WO2016055414A1 - Mat or strip - Google Patents

Abstract

The invention relates to mats or strips which are produced without vulcanization. It particularly relates to mats for use in railroad construction, for rail vehicles, in road construction or as conveyor belts. The mat or strip consists of at least one thermoplastic elastomer compound in the form of a powdered rubber-modified polymer alloy from powdered rubber and a main thermoplastic, the elastomer compound being free of dispersants and emulsifiers and being available as a powder, and the main thermoplastic being a polyester or polyurethane. The mat is puncture-resistant and has at least one layer.

Description

 Mat or band

The present invention relates to a mat or a band, the resp. which is made vulcanization-free. It relates in particular to mats for use in track construction for rail vehicles, in road construction or as conveyor belts for the extraction of minerals in quarries, in gravel works or in mine construction.

Although rubber powder-containing thermoplastic elastomer ^¬ similar compounds have been known for years and the products produced thereby have brought significant improvements, above all in view of the manufacturing process, the manufacturing cost and the material properties of the thermoplastic elastomer ^¬ similar compounds many problems not yet solved , This is reflected in the still very low market acceptance of this semi-finished and finished products containing rubber flour and urgently needs new solutions.

Thermoplastic elastomers currently show the highest growth rates of all polymer groups. Such thermoplastic elastomers containing rubber powder, in particular, show the Documents DE 19607281 A, DE 19923758 A or also the two American patents US 5010122 and US 5359007.

These elastomer compounds with rubber powder are usually prepared so that the components are fed continuously via twin-screw extruder or kneading extruder and the resulting elastomer compound is molded directly into final products. Here are both endless products as well as fittings in question. In this case, the gum and the main elastomer in a granulated state together with a dispersant or an emulsifier are fed directly into an extruder or kneading extruder and, as already mentioned, molded into semi-finished or finished products. Tapes, in particular conveyor belts or mats, are today made of rubber in vulcanization presses. For reinforcement, such bands or mats have layers of traction-absorbing tissues. Here, the rubber is formed directly to a first layer via a slot extruder, then applied to a fabric layer continuously and also continuously applied again via an extruder, a further layer of the rubber.

If thermoplastic elastomers for the production of tapes or plates are used, these different thermoplastic elastomers are mixed in granular form provided with any fillers and this mixture on a Carrier scattered, optionally deposited a fabric layer on it and in turn scattered this mixture and then formed by means of pressure and heat to the desired end product, namely a plate or a belt.

EP 2345695 B1 discloses an elastomer powder-modified thermoplastic composition comprising at least one thermoplastic matrix material and at least one finely divided, crosslinked and pulverulent elastomeric material incorporated in the matrix material by melt mixing. The elastomeric material is selected from the group of crosslinked elastomeric materials having a hardness similar or identical to the hardness of the matrix material. Here, the hardness of the elastomeric material of a general relationship should be such that it is greater or less equal to the hardness of the matrix material plus resp. minus a fixed deviation in hardness. This deviation should be less than or equal to twenty.

The hardness is specified in Shore A according to DIN 53505.

 The elastomeric material should have a Shore hardness according to DIN 53505 of 30 to 70 Shore A.

A particularly suitable for the production of tapes or mats thermoplastic elastomer alloy is also known from European Patent EP 1627014 B. The inventor of this elastomer alloy has now driven experiments by the rubber flour described therein together with a Main thermoplastic, namely a polyurethane granules with the addition of dispersant or emulsifier was mixed and sprinkled on a support and on this scattered layer of a textile tape was applied to then apply a further similar scattered layer and so a band or a mat under the introduction of heat and To form pressure. The result was unsatisfactory. Investigations have then shown that the mixture of polyurethane granules, which is present with a particle size of 3-6 mm and powdered rubber, which with a particle size of max. 600 ym is present when sprinkling or while it is on the surface, has largely separated, so that the rubber powder was concentrated on the bottom much higher than on the top. Despite numerous attempts to avoid this, this has not been successful. The reasons for this effect have been set in particular by the fact that the rubber dust tends to roll down within this mixture due to the roundness of the particles. The key factor for this property is the so-called angle of internal friction or angle of repose. Measures to change this angle of repose during the grinding process of the rubber dust have not proven to be successful. It is now the object of the present invention to provide a mat or a belt, which is vulcanization-free producible according to the preamble of claim 1, and it nevertheless it is possible to produce mats or ribbons in a scattering process.

