Method for evaluating the substrate, forming the fiber layer, and covering structure in granular fiber spraying.

Abstract

To provide a technique in which a formed fiber layer is hardly peeled off even when a cement slurry with a high water-cement ratio, a polymer emulsion or a slurry obtained by mixing an alkali silicate, inorganic powder and water is used as an aggregation material and is sprayed on a surface of a substrate together with a granular fiber to form the fiber layer in a predetermined thickness.MEANS: A technique includes: a step A of spraying a granular fiber together with an aggregation material onto a substrate to form a fiber layer having a predetermined thickness, attaching the granular fiber to a substrate under same conditions as those of a first substrate on which it is confirmed that the formed fiber layer does not fall off, using the aggregation material or liquid containing a main component of the aggregation material, and measuring adhesive force (P1) between the granular fiber and the substrate under the same conditions; a step B of sticking the granular fiber to a second substrate with the aggregation material or the liquid of the main component of the aggregation material and measuring adhesion force (P2) between the granular fiber and the second substrate at that time; and a step C of confirming that the P2 is equal to or larger than the P1.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a spraying technique for granular fibers. In particular, it relates to a granular fiber spraying technique in which a fiber layer formed by spraying granular fibers together with an aggregating material onto a base hardly drops from after spraying until the aggregating material contained in the fiber layer dries or cures.

Background Art

[0002] For the purpose of imparting fire resistance, fireproofing, sound absorption, and / or heat insulation, etc., it has been proposed to provide a fiber layer such as rock wool on a base such as the surface of a structure. In general, a spraying method using a granular fiber and an aggregating material mainly composed of water is used to form the fiber layer. This aggregating material often contains an inorganic binder such as cement or alkali silicate in addition to water, or an organic binder composed of a polymer such as a vinyl acetate resin, an acrylic resin, or a synthetic rubber.

[0003] Rock wool spraying methods using granular rock wool, a typical granular fiber, include dry methods, wet methods, and semi-dry methods. In the dry method, a dry mixture of granular rock wool and cement is discharged from a nozzle, and at the same time, pressurized water is sprayed from multiple nozzles (injection ports) located around or inside the nozzle, or from a nozzle (injection port) located near the center of the nozzle outlet, to mix and spray the two. In the wet method, a sprayable coating material is used, which is made by mixing granular rock wool and cement with a surfactant and a thickener, and a paste made by adding water to this material is sprayed from a nozzle using compressed air. The semi-dry method is a construction method in which granular rock wool and cement are not mixed beforehand. Instead, a cement slurry, which is a mixture of water and cement, is sprayed onto the granular rock wool discharged from the nozzle, either from the periphery of the nozzle or near the center of the nozzle outlet. This mixture combines the rock wool and cement paste to form a fibrous layer (fire-resistant coating layer). For example, granular rock wool is defibrated and crushed in a defibration machine, quantitatively fed out by a rotary valve, pressurized through a hose by an air blower, and supplied to the spray nozzle. Cement is mixed with water in a slurry tank mixer to form a cement slurry, which is then supplied to the spray nozzle through a conveyor pipe by a slurry pump. The cement slurry is sprayed either from an outlet located on the periphery of the spray nozzle or from the center of the nozzle, and combined with the granular rock wool to form a fibrous layer (fire-resistant coating layer) on the surface of the substrate, such as steel or concrete.

[0004] Instead of cement slurry, a polymer emulsion mainly composed of an organic binder made of polymers and water, or an inorganic binder consisting of a slurry mixed with alkali silicate, inorganic powder, and water, is sprayed from the nozzle of a spraying nozzle to form a fibrous layer on the surface of substrates such as steel or concrete.

[0005] Incidentally, the fibrous layer consisting of binder and rock wool, formed by spraying onto the surface of structural members (substrates) using the rock wool spraying method, can sometimes fall off. When a portion of the rock wool layer (fibrous layer) falls off in layers, the fallen fibers must be disposed of as waste, and the missing rock wool layer (fibrous layer) must be re-formed by spraying, which increases the number of work steps and raises costs.

