SI9400441A - Method and apparatus for introducing a substance into a fibre material, particularly into mineral fibre material - Google Patents

Abstract

A method for depositing a substance, or a mixture of substances, on fibres of a fibrous material, in particular of a mineral fibre material, wherein each substance, or a precursor material thereof, in gaseous state at a temperature above the temperature of the fibrous material is made to penetrate into the fibrous material, and which, preferably part thereof, is deposited on the fibres by condensation. The substance or the precursor material thereof may be mixed with a transport gas having a substantially lower dew point temperature than the substance so as to form a polynary gaseous mixture which is made to penetrate into the fibrous material, with the fibrous material being held at a temperature below the dew point temperature of the gaseous mixture so that part of the substance or the precursor material thereof is deposited on the fibres by condensation.

Description

ISOVER SAINT-GOBAIN

Process and preparation for introducing the substance into the fiber material, in particular the mineral fiber material

The invention relates to a method for introducing a substance into a fiber material, in particular a mineral fiber material, according to the introductory parts of claims 1 and 3 and to a device suitable for carrying out the process according to the introductory part of claim 14.

It will often be necessary to bring substances into the cushion or fibrous material, such as, in particular, mineral fiber material intended for thermal insulation. The substance can be introduced for various purposes. It can be a fiber protection substance. It can further be a binder, especially for the manufacture of fibrous material for insulation purposes. Although the invention may be used for the introduction of other substances such as binders, the description provided above clarifies in particular the example of the insertion of a binder in a mineral fiber material, in particular in a material intended for thermal insulation.

In such a case, it is desirable to achieve a homogeneous introduction and distribution of the binder, namely a homogeneous distribution at points of contact between the fibers, that is, at the intersections of the mineral fibers forming the fibrous material.

Homogeneous deposition provides good internal cohesion of the finished product and improved mechanical properties, in particular elastic relaxation following compression to re-obtain the thermal insulation property of the product.

The various procedures described in the prior art allow the insertion of a binder.

It is worth noting that fibrous materials are made of mineral fibers, which are usually obtained by the process of drawing fibers, using either internal or external centrifugation procedures.

Fiber drawing using internal centrifugation processes consists of the addition of a material to be drawn into the fibers in a molten state to the center of a spinner or fiber drawing rotor, comprising a plurality of openings or perforations at its periphery where the filaments are formed. These threads are then retained by high-velocity gas flow and deposited as hardened fibers on the production carrier.

When pulling fibers by means of external centrifugation, the material to be drawn into the fibers, when in the molten state, is added to the outer circumference of the fiber drawing ring, from which it separates under the influence of centrifugal force and forms filaments. Gas streams also contribute to the retention of fibers, which may be deposited on the production carrier as solidified fibers.

When pulling fibers through internal centrifugation processes, the binder is generally sprayed onto the fibers in their path before being deposited on the production carrier.

US-A-2 931 422 describes this type of spray process. The binder, which is generally an organic polymer, is atomized by means of a device located in the center of the fibrous torus that forms under the spinner.

One embodiment, cited as an alternative, is to move the atomization process outside the fiber torus formed under the spinner in order to atomize the branching agent outside the torus.

One of the advantages of atomisation processes is that they take place in a region of very high temperature.

The high temperature present enables the polymerization of the binder to start. This phenomenon is the reason why the fibers stick to each other, which is not desired at this stage of manufacture, because it results in excessively dense fibrous materials with a non-homogeneous structure. The use of high temperatures further improves the conditions for evaporation of the binder.

The doctrine of US patent A-3 901 675 avoids this disadvantage by cooling the fibers by supplying a coolant before the binder. This prevents premature polymerisation of the binder as well as the risk of the volatile binder entering the atmosphere. The additional use of refrigerant can complicate the process and increase manufacturing costs.

Other disadvantages that relate primarily to this atomization process concern the strands and tufts of fibers that form as the fibers grow in turbulent flows over the fabrication carrier. In fact, it can be seen that the binder is often either unable to be deposited on the fibers forming such strands or there will be excessive deposition, i.e., too much binder is deposited on the strands. In any case, the result of inserting the binder is therefore not satisfactory.

US-A-2 936 479 discloses a different method of inserting a binder by continuously inserting it between the powdered fibers before being deposited on a manufacturing carrier. The results obtained by this process are less favorable in terms of homogeneity and exhibit the same disadvantages as the above procedures.

The above processes, on the other hand, involve loss of substance, e.g. binder due to incomplete deposition on the fibers. In the case of a binder, the loss is up to 20% of the atomized binder. This represents a direct economic disadvantage from the loss of the substance.

In addition, the non-fiber bonding agent is removed through a punctured production carrier and is therefore contained in the manufacturing exhaust gas. The filter systems, which are so necessary to avoid the emission of substances into the environment, require additional expenditure. In practice, the amount of production exhaust gas that needs to be cleaned is about 50,000 m ³ / h per single spinner, resulting in increased pollution resulting in significant additional costs.

However, in the case of fiber drawing by means of external drawing procedures, the binder is also generally added by atomization.

EP-0 059 152 describes such a process by which a binder is added to the fibers before they reach the manufacturing carrier. For this purpose, the binder is bonded to the fibers by centrifugation. The problem encountered here is essentially identical to the problem encountered in internal centrifugation processes.

