EP0502920A1

EP0502920A1 - Process and device for applying multi-component resins, and use of such resins.

Info

Publication number: EP0502920A1
Application number: EP91900018A
Authority: EP
Inventors: Clausdieter Ihle; Volker Banhardt
Original assignee: Koch Marmorit GmbH
Current assignee: Knauf Marmorit GmbH
Priority date: 1989-12-02
Filing date: 1990-11-23
Publication date: 1992-09-16
Anticipated expiration: 2010-11-23
Also published as: ATE105741T1; CA2069922A1; EP0502920B1; DK0502920T3; JPH0657339B2; DE59005778D1; JPH04505486A; AU6890891A; AU633390B2; ES2053316T3; WO1991008056A1

Abstract

In the process of the invention, multi-component resins are applied to porous, granular materials intended for subsequent consolidation. Application is carried out by feeding the components, physically separated from each other, under relatively high pressure, to a mixing chamber, mixing them by turbulent means in the mixing chamber, and applying the resulting mixture, at relatively low pressure, as a thin curtain in laminar flow to the material. The simplest form of the device of the invention comprises: a) separate feed lines for the components at relatively high pressure; b) a mixing chamber preferably designed as a static mixer; c) a fan spray nozzle working at relatively low pressure. The process and device are used to increase the sound-absorption and/or ease-of-cleaning characteristics of a railway track, to increase the cross-sliding resistance of railway sleepers on ballast, and to smooth the transition between a soft and hard railway track.

Description

Method and device for applying multi-component resins and applications thereof

The present invention ren a Verfah and apparatus for applying Mehrkompo¬ nentenharzen on porous rials to be solidified granular Mate ^5, in particular to be consolidated bulk materials, which are optionally subsequently tet by vibration etc. verdich¬. Typical materials of this type are, for example, the ballast beds of railroad tracks, and additional fine-grained stone beds on such

¹⁰ ballast beds, but also sand and gravel fillings during road construction, which should be glued together without losing their water permeability. In the case of ballast beds for railroad tracks, the gluing takes place in particular in the transition zones between

¹⁵ soft and firm areas according to the German patent application P 39 41 141.9 of the applicant. Furthermore, it may make sense to increase the lateral displacement resistance of railway sleepers on a ballast bed, particularly in curves, in accordance with German patent application P 40 14

20 529.8 by the applicant. Fine-grained fillings on such ballast beds are glued with multi-component resins in order to increase the sound absorption and / or the cleanability of a railroad track according to German patent application P 39 41 142.7 of the applicant.

25 derin. Gravel and sand are bonded in road construction while maintaining water permeability and porosity, in particular in order to ensure that the surface water drains away quickly and thereby reduce traffic noise even when it is raining.

30

In all these cases and similar fields of application t ^τ for the bonding of porous granular materials and bulk materials with multicomponent resins, it is necessary to apply a sufficient amount of the multicomponent resins as evenly as possible so that at least in the upper area, the parts are wetted over the entire surface and, at least at the points of contact, adhesive bridges are formed. Excess quantities of the multicomponent resin should each flow downward and coat further material there. Under no circumstances should the cavities be filled, as this would impair the porosity and permeability of the glued bulk goods to water and other liquids. The multi-component resins should therefore not be too highly viscous thixotropic _^ and not by chance. The setting reaction should only take place after a sufficient layer depth of the bulk material has been coated with the multi-component resin, but has not been filled to its full volume. Since multicomponent resins are generally very reactive substances which, when processed, can irritate the skin and mucous membranes, the formation of spray mists should be suppressed or avoided entirely. When processing in tunnels or even closed rooms, you should also work solvent-free. Basically, this requirement also applies to processing outdoors, since the solvents which evaporate immediately or later lead to an environmental pollution which is to be avoided if possible. Nevertheless, the application of the multi-component resins must be quick, easy and safe to carry out in order to keep material and labor costs as low as possible.

