EP1045929B1 - Method and device for producing fibrous materials from thermoplastic materials - Google Patents

Abstract

The invention relates to a method for producing fibrous materials from thermoplastic material, wherein thermoplastic material is molten and fed into a rotating reactor to form a molten film and the fibers are formed on and stretched out along an open edge of the reactor. The fibers are formed on the reactor edge without using nozzles or ducts that are susceptible to clogging so that the rotating reactor is heated in such a way that the molten film has a temperature close to decomposition temperature of the thermic plastic material and the reactor is rotated on the edge at an orbital speed of no less than 10 m/s.

Description

The invention relates to a method for producing Fibers made of thermoplastics, in which the thermoplastic melted and melted into one rotating reactor passed to form a melt film and the fibers are formed on an open reactor edge and be stretched.

The invention further relates to a device for manufacturing of fiber materials from thermoplastic materials with a melting device for the thermoplastic and a heated rotating reactor for training a melt film from the molten plastic, the the rotating reactor over an edge of an open side leaving with formation of fibers.

Nonwovens formed from such fibrous materials are in particular for the absorption of petroleum, petroleum products and Heavy metal ions from water are used. For particularly effective Nonwovens, it is desirable that the fibers be as possible have low strength.

The usual way of producing thermoplastic fibers takes place by melting the starting thermoplastic and extruding the molten plastic through thin ones Nozzles for the formation of thin radiation-like fibers. By Stretching can make the extruded fibers even thinner be, at the same time with a special air flow be cooled. These processes are very homogeneous Output thermoplastics ahead, so that in particular the use of recycled plastics that are inhomogeneous are and may contain foreign objects. These would namely clogging the nozzles or channels. The extrusion process also provide that with relative low temperatures just a little above the melting temperature can lie, work is carried out to the cooling measures as simple as possible after extrusion to design. Processing of secondary raw materials and Thermoplastic waste, on the other hand, requires processing higher temperatures that are close to the temperatures of thermoplastic decomposition lie.

From SU 699 041 it is known that the thermoplastic melt feed a rotary pot, on the inner wall of the Melt film formed and the spinning from the melt film by forming fibers on the edge of the pot one passed at high speed over the melt film Gas is made. The reactor is in shape of a pot placed vertically and exists from a cavity and a work surface. Heated up Gas becomes under pressure inside the reactor and cavity fed to the surface of the melt film. On the edge of the pot there are slot nozzles through which the Melt film is divided into individual jets and put together flows with the heated gas. This will make the educated Rays made thinner and stretched.

The invention is based, avoiding the task the disadvantages of the known device thin synthetic To be able to produce fibers with higher yield High quality raw materials, but also from waste thermoplastics can be formed.

According to the invention, a method is used to achieve this object of the type mentioned above, characterized in that the rotating reactor is heated so that the melt film a temperature close to the degradation temperature of the thermoplastic Has plastics and that the reactor with a Web speed of at least 10 m / s on its edge is rotated.

According to the invention, the reactor itself is thus heated, so that the melted thermoplastic has very constant temperature conditions subject to near the degradation temperature for the Thermoplastics can be chosen without the risk that by locally exceeding this temperature Quality of the plastic affected by decomposition processes becomes. The fiber formation occurs in the invention Process due to the high rotation speed or the high web speed at the edge of the Reactor, whereby the cohesive force of the melt film is exceeded is, so that the division into the fibers takes place. On the use of channels prone to blockage or Nozzles can therefore be completely dispensed with.

The fibers stretched on the edge of the rotary pot become expediently stabilized under the influence of an air stream, which is preferably conducted across the grain.

The thermal required for the method according to the invention Uniformity in the reactor is in one preferred embodiment supported by that Interior of the reactor through one with the edge one narrow circumferential gap forming lid largely is completed. The one when heating the melt film escaping gases emerge through the gap and influence the fiber formation according to the invention positive. The lid is preferably positioned stationary. It can be useful if the lid to form a circumferential Gaps with varying width asymmetrical to the Axis of rotation of the reactor is positioned.

With a smooth inner surface of the reactor, the Melt film of spiral streaks, i.e. uneven Thick, train. This can largely be prevented be that the melt film on the inner wall of the reactor is divided by axially extending ribs.

