Dimension-mismatched rock wool fibril and phenolic resin composite artificial board and preparation method thereof

Abstract

The invention discloses a size-mismatched rock wool fibril and phenolic resin composite artificial board and a preparation method thereof.The size-mismatched rock wool fibril and phenolic resin composite artificial board is prepared from, by weight, 82-93% of rock wool fibril and 18-7% of phenolic resin; the silane coupling agent accounts for 2-4wt% of the total amount of the rock wool fibril, and the water repellent accounts for 3-5wt% of the total amount of the rock wool fibril; the rock wool fibril is mainly composed of 2.5-3.5 cm rock wool long fibers, 1.5-2.5 cm rock wool medium long fibers and 0.6-1.5 cm rock wool short fibers, the 2.5-3.5 cm rock wool long fibers account for 20-30% of the total amount of the fibers, the 1.5-2.5 cm rock wool medium long fibers account for 20-30% of the total amount of the fibers, and the 0.6-1.5 cm rock wool short fibers account for 40-60% of the total amount of the fibers. The prepared rock wool fibril and phenolic resin composite artificial board has high strength, high toughness and low water absorption rate of an artificial board and has A-level non-combustible performance of an inorganic board by controlling and adjusting the length and the ratio of the rock wool fibril and using auxiliaries such as the silane coupling agent.

Description

Technical Field

[0001] The invention relates to the technical field of artificial board manufacturing, and in particular to an artificial board composited with rock wool fibers and phenolic resin having mismatched sizes and a preparation method thereof. Background Art

[0002] Artificial boards usually refer to various types of boards that are based on wood (wood fiber) and are hot-pressed with organic binders. Artificial boards include particleboard, density board, blockboard (core board), plywood, etc., which are widely used in home furnishings (furniture, wooden doors, floors), building wall panels, partitions and laminate floors. The prominent problem of artificial boards is their poor flame retardant properties, which can cause indoor fires. In the Notice of the State Administration for Market Regulation on Issuing the "National Key Industrial Product Quality and Safety Supervision Catalogue (2024 Edition)" (State Administration for Market Regulation Quality Supervision

[2023] No. 5), artificial boards for furniture and building decoration materials are included in the national key industrial product quality and safety supervision catalogue.

[0003] In order to avoid the risk of combustion of artificial boards, fiber-reinforced inorganic boards (inorganic boards) have been developed on the market, the main types of which are cement fiber boards, calcium silicate boards, etc. Inorganic boards can achieve Class A non-combustibility, but they are relatively brittle, have high water absorption, and have insufficient freeze-thaw resistance. Their main application areas are partition boards and decorative boards in indoor dry environments. Summary of the invention

[0004] In view of the deficiencies in the existing artificial board and inorganic board technologies, the present invention provides a size-mismatched rock wool fiber and phenolic resin composite artificial board and a preparation method thereof. The composite artificial board is an organic-inorganic composite board.

[0005] The invention discloses a size-mismatched rock wool fiber and phenolic resin composite artificial board, comprising: rock wool fiber, phenolic resin, silane coupling agent and water repellent;

[0006] In terms of weight percentage, the rock wool fibers are 82-93 wt%, the solid content of the phenolic resin is 18-7 wt%; the silane coupling agent accounts for 2-4 wt% of the total amount of the rock wool fibers, and the water repellent accounts for 3-5 wt% of the total amount of the rock wool fibers;

[0007] The rock wool raw fibers are mainly composed of 2.5-3.5 cm rock wool long fibers, 1.5-2.5 cm rock wool medium-long fibers and 0.6-1.5 cm rock wool short fibers, 2-3 cm rock wool long fibers account for 20-30% of the total fiber amount, 1.5-2.5 cm rock wool medium-long fibers account for 20-30% of the total fiber amount, 0.6-1.5 cm rock wool short fibers account for 40-60% of the total fiber amount, and rock wool short fibers below 0.6 cm and rock wool long fibers greater than 3.5 cm account for no more than 15% of the total fiber amount.