Above all, significant losses of the binder are inevitable here as well.

It is an object of the invention to provide a process and preparation by which a substance, e.g. the binder may deposit sufficiently homogeneously on the fibrous material, reducing the risk of loss of part of the agent.

Expressed by process technology, this task is accomplished according to the invention by means of the characterizing features of claims 1 and 3.

The process of the invention for depositing a substance or mixture of substances on a fibrous cushion, in particular on a mineral fiber material, enables the substance to penetrate through the fibrous material or to pass through the fibrous material when in the gas form and simultaneously to dispose of the substance on fibers within the fibrous material in a very homogeneously distributed and very well controlled manner by condensation.

The introduction of the substance into the fibrous material when in gaseous form ensures an even distribution within the fibrous material. Condensation from this uniform distribution of the gaseous substance takes place in the places where the fibers are present, so as to ensure as much homogeneity as possible for the sake of condensation.

If the substance or its corresponding precursor product which is converted to this substance is not provided together with the large quantities of exhaust gas to be disposed of, recovery of the substance or its precursor, insofar as it is not deposited on the fibers, does not present any problems . In the simplest case, a substance that escapes from a fibrous material can be re-directed to the addition of the substance in the condensed state and can again be converted to the gaseous phase along with it. In this way the loss or waste of the substance can be completely eliminated.

Condensation on the fibrous material is due to the fact that the fibers, which are relatively cooler than the substance, absorb enough heat from the vapors around the fibers concerned to initiate separation in accordance with the laws of condensation. The heat released during condensation is heated by the fibers. Therefore, the temperature difference available for condensation decreases continuously, resulting in less and less condensation being obtained from the steam stream until the condensation process is stopped when a certain minimum temperature difference is no longer present. Thus, the temperature difference between a gaseous substance on the one hand and a fibrous material on the other determines the amount of condensate that can be discharged within a given volume of a given fibrous material.

If the substance to be introduced is a binder, it is its job to interconnect or staple the fibers that intersect at their points of intersection or contact, while the fibers may remain without the binder at length between such points of contact. In such a case, it is therefore particularly important to use a binder that does not wet the fibrous material and thus form a droplet on its surface, and that the binder is preferably deposited at points of contact between the fibers.

This object is, in particular, well achieved by the present invention. The points of contact between the fibers form material agglomerations that have an increased mass-to-surface ratio and therefore follow the temperature rise of the fiber material caused by condensation with some delay. Therefore, the touch points appear to be the preferred condensation points where the desired buildup of the binder occurs in the given case.

This process seems to be further supported by the fact that the intersections or sections of close approximation of the two fibers are the preferred positions for the binder droplets, ie from the point of view of reducing the surface tension after contact between the two fiber surfaces. It is for this reason that the automatic placement of binder droplets at intersections between fibers approaching or in contact with each other appears to be advantageous.

When other substances are introduced, e.g. however, it may be advisable to use a substance for wetting the fibrous material, which condenses to form a film surrounding the fibers, thereby wetting the areas between the intersections.

Instead of dumping as much substance as possible, e.g. of the binder, the precursor material may be used, if this is advisable for the reasons of conducting the process, or inevitably when the substance itself is not suitable for transformation to a suitably evaporated state.

The process can be conveniently carried out by preferentially placing a portion of the substance on the fibers of the fibrous material by condensation. Therefore, a sufficient amount of residual substance may remain in the steam stream and may be reintroduced to the process after it has drained to ensure good control or regulation of the process.

If the gaseous substance is at a temperature above its dew point, it must experience a temperature drop to the dew point before condensation can begin.

In such a case, condensation is therefore not possible immediately after entering the fibrous material. When the gaseous substance has cooled and the fibers located on the inlet side of the fibrous material have therefore warmed, there is also no possibility of condensation due to the lack of temperature difference with respect to the fibers. Therefore, if the substance is at a temperature above the dew point, condensation inside the fibrous material is only possible at some distance from the inlet surface so that the substance cannot be deposited in the area adjacent to the inlet surface. If condensation occurs downstream of the inlet surface, there is a risk that the deposited substance is removed again by subsequent drying, because the flowing gas temperature is above the dew point and therefore above the evaporation temperature of the substance.

According to claim 2, therefore, it is advantageous, according to one-component and multiphase thermodynamics, that the temperature of the gaseous mixture does not exceed the boiling point or dew point of the substance when brought into contact with the fibers, that is, the temperature of the gaseous substance does not exceed the isotherm belonging to it. the existing pressure between the boiling point and the dew point within the two-phase region, with almost 100% of the substance initially present in the two-phase region in the form of vapor, and the temperature of the fibrous material at all times lying below the vapor temperature of the substance. This ensures that condensation occurs on the fibers from the first contact after entering the fiber material without first having to cool the gaseous substance to its dew point temperature.

A small decrease in the vapor temperature of a substance which at the time of entry at dew point below this dew point during flow through the fibrous material (preferably caused by a small decrease in pressure due to the effect of the damping of the fibers) does not cause any problems as long as the temperature of the fibrous material remains below that vapor temperature a substance that dominates the site just reached.

