitable tools for the second comminuting aggregate 52, a rotating tool carrier has proved practicable which is equipped on an imaginary cylindrical surface with tool elements which on rotation come into engagement with corresponding counter tools on the inner side of a housing surrounding the rotor. In tests, the tools of the Condux washing granulator CS 500/1000 IIIA of the Condux company in Hanau, which are really provided for other purposes, have been found suitable. However, any other tool equipment suitable for carrying out the desired method step may be used for the invention.

Tn the method scheme of Figure 1 a further processing apparatus 56 can be seen which corresponds in its construction substantially to that of the apparatus 40 and which precedes the apparatus 40 in cascade manner. The second processing apparatus 56 differs from the apparatus 40 essentially in that as first comminuting aggregate 58 it comprises a horizontally operating cutting member. The apparatus 56 is provided because in the present example of embodiment the plait 24 from the pulper 2 is also included in the foreign materials to be reprocessed. The plait 24 is supplied via a feed hopper 60 to the first comminuting aggregate 58 of the apparatus 56 in which it is divided into small length portions. Since the plait contains for example also bale binding wires the plait cutter in the first comminuting aggregate 58 must be made appropriately robust. However, to preserve the further processing aggregates, it is particularly important that in the apparatus 56 the heavy trash, essentially in the form of kire pieces, is separated out via the heavy trash collecting chamber 62. This heavy trash is subsequently drained in a following draining means 64. It is further apparent from the scheme of Figure 1 that the water separated in the draining means 64 is again supplied as rinsing and washing water via a pump 66 to the feed hopper 60 of the apparatus 56. In the trough of the apparatus 56 no separate predisintegration is necessary for the coarsely divided plait and for this reason the trough and agitating mechanism of the apparatus 56 are used here preferably for washing the divided plait material and for assisting the heavy trash separation.

The second comminuting aggregate 68 of the apparatus 56 is constructed similarly to the inlet member 42 of the apparatus 40 because a disintegration of the plait material at this point does not yet take place and indeed should not take place. If an extra processing apparatus is provided for the plait it may be expedient to supply the first light trash component 30 collecting from the draining sieve drum 28 to the plait processing apparatus 56 itself, as indicated by a dashed conduit 70. This step depends completely on the size distribution and the state of the light trash component collecting.

Figure 2 now represents the sequence in the apparatus section in which the foreign material suspension obtained from the processing apparatus 40 undergoes its further processing. Firstly, the material passes to an agitating vat 72 in which the disintegration and the defibration of the fibrous constituents can still be completed. The finely disintegrated foreign material suspension now passes via a pump 74 into a separating or sorting aggregate 76 in which it is divided into a fraction substantially containing fibrous material (fibrous material fraction) and a residual material fraction substantially containing nondefibratable residual materials. A suitable sorting aggregate 76 has for example been found to be a socalled turbowasher of the Voith company of Heidenheim having a hole diameter of 2.6 mm.

The fibrous fraction from the sorter 76 passes to a fibrous material vat 78 and the residual material fraction to a residual materia] vat 80. Firstly, the path of the fibrous fraction will be followed. The further processing in the example of embodiment is directed towards using the fibrous fraction as strength-enhancing long-fibre component in the production of corrugated board raw papers. From the fibrous material vat 78 the fibrous fraction passes to a concentrator 82 usual in the paper industry from whence the concentrated fibrous material is intermediately stored in a container 84. Depending upon the requirements of the following aggregates, the concentrated material may have a consistency between about 6 and 20 % abs. dry, already assuming in the upper region of the range specified a crumbly state so that as illustrated in Figure 2 it must be transported by means of a conveying screw 86 into a following beating aggregate 88. This beating aggregate is preferably a twin-disc refiner provided with stone fittings. The beaten stuff passes via a further conveying screw 90 into a diluting vat 92 from whence it is freed from the remaining impurities in a strong dilution as known to the person skilled in the art in a vertical sorter 94 so that it can be made available for paper making from a halfstuff vat 96.

The residual material fraction from the residual material vat 80 is firstly conducted via a two-stage cyclone separating apparatus 98 in which in particular components are separated which are specifically heavier than the thermoplasts which make up the greater part of the residual materials and which have a specific weight of about 1. The separated heavy materials are washed, the heavy materials themselves being retained on a sieve 100 and the washed-out fibrous materials conducted into the fibrous material vat 78. On a sieve 102 the residual material accept from the cyclone separating apparatus is predrained and then supplied to a centrifuge 104 for further draining. The substantially drained thermoplast material, which has essentially the appearance of confetti, coming from the residual material fraction is then completely dried in a tube drier 106 and intermediately stored in a silo 108.

For drying in the drier 106 biogas may be at least partially employed as forms in the anaerobic biological clarifying of the waste paper filtrate collecting in the waste paper pulping.

The flocky thermoplast material collected in the silo 108 is transformed in an ordinary commercial agglomeration and granulating apparatus 110 to a plastic granulate in usual commercial form which can be used as recycled thermoplast half stuff for a great variety of reprocessing purposes.