[0008] Among them, long rock wool fibers (2.5-3.5 cm) mainly play a reinforcing role in composite materials and improve the tensile strength of materials; however, the long fibers have poor dispersibility and are easily entangled during the mixing process, resulting in uneven distribution and affecting the performance consistency of artificial boards. Medium and long rock wool fibers (1.5-2.5 cm) are of moderate length and can provide a certain reinforcing effect. They have good dispersibility and play a balancing role between long rock wool fibers and short rock wool fibers; however, compared with long rock wool fibers, medium and long rock wool fibers have weaker mechanical property enhancement effects. Short rock wool fibers (0.6-1.5 cm) have good dispersibility and are easy to mix evenly. They can effectively fill the gaps in the material and improve the static bending strength and screw holding force of artificial boards; however, the density of artificial boards made with single short rock wool fibers is too high, which does not meet the actual requirements of lightweight and high-strength artificial boards. In addition, there are problems such as excessive brittleness and poor plastic toughness. By reasonably adjusting the ratio of long, medium and short fibers in rock wool fibers, the density, static bending strength, elastic modulus, screw holding force, brittle toughness and water resistance of the artificial board can be taken into account, the dispersion of the fibers can be improved, the advantages of fibers of different lengths can be fully utilized, and the comprehensive performance of the artificial board can be optimized.

[0009] As a further improvement of the present invention, the material of the rock wool fibers meets the standard requirements of "Rock wool insulation products for construction GB / T 19686" or "Rock wool products for external thermal insulation of building exterior walls GB / T 25975".

[0010] As a further improvement of the present invention, the phenolic resin is a powdered solid phenolic resin with a particle size of no more than 200 meshes or a liquid phenolic resin with a number average molecular weight of no more than 1200 g / mol.

[0011] As a further improvement of the present invention, the silane coupling agent is a water-soluble aminosilane coupling agent, epoxysilane coupling agent, vinylsilane coupling agent, acrylic silane coupling agent and methylsilane coupling agent, or more thereof; when used, the silane coupling agent is miscible with water in a weight ratio of 1:(8-10) to form a coupling agent diluent.

[0012] As a further improvement of the present invention, the water repellent is one or more silicon-based water repellents used in combination. When used, the water repellent is mixed with water in a weight ratio of 1:(2-4) to form a water repellent dilution solution.

[0013] The present invention also discloses a method for preparing a composite artificial board of rock wool fibers and phenolic resin with mismatched sizes, comprising:

[0014] S1. Directly feed the rock wool melt into a centrifuge to form rock wool fibers;

[0015] S2, cutting the rock wool fibers into fibers of a desired length using a cotton cutter to obtain the desired rock wool fibers;

[0016] S3. The cut rock wool fibers are unraveled by 2 to 4 unraveling machines, and the coupling agent dilution liquid is sprayed on the last unraveling machine to mix evenly;

[0017] S4, the rock wool fiber with coupling agent enters into a mixer containing powdered solid phenolic resin, or the powdered solid phenolic resin or liquid phenolic resin is sprayed on the rock wool fiber with coupling agent through a spray device and mixed evenly;

[0018] S5. Spray the water-repellent agent dilution on the rock wool fiber with coupling agent and phenolic resin, mix them evenly, and then transfer them to the molding machine;

[0019] S6, the material transferred to the molding machine is subjected to pre-pressing, hot pressing, and cold pressing to form a composite artificial slab of rock wool fiber and phenolic resin;

[0020] S7, drying and curing the blank, cutting and sanding the blank to form a rock wool fiber and phenolic resin composite artificial board original board.

[0021] As a further improvement of the present invention, when liquid phenolic resin is used, hot air is introduced for drying so that its moisture content is not greater than 10%.