If a multicomponent gas mixture is used in accordance with claim 3 in order to introduce a gaseous substance (which should always be understood to include a possible precursor and / or a mixture of several individual substances), this may lead to management advantages procedure. Maintaining a certain flow is e.g. easier and safer despite volume reduction with simultaneous condensation if a transport gas is used which remains unchanged during the condensation process in the case of inert gas. The even distribution of the condensate over a greater distance from the inlet surface is thus facilitated by the flow of inert gas.

If the multicomponent gas mixture is at a temperature above its dew point for the prevailing pressure and concentration, then the dew point must reach a dew point before condensation becomes possible. In such a case, therefore, no condensation is possible immediately after entering the fibrous material. In order to reduce the temperature of the gas mixture to the appropriate dew point, the gas mixture must be removed from heat. This is only possible. if there is a temperature difference to the colder fibers, it means that the fibers, which are located on the inlet side of the fiber material, are heated to the temperature of the gas mixture. Therefore, condensation will not be possible at that location due to the absence of a temperature difference with respect to the fibers and the absence of components having a temperature below the dew point. It follows that in the case of a temperature in the gas mixture above the dew point, condensation within the fibrous material is possible only at a distance from the inlet surface of the gas, such that the substance cannot be deposited in the λ 'region adjacent to the inlet surface. If condensation occurs downstream of the inlet surface, there is a risk that the deposited substance will be removed again on subsequent drying, because the temperature of the flowing multicomponent gas mixture is above the dew point temperature and therefore above the substance temperature.

According to claim 4, it is therefore advantageous that, in accordance with multicomponent and multiphase thermodynamics, the temperature of the multicomponent gas mixture does not exceed the initial dew point of the multicomponent mixture and with a pressure such as after initial entry into the fiber material.

In any case, the temperature of the fiber material must remain below the dew point corresponding to the composition of the multicomponent gas mixture after leaving the fiber material.

In a particularly preferred manner, the temperature of the multicomponent gas mixture according to claim 5 is very close to the initial dew point of the multicomponent mixture. This makes it possible for the transport gas to inject a large amount of matter into the fibrous material, since a large amount of the substance is soluble in the transport gas near the initial dew point temperature. In addition, this gives the largest temperature difference between the temperature of the fiber material and the temperature of the multicomponent gas mixture without overheating it, and thus the maximum amount of substances that can be deposited.

According to claim 6, the transport gas is saturated with the vapor of the substance and thus contains the maximum amount of the substance in gaseous form at a given temperature or concentration.

According to claim 7, the transport gas is in a particularly preferred way air. Since air can be regarded as an inert gas, since it will not condense under the conditions that occur, the use of air as a transport gas is inexpensive and greatly simplifies the operation of the process.

According to claim 8, the flow of a gaseous substance or a multi-component gas mixture is achieved by forced circulation or flow. In this way, in contrast to the natural, heat-induced current, which typically represents flow rates of about 1 mm / s, the well-defined and reproducible flow characteristics can be achieved and maintained. In addition, higher speeds of 0.3 to 0.5 m / s can be used, if necessary, without difficulty, preferably not exceeding 1 m / s.

According to claim 9, the precursor material used is a monomer that polymerizes during deposition or after deposition in a fibrous material. This is particularly advantageous when the substance is used as a binder, since the binder is generally an organic compound of high molecular weight that cannot be converted into a usable gaseous phase. In this way, the use of the invention is therefore available for depositing a binding agent by the method of the invention, although the binding agent alone is not suitable for treatment by the method of the invention.

According to claim 10, the deposition of the substance is carried out in the fibrous material while it is still on the production carrier. This means that gas intake must be carried out on the fibrous material that has moved to the treatment position and before drying, e.g. in a drying oven. Care should be taken here to match the length of the machining area to the velocity of the fibrous material and the velocity of the gas so that it can pass through the entire height or thickness of the fibrous material, with condensate forming before the fibrous material leaves the treatment area where it is exposed to the gas stream . Where insufficient manufacturing speeds result from low gas velocities and / or high product thicknesses, this can be offset by extending the length of the machining area.

Mineral wool material intended for the manufacture of molded products such as pipe sections can also be treated on a production conveyor in this manner, but the desired form must be given before the binder dries, which is generally not possible on a production carrier. In many cases, the continuous process of manufacturing molded products is therefore interrupted before the drying oven; the woolen material is transported to another preparation for the manufacture of molded articles and treated accordingly. This can be done with a raw material already equipped with a binder, even in the case of long periods before drying.

In such a case, however, it is preferable to transfer the raw material to the preparation for further treatment without a binder according to claim 11, and to add a binder there only. This can be carried out in accordance with the invention by exposing, while stationary, portions of the raw material intended for the manufacture of the molded articles, while stationary, to the gas stream of the condensing substance. On the other hand, this represents the advantage of low fiber temperatures, which prevail due to the long delay after fiber production, so that the low fiber temperature and thus the large temperature difference with respect to the gas temperature can occur without additional expense. On the other hand, there is an advantage in facilitating the flow of the material through the fibrous material when it is stationary. If necessary, a large amount of the substance may thus be introduced into the fibrous material intended for the manufacture of molded articles.

