FI106368B - Process for manufacturing a mineral fiber element and apparatus for carrying out the process - Google Patents

Abstract

A method of producing a mineral fibre element comprising a mineral fibre base layer having a surface coating in the form of a fibrous netting formed of a thermoplastic polymer material wherein such a surface coating is provided on at least a part of the surface of the base layer, wherein the surface coating is formed directly on the surface of the base layer and wherein the surface coating is formed by heating a thermoplastic polymer material so as to melt it and distributing the polymer melt obtained in the form of fibres and/or filaments on the surface of the base layer and cooling it to form a solid layer.

Description

106368

The present invention relates to a method for manufacturing a mineral fiber element comprising a mineral fiber backing layer coated with a fiber mesh formed from a thermoplastic polymeric material, wherein the coating is provided on at least a portion of the surface of the surface.

The mineral fiber material is used for thermal and acoustic insulation in a variety of applications.

In order to increase the touchability of the mineral fiber material during handling and installation, it can be coated with a surface layer, for example consisting of a nonwoven sheet of polymeric fibers.

In addition, such a surface layer reduces or completely eliminates the release of fibrous logs or individual fibers into the environment from, before, during, or after installation of the mineral fiber material.

In addition, a coating of the above type significantly increases the tensile strength of the mineral fiber element.

It is known to produce mineral fiber elements of the type described in the preamble by attaching a prefabricated nonwoven fabric 20 to the surface of a continuous mineral fiber material, using a resin such as phenol-formaldehyde resin as an adhesive and then cutting the coated mineral fiber fiber into a single fiber.

Polymeric nonwoven materials can be produced from thermoplastic polymers, which are characterized by being adherent in molten form. 25 In the production of nonwoven materials, the sizing effect may be used to bind the individual fibers to form a cohesive layer.

However, prior art methods have several drawbacks.

In order to provide the nonwoven material with sufficient strength to withstand tensile stresses during processing, and particularly when applying the material to an uneven surface of the mineral fiber material, the surface weight used should be at least about 20 g / m 2.

However, it is not necessary to use a coating having such a weight in order to achieve a functional coating and thus the prior process will cause some waste of material.

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In addition, the resin used for bonding the nonwoven material increases the calorific value of the coated mineral fiber element, which is undesirable for fire safety reasons.

In addition, the mineral fiber fibers manufactured by the previous process are relatively expensive, partly due to the high cost of nonwoven polymeric materials and partly due to the process comprising at least two relatively difficult technical steps, namely 1) uniform application of adhesive to the substrate and 2) coating mounting and printing on said surface.

10 Finally, it is strenuous and difficult to form a coating that covers the entire surface of the base layer, ie. Both the upper and the lower side of the base layer and the edge surfaces using the previous method.

It is an object of the present invention to provide a method of the type mentioned in the preamble which is simpler than the previous method and which provides a mineral fiber element with better properties.

The process of the present invention is characterized in that the coating is formed directly on the surface of the base layer and that the coating is formed by heating the thermoplastic polymeric material so that it melts and spreading the resulting polymer melt in the form of fibers and / or filaments on the base layer and cooling.

The invention is based on the invention whereby the adhesive action of thermoplastic polymeric materials when the polymer is in molten or semi-molten state to provide a highly effective adhesion between the mineral fiber layer and the coating can be utilized by forming a polymer layer directly on the mineral fiber board.

Further, the invention is based on an invention wherein the nonwoven material used in previous processes 30, due in particular to the strength requirements required to apply said material to the mineral fiber base layer, has properties which are undesirable, unnecessary, and disadvantageous in the ability to obtain a coating whose properties are solely determined by the desired functional aspects.

106368 Thus, the method of the present invention provides the ability to form a freely determinable coating and, as a result, achieves material savings over the prior art.

Furthermore, by using this method, it is possible to form a coating consisting of fibers having a thickness less than the fiber thickness of the nonwoven materials used in the previous process, thereby achieving material savings as well as the ability to increase the fiber content per unit and thereby improve the filtering capacity.