[0006] When using a cement slurry with a higher water-cement ratio than that used in fireproofing, or when using a polymer emulsion or a slurry mixed with alkali silicate, inorganic powder, and water instead of cement slurry, the fiber layer is more likely to fall off compared to the case of a fiber layer formed for fireproofing (fireproofing layer). This is thought to be because the viscosity of the flocculant used is lower than that of the cement slurry used in fireproofing, or because the time it takes for the flocculant to lose its fluidity due to chemical reactions or evaporation of the contained water is longer.

[0007] To reduce the amount of rock wool that falls after being sprayed, the idea arose to use rock wool with a high entanglement force (binding force) between the rock wool fibers when implementing the spraying method. Techniques for measuring the entanglement force (binding force) between rock wool fibers to evaluate the quality of the rock wool, and rock wool spraying techniques that reduce the amount of falling rock wool (fallen fibers) have been proposed (for example, Patent Documents 1 and 2). [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2014-102178 [Patent Document 2] Japanese Patent Publication No. 2014-101705 [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] The present invention aims to provide a technology that minimizes the peeling of the formed fiber layer, even when using a cement slurry with a higher water-cement ratio than that used in fire-resistant coatings, a polymer emulsion, or a slurry mixed with alkali silicate, inorganic powder, and water as a flocculant, and spraying it onto the surface of a substrate together with granular fibers to form a fiber layer of a predetermined thickness.

[0010] The present invention aims to provide a method for evaluating a substrate in which the formed fiber layer is less likely to peel off, even when a cement slurry with a higher water-cement ratio than the cement slurry used in fireproofing, a polymer emulsion, or a slurry mixed with alkali silicate, inorganic powder, and water is used as a flocculant and sprayed together with granular fibers onto the surface of a substrate such as steel or concrete to form a fiber layer of a predetermined thickness.

[0011] Furthermore, the present invention aims to provide a method for forming a fiber layer in which the formed fiber layer is less likely to peel off, even when using a cement slurry with a higher water-cement ratio than that used in fireproofing, a polymer emulsion, or a slurry mixed with alkali silicate, inorganic powder, and water as a flocculant, and spraying it together with granular fibers onto the surface of a substrate such as steel or concrete to form a fiber layer of a predetermined thickness.

[0012] Furthermore, the present invention aims to provide a coating structure in which the formed fiber layer is less likely to peel off, even when a cement slurry with a higher water-cement ratio than the cement slurry used in fire-resistant coatings, a polymer emulsion, or a slurry mixed with alkali silicate, inorganic powder, and water is used as a flocculant and sprayed together with granular fibers onto the surface of a substrate such as steel or concrete to form a fiber layer of a predetermined thickness. [Means for solving the problem]

[0013] The inventors of the present invention discovered that by pre-evaluating the substrate on which the fiber layer is formed by the spraying method, even when using a cement slurry with a higher water-cement ratio than the cement slurry used in fireproofing, a polymer emulsion, or a slurry mixed with alkali silicate, inorganic powder, and water as a flocculant, and forming a sprayed fiber layer of a predetermined thickness on the surface of the substrate together with granular fibers, the formed fiber layer is less likely to peel off, and thus completed the present invention. That is, the present invention, which solves the above problems, is a method for evaluating the substrate in granular fiber spraying, as shown in (1) or (2) below, a method for forming a fiber layer, as shown in (3), and a coating structure, as shown in (4). (1) A step (A) in which granular fibers are sprayed onto a substrate together with an agglutinant to form a fiber layer of a predetermined thickness, and it is confirmed that the formed fiber layer does not peel off, and granular fibers are attached to a substrate under the same conditions as the first substrate using the agglutinant or a liquid (solvent or dispersion medium) of the main component of the agglutinant, and the adhesion force (P1) between the granular fibers and the substrate under the same conditions as the first substrate is measured, The process comprises: attaching granular fibers to a second substrate using the above-mentioned flocculant or a liquid (solvent or dispersion medium) of the main component of the above-mentioned flocculant, and measuring the adhesion force (P2) between the granular fibers and the second substrate at that time (Step B), Furthermore, a method for evaluating a substrate in granular fiber spraying, comprising a step (C) to confirm that the adhesion force (P2) between the granular fibers and the second substrate is equal to or greater than the adhesion force (P1) with a substrate under the same conditions as the first substrate. (2) The method for evaluating a substrate in granular fiber spraying according to (1), characterized in that the adhesion force in step A and / or step B is measured by placing granular fibers on the underside of the substrate, adding the flocculant or a liquid containing the main component of the flocculant to the granular fibers until the granular fibers fall, and determining the adhesion force from the weight of the granular fibers at the time they fall. (3) A method for forming a fiber layer, characterized in that, based on the substrate evaluation method for granular fiber spraying described in (1) or (2) above, the adhesion force (P2) between the granular fibers and the second substrate is confirmed to be equal to or greater than the adhesion force (P1) with a substrate under the same conditions as the first substrate, and the granular fibers are sprayed together with a flocculant to form a fiber layer of a predetermined thickness on the second substrate under the same conditions as the first substrate. (4) A covering structure characterized in that a fiber layer is formed on the substrate surface by the method of forming the fiber layer described in (3) above. [Effects of the Invention]