[0022] As a further improvement of the present invention, in S6:

[0023] The pre-pressing pressure is 0.4-3MPa, the pre-pressing temperature is room temperature, and the pre-pressing time is 1-3min;

[0024] The hot pressing pressure is 5-10 MPa, the hot pressing temperature is 180-260°C, and the hot pressing time is 7-15 min;

[0025] The cold pressing pressure is 5-10MPa, the cold pressing temperature is 15-35°C, and the cold pressing time is 3-8min.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present invention controls and adjusts the length and respective proportions of rock wool fibers, and uses auxiliary agents such as silane coupling agents, so that the prepared rock wool fiber and phenolic resin composite artificial board has high strength, high toughness and low water absorption of artificial boards, and has Class A non-combustible performance of inorganic boards, so as to improve the comprehensive performance of the composite board. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The present invention discloses a flow chart of a method for preparing a rock wool fiber and phenolic resin composite artificial board. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] The present invention provides a rock wool fiber and phenolic resin composite artificial board, comprising: rock wool fiber, phenolic resin, silane coupling agent and water repellent. In which, by weight percentage, the rock wool fiber is 82-93wt%, the solid content of the phenolic resin is 18-7wt%; the silane coupling agent accounts for 2-4wt% of the total amount of the rock wool fiber, and the water repellent accounts for 3-5wt% of the total amount of the rock wool fiber; the rock wool fiber is mainly composed of 2.5-3.5cm rock wool long fiber, 1.5-2.5cm rock wool medium-long fiber and 0.6-1.5cm rock wool short fiber, 2.5-3.5cm rock wool long fiber accounts for 20-30% of the total fiber, 1.5-2.5cm rock wool medium-long fiber accounts for 20-30% of the total fiber, 0.6-1.5cm rock wool short fiber accounts for 40-60% of the total fiber, and the rock wool short fiber less than 0.6cm and the rock wool long fiber greater than 3.5cm account for no more than 15% of the total fiber.

[0031] The rock wool fibrils used in the present invention are fibers sprayed by a centrifuge during the manufacturing process of rock wool products. While spraying the fibers, phenolic resin for bonding the fibers, silane coupling agent for increasing the bonding performance between the fibers and the resin glue, and a water repellent for achieving water repellency are applied. The above-mentioned rock wool fibrils, phenolic resin, silane coupling agent, water repellent, etc. form an intermediate product in the preparation process of rock wool products, which is called spray-bonded cotton. Spray-bonded cotton is formed into a semi-rigid rock wool product rock wool board through cotton collection, cotton laying, rolling, and curing. The fibers obtained by spraying without applying resin glue, coupling agent, water repellent, etc. are called rock wool fibrils.

[0032] The rock wool fibers needed for the rock wool fiber and phenolic resin composite artificial board can be obtained from the non-sprayed glue cotton on the production line.

[0033] Phenolic resin has the characteristics of strong bonding force, high limiting oxygen index, slow combustion, low heat release rate and low smoke production, and is widely used in the manufacture of artificial boards, brake pads, bakelite, etc. There are many types of phenolic resins, including powdered solid phenolic resins and liquid phenolic resins, which are cross-linked and cured by heating to form self-links and connections with other materials. Those skilled in the art know how to select suitable phenolic resins for material design, and the present invention is not limited thereto.

[0034] As the main materials of composite man-made panels, the ratio of rock wool fibers and phenolic resin has a great influence on the performance of the panels. The higher the content of phenolic resin, the higher the strength of the panels, and the higher the heat release rate and total heat release during combustion. As an optimized balance between strength performance and combustion performance, the rock wool fibers are 82-93wt% and the solid content of phenolic resin is 18-7wt% by weight.