To achieve the above-mentioned object, there is also a device of the type mentioned in the introduction characterized in that the rotating reactor is heated from the outside and on its open side through a fixed lid except for a circumferential annular gap formed with the edge is closed.

It is to increase the acceleration of the melt film advantageous if the inner wall of the rotating reactor flared towards the edge, although the Reactor cylindrical for most of its axial length can be trained.

The annular gap can preferably have a width of 15 to 20 mm have, with an asymmetrical to the axis of rotation of the rotating reactor arranged lid with the annular gap a varying width can be formed.

If according to a preferred embodiment of the invention the inner wall of the reactor with axially extending ribs Subdivision of the melt film is provided, these are preferred triangular with its greatest height at the bottom of the Reactor and with its lowest height at the outlet end of the Melted film trained. In conjunction with the preferred Embodiment of a cylindrical reactor which is the open conically extended, the Ribs preferably over the cylindrical part of the reactor and end at the beginning of the conical part.

The reactor is placed on the outside by a heater Brought operating temperature, which is preferably a resistance heater, an induction heater or a magnetic induction heater can be.

Figur 1 -

schematisch eine erfindungsgemäße Vorrichtung

Figur 2 -

eine Draufsicht auf die Lage des Deckels relativ zur Kante des Reaktors

Figur 3 -

zwei Schnittdarstellungen eines Widerstandserhitzers

Figur 4 -

zwei Schnittdarstellungen eines Induktionserhitzers

Figur 5 -

zwei Schnittdarstellungen eines Magnetinduktionserhitzers.

The invention will be explained below with reference to an embodiment shown in the drawing. Show it:

Figure 1 -

schematically an inventive device

Figure 2 -

a plan view of the position of the lid relative to the edge of the reactor

Figure 3 -

two sectional views of a resistance heater

Figure 4 -

two sectional views of an induction heater

Figure 5 -

two sectional views of a magnetic induction heater.

The device shown in Figure 1 shows as assemblies an extruder 1, a device for fiber formation 2, a Unit for the precipitation of the finished fiber 3 and a removal device 4th

The device for fiber formation 2 consists of a hollow rotating reactor 5, the outside with a reactor heater 6 is heated. The open side of the reactor 5 is carried out by a conically expanded cone 7. In the cone 7 is a forming an annular gap 8 immovable cover 9 installed by a rod 10 is attached to a feed head 11 of the extruder 1. The Immovable lid 9 is eccentric to the contour of itself arranged conically expanding cone 7 and is in its axial position adjustable by means of a threaded connection, see above that the gap 8 is adjustable through the lid.

On the inner wall of the reactor 5 are triangular flat Ribs 13 extends in the axial direction. The ribs 13 are located on the entire surface of the reactor 5 in its cylindrical part. They show their greatest height Bottom of the reactor 5 and are at their lowest height (with their tips) oriented in the direction of the melt outlet. The outlet end of the reactor 5 is through a ring air line 14 surrounded from the air with high pressure an opening 15 (Figure 1a) can emerge.

The reactor 5 is mounted on the end of a hollow shaft 16, which is provided with ball bearings 17. The ball bearings 17 are located in a refrigerated case 18. At the other end the shaft 16 is a drive pulley 19 of a belt drive 20 attached, via a driven pulley 21 on the shaft an asynchronous motor 22 is running. Inside the hollow wave 16 runs a feed attachment 23 of a feed head 11 which a central opening 24 for the supply of the melting material from the extruder 1 into the reactor 5.

The whole device for fiber formation 2 is on a separate Frame 32 assembled and set up in a protective chamber 33. In the upper part of the protective chamber 33 is one with a Low pressure fan 35 connected air line 34 attached. The low pressure fan 35 is on the outlet side via an air line 36 with a gas cleaning device 37 connected.

The extruder 1 has a reservoir 39 for a prepared one Thermoplastic on. A drive motor 40 drives over a belt drive 41 and a reduction gear 42 a Screw 43 of the extruder 1. The screw 43 is located itself in a housing with a jacket-shaped heater 38.