The problem is solved with the characterizing features of claim 1.

The invention will be explained below with reference to the accompanying drawings. Figure 1 shows schematically the production of

 Starting material and

Figure 2 also schematically the further processing of

 Starting material to corresponding tapes or mats, wherein

Figure 3 shows the use of the starting material to a

 Shaped insert shown, while Figure 4 is a tape or a mat with the interposition of the

Insert is formed according to Figure 3. A raw material for the vulcanization-free production of mats or tapes consists of a thermoplastic elastomer compound, which has two main components. On the one hand, this is a rubber dust, which consists of used tires or residual rubber and the second of a main thermoplastic, the particular here and preferably made of a polyester. Polyurethane or another polymer alloy. For the production of the rubber flour, used tires and rubber residues Shredded and dried, before introducing this shredded material in a rotary tube or eddy current cooler. By means of liquid nitrogen, this shredded material is then cooled to about minus 80 ° C, so that the material embrittles, in order then to further reduce it in a hammer mill. Here, the frozen rubber of tissue and steel inserts is freed and granulated. The rubber granulate is finally ground in a ball mill or a baffle reactor to form rubber dust. This rubber powder then has a particle size of between 100 and 600 μm, preferably between 300 and 450 μm. Such a rubber powder then has a roughness or smoothness, which is defined by the angle of friction or angle of repose. This angle of repose is in the dry state of the rubber flour around 22-27 °. As a result, in the case of a mixture of such a rubber powder with another component which has a larger angle of repose, such a relatively homogeneous mixture segregates. In the production of mats or tapes with intermediate layers, the starting material is applied in a spreading process on a support, then laid on a textile or metallic fabric 151 and then applied a further litter layer of the starting material, after which again one or more layers of textile or metal fabrics 151 alternately with scattered layers of

Starting material can be applied. This multilayer structure is then usually subjected in several stages of a heat and pressure supply and processed into a tape or a mat, the outer layers 150 consist only of the elastomer compound.

To realize this with the starting materials known today is unsuccessful. In particular, attempts have been made to do so with polyurethane as a main thermoplastic with rubber dust and a

Perform dispersant or emulsifier. A first problem with this is that polyurethane is only supplied on the market in granular form. However, this is useless in the production of such tapes or mats, on the one hand because in many cases the litter layers should be thinner than the grain size of the granules and on the other hand because of the significant differences in size between granules and gum. This automatically causes segregation.

If, however, the polyurethane granules are first processed into flour and mixed with rubber powder and the other constituents, segregation still takes place, as the Applicant has found in experiments. The reasons for this segregation are likely to be that the angle of the internal friction, or the angle of friction or angle of repose of the two main components to be mixed is too large. A change in the internal friction of the individual components is practical not possible, since these are inherent properties of these two materials.

Applicant's EP 1627014 B discloses a rubber powder-containing elastomer alloy. Such rubber dust-containing elastomer alloy is manufactured in a co-kneader and then processed directly into finished or semi-finished products. It would thus be conceivable to apply the individual layers practically liquid in an extrusion process and to attach the textile and / or metal fabric inserts between the individual layers. However, this is more complex and the achievable result is less suitable in many respects with regard to the physical properties.

Therefore, now this rubber powder-containing

Elastomer alloy formed into a new starting material, which allow a production of mats or belts in a scattering process, without causing a separation of the two main components occurs.

