DE1504177A1 - Method and device for the production of board-like or film-like porous plates from thermoplastic material - Google Patents

Description

Method and device for the production of board or film-like porous sheets of thermoplastic material. Method of manufacture Board-like or film-like porous plates or the like made of thermoplastic material, which is crushed into pourable or flowable particles, the particles on a conveyor device can be layered, which the particles at two treatment points continuously bypasses. In addition to plates with a rectangular shape, strands can also be used with other cross-sectional shapes delimited by curved lines be e.g. B.

Tube. The invention also relates to a device for implementation of the procedure.

E2 are already processes for the continuous production of plastic sheets or strands of thermoplastic Plastic material known, that is prepared in powder form, spread out in webs or strands and heated is connected. Specifically, such a known method consists of two Steps, firstly a warming and secondly an application of pressure. Included the plastic powder in the heating zone is initially considerably above the sintering temperature, but heated below the flow temperature and in the subsequent stage to the lower pressing temperature set.

The prior art also includes a device for exercising a such procedure. In this device, too, a Warming zone sintering is achieved by radiant heating, while in the the subsequent part of the heating zone the lower pressing temperature prevails. The plastic powder loses immediately on entering the heating zone the flowability and acquires a dough-like texture. After sintering and setting the lower pressing temperature, the final shaping is achieved carried out one or more pressure rollers. Since the application of the Technique involving the process of sintering each particle a dough-like process Assumes its nature, it changes its shape to a considerable extent. In the second essential stage of the known process in which the sintered, still plastic Plastic web is compacted between press rollers, the shape of the particles learns another, individually uncontrolled change. Finally finds one Deformation when cooling the overall to a relatively high temperature heated particles instead.

The invention is based on the object of porous plastic products to be produced as economically as possible. No additives should be used to connect the particles or chemicals are required, but on the other hand fillers should be in the plate. The aim is to achieve the desired shape of the End product that is already in use when the material enters the second heating stage is present, to be maintained and preferably the package image according to the first irradiation no longer change. In addition, you want the final shape of the plastic products must be set before the first heating zone. this conditional on the shape of the granules and the layer consisting of them as possible changes little and only in a controlled manner. Areas of application for the products should for example, linings for insulation against temperatures, noise, etc., furthermore Diaphragms of all kinds, for example filters.

The object is achieved according to the invention a method of the type mentioned at the beginning, which is characterized by that the particles at the first treatment site to such an extent through and through are heated to a uniform temperature below their softening temperature, that only their rebound resilience is reduced, and that the particles adhere to the second treatment site is exposed to a special type of radiation source, whose rays penetrate through the particles without heating their mass, so that only the contact surfaces of the particles immediately and firmly stick together the particles, while maintaining their shape, form a porous endless plate, which corresponds in shape, size and composition of the particle layer.

In the first treatment site, the particle layer is through and heated through to a uniform temperature.

It is important that the plastic particles are only heated to that extent be that their softening temperature is not reached. The particles are allowed so don't get soft or even runny. Only the rebound resilience should reduced or made to disappear. This ensures that the Particles as well as the spaces between them are fully preserved in their shape stay and that still a safe one in the subsequent second treatment site Connection between the particles is created.

At the second treatment site, there should be no further heating in the Particles take place. Rather, a radiation source should be applied to the particle layer special kind, whose rays penetrate through the particles without to heat their mass.

After leaving the second treatment site, there is a permanent one porous plate, the dimensions of which correspond exactly to the original particle layer , and the shape of the particles themselves, with the exception of the contact surfaces have not changed. The spaces between the particles also remain full obtain.

This process results in a product that consists of many coherent but still existing particles, namely the semolina or powder granules, and depending on the particle size is porous. The porosity can be so great that it is easily visible to the naked eye can be perceived, but it can also be so small that it is merely capillary Has character, resulting in a diaphragm that only has for Gases is permeable. Depending on the raw material, the product can be also either as a hard, stiff piece or as z. B. win easily flexible plate.

One advantage of the process is that the final shape of the plastic product already by acting on the loose particles existing material layer can be determined. Since the package picture of this Material layer due to the heating in the first treatment site and the radiation in the second treatment site, where the connection runs off very quickly, not changed, a pressing process does not necessarily need to be applied to the second treatment site to connect. The new manufacturing process is therefore particularly simple and economical. Because the shape of the particles remains practically unchanged during their connection, can be changed from its original shape without cumbersome and time-consuming attempts can be predicted quite accurately what appearance and what properties they will look like will own them existing plastic sheeting. This is especially true for such establishments cheap, which produce different types of plastic products each in small quantities.