[0014] According to the present invention, even when using a cement slurry with a higher water-cement ratio than the cement slurry used in fireproofing, a polymer emulsion, or a slurry mixed with alkali silicate, inorganic powder, and water as a flocculant, and spraying it onto the surface of a substrate together with granular fibers to form a fiber layer of a predetermined thickness, a technique is obtained in which the formed fiber layer is less likely to peel off.

[0015] According to the present invention, even when a cement slurry with a higher water-cement ratio than the cement slurry used in fireproofing, or a slurry mixed with alkali silicate, inorganic powder, and water is used as a flocculant and sprayed onto the surface of the substrate together with granular fibers to form a fiber layer of a predetermined thickness, a substrate evaluation method is obtained in which the formed fiber layer is less likely to peel off.

[0016] Furthermore, according to the present invention, even when using a cement slurry with a higher water-cement ratio than the cement slurry used in fireproofing, a polymer emulsion, or a slurry mixed with alkali silicate, inorganic powder, and water as a flocculant, and spraying it onto the surface of a substrate together with granular fibers to form a fiber layer of a predetermined thickness, a method for forming a fiber layer is obtained in which the formed fiber layer is less likely to peel off.

[0017] Furthermore, according to the present invention, even when a cement slurry with a higher water-cement ratio than the cement slurry used in fireproofing, a polymer emulsion, or a slurry mixed with alkali silicate, inorganic powder, and water is used as a flocculant and sprayed onto the surface of the substrate together with granular fibers to form a fiber layer of a predetermined thickness, a coating structure can be obtained in which the formed fiber layer is less likely to peel off.

[0018] According to the present invention, since the fiber layer formed by spraying on the base surface is difficult to fall off, the amount of the fiber layer that must be disposed of as waste is reduced. For this reason, it is less likely to form the portion of the fallen fiber layer again by spraying construction, and the labor for re-construction, cleaning, etc. can also be reduced, so the workload can be reduced and the cost for obtaining the coating structure in which the fiber layer is formed on the base surface can be suppressed.

Embodiments for Carrying Out the Invention

[0019] The method for evaluating the base in the granular fiber spraying of the present invention is as follows: on a base under the same conditions as the first base where it is confirmed that the fiber layer formed by spraying granular fibers together with an aggregating material on the base with a predetermined thickness does not peel off, granular fibers are attached with the above-mentioned aggregating material or a liquid (solvent or dispersion medium) of the main component of the above-mentioned aggregating material, and the adhesion force (P1) between the granular fibers at that time and the base under the same conditions as the first base is measured (step A); The method further includes a step (step B) of attaching granular fibers to a second base with the above-mentioned aggregating material or a liquid (solvent or dispersion medium) of the main component of the above-mentioned aggregating material, and measuring the adhesion force (P2) between the granular fibers at that time and the second base. Furthermore, it is characterized by including a step (step C) of confirming that the adhesion force (P2) between the granular fibers and the second base is not less than the adhesion force (P1) between the granular fibers and the base under the same conditions as the first base.