The apparatus 110 will not be described in detail. It is however possible to use a plast agglomerator apparatus original Pallmann of type PFV 250/60.

In the example of embodiment illustrated in Figure 2, from the thermoplast granulating apparatus 110 via a conduit 112 a certain proportion of the thermoplast material is branched off and ground in a mill 114 to a grain size of 0.6 mm and less. This finely ground thermoplast powder is injected via a conduit 116 into the beating aggregate 88 for the fibrous material. As already mentioned at the beginning, by maintaining certain method conditions in this stage thermoplast material can attach itself to the fibrous material in a manner which does not disturb the papermaking process; however, in the further processing of the corrugated board raw paper as intended in the example of embodiment, the thermoplast material can be activated at elevated temperatures so that better strength properties are obtained for the corrugation in the corrugated board.

Claims (16)

1. Method for processing waste paper in which the waste paper is suspended in water and substantially defibrated under the action of agitating means, heavy trash collecting substantially in the pulping aggregate is separated and removed, socalled light trash separated from the fibrous suspension obtained in the pulping aggregate and/or in following sorting stages and the cleaned fibrous suspension used for paper making, characterized in that the foreign material collecting from the individual separating stages is subjected to a separate processing involving the following steps: a) comminution of the foreign material in a first comminuting stage to homogenized sheet portions which are conveyable in aqueous suspension, b) further comminution of the homogenized sheet portions in a second comminuting stage to small sheet pieces, c) disintegration of the small sheet pieces in aqueous suspension, d) separation of the suspension into a fraction containing essentially fibrous material and a fraction containing essentially nondisintegratable residual material, and e) processing of the residual material fraction for collecting and reusing thermoplasts contained therein .

2. Method according to claim 1, characterized in that between the method steps a) and b) an agitating treatment of the foreign material in aqueous suspension is carried out to prepare the disintegration.

3. Method according to claim 1 or 2, characterized in that before the method step a) and/or if applicable during the method step of claim 2, a heavy trash separation is carried out.

4. Method according to at least one of claims 1 to 3, characterized in that the method steps b) and c) are carried out simultaneously.

5. Method according to claim 3 or 4, characterized in that the method steps a), b) and e) according to claim 1 and the method steps according to claims 2 and 3 are carried out using a combined apparatus.

6. Method according to at least one of claims 1 to 5, characterized in that the first comminution of the foreign material according to method step a) is carried out to give sheet portions with a maximum diameter of less than 40 mm. 7 . Method according to at least one of claims 1 to 6 , characterized in that the second comminution of the raw material to small sheet pieces according to method step b) is carried out to give sheet pieces having a maximum diameter of 2 to 15 mm, preferably 6 to 12 mm.

7. 8. Method according to at least one of claims 1 to 7, characterized in that at the exit of the second comminuting stage a sieve is used which substantially limits the size of the passing small sheet pieces.

8. 9. Method according to at least one of claims 1 to 8 in which the foreign material also includes the foreign material plait from the waste paper pulper, characterized in that the plait is subjected before method step a) to a one or two-stage coarse comminution (possibly with heavy trash separation).

9. 10 . Method according to at least one of claims characterized in that the material suspens intermediately stored between method steps for further disintegration in an agitating 1 to 9, ion is c) and d) vat.

10. 11. Method according to at least one of claims 1 to 10, characterized in that the fraction substantially containing fibrous materials is subjected to an after sorting and the rejects from this after-sorting are added to the fraction containing the residual materials .

11. 12. Method according to at least one of claims 1 to 11, characterized in that from the residual material fraction in a sorting stage components specifically heavier than thermoplasts are separated out.

12. 13. Method according to claim 12, characterized in that the separation of the specifically heavy components i by means of cyclone devices.

13. 14. Method according to at least one of claims 1 to 13, characterized in that the residual material fraction is drained and dried.

14. 15. Method according to claim 14, characterized in that the residual material is granulated.

15. 16. Method according to at least one of claims 1 to 15, characterized in that the fibrous suspension separated in step d) of claim 1 is concentrated to material densities of 6 % abs. dry to 15 % abs. dry and the concentrated fibrous material is beaten in a pulp beating aggregate. 16. 17. Method according to claim 16, characterized in that a pulp beating aggregate provided with stone fittings is employed . 17. 18. Method according to claim 16 or 17, characterized in that a fraction of the residual material according to claim 14 or 15 is added in finely ground form to the fibrous material in the beating. 18. 19. Method according to claim 18, characterized in that the residual material is ground to a grain size of 0.6 mm and less. 19. 20. Method according to claim 18 or 19, characterized in that ground residual material is added to the fibrous material in proportions of 20 to 60 % by weight with respect to the fibrous material and residual material. 20. 21. Method according to at least one of claims 18 to 20, characterized in that the temperature regulation in the beating of the fibrous material is carried out in such a manner that the finely ground residual material is fixed on the fibrous material. 21. 22. Further use of the fibrous material according to any one of claims 18 to 20 in the production of paper for the centre ply of corrugated board.

16. A method for processing waste paper according to any preceding claim substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.