The device is started up by switching on the reactor heater 6 and the heater 38 and the Low pressure fan 35 and the gas cleaning device 37. The extruder 1 is water for cooling the housing 18th fed. The container 39 of the extruder 1 is prepared with the Thermoplastic filled. After the target temperatures are reached, the drive motor 22 for the rotation of the reactor 5 turned on and the arrangement in idle 15 to 20 minutes to stabilize operating temperatures let run. After the operating temperatures of the Device are reached, the drive motor 40 is set of the extruder 1 in motion and switches the drives of the unit for fiber filling 3 and the take-off device 4.

The drive motor 40 brings the worm 43 over the belt drive 41 and the reduction gear 42 in rotary motion. The Screw 43 detects the thermoplastic from the container 39 and conveys it to the feed head 11. By passing the fabric through the heated part of the extruder 11 is conveyed, it mixes itself and melts to the viscosity, that of the thermoplastic viscosity in the range of the degradation temperature. Then the molten material passes through the opening 24 of the attachment 23 and the feed head 11 in the reactor 5 where the same temperatures are maintained.

In the reactor 5, the melt is distributed over the circumference of the Inner wall and is thanks to the centrifugal force between the Ribs 13 transported to the open end of the reactor 5. By the thermoplastic layer touching the inner surface and the ribs 13 is pushed forward, it also rises, which creates a thin melt film. There inside of the reactor 5, the ribs 13 are installed, the moves Do not melt in a spiral, what with a smooth surface would happen, but along the reactor generator. As a result, the inner surface is coated with the Melt film much more uniform, what the quality of the Melt increased significantly. By the melt film from the cylindrical part of the reactor 5 in the region of the conical extended cone 7 also decreases its thickness. This causes the resulting in the reactor 5 Gases at their exit a uniform distribution of the Melt film in the area of the cone 7. The melt film is preserved thanks to the rotation of the reactor 5, the kinetic energy, which is greater than the force of the surface tension. Therefore the melt film divides into rays, tears from the Edge of the cone 7 and stretches into fibers.

The production of the fiber in the invention Way is only possible if the linear velocity at the Cone edge of the reactor 5 is higher than 10 m / s. The one from the Openings 15 of the ring air line 14 flowing air flow 44 affects the fiber in the process of stretching. The fibrous material arrives on the conveyor belt 45 Unit for fiber precipitation 3. Using the conveyor belt 45 the pulp is transported to the take-off device 4, where the fibers are formed into finished goods.

The gases generated during the production of the pulp are from the protective chamber 33 through the air channels 34 and 36 using the low pressure fan 35 in the gas cleaning device 37 headed.

The device described enables the production of Fiber from thermoplastics with excellent absorption properties, including industrial and household waste can be used as a raw material.

The reactor heater 6, which is constructed on the outside of the reactor 5, can be used as a resistance heater 25, induction heater 26 or be designed as a magnetic induction heater.

In all cases, these heaters 25, 26 and the reactor 5 thermally insulated with the outer jacket 27.

According to Figure 3, the reactor heater 6 is a resistance heater 25 running, which is in a heat-resistant ceramic solid housing 28 is located. Between the electric heater and the protective jacket 27 is heat-insulating Fabric 29, e.g. Kaolin cotton, housed.

The variant according to FIG. 4 shows a reactor heater 6 as coolable induction heater 26, which in the protective jacket 27 is housed. Here too is the space between the Heater 26 and the protective jacket 27 with heat insulating Fabric filled.

According to FIG. 5, the induction heater 26 also contains Plates 30 made of a ferromagnetic alloy (e.g. Ni-Co), the along the reactor wall on the outer surface of the reactor 5 attached and connected to insulated conductors.

In terms of the process, the starting raw material is in the extruder 1 premelted and stirred so that a homogeneous melt arises whose temperature is close to the degradation temperature of the polymer is. From the extruder 1, the melt is rotating Reactor 5 fed, the wall temperature to a Temperature near the degradation temperature are preheated. By the rotation of the reactor 5, the melt becomes uniform spread on the inner surface. It imagines Paraboloid of the rotation and it moves under the action of centrifugal forces towards the open side. Because the open side of the reactor 5 is in the form of a diverging Has cone 7, the thickness decreases of the film proportional to the enlargement of the page surface. In this way it is possible to use thinner fibers to get. After leaving the edge of the diverging Cone 7 divides the film into individual rays, under the influence of centrifugal force and due to a high rotational speed of the reactor 5 become fiber. The resulting fiber comes into the air stream 44, which is directed perpendicular to the fibers flying apart and thus the fibers in the unit 4 for the precipitation of Compels fibers. The fiber lengthens and cools.

