WO1996003231A1

WO1996003231A1 - Method of processing packaging

Info

Publication number: WO1996003231A1
Application number: PCT/EP1995/002907
Authority: WO
Inventors: Mathias Pauls
Original assignee: Rathor Ag
Priority date: 1994-07-28
Filing date: 1995-07-22
Publication date: 1996-02-08
Also published as: AU3381595A; CA2196088A1; WO1996003204A1; AU3164695A; CA2196177A1; DE59504999D1; EP0776245A1; WO1996003230A1; AU7496194A

Abstract

A method is proposed of processing packaging containing reactive residues. The packaging (13) is fed into a cold zone (2), cooled to a temperature at which the residues contained therein solidify and then shredded while in that cooled state (4). The shredded packaging material (13) is then divided into one fraction containing the reactive residues and at least one other fraction; the fraction containing the reactive residues is fed into a mixing zone (6) into which simultaneously an agent capable of reacting with the residues is also introduced, with a catalyst if appropriate, and the temperature in the mixing zone (6) is maintained at a level below the softening temperature of the residues and of the reactive agent. The resulting mixture of residue-containing fraction, reactive agent and (where appropriate) catalyst is conveyed to a reaction zone (7) at a temperature sufficiently high to allow a reaction and is there allowed to react.

Description

description

Process for preparing packaging

The invention relates to a method for processing packagings which contain reactive residues, in particular cartridges for producing polyurethane foam. In the process, the packaging materials are obtained and the residues contained therein are converted into reusable products.

Residual packaging, such as is accumulated in large quantities, for example in the form of completely or partially emptied cartridges, is increasingly becoming a disposal problem. A dump on landfills is prohibited for reasons of environmental protection, since the residues contained therein can get into the atmosphere, into the ground or into the groundwater and can cause considerable damage there. The same applies to combustion, which is often only incomplete, in particular in the case of chemical-technical products, and generates large amounts of pollutants which, if at all, can only be bound by expensive measures. In this respect, incineration leads to a sharp reduction in the volume of waste, but does not necessarily lead to a solution to the environmental impact.

Special problems arise when the residues contained in the packaging are themselves reactive and, under certain circumstances, also toxic products, as is the case, for example, with isocyanate-containing prepolymers for polyurethane foam is the case. The same also applies to other reactive plastic products, for example self-curing or hardenable mixtures for coatings, adhesive mixtures, etc. The problem with the disposal of prepolymer-containing cartridges for the production of polyurethane films is discussed in more detail below, this case only as Example is given.

Polyurethane foams have found widespread use in many fields. In particular in construction, they are widely used for sealing and insulating, as well as in other technical fields. Polyurethane foams are often applied from cartridges which contain a polyurethane prepolymer together with the required additives. These cartridges cannot be reused after use. On the other hand, they represent problem waste that is not accessible for normal disposal.

In the context of efforts to contain domestic and commercial waste, measures are increasingly being discussed and prescribed which compel manufacturers to take back the packaging of their products after use and to ensure that they are reused or disposed of themselves. Such measures have made it necessary to look for ways of economically treating such waste. There are a number of problems with the treatment of withdrawn cartridges for the production of polyurethane foam, which make economic reprocessing difficult. For example, a portion of the withdrawn cartridges can be under pressure due to moisture penetration in the event of improper storage or treatment Opening as well as burning makes it a problem. Furthermore, the cartridges have a different filling state, from old cartridges with practically complete prepolymer filling, which can no longer be dispensed due to a blocked valve, to practically completely empty cartridges with only the edges adhering rest of prepolymer in uncrosslinked to crosslinked state is sufficient.

So far, a number of processes for the preparation of packaging, including aerosol cans for the production of polyurethane foam, have become known. For example, it has been proposed to inject pressure cans via a lock system into a plant under intergas and to comminute them there. Furthermore, methods have become known for introducing aerosol cans into a plant, comminuting them there and extracting the ingredients with suitable solvents. In this process, both the packaging materials and the ingredients (prepolymer, propellant) are obtained.

These known methods, some of which are quite efficient and are practiced, can be improved with regard to occupational safety, process management and efficiency. It creates problems in a simple manner to separate the residues contained in the packaging and to dispose of them in a suitable manner. Further problems result from the fact that the packaging contains toxicologically unobjectionable substances as well as flammable solvents which, after opening, can give rise to explosive gas mixtures. In particular, however, these methods are designed for the preparation of aerosol cans containing propellant gas and therefore only usable for unpressurized cartridges.