The method is expediently designed so that the particles both treatment sites with waves with a wavelength of 1 x 10 1 to 0.6 x 10 4 cm are irradiated, the wavelengths being shorter at the second treatment site than those chosen at the first treatment site.

In an advantageous dimensioning of the method, the Heat waves at the first treatment: place a wavelength of about 3 x 10 2 cm on and at the second treatment site are waves with one wavelength radiated from about 7,500 to 32,000 A.S.

In a variant of the method, the particles are at the first Treatment site instead of radiated heat waves through one between the Particles passed through air flow is heated.

According to the invention, a second and possibly further layers are applied, which are treated in the same way and are connected to the first layer like the individual particles of the first Layer among themselves. The invention also includes the suggestion that one or more Inlays in the form of threads or bands are introduced into the layer or between the layers Another preferred embodiment of the invention to be used is in that ground or otherwise finely comminuted as a plastic raw material Products e.g. B. rods or plates, including waste, are used by such plastics which have a rebound resilience which changes under the influence of heat can be.

The rebound resilience is the property of resilience of the substance means. This rebound resilience can occur with thermoplastic fabrics be changed under the influence of heat, but it should not be lost, but adjust again when the original temperature conditions reappear getting produced. Since the rebound resilience is inherent in the whole plastic particle, so it is present right down to the core, it must also be changed as a whole, and this is the job of the first treatment center. The purpose of the change The rebound resilience is the preparation for an instant connection of the particles without significant deformation in the second treatment site. The predetermined The shape and size of the material layer is therefore retained.

The plastic web can follow the second treatment site bent into a tube shape and the corresponding seam progressing continuously be welded.

If the plastic sheet is chosen to be sufficiently wide, leave it multiple tubes are formed from a web by moving the web in its longitudinal direction is cut open and the corresponding partial webs, each for itself, to form a device are performed, in which they experience a tubular machining. The pipes can have different diameters, and the individual devices for manufacturing the tubes can be arranged in different levels to suit the spatial conditions to set up accordingly cheap. Such an arrangement can also be made, that the partial tracks lead to different end products.

Another embodiment of the method according to the invention is characterized is characterized by the fact that products, including waste of thermoplastic materials, are used as plastic raw materials Plastics are used which originally or subsequently contain other components, Fillers, preferably non-plastic components in an even distribution, are added, for example cork or wood or corundum or rubber. The foreign matter remain unchanged during the procedure, e.g. B. Pigments, but with them later can exert physical or chemical effects. Such effects are for example with reflective or absorbent fabrics, anti-mesh or pro-mesh or permanent magnetic substances.

Another embodiment of the method according to the invention The basic idea is achieved in that the plastic web preferably directly after its completion is continuously applied to a carrier z. B. on a wall covering film or on a floor covering sheet.

It can also be a matter of placing the plastic sheet under a foreign sheet to be attached or inserted between two foreign tracks'. The strange paths become previously prepared elsewhere and, if necessary, pretreated, z. B. with Coated with adhesive, the adhesive web to a certain extent with the plastic web is concealed. In this way, the plastic sheet can later also be used without workshop equipment stick to a desired location. The width of the foreign path can be equal to or be different from the width of the plastic sheet. Foils are used for third-party railways made of polyvinyl chloride, woven tapes made of natural or artificial threads, including Glass, and ribbons of cellular material with open or closed cells in Question. The feeding of the foreign webs can procedurally also before the first Treatment center are switched on.

A device according to the invention for performing the described Method proposed is essentially characterized in that it has an endless conveyor belt, at the beginning end of a device for uniform Abandonment of gritty or polygonal plastic material is arranged, and that in the connection above and below the conveyor belt, electric or other emitters Emission of heat rays in the range -2 around 3 x 10 2 cm wavelength, z. B. in shape of Baker pipes, and that following it, above or above and below the conveyor belt, electric or other emitters for emitting Rays, preferably in the range of 0.8 x 10 5 cm wavelength, e.g. B. reflector type light beam cr in tubular form, while at the end of the conveyor belt a decrease and Winding or transfer device for the plastic web or the plastic strand is provided.