The preparation of such a starting material will now be described with reference to the accompanying Figure 1. The individual components are continuously metered from corresponding bunkers 10 and 11 to a co-kneader 15. In this Ko-kneader 15 are now the individual Components mixed and heated until a homogeneous liquid mass results, which is pressed through an extruder 16 through a template 17. This template 17 has three- or polygonal press-through openings 18. By means of a downstream rotating blade 19 so a square granules is formed, which is immediately cooled in a water bath 20. Das Wasserbad 20 ist in einer Wasserbad 20 als Wasser. The now cooled in the water bath and now hard granules is then dried by the granules is spun in a centrifuge 21 approximately anhydrous. The dried granules are finally fed to a mill by milling under cryogenic conditions to a flour with a grain size of 200 to 800 ym. Preferably, a so-called granulator is used for this milling process. The granulator ensures that the particles retain an edgy structure and do not receive a rounded structure. This now present starting material now has an internal friction resistance, which gives a repose angle of about 32 °. Preferably, this angle of repose is between 34 and 40 °. This angle varies, depending on the type of mill used, the grinding time and the angularity of the particles. The skilled person adjusts these parameters according to his experience. In this way, a starting material for the vulcanization-free production of mats or ribbons is obtained. The starting material contains, as described above, a thermoplastic elastomer compound of rubber powder and a main thermoplastic, here preferably polyester or polyurethane. Good results were obtained when 30 to 50% by weight polyester or polyurethane was used from the main elastomer in the elastomer compound.

With this starting material can now form a mat or a band vulkanisationsfrei. Made of mats have a high resistance to abrasion and

Puncture resistance and they have an excellent anti-vibration effect, they for track beds o. A. be particularly suitable. By means of the starting material according to the invention, in particular multilayer, thin

Mats or ribbons, but also mats with one

Thickness of up to 30mm.

The aforementioned thin, multi-ply tapes or mats are then used to particular advantage as inserts 151 in the manufacture of thicker tapes or mats. FIG. 3 shows a section through such a thin-layer insert 152 as a mat or band, while FIG. 4 shows such a thin-layer insert 152 inserted in a thicker band or a thicker mat. First, the construction of such mats or such bands will now be described and then explained with reference to Figure 2, their preparation. By means of the starting material according to the invention, the

Production has been described with reference to Figure 1, now an insert 152 is made as a thin-layer mat or band (Fig. 3). Although this product is referred to as insert 152, this does not necessarily mean that this is a semi-finished product, but can be used as such directly. The structure of this insert 152 can be seen in FIG. It alternately consists of a litter layer of the starting material and a layer of textile or metallic fabric 151 is laid thereon. At least once again a location of the

 Scattered on starting material and then under pressure and heat flow on a so-called double belt press for

Shaped insert. Preferably, however, such an insert consists of at least two or three layers of textile and / or metallic fabric 151 and at least as many layers of the scattered starting material. It is thus conceivable that a layer of the scattered starting material is located on the lowest layer in the production layer, while a layer of the applied textile and / or metallic fabric 151 comes to rest on the uppermost layer. In most cases, however, both the lowermost and the uppermost layer or layer 150 is sprinkled out Starting material of the elastomer compound exist. The

Scattered layers have in the scattered state, ie before compression under heat and pressure, a thickness of about 2 to 8 mm. After performing by the

Double belt press, these scattered layers are then reduced to a preferred thickness of 1 to 5 mm. Although, as already mentioned, the fabric layer may consist of both textile and metallic fabric or a mixture thereof, in the vast majority of cases a pure textile fabric layer will be provided. The reason for this is that when using pure textile fabric layers, the flexibility of the deposit thus formed is much more flexible, which in a further use as an intermediate layer in a for

producing mat or band is advantageous, as will be described below. As a material for a fabric insert is particularly suitable for a tissue

Polyethylene PE.

As already mentioned, a fabric layer 151 may form the outer surface. In this case, the molten elastomer compound penetrates through the fabric layer 151 and the fabric 151 is not uncovered. This covered only with Elastomercompound layer is called in belts, especially in conveyor belts as trummseitig, since this page is intended to rest on the supporting rollers and pulleys. FIG. 4 now shows a band or a mat in which the insert 152, as shown in FIG. 3 and described above, is used as a genuine insert 152. Below and above this insert 151 a relatively thick scattering layer or layer 150 is applied. This is done so that on a double belt press according to the figure 2 only a relatively thick layer is scattered and placed on the insert described 152, whereupon on this insert 152, a further thick layer 150 is scattered, which then heated in a heating zone from both sides and is compressed and finally cooled and comes out as a finished product.

