DE4241645A1 - Recovery and recycling of plastic from material combinations - Google Patents

Abstract

In a process for sepg. soluble plastic from other materials, the material combination is subjected to a swelling agent which either breaks the bond between the materials and/or reduces the mechanical strength of the plastic. The swollen plastic is then separated from the remaining material eg mechanical means.

Description

The invention relates to a method for obtaining Plastics and materials from mixtures and / or Combinations and / or combinations of plastics with Plastics and / or other materials according to Preamble of claim 1.

Fall after use or during production large amounts of substances and products collected and should be recycled. In many cases is the collected material Mixtures and / or combinations and / or groups of Plastics with plastics and / or materials such as Glass, wood, paper, and metal.

Because of the decreasing landfill space and the controversial combustion is attempting this recycling complex multi-substance systems. There it due to the low level of properties achieved only a very limited market for mixed processed Plastics or contaminated or with others Materials mixed plastics are tried separate the individual plastics and materials and to obtain pure fractions. These would be for numerous applications can be used and also achieve one in the area of the respective new goods Sales price.

So far, mechanical processes have been used almost exclusively used for separation and sorting. But that can only the separation and sorting of mixtures and removable assemblies for the extraction of Plastics and materials can be achieved. At the Recycling of plastics by remelting is often done  Impurities and foreign substances are included and degraded polymers remain in the plastic and lead to a deterioration in properties.

With many products such as B. White and brown devices manual disassembly, separation and sorting performed that costly, imprecise and too is sometimes dangerous and often reaches its limits. In other cases, after a wash and Crushing the plastics and materials under Utilization of various properties such as density and electrostatic behavior tries to separate. Here z. B. Float-sink process and hydrocyclones used.

Crushing is problematic, as it is often the case necessary grinding a severe damage to the Plastic occurs and washing with water since the Separation of water dissolved or distributed Impurities and pollutants are complex and difficult is and is carried out inadequately.

This mechanical process, which is only for mixtures can be used due to the large number of plastics with different fillers and therefore different properties often only one moderate separation of mixtures.

For the separation of alliances a recently started Process application in which a plastic is specifically targeted a composite dissolved by a solvent and then z. B. is separated by sieving. Then the plastic is separated from solid additives by filtration by evaporating the Solvent recovered in solid form and can for the production of new products can be used. To dissolve the plastic are long times and large amounts of solvent required. If in the optimal Case can be worked with 10% solutions So to loosen 1000 kg of plastic 9000 kg Solvent required. Through these huge amounts of Solvents removed by evaporation and  may then have to be distilled, there are high costs. This is one reason why these procedures are uneconomical.

For the swelling of plastics and the removal of Plastic materials and the ones that can be used for them There is little suitable solvent in the literature Information.

The invention specified in claim 1 is Problem based on the separation and single-variety extraction of plastics and materials from mixtures and / or Combinations and / or combinations of plastics with Plastics and / or other materials at all enable to simplify and economical to make it feasible.

This problem is solved by the in claim 1 listed features solved.

The advantages achieved with the invention exist especially in that plastics and materials according to separation by type from mixtures, Combinations and combinations of plastics with Plastics and / or materials can be recovered can.

This is the swelling process a new separation process, which as such still exists not recorded and named in the known regulations is.

By swelling plastics, the alliances surprisingly, a composite separation will occur reached.

A strong shredding damaging the plastics a regrind is not necessary as it swells the mechanical strength of plastics is so low that this with simple mechanical stress can disintegrate or be easily crushed. This also saves costs.  

The effort is low, because by means of a Solvent separation of groups, cleaning of the plastics and materials involved, the Swelling of a plastic, swelling and Disintegrating a second plastic, dissolving one third plastic, removing a substance from it a fourth plastic and by taking advantage of the the swelling, dissolving or removing substances from Plastics changed properties of plastics separation and sorting is carried out. Due to the variety of available too biodegradable and less toxic solvents there is a wide range of variations.

For swelling and removing substances from plastics small amounts of solvent are required.

The times required for this are short.

The handling of swollen plastic is similar like that of a bulk material and therefore simple. Also the Removal of the solvent appears due to the little interaction with the plastic, which is only is swollen, easier and because of the small amount cheaper solvent.