Further details of the device and further features of the invention result from the following description of an exemplary embodiment, which is shown in the drawing. 1 shows a schematic side view a machine for producing a flat plastic web, FIG. 2 is a diagrammatic view Representation of the plastic sheet at the end of the machine with facilities for dividing and further processing of the web.

In a machine frame, not shown, which is made of sectional steel Can be assembled, a conveyor belt device 1 is arranged, which consists of for example a 60 cm wide conveyor belt made of nettle fabric, from guide and Deflection rollers 2 and 3 and consists of a drive device which is not shown is, and in the usual way on a drive; roller acts, which at the same time a Can be guiding roller. The conveyor belt 1 rotates in the direction of the arrow 4.

Above the point where the upper run 1a of the conveyor belt begins, there is a storage container 5 for the raw material, which at its in the Tape running direction facing front has a lower opening with a Hooking device 6 is provided to the raw material in a uniform layer 7 to be applied to the surface of the tape 1. Layer 7 is for example 50 cm wide and 3 mm thick; it consists of dry, loosely lying plastic grit or powder, which was chosen as the starting material.

Following the doctor blade 6 there is possibly another one Means to the applied plastic layer 7 on an even more precise level to calibrate and, if necessary, to compress the layer more or less. the Device consists of two rollers 8, one of which is above and the other is arranged below the conveyor belt 1. The two rollers, the axially parallel can be placed on top of each other at right angles or at an angle to the direction of transport the layer 7 be arranged.

Made to measure and with the desired compression ratio The pre-material layer that has been provided continues to run and the next action subjected to heat rays generated in a corresponding heating station 9 and be sent out. The station consists of heating elements or Radiant heaters that can be heated with electricity, gas or the like and can be located either above or above and below the conveyor belt 1. The heating elements can be switched on and off individually or in groups, and you The distance to layer 7 can be changed so that the irradiation meets the given conditions, namely the type of raw material, the layer thickness, the transport speed, can be customized.

The heating elements are preferably on holders (not shown) attached, which allow the elements to pivot to the side or to drive up; d. H. to remove from the projection of the conveyor belt. A preferred one Embodiment of the heating elements is that they are essentially U-shaped arranged radiators, e.g. B. Baker pipes exist in relation to the direction of travel of the tape so that the U-legs in this direction and the U-opening opposite run in this direction. The Baker tubes are inside a ceramic bowl arranged and can be equipped with reflectors to reduce the To increase the radiation effect on the running material.

The layer acts in the first irradiation zone 9 7 instead of raw material, which is not easy to see from the outside is. At most, the shift appears somewhat after it has passed through station 9 duller than before. By the chosen wavelength of the heat rays in the area of 3 x 10-2 cm is the material only with regard to its rebound resilience changed as it has already been described. On the whole, there is the material web still made up of loose particles that have not yet bonded with each other are, so that following the station 9 still changes in the shape or the Cross-section of the layer 7 lying on the conveyor belt 1 are possible. However, it is expedient not to have such effects on the layer after the first irradiation to undertake more to the package picture, which the layer now has, and which is particularly suitable for further processing, not to be changed.

Following the first treatment site 9, however, there is one favorable opportunity to purely local, shaping effects on the layer 7 perform, in particular those that only cover the surface of the Layer relate, for example, profilings and in particular patterns, d. H. the formation of evenly spaced ornaments or the like. For this purpose there is an ai: for example above the conveyor belt 1; endless belt formed device 10 with counter-pressure roller 11, wherein the belt 10a provided on its surface with raised engravings for a corresponding pattern can be. The arrangement of several devices 10 one behind the other is possible.

During the procedural treatment of the goods on the conveyor belt 1 is followed by the most essential station, namely irradiation the layer 7 in such a way that the particles of the primary material with each other connect to a homogeneous, porous band. For this purpose are preferably above of the conveyor belt 1 with the material layer 7 radiator 12 arranged, which in the selected embodiment consist of reflector-type bright radiators, as u. a. marketed under the Philips trademark. These emitters emit electromagnetic waves in the range of 0.8 to 3 microns, below Creation of an intense whitish light. Multiple radiation rods can be arranged next to and behind one another so that the layer 7 is as uniform as possible is applied; In addition, the radiators are expediently in accordance with Arrangement in station 9 movable so that their distance from the conveyor belt can be changed and they can also be completely removed from the projection of the conveying path. The setting of the emitters according to position and amount of energy is again carried out accordingly the requirements that the raw material brings.