The invention is therefore based on the object of providing a process by which packaging, for example containers which contain polyurethane prepolymer, in particular for foam production, but also for adhesive purposes, together with solvents, can be processed and the valuable substances contained therein can be obtained , without the uncontrolled release of ingredients harmful to health and the environment and without the process sequence being burdened by reactive components released from the packaging. The process is intended to meet the requirements for occupational safety and, in particular, to convert reactive residues still contained in the packaging into a form suitable for direct further processing.

According to the invention, this object is achieved with a method of the type mentioned at the outset, in which the packaging is introduced into a cold zone and cooled to such an extent that residues therein solidify, the packaging is then comminuted in a cooled state, after which the comminuted packaging is brought into a the reactive fraction containing residues and at least one further fraction are separated, the fraction containing residues is introduced into a mixing zone into which an agent reactive with the residues is simultaneously introduced, optionally together with a catalyst, whereby the temperature in the mixing zone is kept below the softening temperature of the residues and of the reactive agent, and the mixture of residues containing residues and reactive agent and, if appropriate, catalyst is brought to a temperature sufficient for the reaction in a reaction zone and allowed to react completely.

With the method according to the invention, it is possible to open and process packaging in a completely harmless manner. In particular, it is achieved that the various materials contained in the packaging can be separated in a safe manner. The reactive residues, for example in the case of cartridges for the production of polyurethane foam containing prepolymers containing isocyanate, are treated in a manner which is safe from a safety point of view. The freezing of the ingredients contained in the packaging does not result in a reaction-related pressure increase in the process or in undesirable reactions between reactive components. At the temperatures prevailing in the process, the presence of water is also harmless. The latter two points are important in the treatment of products containing isocyanate, for example if water is carried into the process due to damaged packaging. At the same time, reactive second components contained in so-called 2-component foams, for example glycols, carboxylic acids or water, can be introduced into the process without problems. In this respect, the method according to the invention is suitable for treating both cartridges for IC and 2-component foams as well as transition forms between the two at the same time. In the process according to the invention, the packs, for example cartridges, are first introduced into a cold zone and cooled therein to such an extent that the residues therein, including low-boiling solvents therein, solidify. Temperatures of less than -80 ° C to - 100 ° C are generally sufficient for this; However, it is expedient to work in liquid nitrogen as the cooling medium. In this case, it is important that the process be carried out in the absence of oxygen, in order to avoid the condensation of liquid oxygen, which could have an adverse effect in later process steps.

The introduction into the cold zone is expediently carried out with a cellular wheel blow-through lock, with which the packaging to be introduced is introduced into a guide cage running in the cooling medium. In the cold zone, the packaging is then passed a sufficient distance through the cooling medium in order to achieve complete freezing.

After reaching the desired temperature, generally the temperature of liquid nitrogen, the packaging is led into the comminution zone, where it is comminuted in the cold state. The temperatures should advantageously be below -80 ° C to -100 ° C; if necessary, liquid nitrogen or cold gaseous nitrogen must be injected.

The comminution is expediently carried out in a hammer mill which works against a sieve. As a result, a shaking and flexing effect is achieved which - in addition to the comminution to a desired grain size large - brings about a separation of the different materials: metal, paper, plastic and contents. It has surprisingly been found that the packaging materials - metal, paper and plastic - can be separated extraordinarily well from the ingredients - reactive residues and solvents / additives in powder form - the ingredients being obtained as a fine powder.

In a subsequent separation stage, the crushed packaging is separated into at least two fractions, one of which contains the reactive residues, including the propellant, in a solid state. A screen is expediently provided in this separation stage, expediently a vibrating screen through which the fine constituents, predominantly reactive residues and solvent, fall. Metal parts are separated using magnetic methods, larger plastic parts and scraps of paper are screened off on the vibrating screen.

The frozen ingredients from reactive residues and solvents pass from the separation zone into a mixing zone, into which an agent reactive with the residues is introduced at the same time. Temperatures of less than -80 ° C. to -100 ° C. also prevail in this mixing zone in order to ensure the frozen state of the introduced materials and to immediately solidify the injected reactive agent to a fine powder. The result of this is that a uniform mixture of ingredients in powder form and reactive agent is formed, which, however, is not reactive due to the prevailing temperature conditions. can greed. The temperatures in the mixing zone are in each case below the melting point of both the residues and the reactive agent.