[0035] The study of 0.5cm to 5cm original fibers found that the fiber length affects both the performance and the preparation process. When the fiber length is long, such as more than 3.5cm, the difficulty of mixing phenolic resin and original fibers increases significantly, and the strength and screw holding force of the artificial board decrease; when the fiber length is short, such as less than 0.6cm, the phenolic resin and original fibers are easy to mix, but the fibers are not entangled at all, and their strength and screw holding force will also decrease, and the brittleness will increase. The performance and mixing uniformity of original fibers in different length ranges are optimized. When the 2.5-3.5cm (>2.5 and ≤3.5) rock wool long fibers account for 20-30% of the total fiber, the 1.5-2.5cm (>1.5 and ≤2.5) rock wool medium and long fibers account for 20-30% of the total fiber, and the 0.6-1.5cm (≥0.6 and ≤1.5) rock wool short fibers account for 40-60% of the total fiber, a good balance can be achieved. However, in the actual process of preparing raw fibers of different lengths (such as described in S2), it is difficult to control the fiber length within a fixed range. As an acceptable requirement, the rock wool short fibers less than 0.6 cm and greater than 3.5 cm account for no more than 15% of the total fiber length.

[0036] Rock wool fibers are mainly composed of SiO2, Al2O3, CaO, MgO, Fe m O n (Fe2O3, FeO), the melt is rapidly cooled by air blowing to form glassy fibers mainly composed of ionic covalent bonds, while phenolic resin exhibits typical covalent bond properties. The alkoxy group in the coupling agent can form a bond with the rock wool fiber, and the other end (organic functional group) can form a bond with the phenolic resin, thereby increasing the bonding strength between the rock wool fibrils and the phenolic resin. Therefore, the coupling agent is an interface agent. In theory, a single molecular layer of coupling agent can achieve a bridging effect, and the proportion of coupling agent in the fibrils can better describe the interface characteristics. As an optimization result of the proportion of fibrils at 1 to 6wt%, the silane coupling agent accounts for 2 to 4wt% of the total amount of rock wool fibers, which can achieve the effect of coupling enhancement. Too much coupling agent will increase the cost.

[0037] Thanks to the covalent bond properties of the continuous phase phenolic resin, it has better water repellency than cement and calcium silicate. The purpose of the water repellent is to disperse in the material to form a hydrophobic layer with low surface energy. For the optimization of 1-10wt% of the total amount of rock wool fibers, the water repellent can be achieved when it accounts for 3-5wt% of the total amount of rock wool fibers. Too much water repellent not only increases the cost, but also does not contribute to the strength of the board.

[0038] Furthermore, the material of the rock wool fibers of the present invention meets the requirements of the standards of "Rock wool insulation products for construction GB / T19686" or "Rock wool products for external thermal insulation of building exterior walls GB / T 25975".

[0039] Due to the difference in application scenarios, rock wool products are divided into different uses, and have different requirements for the material of the original fiber, corresponding to different standards. Their main difference is reflected in the acidity coefficient. The larger the acidity coefficient, the higher the chemical stability and strength of the fiber material. Among them, "Rock wool products for external thermal insulation of building exterior walls GB / T 25975" requires the acidity coefficient to be no less than 1.8. "Rock wool insulation products for buildings GB / T19686" requires the acidity coefficient to be no less than 1.6. The original fiber of rock wool fiber and phenolic resin composite artificial board is not prepared separately, but the intermediate product in the rock wool industry is used, which has good technical and economic feasibility. As a recommendation, the original fiber that conforms to GB / T 19686 can be used in indoor dry occasions, and the original fiber that conforms to GB / T 25975 can be used in outdoor and humid occasions.

[0040] Furthermore, the phenolic resin is a powdered solid phenolic resin with a particle size not greater than 200 meshes or a liquid phenolic resin with a number average molecular weight not greater than 1200 g / mol.