According to claim 12, it may be advantageous to reverse the direction of flow entering the fibrous material, if possible, to be reproducible. This allows both large surfaces of the fibrous material to be exposed to fresh steam and thus wetted quickly and intensively by condensation. Contrary to the flow in only one direction, which in the beginning greatly reduces the amount of steam or the significantly depleted gas mixture to reach the area of the opposite surface of the fibrous material, until the heating of the upward fibrous material decreases condensation, further improved homogenization of deposition of the substance by the height or thickness of the fibrous material can be achieved. material in this way whenever necessary. In addition, accelerated seepage can be achieved by gaseous substances, i.e. steam does not need to be guided over the entire height or thickness of the fibrous material from one side to deposit the substance even in the region of the opposite surface, but relatively short gusts of steam from both sides may be sufficient. This is especially true if the substance to be deposited, in accordance with its characteristics, has to be concentrated mainly on or near large surfaces, while the same concentration is not required at the center of the fibrous material.

According to claim 13, additional processing is provided between at least some of these plants. In this way, the material which was necessarily heated during condensation of the substance can preferably be re-cooled to maintain the maximum possible temperature difference between the vapor of the substance or the multicomponent gas mixture and the fibrous material.

Expressed in the preparation technology, this objective is achieved by the features of claim 14.

The binary air / substance mixture is then formed in a supersaturated condition in the first preparation, then directed to the fiber material and introduced into the second preparation.

Sub-claims 15 to 19 relate to preferred improvements to the preparation according to the invention.

Further details, features and advantages of the invention are set forth in a further explanation of an embodiment, with reference to the drawing showing:

FIG. 1 is a schematic simplified representation of an apparatus illustrating the process of preparing a multi-component gas mixture and introducing it into the fibrous material on one side thereof and in recovering the substance downstream of the fibrous material;

FIG. 2 in a representation similar to FIG. 1, introducing the multicomponent gas mixture into the fibrous material on both sides as well as recovering the substance from both sides downstream of the fibrous material;

FIG. 3 in a representation similar to FIG. 1 and 2, an apparatus comprising an additional fabrication device between two machining stations;

FIG. 4 Pv diagram showing the PvT behavior of a pure substance; and FIG. 5 is a balanced phase diagram describing the Tx (y) behavior of a two-component two-phase mixture.

In the example shown in FIG. 1 to 3, the binder in the form of monomer as a precursor material should be introduced into the mineral fiber material and condensed on the fibers of the fiber material.

The container 1 has a lower compartment comprising a liquid monomer 2 which passes through the following heat exchanger 4 through a pump 3 positioned downstream of the container 1.

The heat exchanger 4 is provided with an inlet 5 at its lower end in terms of the monomer current 2 and at its upper end with an outlet 6 for fluid 7 to replace the heat coming from the steam boiler 7a or heated by the heating device 7a.

Downstream of the heat exchanger 4, in terms of the monomer current 2, a venturi vacuum cleaner 8 is provided, whose outlet area 8a opens into a conduit 9 leading to the upper portion lb of the container 1. Further, the suction duct 10 for suction of air 11 opens toward the outlet area 8a of the Venturi vacuum cleaner 8 at the lowest pressure point and thus the strongest suction effect.

Container 1, pump 3, heat exchanger 4, Venturi vacuum cleaner 8 and conduit 9 form the first circuit A 'for monomer 2.

The separator 12 is located at the upper outlet 13 of the vessel 1, where the gas mixture 14 leaves the vessel 1. The gas mixture 14 is air 11 saturated with the monomer vapor.

Downstream of the separator 12, the upper outlet 13 of the container 1 opens into the conduit 15, which conveys the gas mixture 14 to the workpiece 16 for the fiber material 17 at a rate determined by the pump 3 for the monomer circulation.

The treatment station 16 essentially consists of an inlet 18 for the gas mixture 14 supplied through the conduit 15, a support frame 19 for fibrous material 17, and a suction hood 20 provided with external thermal insulation 21. The support frame 19 comprises a support surface 19a. , on which the fibrous material 17 rests, and through which the gas mixture 14 can flow, and the gas-tight surface 19b surrounding the support surface 19a to prevent the bypass flow of gas by entangling the fibrous material.

The gas mixture 14 passes through the fibrous material 17 due to forced flow or circulation and condenses after its contact with the fibers during its passage with the gas monomer 2 due to the temperature difference between the gas mixture 14 and the fibrous material 17.

After leaving the fibrous material 17, the gas mixture, which is depleted of the monomer pairs, is recovered in the suction hood 20 and fed to the vessel 1 via the duct 22. Thermal insulation 21 reduces the heat losses in the suction hood 20 to prevent condensation of the gas. monomer 2 on the side of the suction hood 20, thereby preventing the liquid monomer 2 from dripping onto the fibrous material 17. Preferably, the duct 22 is tilted downward in terms of current and connects the suction hood 20 with the suction line 10.

Upstream of the opening 22 of the suction line 10, a damping device 23 is installed in the duct 10. The damping device 23 restricts the air supply 11 to the Venturi vacuum cleaner 8, thereby helping to maintain the high vacuum as desired in the suction line 10.

Container 1, separator 12, conduit 15, machining station 16 with fibrous material 17 on support frame 19, suction hood 20, conduit 22 and suction conduit 10 form the second circuit B 'for the gas mixture 14.

In order to support the effect exerted by the pump 3 on the gas mixture 14, an additional fan can optionally be installed in line 15 or line 22, as shown in the figure for line 22.