Finally, the present invention is based on an invention in which a coated mineral fiber element can be produced more economically and easily by forming a coating directly on the mineral fiber material than by gluing the prefabricated nonwoven material to the mineral fiber material. the process requires only one production step, whereas the previous process requires at least two manufacturing steps.

In addition, the coating formed by this method is easier to shear than the coating of the previous method, which greatly facilitates the cutting of mineral fiber elements, which is usually necessary when installing the elements.

The term "mineral fibers" as used herein includes rock fibers, glass fibers and slag fibers.

As used herein, the term "thermoplastic polymeric material" refers to any natural or synthetic thermoplastic polymer or polymer blend. The thermoplastic material is characterized in that it is solid or semi-solid at room temperature or operating temperature and that it melts when heated and solidifies or becomes solid or semi-solid upon cooling of the material.

The term "thermoplastic polymeric material" also includes materials commonly referred to as "thermoplastic hot melt adhesives" or «.

"hot melt adhesives" or simple "hot melt adhesives".

Examples of thermoplastic polymeric materials include ethylenically unsaturated monomers such as polyethylene, polypropylene, polybutylene, polystyrene, poly (α-methylstyrene), polyvinyl chloride, poly (vinylacetate), polyethyl acrylate, polymethylmethacrylate, copolymers of ethylenically unsaturated monomers such as ethylene and propylene, ethylene and styrene, polyvinyl acetate, styrene and maleic anhydride, styrene and methyl methacrylate, styrene and ethyl acrylate, styrene and ethyl acrylate, styrene and ethyl acrylate, and styrene and ethyl acrylate; polymers and copolymers of conjugated dienes such as polybutadiene, polyisoprene, and polychloroprene; and polymers of bipolyfunctional monomers such as polyesters, polycarbonates, polyamides and polyepoxides.

Particularly preferred thermoplastic polymeric materials are polyesters, polyamides, polypropylene and polyvinyl acetate.

By using the process of the present invention, it is possible, as mentioned above, to produce mineral fiber elements whose coating thickness is freely determinable.

However, in order to achieve a suitable workability of the final product, it is preferred that the coating has a mass per area of from 2 to 50 g / m 2, preferably from 5 to 20 g / m 2, and most preferably from 10 to 15 g / m 2.

The base layer can be of any shape and typically is in the form of an end web (web), a web, a mat or a sheet.

Carpets and boards can be formed by cutting.

The present invention further relates to apparatus for carrying out the process of the present invention, characterized in that it comprises one or more units, each unit comprising devices for melting a thermoplastic polymer material, a plurality of nozzles, devices for extruding the polymer melt through nozzles and applying mineral extruded polymer material. on the base layer and devices for conducting one or more high pressure gas streams precisely over the nozzles to extend the extruded polymeric material and thereby to form thin filaments and / or fibers.

The melting device may take the form of an extruder or a melting chamber which may be heated, for example, by means of electric heating elements.

A preferred embodiment of the apparatus of the present invention is characterized in that it comprises an elongated dispensing chamber which is in fluid communication with the melter via a pump and has a plurality of closely spaced nozzles at its outer end, two chambers located on two side walls of the dispensing chamber a longitudinal ra-35 ko and means for controlling the high pressure gas stream through said side wall chambers and further out through the slits.

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Equipment of the above type is commonly referred to as a "melt blow apparatus".

Another preferred embodiment of the apparatus of the present invention is characterized in that it optionally comprises devices for mixing gas into the polymer melt and comprising a plurality of pressure syringes, each comprising a nozzle, in fluid communication with the melting device and devices for one or more high pressure gas streams. to guide the mouth of each syringe.

Em. This type of equipment is commonly referred to as a "hot melt spray apparatus".

Optionally, the apparatus of the present invention comprises devices for supporting and optionally conveying the base layer.

Such support devices may be, for example, any suitable type of conveyor device, such as a rolling belt, a rolling web, a conveyor belt or a conveyor web.

The apparatus of the present invention may be disposed between or opposite an aperture formed in such a conveyor.

In the apparatus of the present invention, the nozzles are preferably spaced evenly.

When using the apparatus according to the invention, it is preferable to place it above the mineral fiber bed which is continuously transported at a certain distance from the apparatus.