[0041] The full mixing of rock wool fibers and phenolic resin is the basic condition for the preparation of composite wood-based panels. As an optimized test result, the particle size of the powdered solid phenolic resin is no more than 200 mesh, which allows the powdered resin to adhere evenly to the fiber surface, and can achieve uniform dispersion while reducing the amount of resin. Spraying can make the liquid phenolic resin fully wrapped on the fiber surface. As an optimized number average molecular weight of no more than 1200g / mol liquid phenolic resin, the effect is that it is not easy to clog the spray gun. The number average molecular weight is the average value of each molecular weight in the polymer. Commonly used testing methods include gel permeation chromatography (GPC) and other methods.

[0042] Furthermore, the silane coupling agent is a water-soluble aminosilane coupling agent, epoxysilane coupling agent, vinylsilane coupling agent, acrylic silane coupling agent and methylsilane coupling agent, or a combination thereof; when used, the silane coupling agent is miscible with water in a weight ratio of 1:(8-10) to form a coupling agent diluent.

[0043] Rock wool fibrils are ionic covalent bond fibers obtained by blowing glassy melts. Amino silane coupling agents, epoxy silane coupling agents, vinyl silane coupling agents, acrylic silane coupling agents and methyl silane coupling agents can all form coupling forces between fibrils and phenolic resins. Industry insiders can choose one or more of them for composite use to achieve the effect of strengthening rock wool fibrils and phenolic resin composite wood-based panels. As a surface treatment agent, theoretically a single molecular layer of coupling agent can achieve a bridging effect. The beneficial effect of silane coupling agent and water being miscible in a weight ratio of 1: (8-10) is that it is evenly distributed during spraying. Water-soluble coupling agents are easy to dry and do not produce volatile organic compounds.

[0044] Furthermore, the hydrophobic agent is one or more water-soluble silicon-based hydrophobic agents used in combination; when used, the hydrophobic agent is mixed with water in a weight ratio of 1:(2-4) to form a hydrophobic agent dilution liquid.

[0045] There are many types of hydrophobic agents, such as low surface energy hydrophobic agents, biodegradable hydrophobic agents, polymer hydrophobic agents, etc. Among them, silicon-based hydrophobic agents have performance and price advantages and are widely used. Water-soluble silicon-based hydrophobic agents are mixed with water in a weight ratio of 1: (2-4) to improve the uniformity of spraying and also do not produce volatile organic compounds.

[0046] The present invention provides a method for preparing a size-mismatched rock wool fiber and phenolic resin composite artificial board, comprising:

[0047] S1. Directly feed the rock wool melt into the centrifuge to form rock wool fibers.

[0048] In the process of preparing rock wool fibrils that meet the requirements of the standards "Rock wool insulation products for construction GB / T 19686" or "Rock wool products for external thermal insulation of building exterior walls GB / T 25975", resin glue, water repellent, coupling agent and other additives are no longer applied, and the fibrils are directly formed through a centrifuge.

[0049] S2. Cut the rock wool fibers into fibers of required length using a cotton cutter to obtain the required rock wool fibers.

[0050] The cotton cutter is a fiber cutting device that cuts fibers into a certain length. It has a pair of rollers with regularly arranged wing teeth. By controlling the distribution density, shape and rotation speed of the wing teeth, the fiber is disintegrated and cut. The greater the density and speed of the wing teeth, the more short fibers there are; conversely, the smaller the density and speed of the wing teeth, the less short fibers there are. This equipment is a common equipment for the preparation of granular cotton in rock wool products. Engineering technicians should know how to adjust the equipment to control the distribution of fiber length.

[0051] S3. The rock wool fibers are unraveled by 2 to 4 unraveling machines, and the coupling agent dilution liquid is sprayed on the last unraveling machine to mix evenly.

[0052] The cotton disintegrator is a device that disintegrates fibers into a fluffy state, and is also a common device in the textile industry. The purpose of multi-pass cotton disintegration is to completely disperse the fibers so as to facilitate the uniform application of coupling agents, resins, and water-increasing agents in the subsequent process. The coupling agent is a surface treatment agent, and the purpose of this process is to enable it to cover the surface of the treated fiber. In order to prevent the subsequent application of liquid resin from diluting and carrying out the coupling agent, a drying process is set. The test method for moisture content is carried out in accordance with the standard "Granular Cotton for Sound Absorbing Panels JC / T 903". As a recommended method, the coupling agent application step is completed by a uniformly distributed spray device set on the cotton disintegrator housing.