A spray tower, into which the frozen ingredients fall from above, is expediently used as the mixing zone. The reactive agent is sprayed into this powder stream from side nozzles, expediently together with cold gaseous nitrogen, in order to ensure the required low temperatures. Pre-cooling of the reactive agent is advisable, but sprayability must remain guaranteed.

It may be expedient to spray the reactive agent together with a catalyst which requires the reaction with the reactive residues of the packaging. In the case of isocyanate-containing prepolymers, however, this is generally not necessary since the isocyanate-containing mixtures already contain such catalysts.

The powdery mixture of ingredients and reactive agent and, if appropriate, catalyst is then fed into a reaction zone which, for example, consists of a conveyor belt moving continuously under the mixing zone. The powder collected here is then brought to a temperature sufficient for the reaction to react. Contained solvents evaporate on this occasion and are condensed out at a suitable point, which is not a problem when nitrogen is used as the refrigerant. In order to give the reaction product the desired shape, the conveyor belt can be have borders. To separate the reaction product from the conveyor belt, it is possible to provide release agents, for example suitable coatings or release paper. The heating in the reaction zone is expediently carried out using microwaves, which bring about a rapid, direct heating of the powder material from the inside, so that uniform degassing occurs.

Following the reaction zone, further processing and treatment zones can be provided, and finally a lock for discharging the fully reacted material.

As already mentioned, the method according to the invention is particularly suitable for preparing residue-retaining polyurethane foam cartridges. In this case, the reactive agent is in particular a compound containing hydroxyl groups, for example water, ethylene glycol, propylene glycol, glycerol, oligomers and mixtures thereof and derivatives thereof. Ethylene glycol, water and polyether alcohols are preferred, with at least two reactive hydrogen atoms being present in each case. Polycarboxylic acids can also be used. The so-called Jeffamines (trademarks) are particularly suitable among the polyether alcohols.

In the preparation of packaging for the production of polyurethane foams, it is advisable to convert the isocyanate-containing prepolyers into foam materials in the process, which can be used, for example, for insulation and insulation purposes. For example, dam panels can be produced continuously with the method according to the invention, in the case of the propellant gases contained in the powder produced in the mixing zone, foam formation is favored. However, it is also readily possible to produce films or to add additives, for example cellulose-containing materials, and then to compress these mixtures during or after the reaction to give composite materials . However, it is preferred to produce a granulate from reacted material, which is subsequently processed.

The method according to the invention is particularly suitable for processing non-pressurized polyurethane foam cartridges, which are emptied at the place of use with the aid of a suitable gun and then sent back to the manufacturer for processing. These cartridges, which are used for both 1K and 2K foams, are depressurized during storage and generally contain no blowing or foaming agents. If an improvement in the foaming behavior is necessary and this improvement cannot be achieved by using water as the second component, low-boiling solvents may be present, for example pentane, which are liquid at normal temperature, but below the reaction temperatures of Vaporize prepolymer with the second component and cause a blowing effect. The use of the method according to the invention for aerosol cans for the production of polyurethane foam is also possible if an effective propellant gas separation is provided in the area of the reaction zone. The method is therefore in principle suitable for packaging which also contain blowing agents and, if appropriate as a function of the temperature, achieve a driving and / or foaming effect. The method according to the invention is explained in more detail by the accompanying figures. From this shows

1 schematically shows an embodiment of a system for carrying out the method according to the invention;

FIG. 2 shows the entrance area of the system according to FIG. 1;

3 shows the conveying, crushing and sorting part of the plant according to FIG. 1;

4 shows the mixing and reaction zone of the plant according to FIG. 1;

5 shows details of the feeding of the cellular wheel sluice;

6 shows details of the guidance of the transport system in plan view and

Fig. 7 shows the guide of Fig. 6 in cross section.

The illustration shown in FIG. 1 of an embodiment of the processing system according to the invention has an entrance lock 1, to which the cartridges 13 to be treated are fed via a conveyor and sorting belt 11 (FIG. 5). The entrance lock is preferably designed as a cellular wheel blow-through lock, in the chambers 12 of which the cartridges 13 fall from above via a feed funnel 14 (FIG. 2). As a result of the rotation of the cellular wheel 1, the cartridges enter the lower region of the lock and are laterally connected to the line 15 using gaseous nitrogen GAN pushed out. To make this possible, the cellular wheel rotates in a gas-tight container which is open at the top and which can be pressurized with pressurized gaseous nitrogen GAN in its lower region from one side, so that the cartridges 13 located therein are on the opposite side can be ejected into a guide system 21. The nitrogen supply via line 15 is preferably ensured with gaseous nitrogen from the cooling bath 2. It goes without saying that the rotational speed of the cellular wheel 1 and the pressure surges from the nitrogen line 15 for ejecting the cartridges from the cellular wheel are coordinated with one another. For this purpose, the cellular wheel has a sensor marked with M.