[0020] In the present invention, the granular fibers can be used without particular limitation as long as the fibers are aggregated and granular. Examples of the material include rock wool containing slag wool, glass wool, ceramic wool, cellulose fiber, synthetic fibers such as nylon fiber and polypropylene fiber, etc. Since the density of the fiber is large, inorganic fibers are preferable, and rock wool such as rock wool granular cotton is particularly preferable.

[0021] In the present invention, suitable examples of flocculants include water, aqueous solutions, inorganic slurries, polymer emulsions, and inorganic-containing polymer emulsions (polymer-containing inorganic slurries). More preferred examples include aqueous solutions, cement slurries, slurries mixed with alkali silicate, inorganic powder, and water, polymer emulsions, and cement-containing polymer emulsions (polymer-containing cement slurries), due to their high adhesion between granular fibers and between granular fibers and the substrate. Preferred aqueous solutions include aqueous solutions of thickeners and aqueous solutions of alkali silicate, where the viscosity of the aqueous solution increases as the solvent water evaporates, and solutions that solidify or harden upon evaporation of water or reaction with granular fibers. In addition, preferred examples of inorganic powders included in slurries mixed with alkali silicate, inorganic powder, and water include inorganic powders with latent hydraulic properties, such as blast furnace slag powder, and inorganic powders that react with alkali silicate and / or granular fibers, such as pozzolanes like silica fume and fly ash.

[0022] Furthermore, the polymer contained in the polymer emulsion or cement-containing polymer emulsion can be any polymer used as a binder for polymer cement mortar or polymer cement concrete. For example, synthetic rubbers such as styrene-butadiene copolymer, chloroprene rubber, acrylonitrile-butadiene copolymer or methyl methacrylate-butadiene copolymer, natural rubber, polyolefins such as polyethylene and polypropylene, polychloropyrene, polyacrylic acid esters, styrene-acrylic copolymer, all-acrylic copolymer, polyvinyl acetate, vinyl acetate-acrylic copolymer, vinyl acetate-acrylic acid ester copolymer, modified vinyl acetate, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-vinyl chloride copolymer, vinyl acetate vinyl versatate copolymer, acrylic-vinyl acetate-Beova (trade name for vinyl t-decanoate) copolymer, and other vinyl acetate resins, unsaturated polyester resins, polyurethane resins, alkyd resins and epoxy resins, asphalt, rubber asphalt and paraffin, and other bituminous materials are preferred examples, and one or more of these can be used.

[0023] For the reason of good adhesion to the substrate, it is preferable to use one or more polymers selected from the following as polymer emulsions or cement-containing polymer emulsions: vinyl acetate resins such as polyvinyl acetate, vinyl acetate / acrylic copolymer, vinyl acetate / acrylic acid ester copolymer, modified vinyl acetate, ethylene / vinyl acetate copolymer, ethylene / vinyl acetate / vinyl chloride copolymer, vinyl acetate / vinyl versatate copolymer, and acrylic / vinyl acetate / Beova (trade name for vinyl t-decanoate) copolymer; acrylic resins such as polyacrylic acid ester, polymethacrylic acid ester, acrylic acid ester / styrene copolymer, styrene / acrylic copolymer, and all-acrylic copolymer; polyolefin resins such as polyethylene and polypropylene; and synthetic rubbers such as styrene / butadiene copolymer, chloroprene rubber, acrylonitrile / butadiene copolymer, or methyl methacrylate / butadiene copolymer.

[0024] In step A, granular fibers are sprayed onto a substrate together with an agglutinant to form a fiber layer of a predetermined thickness, and it is confirmed that the formed fiber layer does not peel off. As a method for attaching granular fibers to a substrate under the same conditions as the first substrate (hereinafter sometimes referred to as "substrate under the same conditions") using the above-mentioned agglutinant or a liquid (solvent or dispersion medium) of the main component of the above-mentioned agglutinant, suitable examples include a method of applying the agglutinant or a liquid (hereinafter sometimes referred to as "agglutinant, etc.") to the substrate under the same conditions and then attaching the granular fibers, a method of applying or attaching the agglutinant, etc. to the substrate under the same conditions and then attaching the granular fibers applied or attached to the agglutinant, etc. to the substrate under the same conditions.