Figure 4 shows a Pv diagram illustrating the behavior of a pure substance as a function of pressure, specific volume and temperature. The specific volume v and pressure P of the system are plotted on either the X axis or the Y axis. The dashed lines show the isotherms T and T with the points A, B, C, D and E of the state applied to one of these isotherms. The isothermal compression of the gaseous substance starting from point A of the state is initially considered. At point B, a two-phase gas and liquid region is reached at line V of the dew point, with the substance present in both liquid and vapor form. The two-phase gas and liquid region is passed at constant pressure. At point C, the system completely transformed into a liquid state and reached the IV boiling point. By further isothermal compression, the two-phase region of fluid and solid, called the melting region, is reached at point D on the solidification line II. With the substance present in liquid and solid form, it also passed through the melting region at constant pressure until the system was finally fully converted to the solid state at point E on the melting line I. Line IV boiling points and line V of dew meet at critical point III, which is related to the critical pressure P _cr , the critical specific volume in _cr and the critical temperature T _{cr of} this substance. Triple line VI separates the two-phase region of gas and liquid, where the substance is present in liquid and vapor form, from the two-phase region of liquid and solid, where the substance is present in the form of vapor and in the form of a solid.

If such a substance is to be introduced into the fibrous material 17 in the form of vapor, the vapor must be at conditions corresponding to the state of point B in Figure 4, that is, under dew conditions. This ensures that any cooling effect on the steam will cause the condensate to be released immediately, leaving the condensate to continue as long as cooling continues. It also avoids any effect of re-drying, which would otherwise cause the recovered condensate to evaporate again after contact with steam at a temperature still above dew point.

Figure 5 shows a phase equilibrium diagram giving the behavior of Tx (y) two-component and two-phase mixtures. The concentration x of one substance and the temperature T of the mixture are plotted on the X axis or on the Y axis respectively. The diagram is divided into three areas by the dew line VII and the boiling line VIII. In the area above line VII, the mixed components are both present in the form of steam. In the area between dew line VII and boiling line VIII, the constituents of the mixture may be present individually or as a vapor-liquid mixture. In the area under Boiling Line VII, both mixed components may be present in liquid form.

Dew line VII, in accordance with temperature T and concentration x, describes the curve along which the gas mixture begins to condense. Line VIII of boiling point therefore, in accordance with temperature T and concentration x, describes the curve along which the liquid mixture begins to boil. So if e.g. with a decrease in temperature due to heat dissipation, the gas mixture of concentration x reaches a point in line VII of the dew point, the condensate of higher concentration χ corresponding to the isothermal point L _x on line VIII of boiling point will be released, while at the same time the remaining gas mixture will decrease after concentration and will due to the simultaneous condensation of heat, it followed the dew point line VII and finally reached the point 'at dew line VII corresponding to a lower temperature T'. At this temperature, the condensate will have a lower concentration x corresponding to point L on boiling line VIII corresponding to the initial concentration of the gaseous mixture, and the spontaneous condensation will cease, with the remaining concentration of the gaseous mixture corresponding to x '.

During operation, the apparatus of the invention, on the one hand, serves to form a binary gas mixture, namely air saturated with monomer vapor, and, on the other, to transport the gas mixture to the fibrous material 17, introducing it into the fibrous material 17, and condensing the monomer on the fibers of the fibrous material 17 as well as the recovery of these condensable and non-condensable gaseous constituents in the fiber material 17.

Fluid 7 is supplied to the heat exchanger 4 via the inlet 5 through this heat transfer, such as e.g. water. Monomer 2, which is present at the inlet in the liquid exchanger 4, is heated to high temperature by its passage through the heat exchanger 4, which is not high enough to cause a phase transition.

The heated liquid monomer 2 exits the heat exchanger 4 and flows towards the Venturi vacuum cleaner 8, where it is atomized into tiny droplets that evaporate and saturate the air 11 sucked by the suction line 10.

The separator 12 is mounted on the upper outlet 13 of the vessel and allows the separation of unpaired or condensed droplets into the vessel 1. This achieves a gas mixture 14 without liquid content. In the present example, this gas mixture 14 is air 11 saturated with monomer vapor.

The gas mixture is then transported through conduit 15 to processing station 16. This is carried out at the speed determined by the pump 3 for circulation of monomer 2.

For this purpose, pump 3 in circuit A 'creates a vacuum in the suction line 10 by means of a Venturi vacuum cleaner 8 and causes a sufficient amount of air to be introduced 11. Suitable suppression of the inlet air by a damping device 23 in the suction line 10 causes a vacuum in the suction line 10, to support the circulation of gas mixture 14 in circuit B '.

In treatment station 16, the gas mixture 14 flows past the inlet 18 and reaches the fibrous material 17 through the support surface 19a of the support frame 19 and then penetrates the fibrous material 17 due to forced circulation. The gas monomer condenses as it passes through the fibrous material 17 in contact with the fibers, which are also below the dew point temperature of the gas mixture 14 at a temperature below the temperature of the gas mixture 14 and also below the dew point of the monomer 2.

After leaving the fibrous material 17, the gaseous mixture 14, depleted of the monomer vapor, is sucked into the suction hood 20 and guided back to obtain the sowing by mixing it through the duct 22 to the air 11, which is introduced through the suction conduit 10. Adequate formation of conduit 12 protects against the tendency of the monomer, which has condensed there to flow back to the fibrous material 17, ensuring its flow against the vessel 1.