The cartridges pass from the cellular wheel via a guide 21 into the cold bath 2, which is filled with liquid nitrogen. The guide 21 expediently consists of an elongated basket construction which is open on all sides and which enables the unimpeded entry of liquid nitrogen and exit of gaseous nitrogen. Details of the guide 21 and the transport device 23 available for transporting the cartridges 13 are described in more detail below in connection with FIGS. 4 and 5.

The cartridges 13 are cooled to the bath temperature on their way through the cooling bath 2, which is fed with fresh liquid nitrogen LIN depending on the level 24 and has a measuring sensor LIC for level control. The cage structure of the guide 21 ensures the free access of the refrigerant and the rapid removal of the gaseous nitrogen generated. Gaseous nitrogen is drawn off from the bath area via line 16 with the aid of a fan 17. The length of the guide 21 and the transport speed are set in such a way that the cartridges 13 are cooled to a sufficiently low temperature of at least -80 ° C. to -100 ° C. even when the remaining filling is complete.

The cartridges 13 are transported in the guide 21 with the aid of the transport device 23, which expediently consists of a conveyor belt 25 guided in a circle with transport forks 26 protruding therefrom, which engage in the guide 21 from above and the cartridges 13 guided therein in front of them push here. Transport rollers 27 ensure precise guidance of the transport forks 26. The forks 26 are arranged on the conveyor belt 25 at intervals which are matched to the size of the cartridges 13 to be transported. A measuring station M is used to monitor the transport speed and to coordinate it with the feed speed of the cartridges 13.

After passing through the cold bath 2, the cartridges 13 pass from the guide 21 into the conveying device 3 (FIG. 3) in the form of a revolving conveyor belt 31, which has transport segments matched to the size of the cartridges 13. The conveying device 3 is preferably designed as a steep conveyor which picks up the cartridges 13 in the segments formed by transport forks 33 arranged at regular intervals and delivers them overhead into the comminution device 4. The conveyor belt is guided over rollers 32 provided with a measuring station M for monitoring and controlling the conveyor speed. The crushing device 4 consists of a shredder or preferably a hammer mill 41. The hammer mill 41 preferably works against a sieve in order to ensure a certain grain size of the crushed material. At the same time, the sieve 42 produces a flexing effect, which has a positive effect on the separation of the contents which have become brittle due to the cold from the container material. It goes without saying that refrigerant, preferably liquid nitrogen LIN, can be added via line 43 to maintain the required low temperatures of -80 ° C. to -100 ° C. if the temperature control TK reports an impermissible temperature increase. The working speed is checked and controlled via the sensor M. Gaseous nitrogen is discharged via line 44 and recycled or blown off via a valve 45.

The comminuted material passes from the comminution 4 into the sorting device 5. This initially consists of a vibrating sieve 51, on which the coarse and the distant parts are separated. Coarse parts are mainly the comminuted materials of the container, which are shaken off on the inclined sieve 51 and are discharged from the process via a lock, not shown.

Powdery ingredients and fine parts of the container pass through the vibrating screen 51 to a first magnetic separator 52, which separates the remaining iron and aluminum components from plastic particles and ingredients. First magnetic separators 52 become magnetic Components separated and placed on a first conveyor belt 53, which also receives the metal and plastic parts shaken off the screen 51. A second conveyor belt 54 accommodates plastics, contents and non-magnetic metal parts, which are separated into metallic and non-metallic components via a second magnetic separator 55 coupled to the conveyor belt. The metallic components get on the first conveyor belt 53, the non-metallic components are fed directly into the spray tower 6. Cold gaseous nitrogen can be supplied via line 56 if the temperature control TIC reports an inadmissible temperature rise. Measuring sensors M control the working speed of all moving parts of the separation system 5. If the cartridges consist entirely of non-metallic materials, the magnetic separator can of course be dispensed with.

It goes without saying that a temperature of at most -80 ° C. to -100 ° C. is guaranteed both in the comminution system and in the sorting device by means of corresponding supply lines for refrigerants, preferably nitrogen in gaseous or liquid form .