Because the process of film formation in a virtually closed Space takes place, arises within the reactor 5 Gas medium with an overpressure. This can cause degradation processes due to lack of air.

In addition, a stable temperature is generated in the reactor 5. Therefore, possible fluctuations in the heat supply be compensated for the process of film formation. This leads to the reduction of energy costs to the predetermined Maintain temperature. The overpressure inside the Reactor 5 leads to a gas flow that lasts a certain time the fiber supplies sufficient heat so that it still can get longer.

The use of the method according to the invention enables it, high-quality fibers not only with raw materials of one kind, but also with a combination of raw materials. This is because the raw material is first in the extruder 1 is melted down and stirred and then a certain Time remains within the reactor 5. This will make the the entire amount is evenly heated and the viscosity averaged, so that the production of the fiber from a homogenized Melt occurs.

In the event of a malfunction that causes the melt to fail Viscosity not reached, takes place under influence the centrifugal force self-cleaning the reactor 5.

The use of thermal stabilizers in dendritic Form that has free ions allows for quick Suppression of the processes during the degradation of polymers bringing together free radicals of the torn Polymer chains. This results in an increase in the amount of fibers compared to the heavy metals, and the output of pollutants in the environment is reduced.

Example 1:

Most of the fibers produced have a thickness of 5 up to 20 µm and are wound in braids, their cross-sectional size is in the range from 25 to 100 µm. The braid contains spherical and drop-like particles, some of which grown together with the fibers, partly isolated from the fibers are. There are also numerous fiber thickenings, their length between three and ten times the cross-sectional size of these thickenings. The cross sections these thickenings and the spherical and drop-like particles are in the range of 30 to 200 µm.

Example 2:

It is a coarse fiber pattern in which the largest Part of the fibers has a thickness of 50 to 400 microns. There are a smaller number of thinner fibers with a size of 5 up to 20 µm. There are numerous spherical and drop-like particles available with a size of 50 to 300 µm.

Example 3:

Most of the fibers have a cross section from 1 to 10 µm. Coarse fibers with a thickness of 20 are present up to 50 µm with the thickenings up to 100 µm. There are also spherical and drop-like particles.

Example 4:

Most of the fibers have a cross section from 1 to 10 µm. A small number of fibers are up to 20 in size µm. The thicker fibers have thickenings with the maximum Cross section from 50 to 150 µm. The existing spherical and drop-like particles have a size of 100 to 400 microns.

The thickness and the porosity of the fiber samples in bulk without compression was determined picnometrically according to the standards GOST 18955. I-73 with the use of tetrachloride carbon as picnometric liquid and the balance WLR-200, which gave the measuring accuracy of ± 0.05 mg to have. The information obtained is shown in Table 1. The density and porosity data for loose storage at 20 ° C. Pattern number 1 2 3rd 4th The density, kg / m ³ 911 903 907 909 Bulk density, kg / m ³ 102-117 167-174 112-127 123-136 Porosity,% 87.1-88.8 80.7-81.5 86.0-87.6 85.0-86.0 Behavior of the pore space to the polymer space 6.75-7.93 4.75-7.93 6.14-7.06 5.67-6.0

The absorbency of the fiber pattern for the process of Collecting petroleum and petroleum products from water level with repeated use of the substance in the absorption-regeneration cycle was determined using the following methodology.

The fiber pattern in the initial state was left with the water level contact the 3 to 6 mm thick layer of petroleum contained. West Siberian petroleum was used for the tests and as a petroleum product the industrial oil I-L-A-10 (GOST 20799-88) and 3-02 brand diesel (GOST-305-82).

