DE4315014A1 - Method and device for producing molded parts from plastic waste - Google Patents

Description

The invention first relates to a method for the manufacture provision of molded parts from plastic waste, in particular from a different sort of household waste Fraction containing plastics and contaminants, wel surface has been roughly shredded into plastic chips.

Such a method is for example from the DE-OS 23 40 505 known, in which one of different existing thermoplastic materials under Forming a mat is applied to a conveyor that Material mat by passing through an oven on the Softening point of the material is heated, being a he soft, sheet-like material mat is created from which to a desired at least one additional pressing process End product is designed.  

This method has the disadvantage that it is relatively is agile, because first of all a flat, plastic intermediate product is generated, which is then in at least one further Ver process step is processed to the final product.

In addition, the is necessary with this procedure che energy consumption relatively high.

The object of the invention is therefore to be as simple as possible ches and economical process for producing a To create molded part from plastic waste.

The object of the invention is compared to that by Prior art characterized prior art in particular solved by the features of claim 1, according to which art shredded material filled in at least one mold and heated under the action of a pressing force in the same be, with the plastic chips with softening are sintered to each other, and after cooling in the Form a stable molded part.

With the help of the method according to the invention can now more advantageously in particular plastic waste different types, which z. B. from the collection of Dual Systems Germany (DSD) come directly and without time-consuming preparation by means of processing level in marketable products.

The manufactured by the inventive method Molded parts have the advantage that they are intermediate or manufactured using minimal energy  End products that have a high strength and different from those despite their composition plastics do not pose a risk to the environment. So on the one hand, the existing ones in the plastic waste Germs killed by the heat treatment and others on the one hand, the finished molded part is not leachable.

In addition, the inventive method also still have the advantage that it is by the method manufactured molded parts so that they can be used without risk Raw material depot deals, whereby "used" molded parts always again in roughly crushed state the process or one later energetic use can be supplied. Ultimately, through the direct use of the in process plastic waste compressed by a factor of around 5 Raw material for the production of new products not only that Capacity of plastic recycling plants, but also the Landfills significantly relieved.

In a method according to the invention, art Chips of material depending on the thickness of the to be created molded parts for a certain time to about 180 ° Cel sius heated and then cooled to the release state.

The heating of the raw material to approx. 180 ° has operational experience the advantage that the necessary strength after reaching the demoulding state des achieved, with only a relatively low energy is necessary.  

In a further method according to the invention, a constant pressing force is applied during the heating and cooling. This isobaric procedure has the
Advantage that the desired strength of the molded parts is achieved even with fluctuating composition of the plastic waste.

In addition, there is also a method according to the invention conceivable, during which the heating and cooling Mold volume remains constant. This isochore procedure guarantees the production of molded parts with always the same Dimensions.

Modifications of the method according to the invention result itself from further claims.

Furthermore, the invention relates to a device for Production of molded parts with at least one press, wel che an upper and lower press plate and a mold has, the mold from a Ma to be pressed material receiving lower part and a shape occlusive as well as the pressing force on the material bearing cover.

Such a device is e.g. B. from processing known from plastic powder by means of the sintering technique. Here are powdered plastics with preferably be limited thermoplasticity, e.g. B. Polytetrafluoroethylene (PTFE) or high-molecular low-pressure polyethylene processed. At The plastic powder is used in this press sintering process Room temperature compressed in the mold and then  out of shape at temperatures above softening point sintered.

This device is based on practical experience Processing of raw material from different plastics not suitable.

The object of the invention is therefore to provide a device for Production of molded parts, in particular from one of the Household garbage sorted, different plastics and waste to create cleaning group, which is possible is as simple as possible and allows you to work economically Lich reasonable effort to produce molded parts.

The solution to this problem essentially arises from the fact that the device is at least two, with one fixed standing upper and a movable lower press plate Provided presses, one of which is heated and one is cooled, and that the presses with one another with an Direction to transport the molds are connected, each Press form with the press open with the one in the conveying direction moving transport device automatically moving is connected uniformly.

The device according to the invention has the basic one Advantage that the molded parts directly from the raw material only Using at least two presses, which are made with an automatic transport device for the molds are connected. This device is very simple, so that the operational process is very clear. A with the raw material filled mold at the end of the Er  heating phase automatically after opening the press transported to the next press, in which the form and its in just be cooled down to the release state. Ins overall, it is technically simple and economical che way of producing molded parts from plastic waste len possible.