The powdery ingredients and plastic parts which reach the spray tower 6 (FIG. 4) and which have a temperature of at most -80.degree. C. to -100.degree. C., so that solvents contained therein are also present in a solid state with reaction medium sprayed in via spray line 61 and possibly catalyst in the upper region of spray tower 6. The reaction medium, preferably ethylene glycol, is in the liquid state in the pre Ratstank 62, the catalyst in the storage tank 63. Dosing stations are assigned to both tanks.

Reaction medium from the container 62 and catalyst from the container 63 are injected via the line 61 into the spray tower 6 in a metered ratio to the reactive constituents, it being possible for a precooling section to be provided in the course of the line 61 in order to distribute the materials onto a cool to acceptable temperature (above the melting point). However, the spray material solidifies within the spray tower even at temperatures below -80 ° C to -100 ° C. To maintain the temperature in the spray tower, it is therefore expedient to additionally introduce cooling medium, for example liquid nitrogen LIN via line 64 or gaseous nitrogen via line 65 when the temperature control TIC reports a need. It is expedient to inject the cooling medium in the lower regions of the spray tower in order to ensure an additional swirling and mixing of reactive compound, catalyst and reactive can content through the cold nitrogen rising in the spray tower 6.

The mixture of reactive cartridge contents, reactive compound and catalyst in powder form reaches the reaction space 7 from the spray tower 6. A reaction belt 71 is arranged within the reaction space 7, which takes up the falling material from the spray tower 6 and leads into the actual reaction zone 72, where the reaction is induced by heat. For this purpose, warm elements 73 are arranged above the conveyor belt 71, which react the reaction material on the conveyor belt 71 with microwave or heat infrared rays to a temperature sufficient for the reaction, for example about room temperature or above.

In order for the reaction material 74, e.g. H. the mixture of reactive cartridge content, reactive compound and catalyst to prevent the conveyor belt 71, it may be appropriate to cover the conveyor belt with a release film 75 which is unwound from a roll 76a and wound onto a second roll 76b. The separating film can be used several times if necessary.

The reaction material reacts on the conveyor belt 71 to the respectively desired product. At the same time, solvents and adsorptively bound nitrogen from the refrigerant are still released in the mixture from the spray tower and are sucked off via line 77 and fed to a separation (not shown) and extraction of solvents. In the presence or formation of a foaming agent, such as pentane or CG ^, the exit from the reaction material 74 causes a partial foaming of the reaction material, which is not undesirable for certain purposes.

At the end of the conveyor belt 71 there is a scraper 78, with which the reacted reaction material is released from the conveyor belt or the separating film and discharged from the process via the product lock 8 and discharged via a conveyor belt 81. Nitrogen lines 81 and 82 regulate the supply of protective gas in the lock area, nitrogen being expediently used as the protective gas, but this need not be cooled. Further nitrogen lines 83 and 84 in the area of the entry and exit steps of the separating film 75 prevent the oxygen from entering the system in this area. The use of cooling nitrogen is not necessary here either.

It goes without saying that the method according to the invention is carried out in a cold and heat insulated system. In particular, the entry of oxygen must also be prevented in order to prevent liquid oxygen from condensing into the cooling bath 2. It is advantageous for the gas flow that the entire process is carried out into the spray tower 6 at temperatures at which solvents and foaming agents are in a solid state. This allows them to be withdrawn centrally via the suction line 77 in the reaction space 7 and fed to the extraction. The fully reacted / hardened polyurethane material that emerges from the process from the product lock 8 can be used as granules for any further use. For example, the use for insulating materials and in composite materials comes into question.

5 shows details of the lock system at the entrance to the process, the cellular wheel blow-through lock being rotated by 90 ° in relation to the illustration in FIGS. 1 and 2.

The cartridges intended for the process with the polyurethane prepolymer residues 13 are introduced into the cells 12 of the cellular wheel blow-through lock 1 via the conveyor and sorting belt 11. A feed hopper 14, under which the lock rotates away, ensures the precise insertion of the cartridges 13. The conveyor and sorting belt 11 expediently has ribs or forks 15 which separate the cartridges 13 transported on the conveyor belt from one another. In this way, the cycle of the cartridge dispensing can be matched exactly to the transport speed of the cellular wheel sluice 1 and the transport cycle in the guide 21 of the cooling bath 2 at a predetermined conveying speed. The specification of a cycle also allows the cartridges 13 to be discharged from the lock 1 with the aid of pressurized nitrogen through the line 15 (FIG. 2).