[0053] S4. The rock wool fibers with coupling agent are put into a mixer containing powdered solid phenolic resin, or the powdered solid phenolic resin or liquid phenolic resin is sprayed on the rock wool fibers with coupling agent through a spray device and mixed evenly.

[0054] The resin mixer is actually a cotton unwinding machine. Evenly distributed spray devices are set on the box to complete the fluffy glue spraying. As a recommendation, the spray device can also be set in a pair of roller hollow cavities to spray glue in the radial direction. For powdered solid phenolic resin, the "wet cotton" with coupling agent diluent in the S3 process is conducive to the uniform adhesion of the powdered solid phenolic resin to the fiber surface.

[0055] When liquid phenolic resin is used, hot air is introduced for drying so that its moisture content is no more than 10%. Among them, pores are a key indicator affecting the mechanical strength of the composite board. When the moisture content of the liquid resin is low, the porosity during the composite board forming process can be effectively controlled.

[0056] S5. Spray the water repellent dilution on the rock wool fiber with coupling agent and phenolic resin, mix well, and then transfer to the molding machine.

[0057] As a recommendation, spraying of the water repellent dilution can be carried out in succession in the S4 mixer, and a set of water repellent spray devices evenly distributed on the box body is set.

[0058] S6. The material transferred to the molding machine is subjected to pre-pressing, hot pressing and cold pressing to form a composite artificial board blank of rock wool raw fiber and phenolic resin.

[0059] The pre-pressing pressure is 0.4-3MPa, the pre-pressing temperature is room temperature, and the pre-pressing time is 1-3min; the hot pressing pressure is 5-10MPa, the hot pressing temperature is 180-260℃, and the hot pressing time is 7-15min; the cold pressing pressure is 5-10MPa, the cold pressing temperature is 15-35℃, and the cold pressing time is 3-8min.

[0060] The main process parameters of hot pressing include temperature, pressure and time. Among them, the hot pressing process is to use temperature to make the phenolic resin undergo a cross-linking reaction to form a composite material of bonded fibers. The optimal reaction temperature varies depending on the different phenolic resins. Differential scanning calorimetry (DSC) is one of the methods. Technical personnel in the industry know how to determine the reaction and curing temperature of phenolic resins. In addition to being related to the type of phenolic resin, the reaction and curing time is directly related to the thickness of the board. The thicker the board, the longer it takes. By observing the reaction color of the phenolic resin and testing the performance, it can be judged whether the reaction and curing are completed. Pressure is the main control of the density of the board. The density is closely related to the performance of the board, but there is a saturation value. The comprehensive performance does not increase accordingly with the increase in density. The hot pressing pressure of 5 to 10 MPa is the result of the performance-optimized parameters.

[0061] S7, drying and curing the blank, cutting and sanding the blank to form a rock wool fiber and phenolic resin composite artificial board original board.

[0062] As a process, the blank is cured to release the stress caused by the curing of the resin, and the uneven surface is sanded to provide a smooth surface for veneer.

[0063] The specific embodiments are as follows:

[0064] The sources of some components in the embodiments and comparative examples are as follows:

[0065] Rock wool fiber: rock wool fiber (purchased from Beijing Jinyu Energy Saving and Insulation Technology (Dachang) Co., Ltd.)

[0066] Phenolic resin: thermoplastic phenolic resin (purchased from Jinan Shengquan Group Co., Ltd.), thermosetting phenolic resin (purchased from Jinan Shengquan Group Co., Ltd.)