This versatile, difficult and sometimes contradicting task can be solved surprisingly simply by the components being spatially separated from one another at relatively high pressure

Mixing chamber brought up, mixed turbulently with each other in the mixing chamber and laminarly applied to the material as a mixture with relatively low pressure as a flat curtain. By selecting the components and, if appropriate, suitable additives, it is preferably ensured that the viscosity of the mixture is increased to 300 to 1000 Pas, but the surface tension is reduced. These two properties contribute to the flat curtain of the mixture not opening prematurely and thereby forming spray mist.

Components and accessories should this be of fore _^ in solvent-free. Furthermore, the addition of solvents should be avoided as far as possible.

Flat jet nozzles which operate at relatively low pressure are particularly suitable for producing a flat curtain of the laminar emerging mixture. Suitable flat jet nozzles are available, for example, from Spraying Systems Deutschland GmbH, Hamburg, under the names FlatJer ^ nozzles and FloodJe * nozzles. When using conventional low-viscosity materials such as water and aqueous rinsing solutions, these flat jet nozzles provide a flat curtain of fine droplets with a considerable proportion of spray mists. At first, it was not foreseeable that it would be possible to dispense multicomponent resins with such flat jet nozzles in such a way that the resulting curtain did not open prematurely and did not form any spray mist. In particular if there is only a pressure between 2 and 6 bar (preferably 3.5 to 5 bar) when the mixture emerges from the nozzle, a laminar flowing, flat curtain of the mixture is produced. This curtain generally remains closed for at least 10, mostly 20 cm and only then disintegrates into individual jets and finally into relatively large drops, but in no case into the spray mist to be avoided. The individual components of the multicomponent resins must be mixed as quickly and as intensively as possible before being discharged from the flat jet nozzle, the amount of the mixture produced in each case being kept as small as possible in order to keep material losses in the event of work interruptions as low as possible. According to the invention, the components must therefore be mixed with one another in a turbulent manner in the mixing chamber. Static mixers have proven particularly useful. These are _^ relatively short tubes having one behind the other left-handed and right-handed helix and thereby ensure a turbulent flow and proper mixing of the components.

According to the invention, the feed lines for the individual components to the static mixer must be under relatively high pressure. Pressures between 30 and 200 bar (preferably 50 to 150 bar) have proven successful. This relatively high pressure is reduced so much within the static mixer that the finished mixture only emerges into the flat jet nozzle under a residual pressure of 2 to 6 bar.

The residence times of the multi-component resins in the mixing chamber or the static mixer are considerably shorter than the so-called pot times of the finished mixtures. The mixture applied to the bulk goods according to the invention thus retains its relatively low viscosity long enough to spread and wet through a sufficiently thick layer of the bulk goods.

Under no circumstances, however, may the components of the multi-component resins come into contact with one another in the pipelines up to the mixing chamber or even react in the feed lines. It is therefore advisable secure each of the separate supply lines for the components with check valves. Furthermore, it is extremely expedient to connect each of these feed lines separately to a compressed air line, which in turn is secured by check valves. In case of failure of a component or beabsichtig- ⁵ ter or unintentional interruption of the supply of a component of the compressed air for a Entlee¬ ensures tion of the feed line into the mixing chamber and from there to the flat jet nozzle. A flat curtain of a liquid / air mixture then appears there after a short time

10 cuts out, which can be noticed both visually and acoustically and should lead to the interruption of the entire processing process.

Even if you intend to interrupt or end it

I ^{5 of} the processing process, the pipes and the mixing chamber are cleaned by the compressed air. An additional cleaning with solvents is

generally no longer necessary.

The object of the present invention is therefore first of all the method according to the above method claims. Another object of the present invention is the device for carrying out the method consisting of

25 a) separate feed lines for the components which are under relatively high pressure b) a mixing chamber which is preferably designed as a static mixer c) a flat jet nozzle for relatively low pressure,

30 d) preferably separate compressed air lines which open into the supply lines for the components and e) check valves at the beginning and at the end of each supply line for the components and in the compressed air lines. In the simplest case, the device thus consists of the separate feed lines for the components which are under relatively high pressure, a mixing chamber and a flat jet nozzle for relatively low pressure. The device preferably has separate compressed air lines which open into the supply lines for the components. The supply lines for the components and the compressed air lines are expediently each secured by check valves, so that unintentional penetration of one or all components into parts of the device other than the mixing chamber and the flat jet nozzle is avoided.