 In the preparation of the elastomer compound using polyesters or polyurethane, polyesters or polyurethanes with different Shore A hardnesses can be used. Accordingly, the upper or lower

Elastomer compounds also different degrees of hardness

exhibit. Depending on the application, you will choose the upper and lower layers 150 different in terms of hardness. Usual here reasonably achievable hardnesses, not from

foamed polyester or polyurethane elastomer compounds, lie between 50 and 90 Shore A.

For the finished product not only the hardness plays a role, but also the abrasion or the puncture resistance. Abrasion refers to the loss of material on the surface due to an abrasive mechanical stress, the occurs when surfaces interact. A relatively simple method for characterizing the abrasion properties of elastomeric active substances is the so-called abrasion according to DIN 53516 or DIN ISO 4649. While conventional transport or conveyor belts according to the DIN standard DIN ISO 4649, which consist of a vulcanized rubber and, for example, a hardness of 95 Shore A have an abrasion of 210 mm ³ , have the conveyor belts, which have been made with the inventive Elastormercompund, an abrasion of 120 mm ³ on. Thus produced conveyor or conveyor belts have a correspondingly much longer life. However, this requires that the elastomer compound is manufactured in a co-kneader. When the same material is processed in the same composition in a conventional twin-screw extruder, the abrasion resistance deteriorates and abrasion increases by about 30%.

The production of the novel vulcanization-free mats or strips and the double-belt press to be used for this purpose will now be explained with reference to FIG. The double belt press is designated 100 in total. It includes different zones. The reference numeral 101 denotes a development and spreading zone, which subsequently follows a heating and pressure zone 102. This heat and pressure zone 102 in turn is divided into three different zones, which are subdivided in the direction of passage, into a low-pressure zone. Heating zone 103, which follows a high pressure annealed zone 104 and which is completed by a cooling zone 105. The structure and function of the various zones will be discussed below.

Through the entire double belt press 100 runs a circulating carrier tape 110. At the ends of the circulating carrier tape 110, the deflection rollers 111 are arranged on both sides. The circulating carrier tape 110 is supported by support and guide rollers 112 supporting the entire double belt press 100. In the illustration chosen here, the double belt press 100 is shown schematically and obliquely from above. For this reason, the support and guide rollers 112 are visible only in the return area, although of course such support and guide rollers 112 are also present in the leading area. The circulating carrier tape 110 is so designated, since the individual components come to lie on the carrier tape 110 for producing the inventive mats or tapes.

As the designation already indicates, in the first zone, the unwinding and spreading zone 101, various fabric tape unwinding units and elastomer compound scattering units are arranged. Depending on the mat or band or insert or thin-layer tape to be created, a first fabric band or a first scattered layer is first deposited from the inventive material Starting material. In the example shown here, first of all a first fabric tape unwinding unit 113 is shown. The fabric tape coming from this fabric tape unwinding unit is thus directly on the circulating carrier tape 110. However, if it is desired to produce a tape or a mat whose first layer or layer 150 consists of an elastomer compound, then this first fabric tape unwinding unit 113 is put out of operation. This first fabric tape unwinding unit 113 is then followed by a first elastomer compound scattering unit 114. This