The processes that take place in the stage with the radiators 12 were already explained in more detail at the beginning, so that only needs to be stated at this point is that the layer 7 behind the radiators 12 as a coherent whole the conveyor belt 1 rests.

The still malleable nature of the layer as long as it is not has already cooled down again, it can be used to add further features to its shape to convey, in particular to design the surfaces of the band 7. Is to a pair of rollers 13 is arranged behind the station 12.

Instead of the rollers 13 or following them there is one Cooling level. This is preferably on the one hand or by appropriate fan 14 formed on both sides of the belt, from which distributors such. B. Cross tubes with holes, a stream of cold air, covering the entire strip evenly, emerges. It is also possible to pass the tape through a coolant bath.

Finally, there is a scraper plate at the end of the conveying path 15, which lifts the plastic belt 7 from the supporting conveyor belt 1 and preferably leads to a winding station, not shown, where the tape is removed in rolls will. By cutting devices, e.g. B.

Kreismeser, the tape behind the cooling zone 14 can also be in his Cut lengthways into partial webs, which are then wound up separately or differently Machines are passed on so that further processing takes place there. This can z. B. exist in the manufacture of tubes by the partial tracks in the already described way are bent together and welded to the resulting seam. These pipes are particularly suitable for use as drainage pipes.

The lower run ib of the conveyor belt 1 contains facilities for cleaning and removal of any remaining raw material, for example a brush roller 16 and compressed air or pressurized water nozzles, not shown, which wash the belt.

The possibility of applying a second layer of plastic has already been pointed out. A second squeegee box is used for this purpose, for example arranged, the a second plastic layer in the same or different width on the crop layer, in a place that depends on the expediency certain, for example only after completion of the first plastic tape, approximately between the steps 13 and 14 according to FIG. 1. The second layer can be formed from the same or a different starting material, whereby the grain size can also be different from that of the first layer. For the second There must also be a corresponding sequence of treatment stages on the layer Conveyor belt are located.

The insertion or application of foreign components in or on the plastic band is best done between steps 9 and 12 according to FIG. 1. Glass threads, rubber threads, steel or copper wires can be processed to achieve the To give the end product appropriate special properties.

The product can also be used in the course of liner manufacture with the aforementioned additional layers of other materials are provided, either at a point that is switched between the mentioned treatment stages, or at a point that follows on from the stages of the narrower procedure . Other processing operations are also preferably carried out immediately after the last one procedural stage described appended, z. B. bending, pressing, drawing, punching and / or Cutting operations. In case these operations are easier to perform when the material If there is still a certain plasticity inherent, this can go up to the attainment of the relevant Stage can be obtained by means of preventing cooling.

In Fig. 2 an example is given for the division of a finished Plastic sheet in three partial sheets, of which the two outer sheets continuously Pipes of different diameters are further processed, while the middle one Bahn remains a band-shaped end product. The division of the Lanes is done by circular knives, and the rear partial track is then on a higher, the front partial path is guided to a lower processing level. In this way the now parallel processing stages can be accommodated better spatially.

The in the above description, in the drawing and in the The following claims disclosed features of the subject of the application can both individually and in any combination with one another for the realization be essential to the invention in its various embodiments.

Claims

Claims (25)