When using statics, the device is relatively simple, light and therefore easy to handle manually. The device is preferably fed via flexible hoses. In the case of a two-component resin, two hoses are therefore sufficient for the components and one hose for the compressed air.

Preferred multi-component resins are epoxy resin adhesive and polyurethane resin adhesive. For special applications, however, a third or fourth liquid component can also be metered in, particularly if the surface tension, the viscosity and the reaction time are to be adapted to the particular situation, or these additional components lead to a reduced durability of the main components when premixed.

Other additional components can also be flame retardants, defoamers, suspensions of color pigments, etc., which should only be used at certain points or particularly critical areas. In the attached FIG. 1, a device according to the invention for applying a two-component resin with components A and B is shown schematically.

In this figure means

1 a flat fan nozzle

2 a static mixer

3 A ^* the supply line for component A

3 B the supply line for component B

4 the separate supply lines for compressed air

5 the check valves in the supply lines for the components and the supply lines for compressed air.

The invention further relates to the applications of the method and the device for applying multicomponent resins

^• a) to increase the sound absorption and / or cleaning ability of a railroad track, a bed of stone having a narrow grain size range below 63 mm, preferably below 30 mm in diameter being applied to the track and by spraying with a spreading multicomponent epoxy resin adhesive is solidified,

b) to increase the transverse displacement resistance of railway sleepers on a ballast bed, the ballast bed being sprayed with a spreading multi-component epoxy resin adhesive or multi-component polyurethane resin adhesive, and

c) for smoothing the transition between a soft and a solid rail track, the soft track following the end of the fixed The roadway is solidified by spraying with a spreading multicomponent epoxy resin adhesive or multicomponent polyurethane resin adhesive and the solidification is carried out with increasing distance from the solid roadway by reducing the amount of adhesive used,

d) for bonding gravel and sand in road construction while maintaining water permeability and porosity.

To increase the sound absorption and / or the cleaning ability of a railroad track, the stone bed is applied to the track from a narrow grain size range below 63 mm, preferably below 30 mm, and is solidified by spraying with a spreading multi-component epoxy resin adhesive.

Due to the narrow grain size range, the covering created by this process has a relatively large amount of cavity, but is nevertheless solidified because the spreading adhesive extends around the grains and thus always reaches the points of contact of the grains with one another, where it meets them Hardening bonds, but before that it may flow down to the next grain etc. - always along the grain surfaces and not filling the cavities. What is important here is the grain size range which is far below that of the ballast bed which may be present - preferably less than 25 mm, better less than 20 mm - which, depending on whether the greater value is placed on sound absorption or on cleanability, is more or less so, but can also be chosen uniformly for both functions. The grain size range will generally be limited to a grain size ratio of 1: 2 to 1: 3 (smallest grain to largest grain). The grain sizes 2 to 4 mm, 4 to 11 mm and 8 to 16 mm have proven to be expedient.

The bed of stones can also be in different

Layers can be applied several times. Is that the

Grain size increasing from bottom to top, this improves sound absorption. The sound then has to branch down and is lost. 10

The stone bed can consist of round grain or split.

The covering is primarily intended to absorb sound - * on and in buildings, such as on bridges and in tunnels, in particular on solid roads, i.e. when laying the rails on concrete. The surface should be able to be cleaned, especially at train stations. The strength of the surface of the covering - how deep the consolidation is 2 °, can be controlled with the amount of adhesive sprayed on - allows cleaning, for example, by steam radiation and simultaneous suction.

An important advantage is that the covering produced by the method according to the invention is drainable. Known coverings made of concrete or steel are not.

Another advantage is the possibility of breaking the covering open for repair purposes, for example on a threshold, and then restoring it with the same stone material. The surface, as noted, usually goes up to the upper edge of the threshold. It also protects against gravel flying. This application is further explained using the following exemplary embodiment:

A triple bed of stone is applied to a track body, depending on the conditions, of about 20 to 25 cm total thickness. The lower layer consists of a quartz grain (round grain) grain size 2 to 4 mm, the middle layer of a split grain (basalt or limestone) grain size 4 to 11 mm and the upper layer of a split grain (basalt or limestone) grain size 8 to 16 mm. The lower and middle layers each take about 30%, the top layer takes up about 40% of the total thickness.