[0067] Curing agent: Hexamethylenetetramine (purchased from Jinan Shengquan Group Co., Ltd.)

[0068] Example 1

[0069] This embodiment provides a method for preparing a composite artificial board of rock wool fibers and phenolic resin with different length ratios, and the specific steps are as follows:

[0070] Step S1: Weigh 30 parts of rock wool long fibers (the cutting length of the cotton cutter is set to 3 cm), 30 parts of rock wool medium and long fibers (the cutting length of the cotton cutter is set to 2 cm), and 40 parts of rock wool short fibers (the cutting length of the cotton cutter is set to 1 cm), and place the three rock wool fibers of different lengths in a cotton disintegrating device to ensure that the three fibers are fully mixed.

[0071] Step S2: Weigh 3 parts of γ-aminopropyltriethoxysilane (KH550) and prepare a coupling agent solution with deionized water in a ratio of 1:10, use a vacuum pump to pressurize and atomize, and spray the coupling agent solution evenly onto the surface of the rock wool fiber to obtain coupling agent-modified rock wool fiber.

[0072] Step S3: The rock wool fibers are transferred to a mixer, 10 parts of phenolic resin (with a particle size of 200 mesh) are added, and the mixture is mixed mechanically for 10 minutes to ensure that the fibers and the resin are fully mixed.

[0073] Step S4: Weigh 3 parts of an organosilicon water repellent and mix them with deionized water in a ratio of 1:3 to form an organosilicon water repellent solution. Use a vacuum pump to pressurize and atomize, and evenly spray the water repellent solution onto the surface of the rock wool fiber with the coupling agent and the phenolic resin.

[0074] Step S5: spray 0.2 parts of release agent evenly on the surface of the hot pressing mold.

[0075] Step S6: Weigh 100 parts of the evenly mixed rock wool fiber-phenolic resin raw material and spread it evenly into a customized mold.

[0076] Step S7: Put the mixture together with the mold into a flat vulcanizer for pre-pressing. Pre-pressing pressure: 1.5 MPa; pre-pressing temperature: 20° C.; pre-pressing time: 2 min. The fiber-resin mixture in the mold is preliminarily compacted into a man-made board embryo.

[0077] Step S8: Put the pre-pressed sample together with the mold into a flat vulcanizer for hot pressing. Hot pressing pressure: 8MPa, hot pressing temperature: 190°C, hot pressing time: 10min. Under this hot pressing process parameters, the mixed material is hot pressed into an artificial board.

[0078] Step S9: Place the hot pressed sample together with the mold on a flat vulcanizer for cold pressing. Cold pressing pressure: 8 MPa, cold pressing temperature: 20° C., cold pressing time: 5 min. The composite material artificial board is cooled under these cold pressing process parameters.

[0079] Step S10: releasing the pressure and demoulding the product from the mold.

[0080] Step S11: After the finished product is left to stand at room temperature for 2 hours, the composite artificial board is cut to remove the burrs around the edges, thereby obtaining a composite artificial board of rock wool raw fibers and phenolic resin modified by a coupling agent (KH550) and having a ratio of long, medium and short fibers of 30:30:40.

[0081] Example 2

[0082] This embodiment provides a method for preparing a composite artificial board of rock wool fibers and phenolic resin with different length ratios. The specific steps are the same as those in Example 1, with the only difference being that the ratio of long, medium and short fibers is 20:20:60.

[0083] Example 3

[0084] This embodiment provides a method for preparing a composite artificial board of rock wool fibers and phenolic resin with different length ratios. The only difference from Example 1 is that the aminosilane coupling agent (KH550) used in this embodiment is replaced by an epoxy silane coupling agent (KH560), and the remaining steps are the same as Example 1.

[0085] Comparative Example 1

[0086] This embodiment provides a method for preparing a composite artificial board of rock wool fibers and phenolic resin with different length ratios. The specific steps are the same as those in Example 1, with the only difference being that the ratio of long, medium and short fibers is 40:40:20.