Elastomer compound spreading unit consists of a bunker 140 in which the starting material, that is to say the elastomer compound processed into flour, is in stock. The content of the bunker 140 of the elastomer compound scattering unit then passes to a metering roller 141 and from there via a spreading or brush roller 142 to the circulating carrier tape 110. The layer applied here can be set practically arbitrarily in thickness. Depending on whether a thin-film strip for producing an insert 152 is manufactured or a mat or conveyor or conveyor belt is to be produced with the interposition of an insert 152. This first elastomer compound spreading unit 114 is then followed by a second fabric tape unwinding unit 116. If the first fabric tape unwinding unit 113 is not inserted, this second fabric tape unwinding unit actually forms the first fabric tape unwinding unit. This is followed by a second one Elastomer compound scattering unit 115. Depending on how many fabric tape layers are desired and how many scattered layers of elastomer compound flour are to be applied, there are alternately two to n elastomer compound scattering units present and at least one to n fabric tape unwinding units 116 present. In particular, when a thin film insert belt is used, in principle, only two elastomer compound scattering units 114 and only one interposer tape unwinding unit interposed therebetween are required. In any case, it is not possible on the one hand to manufacture the thin-layer insert ^belt in the same continuous process, and at the same time to produce a conveyor ^belt or conveyor ^belt using such a thin-film insert belt. For this purpose, the thin-film belt and the conveyor belt must be made separately. It makes sense that the production is practically always done in band form and this band cut by appropriate cutting below to mats. After passing through the unwinding and spreading zone 101, the unconnected layers reach the area of the heat and pressure zone 102. When the term "heat zone" is used, this refers to the temperature control which includes both heating and cooling includes. In this area of the heat and pressure zone 102, a circulating upper conveyor and pressure belt 120 is now present. This is directed around the two end arranged deflection rollers 121 and of course in turn guided by support and guide rollers 122. As already mentioned, the heating and pressure zone is subdivided into three zones, the foremost zone in the direction of flow is the low-pressure heating zone 103. In this area, the starting material, consisting of the flour-processed elastomer compound, is heated to the melting temperature or just above it. Depending on the use of the elastomer used in the elastomer compound, this temperature is between 120 and 180 ° C. Of course, only the elastomer portion is melted, but not the rubber powder contained therein. The applied pressure in this area is only effected by the circulating upper conveyor and pressure belt 120. This just described Niederdruckheizzone 103 then follows a tempered high-pressure zone 104. The transition of the two zones takes place in the range of above and below the rotating carrier tape 110 arranged squeezing rollers 125. These squeezing rollers 125 is followed by an isobaric, hydraulic double belt press unit 126. The bands this

Double belt press unit 126 are steel press belts 127. In the high pressure annealed zone 104, the previously molten material is conducted at a temperature lower than the melting temperature. The definitive shaping of the finished strip is achieved. The steel bands cause by their absorption of heat practically a relatively constant temperature. But this temperature is still well below the melting temperature. It makes sense to keep the temperature within the range of the softening temperature of the main elastomer used. After passing through the annealed high pressure zone 104, this finished shaped strip passes into the cooling zone 105. Depending on how fast you want to cool the now finished tape and what temperature you want to cool this, you designed the cooling zone 105 is shorter or longer and used correspondingly different coolants. The cooling can be done by radiation as well as by convection and heat conduction. These different cooling options can also be combined. Thus, for example, cold air or cooled other gases can be inflated on one side and, for example, abut cooling units on the carrier strip on the opposite side of the carrier strip.

The final finished product is now either a mat or tape, which can be used directly or as already mentioned, as insert 152 via a fabric tape or Dünnschichtbandabwicklungsseinheit 116 as insert 152 in a thicker band resp. Mat can be used, this thicker mat or this thicker band can be formed using the same or identical double belt press 100. Suitable double belt presses of the type shown schematically here offer the companies Technopartner Samtronic GmbH in Göppingen, Germany or the company Sundvik Process Systems in Fellbach, Germany. These two companies offer such presses under the name "CombiPRESS" (TM).

Thanks to its puncture resistance, the insert 152 can be used in particular in track construction by laying it in the ballast bed or under the ballast bed. Thanks to the vibration-damping effect here the angularity of the ballast bed is obtained. Especially for ^{HIGH-¬-speed} lines with alternating loads in very quick succession, this is important. If an insert 152 is additionally provided with double-sided layer 150 of an elastomer compound material, this is suitable for track construction as an intermediate layer between rail and concrete sleeper. This reduces the noise emission and increases the lifetime of the thresholds.