The apparatus according to the invention is preferably disposed so that a row of nozzles extends over the entire width of the base layer, i.e. in a direction perpendicular to! 25 perpendicular to the direction of travel of the conveyor.

The apparatus according to the invention preferably comprises a suction device, such as a suction box, located below the bottom layer and opposite the nozzles, and removes the gas used to extend the extruded polymeric material through the nozzles.

When it is desired to cover both sides, both top and bottom, of a conveyor-movable base layer * this can be accomplished by using two apparatuses of the invention, said apparatuses being disposed below and above the base, and each apparatus having a compatible suction device 35 sides.

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Alternatively, two apparatuses may be used which are disposed relative to one another for transfer to the same side of the substrate layer, thereby rotating the base between the two apparatuses.

The melt injection equipment, see above definition, is suitable for operation without a cooperating suction device.

Thus, when both sides of the base movable by the conveyor device, both the bottom and the top side, are coated using melt injection equipment, the desired coating can be achieved by using two such devices positioned above and below the base opposite each other or by using nozzles 10 .

A particularly preferred embodiment of the melt injection equipment described above is characterized in that one or more units together comprise a plurality of pressure syringes which can be positioned and / or moved so that the polymer material from the syringes can be distributed over the entire surface of the substrate.

The above-mentioned particularly advantageous embodiment of the apparatus according to the invention makes it possible to manufacture fully coated mineral fiber elements.

Thus, for example, in the coating of web, mat or plate-shaped soles, it is possible to coat both the top 20 and the bottom of the sole as well as its peripheral sides in a simple manner.

Em. the particularly preferred apparatus preferably comprises, in part, one or more pressure sprays which are circumferentially formed around the entire base layer transported by the conveyor device and are spaced evenly to allow the top and bottom of the base layer as well as the side edges to be coated. which may be displaced in a vertical direction or plane and which may be used to coat the surfaces of the bottom end edges.

Advantageously, such transportable pressure sprays can be automatically controlled.

30 Em. a particularly preferred embodiment of a melt blasting apparatus, wherein the apparatus comprises a suction device, comprises a dispensing chamber having a length greater than the entire width of the bottom layer, the width direction being parallel to said chamber.

By utilizing the above-mentioned particularly preferred embodiment of the apparatus of the present invention, for example, when coating a web, mat or plate-shaped base, it is possible to coat both the upper and lower sides of the base and its sidewall surfaces, since polymeric material injected widthwise on said * side edges surfaces partly by means of a suction device.

The high pressure gas used to extend the polymer extruded material from the nozzles is preferably atmospheric air.

Preferably, the high pressure gas used is hot to prevent excessive cooling of the extruded polymer melt prior to depositing it on the substrate surface.

The gas may be pressurized, for example, by means of a fan or a compressor 10.

As mentioned above, the melt injection apparatus of the invention may optionally comprise devices for mixing gas in its polymer to form a melt / gas mixture.

When such a melt / gas mixture is dispensed from the melt injection apparatus mentioned above, the gas diffuses into the polymer melt and, as a result, certain foaming of the distributed polymer material occurs during cooling of the melt and subsequent solidification to form a mesh consisting of foam fibers.

By using foam fibers it is possible to form a coating which covers a larger portion of the surface of the substrate board, thereby increasing its handling and mineral fiber retention capacity compared to a coating consisting of non-foamed fibers having the same basis weight.

Alternatively, the aforementioned increased hiding power can be utilized to form a coating with a lower basis weight and thus reduce material I consumption.

The gas to be mixed with the polymer melt may be nitrogen or carbon dioxide.

The invention will now be described in more detail with reference to the drawings, in which: Figure 1 is a perspective view of a preferred embodiment of the apparatus of the present invention.

Figure 2 is a sectional view of the bottom of the distribution container of the apparatus of Figure 1, and

Figure 3 is a perspective view of another preferred embodiment of the apparatus of the present invention.