[0025] In step A, preferred methods for measuring the adhesion force (P1) between granular fibers attached to a substrate under the same conditions and the substrate under the same conditions include, for example, a method using a universal testing machine, a tensile testing machine, a push-pull gauge (force gauge), a load cell combined with a data converter such as a data logger, a hanging scale, etc. (hereinafter sometimes referred to as "the method of measuring with a universal testing machine, etc."), and a method in which the granular fibers are placed on the underside of the substrate, and the above-mentioned flocculant or the liquid of the main component of the above-mentioned flocculant is added to the granular fibers until the granular fibers fall, and the P1 is determined from the weight of the granular fibers at the time of falling (hereinafter sometimes referred to as "the method of determining from the weight of granular fibers at the time of falling").

[0026] When using a method involving a universal testing machine, a plate or block is attached to the surface of granular fibers that have been attached to a substrate under identical conditions using adhesive. The plate or block is then pulled using a universal testing machine, and the stress at the point when the granular fibers detach from the substrate under identical conditions is measured. This stress is then divided by the contact area between the granular fibers and the substrate under identical conditions. This value is defined as the adhesion force (P1) between the granular fibers attached to the substrate under identical conditions and the substrate under identical conditions.

[0027] In the method of determining the adhesive force from the weight of granular fibers upon fall, the weight of the granular fibers at the time of fall is measured, and this weight is divided by the contact area between the granular fibers and the substrate under identical conditions. This value is taken as the adhesive force (P1) between the granular fibers attached to the substrate under identical conditions and the substrate under identical conditions. The flocculant used when attaching the granular fibers to the substrate under identical conditions may be different from the flocculant added until the granular fibers fall, but it is preferable that they be the same.

[0028] In step A, the method for measuring the adhesion force (P1) between granular fibers attached to a substrate under identical conditions and the substrate under identical conditions is more preferable because it is easier to measure, and is determined from the weight of the granular fibers when dropped.

[0029] In step B, the method for measuring the adhesion force (P2) between the granular fibers attached to the second substrate and the second substrate is preferably a method that can be selected from the method for measuring the adhesion force (P1) between the granular fibers attached to the substrate under the same conditions and the substrate under the same conditions in step A, and it is preferable to use the same method as when measuring P1.

[0030] In step A and / or step B described above, it is preferable to measure the adhesion force by placing the granular fibers on the underside of the substrate, adding the flocculant or the liquid main component of the flocculant to the granular fibers until the granular fibers fall, and determining the adhesion force from the weight of the granular fibers at the time of falling. Determining the adhesion force from the weight of the granular fibers at the time of falling means measuring the weight of the granular fibers at the time of falling as described above, and determining the adhesion force from the contact area between the granular fibers and the substrate. That is, the adhesion force (P1 or P2) is the value obtained by dividing the weight of the granular fibers at the time of falling by the contact area with the substrate.

[0031] In step C, it is confirmed that the adhesion force (P2) between the granular fibers and the second substrate is greater than or equal to the adhesion force (P1) with the first substrate under the same conditions. Based on this, if the flocculant is a flocculant, the granular fibers are sprayed onto the second substrate together with the same flocculant, or if the flocculant is a liquid whose main component is the same liquid as the flocculant, the granular fibers are sprayed onto the second substrate together with the same flocculant, forming a fiber layer of a predetermined thickness, and the formed fiber layer is evaluated as being difficult to peel off. In step C, when determining the adhesion force (P1) between the granular fibers and the substrate under the same conditions as in step A, and the adhesion force (P2) between the granular fibers and the second substrate in step B, if the contact area between each substrate and the granular fibers is the same, the adhesion force (P1) between the granular fibers and the substrate under the same conditions in step A, and the adhesion force (P2) between the granular fibers and the second substrate in step B can be considered by substituting the weight of the granular fibers at the time of dropping in step A (W1) and the weight of the granular fibers at the time of dropping in step B (W2), respectively. That is, it is confirmed that the weight of the granular fibers at the time of dropping in step B (W2) is equal to or greater than the weight of the granular fibers at the time of dropping in step A (W1).