While mixing the depleted gas mixture 14 with cold air 11, the resulting cooled gas mixture may be over saturated with steam of monomer 2 at such a low temperature. This allows the monomer parts to condense, which is then obtained in the vessel 1 as condensate flowing out of the ducts 22.

Atomization and evaporation at the outlet 8a of the Venturi vacuum cleaner 8 can be controlled to result in a temperature increase based on the heat input from the internal energy of the monomer 2 present in the Venturi vacuum cleaner 8. This supplies heat to the circuit B '. raises the temperature of the gas mixture 14 thus created to or over the temperature of its dew point. If necessary, the thermal balance can be affected by preheating the air 11.

The apparatus therefore permits the introduction of the monomer into the fibrous material 17 without any loss of input components, since the steam of the monomer 2, which has not condensed in the fibrous material 17, is fully recovered. The heated liquid monomer 2, which failed to evaporate after passing through the Venturi vacuum cleaner 8, and the monomer 2, which condensed downwards with respect to the fibrous material 17, are recovered in the vessel 1 by means of a separator 12 and fed to reheat in a thermal exchanger 4.

The condensed part of the monomer continuously removes the gas volume from the circuit B ', replacing this volume with the intake air volume IT. The intake air 11 ', however, forms the fresh gas mixture 14 together with the fresh monomer 2 which has evaporated in the Venturi vacuum cleaner 8.

As regards the production of a gas mixture 14 saturated with monomer vapor at a certain temperature, knowledge of all relevant data for the components used is required.

If the operating parameters of the Venturi vacuum cleaner 8 as well as the airflow 11 and the liquid monomer 2 are known, the initial data relating to the air 11 and the monomer 2, together with the densities, inlet and outlet temperatures, specific heat, vapor pressures and evaporation temperatures and beyond the thermal transfer capacity of the fluid 7 to transfer heat inside the heat exchanger 4, then, by applying the laws of thermodynamics, the inlet temperature of the heated liquid monomer 2 can be determined at the inlet of the Venturi vacuum cleaner 8, which is necessary to saturate the air 11 with steam of monomer 2 at the selected temperature.

Where necessary, additional temperature adjustments may be made in a way that is not presented, but is normal, e.g. by means of a heat exchanger in the upper part lb of container 1 or anywhere along the lines 15. In this way, the temperature of the gas mixture 14 may be adjusted in any case so that it is present at the desired temperature, such as e.g. in particular at a temperature corresponding to its dew point temperature in the inlet region 18.

The support frame 19 for the fibrous material 17 may consist of a fabrication carrier of the fabricating device for the fibrous material 17, which is then in a uniform and continuous motion in a direction perpendicular to the plane of the drawing. The support frame 19 may, however, also be stationary or stationary so that pieces of raw material are processed for molded articles.

As described above, Figure 1 represents insertion into stationary fibrous material in circuit B '. As for circuit A ', Figures 2 and 3 correspond to the representation in Figure 1, while different embodiments are shown with respect to circuit B'. To facilitate understanding, the same reference codes as in Figure 1 are also used in Figures 2 and 3 for identical or equivalent parts.

In Figure 2, the endless fabric fibrous material 17 travels past a machining box 30 comprising two punched carriers 31 which support the fabric of fibrous material 17 during its travel within the box 30. During machining travel 31 a machining box 32 comprising two is mounted. sequential machining chambers 33 and 34. Machining chambers 33 and 34 accept the traveling fabric of fibrous material 17 essentially in a gas-tight manner, avoiding excessive gas exchange between the interior and exterior of the machining chambers 33 and 34; this essentially gas-tight seal is supported by the proper sealing of the side walls of the machining box 30 as shown in the drawings.

The conduit 15a that branches off from the conduit 15 and the duct 22a that branches off from the conduit 22 are opened into the first treatment chamber 33 by introducing a multi-component gas mixture from conduits 15 to the underside of the fabric of fibrous material 17 and sucking gas, emanating from the upper side of the fibrous material 17 into conduit 22. The conduit I5b, which branches off from conduit 15, and conduit 22b, which branches off from conduit 22, are opened into a second treatment chamber 34 by introducing a multi-component gas mixture from water 15 to the upper side of the fabric of the fibrous material 17 and sucking gas exiting the underside of the fibrous material 17 into the duct 22. The direction of the gas flow through the fibrous material and the treatment chambers 33 and 34 is shown by arrows 35 and 36 respectively.

The arrangement according to Fig. 2 allows for alternating current to be produced through the fiber material 17 in both directions, so that related advantages such as improved homogenization are achieved.

In Fig. 3, the two machining boxes 30 are arranged in series along the travel path of the fabric of fibrous material 17 with an additional and special machining box 14 between them. Any desired special treatment may be carried out in the special treatment casing 24, including intermediate cooling treatment between the treatment casing 30, so as to avoid continuous heating of the fibrous material 17 during passage through successive treatment cages 30. The arrangement within the special treatment casing 24 is similar to the arrangement within the processing casing 24 30 as shown schematically in Fig. 3, the refrigerant gas water 37 is opened up and down relative to the fabric of fibrous material 17 so as to produce a alternating cooling gas flow in accordance with arrows 38 and 39 through fibrous material 17.