Fig. 1 shows an apparatus 1 comprising an open container 2 for a thermoplastic polymeric matrix in solid form, for example in pellet form, a lower part of the container 2 in the form of a funnel 2, which lowers into a tube 4 for connecting the container 2 to the extruder 5 , wherein heating and melting of the polymeric material takes place and from which the polymer melt is extruded.

Extrusion of the polymer melt from the extruder 5 is accomplished by means of a rotary screw conveyor located inside the extruder 5 and rotated by a motor (not shown).

The polymer melt extruded from the extruder 5 is conveyed through a tube 6 and by means of a pump (not shown) to an elongated distribution vessel 7 which tapers downwardly and has a plurality of nozzles arranged in a row through which pressure is exerted by the pump.

The sidewalls of the dispensing container 7 are double walls for forming slot-like chambers outside the dispensing container. A slot 15 extending along a row of nozzles is formed at the lower end of both side wall chambers.

Through the tube 10, hot air is blown into these two sidewall chambers by means of a fan 8 driven by the engine 9 and further through two associated slots and thus near the nozzles where the air extends the poly-20 filaments extruded through the nozzles and breaks said strands to fibers and / or filaments.

The dispensing container 7 is disposed on a conveyor belt (not shown) transversely to the mineral fiber base 12 to be transported transverse to the direction of bottom propagation. The length of the distribution container 7 corresponds to the width of the mineral fiber board 12.

The fibers and / or filaments 11 from the delivery container are deposited on the surface of the mineral fiber base 12 to form a continuous web 13.

Below the mineral fiber base 12 is located a suction box 14 opposite the dispensing container 7 and between two conveyor belts (not shown), said suction box removing air blown through the slits of the side wall chambers.

30 The suction box 14 is connected to the suction pump (not shown) via a pipe 15.

Fig. 2 is a cross-sectional view of the bottom of the dispensing container 7 of the apparatus of Fig. 1. The dispensing container 7 comprises an inner chamber 20 for the polymer melt and two side chambers 21 for supplying air.

The inner chamber 20 tapers downwardly and at the outermost point 35 of the mouth portion 22 there is an opening 23 for dispensing the polymer melt.

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At the bottom of each side wall chamber 21, a slot 24 is formed at the outermost part of the barrier portion 22 through which air is blown out of the side wall chambers 21.

The air blown through the slits 24 is led to the tip of the inner chamber 20 where it comes into contact with the split polymer melt to extend and break the melt.

Figure 3 shows an apparatus 3 comprising a polymer melting chamber 31 for producing a polymer melt and this chamber 31 is connected via a tube 32 to an elongated molten delivery chamber 33 connected by a plurality of tubes 34 to a plurality of vertical injection nozzles spaced along the length of the delivery chamber 33 the channel formed as a nozzle.

The chamber 31 includes a melting chamber in which a thermoplastic solid, e.g. pellet-shaped, polymeric material fed therein is heated and thus melted by means of electric heating elements, from which the polymer melt thus obtained is pumped through tube 32 to distribution chamber 33 and then to pumps 34.

Further, the apparatus 30 comprises means (not shown) for supplying air to each of the pressure nozzles 35.

The air supplied to the pressure nozzles 35 is divided into a plurality of extension streams and a plurality of directional streams in each pressure nozzle 35.

The extension streams extend the polymer material distributed from the nozzle and optionally break it into individual fibers and / or filaments 36, whereby the directional streams primarily divide the fibers and / or filaments 36 obtained in ai-I. 25 in the longitudinal direction of the spray gun, and optionally also extend and break the polymer material.

The injection nozzles 35 comprise a plurality of channels for directing the elongation streams, said channels lowering near the nozzle channel and their shape giving the individual partial streams a direction such that most of the polymer fibers and / or filaments formed from the nozzle 30 are spaced so that the polymer material and a circular layer of circular solid support.

Further, the injection nozzles 35 comprise a plurality of channels for controlling the directional currents, said channels lowering both in the axial direction and in the radial direction from the mouth of the nozzle forming channel than the directional currents. The shape of the channels is such that it gives the sub-streams a direction such that most of the polymeric fibers and / or filaments 36 are distributed such that the polymeric material forms an elongated, substantially oval-shaped deposit on a horizontal solid support.