[0032] The present invention provides a method for forming a fiber layer, characterized by forming a fiber layer of predetermined thickness by spraying granular fibers together with an agglutinant onto a second substrate under the same conditions as the first substrate, after confirming that the adhesion force (P2) between the granular fibers and the second substrate is equal to or greater than the adhesion force (P1) with the first substrate under the same conditions, based on the substrate evaluation method for granular fiber spraying described above. This method forms a fiber layer of predetermined thickness by spraying granular fibers together with an agglutinant onto the second substrate, and the formed fiber layer is less likely to peel off.

[0033] The coating structure of the present invention is characterized in that a fiber layer is formed on the substrate surface by the above-described method for forming the fiber layer. [Examples]

[0034] The present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way to these examples.

[0035] [Example 1] [Spray test] Using a spraying system for a semi-dry rock wool spraying method used for fireproofing, a rock wool layer (fiber layer) consisting of granular rock wool and a flocculant made of a slurry of alkali silicate, inorganic powder, and water was sprayed to a thickness of 80 mm onto the following substrate. The rock wool layer formed by spraying was left to stand on the underside of a galvanized steel sheet, and the presence or absence of shedding (peeling) of the rock wool layer was checked. The results are shown in Table 1. The materials used were granular rock wool (EM non-combustible insulation material Neo granular cotton manufactured by Taiheiyo Material Co., Ltd.) and an inorganic slurry (solid content 15.5% by mass) consisting of sodium silicate, blast furnace slag powder, and water as the flocculant. <Primer> Substrate 1: Galvanized steel sheet (900 x 450 mm) Primer 2: Apply acrylic copolymer emulsion as a primer at a rate of 60 g / m². 2 Galvanized steel sheet (900 x 450 mm) coated and dried. Primer 3: Epoxy-modified acrylic resin emulsion applied as a primer at a rate of 120 g / m². 2Galvanized steel sheet (900 x 450 mm) coated and dried.

[0036] [Table 1]

[0037] The spray test results showed that the rock wool layers formed on substrates 1 and 2 did not fall off, but the rock wool layer formed on substrate 3 fell off on the same day it was sprayed.

[0038] [Measurement of adhesion strength to the substrate] A rock wool mat (50 x 50 x 10 mm) was prepared by packing 2 g of granular rock wool into a mold. 1.0 g of water was sprayed onto the same substrate used in the spray test, covering an area large enough to accommodate the rock wool mat, and the prepared rock wool mat was placed and attached. The steel plate was inverted so that the rock wool mat was on the underside of the plate, and the plate was left to stand. Next, water was sprayed onto the rock wool mat from below using a spray bottle. The mass of water sprayed until the mat could no longer withstand its weight and fell was determined, and the adhesive force (P) between the water-bonded rock wool mat and the substrate was calculated from the weight of the mat at the time of fall. The results are shown in Table 2.

[0039] [Table 2]

[0040] Similarly, the adhesion force (P) between the substrate and the rock wool mat was determined using the substrates shown below. The results are shown in Table 3. <Primer> Substrate 4: Calcium silicate board (900 x 450 mm) Primer 5: Apply acrylic copolymer emulsion as a primer at a rate of 120 g / m². 2 Calcium silicate board (900 x 450 mm) coated and dried. Primer 6: Epoxy-modified acrylic resin emulsion applied as a primer at a rate of 120 g / m². 2Calcium silicate board (900 x 450 mm) coated and dried. Substrate 7: Black steel plate (900 x 450 mm) Primer 8: Epoxy-modified acrylic resin emulsion applied as a primer at a rate of 120 g / m². 2 ) Black steel plate (900 x 450 mm) coated and dried.