The results of experiments conducted on stationary mineral fiber material 17 are presented below to facilitate interpretation of the results.

Example 1

Deposition of DCPOEMA (dicyclo-pentenyloxy-ethylmethacrylate) in its vapor phase in a fibrous material already containing ammonium persulfate as catalyst. The networking is then achieved by supplying heat.

The original fibrous material was made on a pilot pilot line and ammonium sulfate, a water-soluble solid, was sprayed onto the fibers in a conventional manner using a spray head at a ratio of 1.5%.

The fibrous material was then cut to size (750 x 750 mm ² ), and a two-component air / monomer mixture was allowed to penetrate the static pilot device, impregnating the fibrous material with the DCPOEMA monomer vapors, according to the invention. condensation occurred on the fibers. Since the normal boiling point of the monomer is very high (350 ° C at 1 bar), saturation of air at 100 ° C (measured immediately before entering the fibrous material) with steam of the monomer takes about 20 minutes.

The planar density (g / m ² ) of the fibrous material lies between 500 and 600 g / m ² in all experiments.

No. Duration input The mean dew point during the experiment Proportion of condensate polymerized after intake (incandescent loss) 1 2 min. 98 ° C 9% 2 5 min. 103 ° C 23% 3 5 min. 100 ° C 18% 4 10 min. 106 ° C 34% 5 10 min. 110 ° C 40%

The proportion of condensate that has polymerized after intake is calculated as follows:

The impregnated fiber material is kept in an oven at 150 ° C for 15 minutes to allow the monomer to cross-link.

The annealing loss at 550 ° C is then measured on the finished product in the usual manner.

It is obvious that the amount of inert material increases with the passage time and with the dew point.

The final product is black in color with satisfactory cohesion and flexibility.

Implementation case 2

The two-component trimethylolpropantrimetacrylate (TMPTMA) / catalyst mixture was introduced in the evaporated phase into the crude fiber material and the monomer was then cross-linked by irradiation with an ultraviolet lamp.

TMPTMA is a three-functional methacrylic monomer with a very high boiling point of 370 ° C.

The commercial name of this catalyst is IRGACURE 369 (CIBA GEIGY). The chemical designation is 2-benzyl 2 dimethylamino 1- (4 morpholinophenyl) -butanone 1.

The catalyst, a solid, was dissolved in the monomer and the mixture was saturated in the vapor phase inside the fibrous material.

It should be noted that, unlike in the extensive process of preparation of the mixture used in the preparation of Figures 1 to 3, the air stream which has already been sufficiently preheated is mixed with the hot, evaporated monomer in the upper section of the container. Thus, the preheating of the air can be arranged more simply and the mixing of the heated air with the evaporated monomer can be conveniently carried out more easily.

The monomer was introduced into samples of cylindrical fibrous material 9 cm in diameter in the vapor phase at 90 ° C at a flow rate of 50 1 / min. It is appreciated that the polymerization of the monomer in the vessel can start at temperatures above 90 ° C, but on the other hand it is difficult to initiate the transition of the monomer to the vapor phase at temperatures below 90 ° C. Therefore, at the selected temperature of 90 ° C, it is still possible to satisfactorily create a mixture of evaporated monomer and preheated air.

No. Transporten gas Duration input Input temperature Condensate input (weighed before and after impregnation) 6 nitrogen 5 min. 90 ° C 13.8% by weight 7 nitrogen 5 min. 90 ° C 11.8% by weight 8 nitrogen 5 min. 90 ° C 10.2% by weight 10 nitrogen 5 min. 90 ° C 13.3% by weight 18 air 5 min. 90 ° C 7.6% by weight

The introduction of the monomer was carried out with the help of two different transport gases, namely air and nitrogen, through this experimental preparation. This offered the opportunity to test whether air as a transport gas preferentially impedes the polymerization of the monomer under adverse conditions (pressure, temperature, mixing ratio), if the polymerization of the monomer is to be carried out by irradiation after it has been introduced. However, the study actually shows that airborne intake as a transport gas can be carried out without inhibiting polymerization.

The use of an inert gas, i.e. nitrogen, may be preferred in certain circumstances with respect to the polymerization of the monomer by irradiation after its introduction.

Example 3:

In this embodiment, a lubricant of 3018 (di-2-ethylhexylazelate) was tested. This material has an acid number of 0.5 mg KOH / g, a hydroxyl number of 3 mg KOH / g and a water content of 0.1%. Furthermore, this material can be used up to a minimum temperature of -60 ° C and has a dynamic viscosity at 25 ° C of 16 mPa.s and at 90 ° C of 3 mPa.s, a flash point above 210 ° C, a density ratio of 25/25 ° C 0, 92 and refractive index N25 / D 1,448.

In the lubricant test, layer 3018 as a substance to be introduced to cover the surface of the fibers to be finalized after condensation, the following results were obtained.