A row of pressure syringes 35 is positioned above the mineral fiber base 37 carried by the conveyor belt (not shown) transverse to the direction of web advancement. The injection nozzles 35 are spaced evenly and extend over the entire width of the mineral fiber nozzle 37.

The fibers and / or filaments 36 from the pressure syringes 35 are deposited on the upper surface of the mineral fiber web 37 so as to form a continuous web 38.

10 Below the mineral fiber plate 37, a suction box 39 is located opposite the line of injection nozzles 35 and between two conveyor belts (not shown), said suction box removing the blown air from the pressure nozzles 35.

The suction box is connected to the suction pump (not shown) via pipe 40.

The invention will now be described in more detail by the following examples.

Example 1 In a full-size test apparatus, a series of tests were performed in which the rock-fiber webs were coated with a thermoplastic polymer material using the method of the present invention.

Tests were performed using a melt blasting apparatus comprising a distribution chamber positioned above the fibrous web having a length greater than the width of the fibrous web and a suction box located below said webs and opposite the distribution chamber. The distance between the nozzles of the delivery chamber and the upper surface of the fibrous web was about 0.5 m.

: 25 The fibrous webs contained about 1.6% by weight of binder in the form of phenol-formaldehyde and had a specific weight of about 30 kg / m 3 and a thickness of about 100 mm. The surface temperature of the webs was about 20 ° C.

The starting material of the polymer was a granular polyester marketed under the name EMS G760.

The polyester was melted in an extruder and then the melt thus obtained was extruded through the nozzles of the delivery chamber and the extruded polymer filaments were extended by two gas streams and broken to form separate fibers deposited on the upper surface and side edges of the fibrous webs.

For the tests, a coating with a basis weight of 10 35 g / m2 and 15 g / m2 was formed. The coating had the appearance of a nonwoven material.

u 106368 The workability of the coated fibrous webs was fully consistent with the workability of the earlier mineral fiber elements, which were coated with polyester.

The average diameter of the polyester fibers applied was about 5 mm.

5 The calorific value of the coating having a basis weight of 10 g / m2 was 0.3 MJ / m2, while the calorific value of the coating having a basis weight of 15 g / m2 was 0.45 MJ / m2 It should be noted that polyester nonwoven fabric with a basis weight of 20 g / m 2 and a phenol-formaldehyde-resin adhesive layer having a calorific value of 1.0 MJ / m 2.

In addition, the air permeability of the fibrous web was determined and the results showed that no significant difference in air permeability was observed between said coated webs and the corresponding uncoated webs.

In addition, the tests produced a mineral fiber web having a coating of 15 g / m 2 on both sides.

The tensile strength of this web was determined and as a result it was found that the tensile strength was 25% higher than that of the corresponding uncoated fibrous web.

Example 2 In a full-size test apparatus, a series of tests were performed in which stone-20 fibrous webs were coated with a thermoplastic polymeric material using the method of this invention.

The original test kits were performed using a melt blasting apparatus with pressure nozzles placed in a row above the rock fiber web and 10 cm apart, and each individual pressure nozzle applied a 10 to 15 cm wide layer. The distance between the nozzle mouths of the injection nozzles and the upper surface of the fibrous web was about 0.3 to 0.5 m.

Air at a pressure of 0.4-0.5 MPa (4-5 bar) and a temperature of 210-230 ° C was used as the extension and directional gas.

The fibrous webs contained about 1.6% by weight of binder in the form of phenol-formal-30 dehyde and had a specific weight of about 30 kg / m 3 and a thickness of about 100 mm. The surface temperature of the webs during coating was about 20 ° C.

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The polymeric material used was polyester marketed under the name Dynapol S 390 HQIs.

The polyester was melted in a melting vessel at a temperature of about 220 ° C and then the melt thus obtained was extruded through the nozzles of the injection jets and the extruded polymer filaments were lengthened by a plurality of air streams and broken to form discrete fibers. All Tainai surfaces were coated.