In an advantageous embodiment of the Invention contemporary device, the mold to the parallel to Direction of conveyance existing limits of the lower part tenflansche through which the lower part when open Press is held in the transport device. These be special inventive design of the molds possible it is clear that by simply opening the presses Press mold practically falls on the transport device and auto can be transported matically to the next press, where it is is immediately resumed. Here is the transport system advantageously as a conveyor chain, conveyor belt, push ball system, guide roller system or the like.

An advantageous further development of the fiction The device has several presses arranged in rows are arranged, the presses starting from the first initially arranged a gradually increasing temperature then have a gradually falling temperature.

This larger capacity device has the basic advantage that all are connected in series th presses with each other through the same transport device are connected, so that the effort for the transportation of a individual molds from press to press is very low. Dar  moreover, the individual presses essentially have one constant temperature, so that the material stress reduced and the life of each press Lich increased.

Other advantages of the device according to the invention ben from the following claims and the description Exercise of the embodiments.

Ultimately, the invention also relates to a work process Ren to use an entire system, which consists of several in Row arranged pressing devices is formed, the connected to each other by means of a transport device are, with one in each operating state Press device has no mold.

The object of this invention is to provide a working method create with which an overall system according to the generic term of Claim 20 in the most economical way possible can be operated.

The solution to this problem essentially arises from the characterizing part of claim 20, according to which respective pressing devices that have no mold include pressing device between them, can be opened or closed simultaneously, the in the latter arranged mold by means of Transport device in the free in the conveying direction Press device is moved.  

It is through this working method according to the invention possible in an advantageous manner with a device for Manufacture of molded parts with a relatively low order driving power for the presses, because with Verwen only two at a time Presses are opened or closed.

In summary, the costs for one of the like device due to the significantly reduced instal drive power reduced.

Further advantages of the invention result from the following description of the embodiments.

Show it:

Fig. 1 is a perspective view of a compression mold,

Fig. 2 is a simplified sectional view of a closed press,

Fig. 3 is an illustration of Fig. 2 was in the open to,

FIGS. 4 and 5 is a schematic representation of an Ar beitsverfahrens for use of an existing from being arrange in series th press devices entire plant and

Fig. 6 is a schematic representation of an overall device constructed from parallel parallel devices.

In the drawings, a pressing device for the manufacture of molded parts from plastic waste is designated as a whole by the reference number 10 .

Fig. 1 shows the existing cast iron or aluminum die 11 which consists of a base 12 and a lid 13. The lower part 12 has a right-angled recess 14 for receiving the material to be pressed, the recess 14 having a size which enables the cover 13 to be immersed in the latter in a sealing manner while the lower part 12 is closed .

On both sides of the mold 11 , a transport device 15 is indicated by dash-dotted lines, with which the mold 11 can be transported in the direction of the arrow marked x. The transport device 15 can, for. B. as a conveyor chain, conveyor belt, push belt system, guide roller system or the like. The facing to the Transporteinrich device 15 side walls 16 are provided on both sides with a flange 17 , by means of which the mold 11 is mounted overall on the transport device 15 .

In FIGS. 2 and 3, a press apparatus 10 is shown including schematically IMP EXP. One can see an upper, movable press plate 18 and a lower, movable press senplatte 19 between which a mold 11 is arranged. On both sides of the pressing device 10 , the transport device 15 is also shown schematically.

Ultimately, heating and cooling pipes 20 are present in the upper and in the lower press plate 18 and 19 , with which the press plates 18 and 19 can be brought to a certain desired temperature. For this purpose, the heating or cooling tubes 20 can be charged with a heat exchanger medium.

In the closed state of the press device 10 shown in FIG. 2, the press mold 11 is pressed against the upper press plate 18 by means of the lower press plate 19 , the cover 13 tending to be immersed in the recess 14, not shown, of the lower part 12 . The lid 13 closes the recess 14 so that no plastic waste can escape to the outside. It is also seen that the die 11 direction when closing the Preßvor 10 is lifted by the transport device 15, so that the side 17 above the processing Transporteinrich arranged 15th

In Fig. 3, however, the open state can be seen a press. In this case, the lower press plate 19 moves downward, the mold 11 following this movement until the side flanges 17 rest on the transport device 15 . In this case, the transport device 15 moving in the x direction (see FIG. 1) can transport the mold 11 to the next pressing device 10 .

The operating sequence of a press device 10 shown in FIGS . 1 to 3 is now as follows:

First, a defined amount of coarsely comminuted plastic waste is filled into the depression 14 of a mold 11 and then the lid 13 is placed on it. Thereafter, the mold 11 is transported by means of the transport device 15 into a first pressing device 10 heated via the heating pipes 20 , which is then immediately closed. Under the action of a pressing force F (see FIG. 2), the cover 13 is pressed into the depression 14 of the lower part 12 . In the control of the isochoric press device 10 stops 14 are for example provided on the side walls of the groove, which delimit the immersion of the lid. 13

In the manufacture of the molded parts there is a volume reduction of the filled plastic waste by about a factor of 5. As a result of the heating of the plastic waste in the mold 11 by means of the upper and lower press plates 18 and 19 , the contact heat acting on the mold 11 becomes Plastic waste is heated, the plastic chips being sintered together with softening.