[0041] [Table 3]

[0042] When a rock wool layer was sprayed onto substrate 1 to a thickness of 80 mm, the formed rock wool layer did not fall off. Therefore, substrate 1 with the 80 mm thickness sprayed onto it is the first substrate. In addition, in measuring the adhesion force to the substrate, a rock wool mat was attached to substrate 1 with water, and the adhesion force (P) between the water-attached rock wool mat and the substrate was calculated from the weight of the mat when it fell. The result was 0.752 gf / cm². 2 ) represents the adhesion strength (P1) between the granular fibers (rock wool mat) and the substrate under identical conditions. Furthermore, substrate 1, which was used when measuring the adhesion strength to the substrate, is the "substrate under identical conditions" (a substrate under the same conditions as the first substrate).

[0043] Substrates 2 to 8, which were used when measuring the adhesion force to the substrate, are the "second substrates," and the adhesion force (P) between the substrate and the rock wool mat attached with water, which was determined in the measurement of the adhesion force between the granular fibers (rock wool mat) and this second substrate, is the adhesion force (P2) between the granular fibers (rock wool mat) and the second substrate. When a rock wool layer (fiber layer) is formed to a predetermined thickness (thickness 80 mm) by spraying granular fibers together with an agglomerate onto a second substrate (substrate 2, and substrates 4 to 7) that has the same conditions as the second substrate (substrate 2, and substrates 4 to 7) where this adhesion force (P2) between the granular fibers and the second substrate is greater than or equal to the adhesion force (P1) with the substrate under the same conditions as the granular fibers (rock wool mat), it can be seen that the formed rock wool layer is less likely to fall off during the drying or hardening period. [Industrial applicability]

[0044] The present invention can be suitably used, for example, in construction work to form a fibrous layer on the surface of a structure that has fire resistance, fire prevention, sound absorption, and / or heat insulation properties, i.e., in fireproofing work, fire prevention work, soundproofing work, heat insulation work, etc. Furthermore, since the effect of the present invention, in which the formed fibrous layer is less likely to peel off, can be obtained even when using a cement slurry with the same or lower water-cement ratio as the cement slurry normally used in rock wool spraying methods for fireproofing, the present invention can also be suitably used in fireproofing work using rock wool spraying methods with cement slurry.

Claims

1. Step A: A step in which granular fibers are sprayed onto a substrate together with an agglutinant to form a fiber layer of a predetermined thickness, and it is confirmed that the formed fiber layer does not peel off, and then granular fibers are attached to a substrate under the same conditions as the first substrate using the agglutinant or a liquid (solvent or dispersion medium) of the main component of the agglutinant, and the adhesion force (P1) between the granular fibers and the substrate under the same conditions as the first substrate is measured. The process comprises: 1) attaching granular fibers to a second substrate using the above-mentioned flocculant or a liquid (solvent or dispersion medium) of the main component of the above-mentioned flocculant; and 2) measuring the adhesion force (P2) between the granular fibers and the second substrate at that time using the same method as when measuring the adhesion force (P1) between granular fibers attached to a substrate under the same conditions in step A and the substrate under the same conditions; Furthermore, a method for evaluating a substrate in granular fiber spraying, comprising a step (C) to confirm that the adhesion force (P2) between the granular fibers and the second substrate is equal to or greater than the adhesion force (P1) with a substrate under the same conditions as the first substrate.

2. The method for evaluating a substrate in granular fiber spraying according to claim 1, characterized in that the adhesion force in steps A and B described above is measured by placing granular fibers on the underside of the substrate, adding the flocculant or a liquid containing the main component of the flocculant to the granular fibers until the granular fibers fall, and determining the adhesion force from the weight of the granular fibers at the time they fall.

3. A method for forming a fiber layer, characterized in that, using the substrate evaluation method for granular fiber spraying according to claim 1 or 2, the adhesion force (P2) between the granular fibers and the second substrate is confirmed to be equal to or greater than the adhesion force (P1) with a substrate under the same conditions as the first substrate, and the granular fibers are sprayed together with an agglomerate to form a fiber layer of a predetermined thickness on the second substrate under the same conditions as the first substrate.

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