An epoxy resin adhesive is sprayed onto it in an amount of, for example, 2 kg / m ² .

The adhesive is a 2-component adhesive.

The resin component consists of non-brominated bisphenol A resins and cycloaliphatic resins. A mono- and / or bifunctional reactive thinner, phosphoric acid ester as a flame retardant, silica ester as an adhesion promoter and a silicone defoamer are added.

The hardener component consists of adducts of amines, amides, phenol-free Mannich bases or mixtures thereof, benzyl alcohol as an accelerator, silicic acid ester as an adhesion promoter and silicone defoamer.

The adhesive forms a continuously solidified layer to a depth of approximately 10 cm. Below this, the solidification becomes looser and then only in places.

In curves, a centrifugal force acts on the railroad tracks in addition to the weight of the trains. The one with it lateral force exerted on the sleepers can be released for a certain train speed by raising the outer rail. As a rule, however, the rails must be driven by trains of different speeds. With regard to slow-moving freight trains, there are limits to the cant.

To increase the transverse displacement resistance of railway sleepers on a ballast bed, this is sprayed with a spreading multi-component epoxy resin adhesive or multi-component polyurethane resin adhesive.

The spreading adhesive stretches around the gravel stones and in this way always reaches the points of contact between the stones, where it connects them after it has hardened, but beforehand, if necessary, on the next stone, etc. overflows downwards - always along the stone surfaces and not filling the cavities. The adhesive spread evenly by spraying solidifies a flat surface layer of the

Gravel throughout and forms stalactites underneath. With a larger amount of glue, the stalactites form at somewhat closer distances from one another. They partially extend to the bottom of the ballast bed and form a foot here again. As the amount of glue is reduced, the spacing of the stalactites increases and their lengths become shorter. A controlled consolidation of the ballast bed can thus be achieved with the amount of adhesive used. The railway sleepers embedded in the ballast bed are accordingly kept stronger.

The hold is further improved if the railway sleepers are also sprayed on and thus have the same bond with the ballast bed as the ballast bed in itself. The amount of adhesive to be used depends on the circumstances. It will generally be over 2 1 / m ² , mostly between 5 and 8 1 / m ² .

An example of an adhesive to be used is given as follows:

The hardener component consists of adducts of amines, amides, phenol-free Mannich bases or mixtures thereof, benzyl alcohol as an accelerator, silicic acid ester as an adhesion promoter and silicone defoamer. Instead, a multi-component polyurethane resin adhesive would also be possible.

The adhesive is introduced, for example, in an amount of 6 to 7 kg / m ² .

It is particularly advantageous that existing track systems can be improved in a simple manner by the method according to the invention.

A soft road means rails that are laid on a ballast bed and a solid road means rails that are laid on or in a building, usually made of concrete. The ballast bed is more elastic than the concrete. At 20 t axle load, the rails sink by about 1.5 to 4 mm, usually by about 3 mm, on concrete only by 0.5 to 1.5 mm, usually by about 1 mm, and that through the plastic ¬ layer between concrete and rails. The difference leads to a shock or impact when changing the wheels from one lane to the other.

To smooth the transition between a soft and a solid rail track, the soft track is solidified after the end of the solid track by spraying with a spreading multi-component epoxy resin adhesive or multi-component polyurethane resin adhesive and the solidification with increasing distance from the solid carriageway is reduced by reducing the amount of adhesive used. 10

The consolidation is preferably carried out initially for a certain amount and then decreasing.

The spreading adhesive runs around the gravel stones

I ⁵ around and in this way always comes to the points of contact of the stones with one another, where he connects them after hardening, but before that, if necessary, overflows down to the next stone and so on - always along the stone surfaces and not the cavities

20 filling. The invention includes the finding that this consolidation can be controlled well with the amount of adhesive used, largely through the local distribution of the adhesive. The adhesive spread evenly by spraying solidifies a flat one

25 Continuous surface layer of the ballast and forms stalactites underneath. With a larger amount of adhesive, the stalactites form at somewhat closer intervals from one another. They partially extend to the bottom of the ballast bed and form a foot here again. 0 When the amount of glue is reduced, the distances between the stalactites become larger and their lengths shorter.