In the tests, a coating having a basis weight of 15 g / m 2 was formed and the adhesion between the fibrous material and the coating was satisfactory, since the tear test showed that the fibrous material spreads into separate layers before the coating wore off the fibrous material. The average diameter of the polyester fibers applied was about 40 mm. The coating was tactile.

The second test run was performed using a molten injection apparatus which included devices for mixing the gas into the polymer melt. The other hardware features were identical to the hardware features used in the original test series, as were the other test conditions identical to those of the original test series.

In this series of tests, a synthetic hot melt marketed as Henkel Q2279 was used as polymer material.

The polymer was melted in a melting vessel at a temperature of about 160 ° C, and then the foaming gas, nitrogen, was mixed with the molten and the molten-gas mixture was then extruded from the injection nozzles.

The extruded melt / gas mixture was extended by numerous air streams and broken to form discrete fibers which were deposited on the surface of the rock fiber webs. All Tainai surfaces were coated.

The tests provided a coating having a basis weight of 15 g / m 2 and satisfactory adhesion between the fibrous material and the coating because tear tests showed that the fibrous material breaks into separate layers before the coating wore off the fibrous material.

; The average diameter of the polymer fibers applied is about 80 mm, and the formed mesh covers a greater portion of the surface of the fibrous material than the mesh formed in the original test series, but the mesh consisting of the foamed fibers was still air permeable.

The coating formed in the second set of tests was better to the touch and the fiber retention capacity was better compared to the original set of tests; p '·

Claims (10)

A process for producing a mineral fiber element comprising a mineral fiber base layer (12; 37) having a surface coating in the form of a fiber network 5 (13; 38) formed from a thermoplastic polymeric material, such a surface coating being provided on at least a portion of of the base layer surface, characterized in that the surface coating is formed directly on the surface of the base layer and that the surface coating is formed by heating a thermoplastic polymer material to melt it and propagate the obtained polymer melt in the form of fibers and / or filaments (11; 36). on the surface of the base layer and cooling it to form a solid layer. Method according to claim 1, characterized in that the surface coating has a basis weight of 2 - 50g / m2, preferably 5-20g / m2 and most preferably ΙΟΙ 5 g / m2. 15 Method according to claim 1 or 2, characterized in that the base layer is in the form of an endless web, a web, a mat or a disc. Apparatus (1; 30) for applying the method according to any of claims 1-3, characterized in that it comprises one or more units, each unit comprising means (5; 31) for melting a thermoplastic polymer material. a number of nozzles, means (23; 35) for extruding the obtained polymer melt through the nozzles and propagating the extruded polymer material onto the surface of a mineral fiber base layer (12; 37), and means (24) for conducting one or more high pressure gas streams close past the nozzles for stretching the extruded polymeric material to form thin filaments (11; 36) and / or fibers. Apparatus (1; 30) according to claim 4, characterized in that it comprises means for supporting and selectively transporting the base layer. Apparatus according to claim 4 or 5, characterized in that it comprises a suction device (14,15; 39, 40). Apparatus (1) according to any of claims 4-6, characterized in that it comprises an oval dispensing chamber (20) which, via a pump, is in liquid communication with the melting agents (5) and which at its outer end comprises a number of tightly adjacent adjacent nozzles (23), two chambers (21) which lie along both side walls of the dispensing chamber (20) and at whose outer ends a longitudinal gap (24) is formed, and means for passing a high pressure gas stream through the side wall chambers and out through the slits. • · 1β 106368 Apparatus (30) according to any of claims 4-6, characterized in that it optionally comprises means for admixing a gas into the polymer melt and comprising a plurality of syringes (35), each comprising a nozzle and which via a nozzle. pumps are in fluid communication with the melting agents 5 (31), and means for conducting one or more high pressure gas streams past each orifice of the syringes (35). Apparatus (30) according to claim 8, characterized in that one or more units together comprise a number of syringes (35) which can be placed and / or moved in such a way that the polymeric material (36) emanating from the syringes can distributed over the entire surface of the base layer (37). Apparatus (1) according to claim 7, wherein the apparatus comprises a suction device (14, 15), characterized in that it comprises a dispensing chamber (20) of a length exceeding the dimension of the base layer (12) in the direction parallel to the said chamber. »» I