Thereafter, the pressing device 10 opens until the pressing mold 11 with the side flanges 17 rests on the transport device 15 and can be transported to the next pressing device 10 . In this pressing device 10 , however, it is a cooled, in which the mold 11 and the blank is cooled after closing in the course of a further half an hour to the release state.

Basically, it is provided that the removed To use heat to heat other moldings  the energy expenditure for the production of a molding mini lubricated.

With a desired molded part thickness of approximately 25 mm, the heating time of the molded part is approximately half an hour, the plastic waste being heated to approximately 180 ° Celsius. Basically, the residence time of the plastic waste in a device 10 depends on the thickness of the molding to be produced. It should be taken into account that a quadrupling of the dwell time is necessary when the molding thickness is doubled.

FIGS. 4 and 5 then show a plurality of devices 10 Preßvor composite overall system R for the manufacture of molded parts from waste plastics, which switches ge in series and are connected to one another via the transport means 15. The peculiarity of this overall system R be is that each pressing device 10 has a gradually higher or lower temperature.

In the present example, the overall system R consists of pressing devices a to i, with, for example, the pressing devices a to e having a gradually higher temperature and the pressing device f to i a gradually lower temperature. In effect, this means that the plastic waste gradually passes through all the pressing devices a to i during the heating and cooling times. It should be noted that the filling station and the demolding station are not shown in FIGS. 4 and 5.

FIGS. 4 and 5 also show a completely be-determined working method of using such a Ge overall plant R. basis of this operating method is that the number of steps the overall system R passing through press molding 11 is always at one less than the number of press devices a to i of a complete system R.

In Fig. 4 is indicated schematically that the Preßvor directions e and g were opened or closed simultaneously in the direction of the arrows marked with y and z respectively. While there is a press mold 11 in each of the press devices e and g, the press device f has no press mold 11 . For this reason, the mold 11 of the pressing device e, which device e is uniformly connected to the transport device 15 when the pressing device e is opened, can be transported in the x-direction into the “empty” pressing device f. When the pressing device f is reached, the pressing mold 11 is then automatically picked up by the same and loaded with a pressing force F, while at the same time the pressing device d upstream of the pressing device 11 having no pressing mold 11 opens against the transport direction x.

In the next cycle, the mold 11 located in the pressing device d is transported by means of the transport device 15 into the "gap" which results in the pressing device e. Ultimately, the working process is continued in that the pressing device e closes and the pressing device c is opened at the same time.

In this way, the simultaneous opening or closing of two pressing devices and the transport of a mold 11 in the next, a "gap" having pressing device a to i, the drive power required for the overall system R is significantly reduced. This is achieved in that the drive power only has to be dimensioned such that two pressing devices a to i can be opened or closed at any time and the pressing force F provided in all other pressing devices a to i is maintained.

Due to this working process, the position moves the "press-free" press device constantly around.

Ultimately, Fig. 6 shows a further alternative to the construction of an overall system P from pressing devices 10 '. Here at the entire system P consists of a parallel connection of two series-connected Preßvorrichtun conditions 10 ', of which the first is heated and the second is cooled. This overall system P is enclosed by a common transport device 21 , the respectively arranged in series cooled or heated pressing devices 10 'are connected to each other with a further transport device 22 , which has a transport connection to the common transport devices 21 by means of a transfer station, not shown.

The entire system P thus consists of an essentially rotating transport device 21 , in the area of which a filling and demolding station 23 for the molds 11, including the lid placement station 24, can be seen. The filled with plastic waste molds 11 are then by means of the rotating transport device 21 , which, for. B. transfer car can be transported to the transfer station to the series-connected pressing devices 10 'leading further transport device 22 . There takes the form of a chain conveyor Transportein direction 22, the die 11 and transports it to the pressing devices 10 '. After the dwell time in the first, heated pressing device 10 ', the die 11 falls in the manner previously described on the chain tenbahn 22 and is transported to the cooled press device 10 . After the mold 11 has reached the Entformungszu stand, it is moved to the transfer point with the rotating common transport device 21 and from there to a cover removal station 25 and the Ent forming station 23 transported.

After removal from the mold, the molds 11 can in turn be filled with plastic waste in the filling station 23 .