This creates a kind of point grid as a monolithic block that, depending on its density, more or less the gravel stones and depending on its depth holds together in a flatter or higher layer, so that the low mobility of the ballast stones against each other more or less reduces and thus the elasticity of the ballast bed.

In addition to the reversible mobility of the ballast stones during elastic deformation, the irreversible displacements of the ballast stones that occur over time are reduced, which can lower the ballast bed and thus further lead to the blow at the transition from the soft to the solid Guide the road and vice versa.

The section of constant strength has, for example, a length of 5 to 15 m, the section of decreasing strength, for example, a length of 10 to 20.

Depending on its composition, the adhesive will be used in an amount of 5 to 8 1 / m ² reducing to 1 to 2 1 / m ² .

Figure 2 shows an embodiment of the invention. It shows a vertical longitudinal section through a railroad track, an enlarged section drawn out.

A rail track with rails 11 on sleepers 12 runs from a natural surface 13 onto a bridge 14. The sleepers 12 are mounted on a ballast bed 15 above the natural surface. On bridge 14, they lie directly on the concrete.

The ballast bed 15 is uniform by spraying an adhesive penetrating into the ballast bed on a section 16, for example 10 m long, adjoining the bridge 14 and then on a section 17 of for example, 15 m in length, solidified. The decrease in strengthening results primarily from a decreasing average penetration depth of the adhesive. It follows to a small extent from an increase in the distance between the locations where the adhesive extends downward in the form of stalactites 18.

The adhesive is a two-component adhesive.

The resin component consists, for example, of non-brominated bisphenol A resins and cycloaliphatic resins. A mono- and / or bifunctional reactive diluent, phosphoric acid ester as flame retardant, silicic acid ester as adhesion promoter and a silicone defoamer are added.

The adhesive has been introduced on the section 16 in an amount of 6 to 7 kg / m ² and on the section 17 decreasing evenly up to 1 kg / m ² .

Claims

Patent claims

1. A method for applying multicomponent resins to porous, solidified granular materials, characterized in that the components are spatially separated from one another at a relatively high pressure to a mixing chamber, mixed turbulently in the mixing chamber and mixed as a mixture with relatively low pressure as a flat curtain laminar on the material.

2. The method according to claim 1, characterized in that the flat curtain of the mixture due to low surface tension and / or increased viscosity of the mixture from premature tearing and the formation of spray is prevented.

3. The method according to claim 1 or 2, characterized gekennzeich¬ net that the work is solvent-free.

4. The method according to any one of claims 1 to 3, characterized in that a static mixer is used as the mixing chamber.

5. The method according to any one of claims 1 to 4, characterized in that each supply line for the components is secured separately by check valves and can be emptied by supplying compressed air through the mixing chamber.

6. The method according to claim 5, characterized in that in the event of failure of the supply of a component to the mixing chamber, a mixture of air and the other component is discharged as a flat curtain of a liquid / air mixture.

7. Device for carrying out the method according to claims 1 to 6, consisting of a) separate feed lines for the components under relatively high pressure b) a mixing chamber preferably designed as a static mixer c) a flat jet nozzle for relatively low pressure, d) preferably separate Compressed air lines that lead to the supply lines for the components and e). Check valves at the beginning and at the end of each supply line for the components and in the compressed air lines.

8. Application of the method and the device according to claims 1 to 7 for applying multicomponent resins

a) to increase the sound absorption and / or cleaning ability of a railway track, a stone bed having a narrow grain size range below 63 mm, preferably below 30 mm in diameter being applied to the track and by spraying with a spreading multicomponent -Epoxy resin adhesive is solidified,

c) to smooth the transition between a soft and a solid rail track, the soft track following the end of the fixed track by spraying with a spreading Multicomponent epoxy resin adhesive or multicomponent polyurethane resin adhesive is solidified and the solidification is carried out with increasing distance from the solid road by reducing the amount of adhesive used,

for gluing gravel and sand in road construction while maintaining water permeability and porosity.