The degree of saturation of the material with the liquids was checked according to the weighing method. Then the sample saturated with petroleum (petroleum product) was thrown at the separation factor 100 ± 3. The content of the petroleum (petroleum products) remaining on the fibers was determined according to GOST 6370-83. Fugate was dewatered with copper sulfate according to GOST 26378.0-84 and then the oil content (content of the petroleum product) was determined according to GOST 6370-83. On the basis of the information obtained, the behavior of the mass of the petroleum soaked up in the given process was calculated before and after spinning to the mass of the sample to be checked. The results are shown in Tables 2 and 3. Absorption capacity of example 4 with respect to the industrial oil ILA-10 and the diesel oil 3-02 in the repeated saturation cycles of the fiber with the petroleum products (absorption - regeneration) Absorption regeneration cycle number Behavior of the mass of the petroleum product to the mass of the fibers for: Industrial oil Diesel oil before skidding after spinning before skidding after spinning 1 12.99 0.376 9.95 0.132 2 8.54 0.409 7.28 0.195 5 7.97 0.446 7.22 0.201 10 7.75 0.443 6.27 0.204 15 7.913 0.454 6.31 0.210 20th 7.82 0.451 6.22 0.215

For comparison, the absorption capacities of the known Substances specified for the collection of hydrocarbons used (g / g): lignin - 2.2; Peat - 2.6-7.7; Filter pearlite - 7.0-9.2; Asbestos (in case of fibrillation) - 5.8-6.4; Dornit - 1.9-2.5, technical wadding - 7.0-7.2. there one has to take into account that all these known substances only Are disposable. The investigations carried out with the mentioned substances have shown that they have such properties own that allow them for oil gathering and to use petroleum products from the water level.

• Hydrophobie, gutes Anfeuchten mit Erdöl und Erdölprodukten;
• ihre Dichte ist niedriger als Wasserdichte, was die Schwimmfähigkeit dieser Stoffe beeinflußt;
• hohe Porosität der Stoffe;
• hohe Absorptionskapazität der Stoffe, in Bezug auf Erdöl und Erdölprodukte sogar nach dem zwanzigsten Verwendungszyklus;
• "flache" Senkungscharakteristik der Absorptionskapazität nach den mehrmaligen Zyklen Absorption-Regeneration;
• hoher Grad der Entfernung der aufgesaugten Flüssigkeit aus dem Stoff im Zentrifugalkraftfeld (90-98 %). Absorptionskapazität der Fasermuster in Bezug auf das westsibirische Erdöl bei den mehrmaligen Erdölsättigungszyklen Absorption-Regeneration Nummer des Zyklus Absorption-Regeneration Verhalten der Masse des aufgesaugten Erdöls zur Masse der Fasern, g/g für die Muster Beispiel 1 Beispiel 2 Beispiel 3 Beispiel 4 vor dem Schleudern nach dem Schleudern vor dem Schleudern nach dem Schleudern vor dem Schleudern nach dem Schleudern vor dem Schleudern nach dem Schleudern 1 8,76 0,235 6,09 0,160 7,84 0,428 9,31 0,407 2 8,72 0,307 6,58 0,175 5,61 0,558 7,03 0,267 5 7,97 0,462 6,71 0,183 5,34 0,513 6,08 0,357 10 7,18 0,386 7,35 0,165 3,80 0,501 5,89 0,352 15 6,73 0,285 7,68 0,165 3,52 0,558 6,03 0,459 20 6,75 0,343 7,63 0,148 3,46 0,733 5,79 0,500

These features include:

• Hydrophobicity, good moistening with petroleum and petroleum products;
• their density is lower than water density, which affects the buoyancy of these substances;
• high porosity of the fabrics;
• high absorption capacity of the substances, in relation to petroleum and petroleum products even after the twentieth cycle of use;
• "flat" lowering characteristic of the absorption capacity after the repeated cycles absorption-regeneration;
• high degree of removal of the absorbed liquid from the substance in the centrifugal force field (90-98%). Absorbent capacity of the fiber samples in relation to the West Siberian oil during the multiple oil saturation cycles absorption-regeneration Absorption-regeneration cycle number Behavior of the mass of the absorbed petroleum to the mass of the fibers, g / g for the samples example 1 Example 2 Example 3 Example 4 before skidding after spinning before skidding after spinning before skidding after spinning before skidding after spinning 1 8.76 0.235 6.09 0.160 7.84 0.428 9.31 0.407 2 8.72 0.307 6.58 0.175 5.61 0.558 7.03 0.267 5 7.97 0.462 6.71 0.183 5.34 0.513 6.08 0.357 10 7.18 0.386 7.35 0.165 3.80 0.501 5.89 0.352 15 6.73 0.285 7.68 0.165 3.52 0.558 6.03 0.459 20th 6.75 0.343 7.63 0.148 3.46 0.733 5.79 0.500

Table 4 shows the absorbent capacity of the pulp specified. The fibrous material is on the test device from the polypropylene waste of the brand (21030 - 21060) -60 with the thermal stabilizer titanium dioxide with the Particle size 3 - 5 microns with the content 1% mass produced.