When processing swollen plastics advantages arise from the possibilities of targeted Appreciation in processing and for special Applications.

The complete and thorough separation of adhering impurities is possible.

The removal of impurities from the Solvent after several rounds by distillation simply possible.

In contrast to solving, swelling becomes Compound separation materials that are not from Solvents can be modified plastics, get that are not contaminated such. B. with dissolved plastic.

Some embodiments of the invention are described in  following described in more detail.

Car trim strips fall during production and Processing and in car dismantling in large pieces at. They consist of a composite of soft Polyvinyl chloride with aluminum profiles.

They are shredded in a large container with the treated twice the amount of ethyl methyl ketone. To the soft disintegrates within a few minutes with gentle stirring Polyvinyl chloride and the aluminum profiles will be exposed. The content is left out of the container and at the same time through a sieve with a round perforation a diameter of 2 cm and then by a Sieve with a round perforation with a diameter of 1 mm given. The aluminum profiles sit on it the first sieve and the swollen soft PVC on the second sieve. The solvent is collected and can be used again without preparation.

By evaporating the solvent from the swollen The plastic can be made of soft polyvinyl chloride be recovered.

To a heavily contaminated with oily soiling granular mixture of polystyrene, polyvinyl chloride and polyethylene with a grain size of 5 mm is in a beaker with stirring three times the amount Given ethyl acetate as a solvent.

After a few minutes the polystyrene and the Impurities dissolved and the polyvinyl chloride strong swollen. The size is about 150% gone up.

The mixture is shaken with the ethyl acetate through a sieve with a round perforation with a Diameter of 7 mm and then through a sieve a round hole with a diameter of 1 mm given. The polyvinyl chloride stays on the first sieve, the polyethylene on the second sieve while the Polystyrene and the impurities in the ethyl acetate  flow through and be caught. The polystyrene is by failures by adding z. B. of ethanol be canceled. The impurities are caused by Distillation of the ethyl acetate after repeated use severed.

There are the plastics after drying the polyethylene and recovered pure polyvinyl chloride.

Claims (26)