Claims (20)

1. A process for the production of molded parts from plastic waste, in particular from a sorted from domestic waste, different plastics and contaminants having fraction, which has been roughly shredded into plastic chips, characterized in that the plastic chips are filled into at least one mold and under the action of one Pressing force are heated in the same, the plastic chips being sintered together with softening and, after cooling in the press mold, form a stable molded part. 2. The method according to claim 1, characterized in that that the plastic chips depending on the thickness of the a certain amount of time to be created Heated to 180 ° Celsius and then to the release state be cooled. 3. The method according to any one of claims 1 or 2, characterized characterized in that during the heating and cooling a constant pressing force is applied. 4. The method according to any one of claims 1 to 2, characterized characterized in that during the heating and cooling the mold volume remains constant.   5. The method according to any one of claims 1 to 4, characterized characterized in that the plastic chips in differ presses are gradually heated and cooled. 6. The method according to any one of the preceding claims, since characterized in that before filling the plastic cut a layer into the mold for lamination Plastic material, such as film, granules or the like, introduced becomes. 7. The method according to any one of the preceding claims, since characterized in that in the mold reinforcing material rialien or fillers are introduced. 8. The method according to any one of the preceding claims, since characterized in that the plastic fraction in art shredded fabric with an edge length of approx. 15 to 50 mm is divided. 9. Device for the production of molded parts with at least one press, which has an upper and lower press plate and a press mold, the press mold consisting of a lower part receiving the material to be pressed and a mold which closes the mold and transfers the pressing force to the material , characterized in that the device has at least two, with a fixed standing upper and a movable lower press plate ( 18 , 19 ) provided presses ( 10 , 10 ', ai), one of which is heated and one cooled, and that Presses ( 10 , 10 ', ai) are connected to one another with a device for transporting ( 15 , 22 ) the molds ( 11 ), each press mold ( 11 ) with the press open ( 10 , 10 ', ai) with which in the conveying direction (x, x ') moving transport device ( 15 , 22 ) is automatically connected in a uniform motion. 10. The device according to claim 9, characterized in that the mold ( 11 ) at the parallel to the conveying direction (x, x ') existing limits of the lower part ( 12 ) Seitenflan cal ( 17 ) through which the lower part ( 12 ) at ge opened press ( 10 , 10 ', ai) is held in the transport device ( 15 , 22 ). 11. The device according to claim 10, characterized in that the transport device ( 15 , 22 ) is designed as a conveyor chain, conveyor belt, push bar system, guide roller system or the like. 12. Device according to one of claims 8 to 11, there characterized in that several Pres sen (a-i) form an overall system (R), the presses (a- i) starting from the first arranged one stu then gradually increasing temperature falling temperature. 13. The apparatus according to claim 12, characterized in net that the device from a number (n) of presses (a- i) and a number (n-1) molds. 14. Device according to one of claims 9 to 11, characterized in that each individual device consists of two, each shape ( 11 ) successively receiving presses ( 10 , 10 '), one of which can be heated and one can be cooled. 15. The apparatus according to claim 14, characterized in that a plurality of such devices are arranged parallel to each other in an overall system (P) having a common filling or demolding station ( 23 , 24 , 25 ), which with each device ( 10 ') Is connected via a common transport device ( 21 ). 16. The apparatus according to claim 15, characterized in that the presses ( 10 ) arranged one behind the other are connected to one another by means of chain tracks ( 22 ) and to the filling or demolding station ( 23 , 24 , 25 ) via transfer carriages. 17. Device according to one of claims 8 to 16, characterized in that the presses ( 10 , 10 ', ai) can be heated or cooled by means of heating / cooling coils ( 20 ) arranged in the latter. 18. Device according to one of claims 8 to 17, characterized in that the device is provided with a heat recovery system which the energy generated in the cool th presses ( 10 , 10 ', ai) for heating the upstream presses ( 10 , 10 ′, ai) uses. 19. Device according to one of the preceding claims, characterized in that the lower part ( 12 ) of a mold ( 11 ) with the immersion of the cover ( 13 ) limit the stops is provided. 20. Working method for using an entire system, which is formed from a plurality of pressing devices arranged in series, which are connected to one another by means of a transport device, wherein in each operating state a pressing device has no pressing mold, characterized in that the pressing devices (e and g; d and f), each enclosing the press-free press device (f; e) between them, are simultaneously opened or closed, the press mold ( 11 ) 'being the press device (e; d) upstream of the press-free press device (f; e) is arranged, is moved by means of the transport device ( 15 ) into the press device (f; e) which is free of the mold in the conveying direction (x).