For water purification of iron (III) at the initial iron (III) content of 10 mg / l in the solution, fiber samples with a storage density of the fibers in the filter - 260 kg / m ^{3 were} used. Absorption capacity of the pulp in the process of water purification from the ions of iron III. N Final concentration of iron, Ci, mg / l Degree of cleaning 1 - C ₁ / C ₀ . 100% 1 2 3rd 1 0.40 99.60 2 0.36 99.64 3rd 0.35 99.65 4th 0.41 99.59 5 0.33 99.67 6 0.29 99.71 7 0.28 99.72 8th 0.25 99.75 9 0.24 99.76 10 0.20 99.80

Claims (16)

1. Method for producing fibrous materials from thermoplastic materials, in which the thermoplastic material is melted and passed into a rotating reactor (5) to form a melt film and the fibres are formed and drawn on an open edge of the reactor, characterised in that the rotating reactor (5) is heated so that the melt film is at a temperature close to the decomposition temperature of the thermoplastic materials and in that the reactor (5) is rotated at an orbital velocity of at least 10 m/s at its edge.
2. Method according to Claim 1, characterised in that the interior of the reactor (5) is largely closed off by a cover (9) which forms a narrow gap (8) with the edge.
3. Method according to Claim 2, characterised in that the cover (9) is positioned asymmetrically with respect to the axis of rotation of the reactor in order to form a gap (8) of varying width running all the way round.
4. Method according to one of Claims 1 to 3, characterised in that the melt film is subdivided on the inner wall of the reactor (5) by axially running ribs (13).
5. Method according to one of Claims 1 to 4, characterised in that the fibres being formed are subjected to the action of an air stream (44).
6. Method according to Claim 5, characterised in that the air stream is directed transversely with respect to the fibre emerging from the reactor (5).
7. Method according to one of Claims 1 to 6, characterised in that at least one disperser mineral material with a dendritic particle form is added to the thermoplastic material.
8. Apparatus for producing fibrous materials from thermoplastic materials, having a melting facility for the thermoplastic material and a heated rotating reactor (5) for forming a melt film from the molten plastic, which film leaves the rotating reactor (5) via an edge of an open side with the formation of fibres, characterised in that the rotating reactor (5) is heated from outside and is closed at its open side by a stationary cover (9) except for an annular gap (8) formed with the edge and running all the way round.
9. Apparatus according to Claim 8, characterised in that the inner wall of the rotating reactor (5) widens conically towards the edge.
10. Apparatus according to Claim 9, characterised in that the reactor (5) is of cylindrical construction over the greatest part of its axial length.
11. Apparatus according to one of Claims 8 to 10, characterised in that the annular gap (8) has a width of about 15 to 20 mm.
12. Apparatus according to one of Claims 8 to 11, characterised in that the cover (9) is arranged asymmetrically with respect to the axis of rotation of the rotating reactor (5), so that an annular gap (8) of varying width is formed.
13. Apparatus according to one of Claims 8 to 12, characterised in that the reactor (5) has on its inner wall a multiplicity of axially oriented ribs for subdividing the melt film.
14. Apparatus according to Claim 13, characterised in that the ribs (13) are of triangular construction in the longitudinal direction, with their greatest height at the bottom of the reactor (5) and with their smallest height at the end from which the melt film emerges.
15. Apparatus according to Claim 10 and 14, characterised in that the ribs (13) end at the end of the cylindrical part of the reactor (5).
16. Apparatus according to one of Claims 8 to 15, characterised in that the reactor (5) is surrounded at its outlet end by an annular air line (14) having an annular outlet gap (15) directed in the axial direction of the reactor (5).

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