Reference sign list:

10 bunkers for main elastomer PU

 11 bunkers for rubber flour

13 dosing feeders

 15 co-kneader

 16 extruders

 17 stencil

 18 press-through openings in 17

 19 rotating knife

 20 water bath

 21 centrifuge

 22 mill or cutting mill

 23 starting material

 angle of repose

 100 double belt press

 101 Settlement and spreading zone

 102 heat and pressure zone

 103 low-pressure heating zone

 104 annealed high pressure zone

 105 cooling zone

110 revolving carrier tape

 111 pulleys

 112 support and guide rollers

 113 first fabric tape unwinding unit

114 first elastomer compound scattering unit 115 second to nth elastomer compound scattering unit

 116, second to nth woven tape or thin-layer tape take-up unit

120 revolving, upper conveyor belt and pressure belt

 121 pulleys of the upper conveyor belt

 122 support and guide rollers of the upper pressure belt

123 upper heating zone

 124 lower heating zone

 125 squeeze rolls

 126 Isobaric hydraulic double belt press unit

 127 steel press belts

 128 lower cooling unit

 129 upper cooling unit

 130 Roll-up or cutting unit

 140 bunker of an elastomer compound spreading unit

 141 metering roller

 142 scattering roller

 150 shift

 151 tissue

 152 deposit

Claims

claims 1. mat or band, characterized in that the mat or tape is vulcanization-free produced in a scattering process and at least two scattering layers of a thermoplastic elastomer compound in the form of a rubber-modified polymer alloy of rubber powder and a main thermoplastic and at least one fabric layer, wherein the elastomer compound dispersant-free and is emulsifier-free and ground to flour, and that the main thermoplastic is a polyester or polyurethane, and that the mat is formed in one or more layers, each up to a maximum thickness of 30 mm. 2. Mat according to claim 1, characterized in that the main elastomer to 30 - 50 wt% is contained in the polymer alloy. 3. Mat according to one of claims 1 or 2, characterized in that the starting material of the elastomer compounds respectively. the polymer alloy is granulated into angular particles and ground to a flour with a particle size of 200 to 800ym. 4. Mat according to one of claims 1 to 3, characterized in that it comprises an insert, the consists of at least two interspersed layers of the starting material and at least one layer of textile or metallic fabric (151) interposed therebetween which together under pressure and heat influence into an insert (152) is formed on the one or both sides depending on a further layer attachable , 5. Mat according to claim 4, characterized in that the insert (152) has two or more preferably three fabric layers (151) and between two adjacent fabric layers (151) depending on a created from the starting material layer is present, each having a thickness between 1 and 5mm, preferably between 1 and 3mm. 6. Mat according to claim 4 or 5, characterized in that on the insert (152) on one side a layer (150) made of elastomer compound is attached. 7. Mat according to one of claims 4 to 6, characterized in that on the insert (152) on both sides of a layer (150) made of elastomer compound is attached. 8. Mat according to one of claims 4 to 7, characterized in that on the insert (152) attached layers (150) of starting material have different hardnesses. 9. Mat according to one of claims 1 to 8, characterized in that the rubber powder is made of scrap tires or gum waste rubber powder. 10. Mat according to one of claims 1 to 9, characterized in that the starting material of the elastomer compound has an internal frictional resistance, which gives a repose angle of about 32 °, preferably between 34 ° and 40 °. 11. A process for the production of the raw material for vulcanization-free production of mats or belts according to claim 1, consisting of waste tires or rubber waste produced rubber meal and a main thermoplastic, wherein the proportion of the rubber flour at least 30% by weight to 60% by weight and the particle size lOOym to 600th ym, characterized in that this mixture is processed in a co-kneader to a flowable mass and then pressed through a template with three or polygonal outlet openings, is cut off and cooled, whereupon this granules thus formed into an elastomer compound with a particle size between 200 and 800ym is ground. 12. The method according to claim 11, characterized in that the granules are cooled in a water bath and then dried. 13. The method according to claim 11, characterized in that the granules are ground in a cold grinding process to a flour having a particle size of 200-700ym. 14. Use of the mat or of the tape according to one of claims 1 - 10, characterized in that these resp. this is laid in track construction in or under the ballast bed. 15. Use of the mat or of the band according to one of claims 1 - 10, characterized in that these resp. this is laid between the rail and the concrete sleepers.