As can be seen from FIG. 5, the blow-through sluice 1 opens at its lower end (opposite the feed hopper 14) into the guide 21 into which the cartridges slide and with the aid of the pressure surge from the line 15 in the direction of the transport device 23 are expelled.

6 and 7 show details of the guide 21 and the transport device 23 for transporting the cartridges 13 within the guide 21.

The guide 21 has an overall elongated, cage-like or basket-like structure. The guide essentially consists of guide rails 22 guided in parallel, which leave enough space for the entry of liquid nitrogen and the exit of evaporated nitrogen. The guide rails 22 are held together on the outside by fixing rings 27 such that the relative position to one another is fixed. The fixing rings encompass the entire guide 21 with the exception of the upper end, where the space between two guide rails 22 is free remains so that a transport fork 26 or the like can engage from above and push the cartridges 13 located in the guide 21 through the guide. The result is the image of an elongated cage made of rails 22 guided in parallel and encompassing fixing rings 27, which in the upper region leaves a free space for the movement of the transport fork 26 over its entire length. The size of the cage is matched to the size of the cartridges and is selected so that the cartridges cannot tilt when being passed through. In the illustration, the cartridge 13 is transported with the bottom first in the direction of the arrow, the fork 26 encompasses the nozzle 18.

The transport forks 26 are located on a transport belt 25 which, via a correspondingly arranged system of transport rollers 27, conveys the cartridges through the guide 21 to the conveyor belt 31, where they fall out of the guide 21 and from the transport elements 32 of the conveyor belt Conveyor belt 31 can be added. From the end of the guide 21, the conveyor belt 25 is moved back over the bath 2 in the direction of the rotary valve 1, where the forks 26 engage in the guide 21 again at a designated location and transport the cartridges located in the guide through the bath 2. It goes without saying that the entire guide 21 runs in the area of the actual cooling section in the cold bath 2 in such a way that liquid nitrogen is rewound on all sides of the cartridges.

Claims

Expectations

1. A process for the preparation of packaging containing reactive residues, characterized in that the packaging is brought into a cold zone and cooled to such an extent that residues therein solidify, the packaging then being broken up in a cooled state ¬ are reduced, after which the comminuted packs are separated into a fraction containing the reactive residues and at least one further fraction, the fraction containing reactive residues is introduced into a mixing zone, into which an agent reactive with the residues is simultaneously introduced, optionally together is introduced with a catalyst, the temperature in the mixing zone being kept below the softening temperature of the residues and of the reactive agent, and the mixture thus obtained of a fraction containing reactive residues and thus reactive agent and, if appropriate Catalyst is brought into a reaction zone to a temperature sufficient for the reaction and allowed to react completely.

2. The method according to claim 1, characterized in that it is carried out at a temperature <-80 ° C.

3. The method according to claim 2, characterized in that the method is carried out in the absence of oxygen.

4. The method according to claim 3, characterized in that the packaging is passed through a bath with liquid nitrogen.

5. The method according to any one of the preceding claims, characterized in that the packaging is introduced into a cooling section with the aid of a cellular wheel blow-through lock.

6. The method according to any one of the preceding claims, characterized in that the packaging is crushed at a temperature <- 80 ° C with a hammer mechanism working against a sieve.

7. The method according to any one of the preceding claims, characterized in that the reactive residues contained in the packaging are pulverized during comminution.

8. The method according to any one of the preceding claims, characterized in that the mixing zone is a spray tower.

9. The method according to claim 8, characterized in that the reactive agent is sprayed into the powder passing the spray tower from reactive residues.

10. The method according to claim 8 or 9, characterized gekenn¬ characterized in that gaseous or liquid cold nitrogen is injected for temperature control in the spray tower.

11. The method according to any one of the preceding claims, characterized in that the reaction zone is heated with microwaves.

12. The method according to any one of the preceding claims, characterized in that gases released in the reaction zone are separated by condensation.

13. The method according to any one of the preceding claims, characterized in that the packaging, Kartu¬'s and the reactive residues contained therein are prepolymers containing isocyanate groups for the production of polyurethane foam.

14. The method according to claim 13, characterized in that the reactive agent is a hydroxy group-containing compound.

15. The method according to claim 14, characterized in that the hydroxy group-containing compound is ethylene glycol or a polyether alcohol.

16. The method according to any one of the preceding claims, characterized in that additives are added in the mixing and / or reaction zone.