Patent claims 1. A method for producing board-like or film-like porous plates or the like - made of thermoplastic material, which in bulk or flowable particles are comminuted, the particles being transferred to a conveying device are evenly layered, the particles continuously at two treatment sites passes, characterized in that the particles at the first treatment site to such an extent, through and through, to an even temperature below theirs Softening temperature are heated, that only reduces their rebound resilience is, and that the particles at the second treatment site of a radiation source be exposed to a special kind, the rays of which penetrate through the particles, without heating their mass, so that only the contact surfaces of the particles immediately stick together firmly and the particles remain porous while maintaining their shape Form endless plate, which in shape, size and composition of the particle layer is equivalent to. 2. The method according to claim 1, characterized in that the particles at both treatment sites with waves with a wavelength of 1 x io-1 to 0.6 x 10-4 cm are irradiated, the wavelengths at the second treatment site shorter than those chosen at the first treatment site. 3. The method according to claim 2, characterized in that the heat waves have a wavelength of about 3 x 10-2 cm at the first treatment site and that at the second treatment site, waves having a wavelength of about 7500 up to 32000 A. E. are emitted. 4. The method according to claim 3, characterized in that the particles at the first treatment site instead of radiated heat waves through one air flow passed between the particles are heated. 5. The method according to any one of claims 1 - 4, characterized in that that the process steps of changing the rebound resilience and sticking together are temporally or temporally and spatially separated from each other. 6. The method according to any one of the preceding claims, characterized in, that a second and possibly further layers are applied to the first material layer which are treated in the same way and connected to the first layer like the individual particles of the first layer with each other. 7. Verfa-hren according to one of the preceding claims, characterized in that that one or more deposits in thread or tape form in the layer or between the layers are introduced. 8. The method according to claim 1, characterized in that the plastic raw material ground or otherwise finely comminuted products, e.g. B. rods or Sheets, even waste, are used from such plastics, which have a rebound resilience which can be changed by the influence of heat. 9. The method according to one or more of the preceding claims, characterized in that the plastic web is connected to the second radiation zone bent into a tube shape and the corresponding seam progressing continuously is worn out. 10. The method according to one or more of the preceding claims, characterized in that products, including waste, of thermoplastics are used, which were originally or subsequently other components, preferably non-plastic components in an even distribution, are added, for example cork or wood or corundum or rubber. 11, method according to one or more of the preceding claims, characterized in that the plastic web preferably immediately after its Completion is continuously applied to a carrier, e.g. B. on a Wall covering film or on a floor covering sheet. 12. Apparatus for performing the method according to claim 1, characterized characterized in that it comprises an endless conveyor belt at the beginning end thereof a device for uniform feeding of plastic material in the form of semolina or flour is arranged, and that following it, above or above and below the conveyor belt, electrical or other radiators for emitting heat rays in the range of 3 x 10-2 cm wavelength, e.g. B. in the form of Baker tubes arranged and that following this, above or above and below the conveyor belt, electrical or other emitters for emitting rays, preferably in the area around 0.8 x 10-5 cm wavelength, e.g. Refector-type bright radiators in tubular form, arranged are, while at the end of the conveyor belt a removal and winding or transfer device is provided for the plastic web or the plastic strand. 13. The apparatus according to claim 12, characterized in that the Radiant heaters at the first treatment point made of essentially U-shaped Radiating elements, e.g. B. Baker pipes, which is in relation to the direction of travel of the tape so that the U-legs in this direction and the U-opening opposite run in this direction. 14. Apparatus according to claim 12 or 12 and 13, characterized in that that the conveyor belt consists of textile goods, preferably a cotton fabric, z. B. nettle. 15. Apparatus according to claim 12 or 12 and 14, characterized in that that the conveyor belt contains glass fibers. 16. The device according to claim 12, characterized in that in the connection sliding surfaces to the second treatment point below and above the conveyor belt are arranged, the distance from each other is adjustable and between which both the conveyor belt as well as the plastic layer on it passed through tightly is to design the two-sided surfaces of the plastic layer, e.g. B. to smooth or to profile. 17. Apparatus according to claim 12, characterized in that in the connection a cooling device is arranged at the second treatment site, preferably consisting of cold air outlet nozzles that are evenly distributed over a Area of the railway path are arranged. 18. The device according to claim 12, characterized in that in the the first and second treatment sites each have a plurality of individually or in groups that can be switched on Radiators are arranged. 19. The device according to claim 18, characterized in that the Spotlights are set up adjustable in height and side. 20. Apparatus according to claim 18 or 18 and 19, characterized in that that the radiators can be removed from the projection of the conveyor belt, preferably swiveled away, are set up. 21. Apparatus according to claim 12 and 17, characterized in that one or more than one knife is arranged in connection with the cooling device, to cut the plastic sheet lengthways into partial sheets. 22. The apparatus according to claim 21, characterized in that the Partial tracks for further processing are guided at different levels. 23. The device according to claim 12, characterized in that between the feeding device, e.g. B. a squeegee box, and the first treatment site a pair of rollers for calibrating the plastic layer entering the first irradiation zone is arranged. 24. The device according to claim 12, characterized in that preferably one or more than one further feeding device following the feeding device is arranged to have one or more than one further layer of material on top of the first Apply layer. 25. The device according to claim 24, characterized in that the Equipment for applying the further layer or Layers are arranged in a place where the first plastic layer is already completed, for example in front of or behind the to the second treatment site subsequent cooling device. L e r s e i t e