$ t. Flat Duration Tempe- Temperature at The share is paid density input ratura getting on the train- condensing care you acne neni material zata 1 759 g / m ² 2x5 min. 25'C 108 ° C-11 ° C 1.4% by weight 2 826 g / m ² 2x5 min. 25 ° C 114'C-116'C 1.3% by weight 3 846 g / m ² 2x5 min. 25'C 115 ° C-116 ° C 0.8% by weight 4 855 g / m ² 2x5 min. 25'C 117'C-119 ° C 0.8% by weight 5 886 g / m ² 2x5 min. 25-C 117 ° C-119 ° C 0.7% by weight 6 821 g / m ² 2x2 min. 25'C 116 ° C-117 ° C 0.7% by weight 7 870 g / m ² 2x2 min. 25'C 115'C-116 ° C 0.25% by weight 8 924 g / m ² 2x2 min. 25 'C 114'C-113'C 0.33 wt.% 9 805 g / m ² 2x2 min. 25'C 114 ° C-113 ° C 0.75 wt.%

Fibrous material at rest with a mean planar density of about 850 g / m ² was introduced at a temperature of 25 ° C before application and the mixture was injected with a mixture of 2x5 minutes or 2 x 2 minutes. It can be clearly recognized that, on average, about 1% and 0.5% of the lubricant may condense during application over a period of 2x5 minutes at a mean injection temperature of 116 ° C, or during injection over a period of 2x2 minutes at a mean injection temperature of 114 ° C. It is also apparent here that the amount that can be introduced can increase with time and with dew point.

When the fibers are examined closely under a microscope, a thin oil film can be detected on the surface of the fibers. Thus, it is basically possible to cover fibers using the process of the invention in the finishing or enhancement of various physical or thermal properties.

For

ISOVER SAINT-GOBAIN:

PATENT OFFICE

LJUBLJANA

Claims (19)

PATENT APPLICATIONS A method of depositing a substance or mixture of substances on fibers in a fibrous material, in particular mineral fiber material, characterized in that each substance or its precursor material is gaseous at a temperature above the temperature of the fibrous material and preferably is penetrated into the fibrous material part condenses on the fibers due to condensation. A method according to claim 1, characterized in that the gaseous substance, when brought into contact with the fibers of the fibrous material, is kept at a temperature not exceeding the boiling point of the substance. 3. A process for depositing a substance or mixture of substances on fibers in a fibrous material, in particular mineral wool material, characterized in that each substance or its precursor material is mixed with a transport gas having a substantially lower dew point than the substance, such that a multicomponent gas mixture is formed and the said multicomponent gas mixture is allowed to permeate into the fibrous material, keeping the fibrous material at a temperature below the dew point for said gas mixture, of which at least a part is impinged on the fibers. Method according to claim 3, characterized in that the multi-component gas mixture, when brought into contact with the fibers of the fibrous material, is kept at a temperature not exceeding the initial dew point of the mixture. Method according to claim 3 or 4, characterized in that the temperature of the multicomponent gas mixture is selected very close to the initial dew point of the mixture. Method according to any one of claims 3 to 5, characterized in that the transport gas is saturated with steam of this substance. Method according to any one of claims 3 to 6, characterized in that air is used as the transport gas. A method according to any one of claims 1 to 7, characterized in that the flow of the gaseous substance or multicomponent gas mixtures is carried out by forced circulation or flow. A process according to any one of claims 1 to 8. characterized in that the monomeric gaseous precursor of the substance is polymerized during or after deposition in a fibrous material under the influence of factors such as heat, catalytic substances, radiation and other monomeric substances or gas. A method according to any one of claims 1 to 9, characterized in that the deposition is carried out after the fibers forming the fibrous material have been admitted to the production carrier and while the fiber material is still on the production carrier. A method according to any one of claims 1 to 9, characterized in that, in the case of the manufacture of molded products, such as pipe sections, the deposition is carried out after removal of the fibrous material from the manufacturing carrier. A method according to any one of claims 1 to 11, characterized in that the direction of the gas flow through the fibrous material, preferably repeated, is reversed after a predetermined flow time in one direction. A method according to any one of claims 1 to 12, characterized in that additional treatment such as cooling is provided at least between the individual plants. 14. A device for depositing a substance on the fibers of a mineral fiber material (17), characterized in that the manufacturing equipment (circuit A ') for the binary gas / air mixture is provided, the air being saturated with the vapor of the substance as the transport gas, to be deposited, or a precursor thereof, at a given temperature, and by means of a device (circuit B ') for directing the binary gas / air mixture to penetrate said fibrous material (17). Apparatus according to claim 14, characterized in that said manufacturing equipment (circuit A ') comprises - heat exchanger (4) for heating the substance in its liquid state, - a pump (3) for pushing the heated liquid substance towards the inlet of the Venturi vacuum cleaner (8), and - air intake means (line 10) (11) opening against the vacuum region of said Venturi vacuum cleaner (8) to form a binary gas / air mixture. Apparatus according to claim 14 or 15, characterized in that said guidance equipment (circuit B ') comprises means for generating a pressure difference over the fibrous material so as to cause the binary gas / air mixture to seep into said fibrous material (17) at a predetermined flow rate. Apparatus according to claim 16, characterized in that said means for generating a pressure difference through said fibrous material (17) comprises vacuum means in a downward direction behind said fibrous material (17). Device according to claims 16 and 17, characterized in that said vacuum means comprises said Venturi vacuum cleaner (8). Device according to any one of claims 14 to 18, characterized in that the filter means (12) are inwardly relative to the fibrous material (17) so as to hold any liquid substance above a certain particle size in order to carry it along with the binary air / substance mixture.