1. A process for the production of plastics and materials from mixtures and / or combinations and / or composites of plastics with plastics and / or other materials, characterized in that they are associated with an agent that swells one or more plastics and / or that dissolves substances from one or more plastics and at the same time does not swell or / or dissolve one or more other existing plastics less or less and / or neither swells nor dissolves and thus by the use of the changed shape and properties of the plastics a separation and / or sorting of the plastics and / or other materials is carried out and thus pure plastics and / or materials are obtained. 2. The method according to claim 1, characterized in that the mixtures and groups are old Fabrics that are more or less strong Contamination from different materials such as B. oil, dirt, dust or food exhibit. 3. The method according to claim 1 or 2, characterized in that the mixtures and / or composites before treatment by means of mechanical methods to a uniform size can be crushed.   4. The method according to any one of claims 1 to 3, characterized in that the mixtures and / or composites before treatment roughly by means of mechanical methods be crushed. 5. The method according to any one of claims 1 to 4, characterized in that the agent is an organic solvent or Mixture of miscible and / or immiscible organic solvents is like that is chosen to be in one or more Plastics from the mixture and / or from the composite diffuses in and so swells and / or fabrics dissolves, but does not dissolve. 6. The method according to any one of claims 1 to 5, characterized in that the agent also cooled below room temperature and / or is heated above room temperature. 7. The method according to any one of claims 1 to 6, characterized in that through the different sources of within the network existing plastics and / or materials themselves the size of the plastics changed differently and thus the size ratio of the plastics and / or materials changed to each other and so partly with mechanical support such as e.g. B. stirring or shaking a separation of the Verbund is carried out.   8. The method according to any one of claims 1 to 7, characterized in that the size of one or more plastics by the Swelling increases and by mechanical methods such as e.g. B. by sieving the or the swollen Plastics from not or less swollen Plastics and / or materials that thereby a are smaller in size, separated and thereby sorting is performed. 9. The method according to any one of claims 1 to 8, characterized in that by swelling plastics the density the plastics changes and so through a density specific separation process such. B. the swimming Sink separation is a separation and sorting of other plastics and / or materials in the Means also carried out after adding other means becomes. 10. The method according to any one of claims 1 to 9, characterized in that through the swelling of plastics mechanical strength changes and by one mechanical process such as stirring or shaking Disintegrate the swollen plastic into smaller ones Pieces is achieved and thus a separation from im Composite plastics and / or Materials is carried out.   11. The method according to any one of claims 1 to 10, characterized in that through the swelling of plastics mechanical strength changes and by one mechanical process such as stirring or shaking Disintegrate the swollen plastic into smaller ones Pieces is achieved and then by a mechanical process such. B. by sieving the swollen and crumbled plastic from not or less swollen and swollen but not disintegrated plastics and / or materials is separated and thereby a sorting is carried out. 12. The method according to any one of claims 1 to 11, characterized in that by swelling plastics the plastics become softer and so through mechanical processes can be ground, making mechanical Methods such as B. Seven a separation of neither dissolved still swollen plastics and / or Materials is carried out. 13. The method according to any one of claims 1 to 12, characterized in that the mean of swollen and / or neither swollen still dissolved plastics like soluble substances e.g. B. releases plasticizer and a separation of and other plastics and / or materials from that Means with the soluble substance by mechanical Methods such as B. Seven is performed.   14. The method according to any one of claims 1 to 13, characterized in that by removing soluble substances such as B. Plasticizers in combination with other plastics and / or materials present plastics themselves the size of the plastics in relation to others Plastics and / or materials reduced and so partly with mechanical support such as e.g. B. stirring or shaking a separation of the Verbund is carried out. 15. The method according to any one of claims 1 to 14, characterized in that the size of one or more plastics by the Removing soluble substances such. B. Softeners decrease and by mechanical processes such as B. by sieving the or the shrunk Plastics from unmodified or swollen Plastics and / or materials that make it bigger are separated and thereby a sort is carried out. 16. The method according to any one of claims 1 to 15, characterized in that by removing soluble substances such as B. Plasticizers increase the density of Plastics changes and so through a density specific separation process such. B. the swimming Sink separation is a separation and sorting of other plastics and / or materials in the Means also carried out after adding other means becomes.   17. The method according to any one of claims 1 to 16, characterized in that the mechanical strength and / or hardness by the Removing soluble substances such. B. Plasticizers made of plastics increases and thus one Separation of swollen or non-swollen Plastics and / or materials by mechanical Methods such as B. Sieving, breaking or pushing through a gap is carried out and thereby a Sorting takes place. 18. The method according to any one of claims 1 to 17, characterized in that the agent, which is a solvent or a mixture of solvents is chosen so that the Agent or a component of the agent dissolves several plastics. 19. The method according to any one of claims 1 to 18, characterized in that the or the dissolved plastics by mechanical Methods such as B. Seven of all others do not dissolved plastics and / or materials separated and sorting takes place. 20. The method according to any one of claims 1 to 19, characterized in that Contamination of the old substances by means replaced and by mechanical methods such. B. Seven of the plastics and / or materials can be separated.   21. The method according to any one of claims 1 to 20, characterized in that from and / or from the plastics and / or Detached and / or detached materials by any other means that is not the one to solve used means is miscible and an organic Represents solvent or aqueous medium from which agents used for dissolving are extracted and by a mechanical method such. B. Decant using the different Density of funds to be separated. 22. The method according to any one of claims 1 to 21, characterized in that after separation of the agent together with in it dissolved substances released from plastics were not contaminants and plastics dissolved plastics and / or materials mechanical processes such as B. Seven means like that is processed so that the solutes, Contaminants and plastics are separated. 23. The method according to any one of claims 1 to 22, characterized in that the plastics dissolved in the agent Failures, e.g. B. by adding one for the Plastic non-solvent to the agent or through Cooling of the agent is achieved in a solid Form are transferred while the mean is solved Substances and impurities remain in solution, and so by a mechanical method such. B. Seven of the agent and the substances still dissolved in it and Contaminants are separated.   24. The method according to any one of claims 1 to 23, characterized in that in the means used or by addition another means simultaneously a swim-sink Separation is carried out. 25. The method according to any one of claims 1 to 24, characterized in that the solvents used are biodegradable and are not or only slightly toxic. 26. The method according to any one of claims 1 to 25, characterized in that the materials obtained, which are also by the Solvent treatment not modified plastics can be clean with no buildup of additives and / or plastics.