[0087] Comparative Example 2

[0088] This embodiment provides a method for preparing a composite artificial board of rock wool fibers and phenolic resin with different length ratios. The specific steps are the same as those in Example 1, with the only difference being that the ratio of long, medium and short fibers is 10:10:80.

[0089] Comparative Example 3

[0090] This comparative example provides a method for preparing a composite artificial board of single-length rock wool fibers and phenolic resin, and the specific steps are as follows:

[0091] Step S1: Weigh 100 parts of rock wool long fibers (the cutting length of the cotton cutter is set to 3 cm), place them in a cotton disintegrating device and disperse them evenly.

[0092] Step S2: Weigh 3 parts of γ-aminopropyltriethoxysilane (KH550), and prepare a coupling agent solution with deionized water in a ratio of 1:10. Use a vacuum pump to pressurize and atomize, and spray the coupling agent solution evenly onto the surface of the rock wool fiber to obtain coupling agent-modified rock wool fiber.

[0093] Step S3: The rock wool fibers are transferred to a mixer, 10 parts of phenolic resin (with a particle size of 200 mesh) are added, and the mixture is mixed mechanically for 10 minutes to ensure that the fibers and the resin are fully mixed.

[0094] Step S4: Weigh 3 parts of organosilicon water repellent, and prepare an organosilicon water repellent solution with deionized water in a ratio of 1:3. Use a vacuum pump to pressurize and atomize, and spray the water repellent solution evenly onto the surface of the rock wool fiber.

[0095] Step S5: spray 0.2 parts of release agent evenly on the surface of the hot pressing mold.

[0096] Step S6: Weigh 100 parts of the evenly mixed rock wool fiber-phenolic resin raw material and spread it evenly into a customized mold.

[0097] Step S7: Put the mixture together with the mold into a flat vulcanizer for pre-pressing. Pre-pressing pressure: 1.5 MPa; pre-pressing temperature: 20° C.; pre-pressing time: 2 min. The fiber-resin mixture in the mold is preliminarily compacted into a man-made board embryo.

[0098] Step S8: Put the pre-pressed sample together with the mold into a flat vulcanizer for hot pressing. Hot pressing pressure: 8MPa, hot pressing temperature: 190°C, hot pressing time: 10min. Under this hot pressing process parameters, the mixed material is hot pressed into an artificial board.

[0099] Step S9: Place the hot pressed sample together with the mold on a flat vulcanizer for cold pressing. Cold pressing pressure: 8 MPa, cold pressing temperature: 20° C., cold pressing time: 5 min. The composite material artificial board is cooled under these cold pressing process parameters.

[0100] Step S10: releasing the pressure and demoulding the product from the mold.

[0101] Step S11: After the finished product is left to stand at room temperature for 2 hours, the composite artificial board is cut to remove the burrs around the edges, thereby obtaining a composite artificial board of rock wool fibers and phenolic resin that is modified by a coupling agent (KH550) and is entirely long-fibered.

[0102] Comparative Example 4

[0103] This comparative example provides a method for preparing a composite artificial board of single-length rock wool fibers and phenolic resin. The specific steps are the same as those of Comparative Example 3. The only difference is that the 100 parts of rock wool long fibers (the cutting length set by the cotton cutter is 3 cm) in Comparative Example 3 are replaced by 100 parts of rock wool medium and long fibers (the cutting length set by the cotton cutter is 2 cm).

[0104] Comparative Example 5

[0105] This comparative example provides a method for preparing a composite artificial board of single-length rock wool fibers and phenolic resin. The specific steps are the same as those of comparative example 3. The only difference is that the 100 parts of rock wool long fibers (the cutting length set by the cotton cutter is 3 cm) in comparative example 3 are replaced by 100 parts of rock wool short fibers (the cutting length set by the cotton cutter is 1 cm).

[0106] Comparative Example 6

[0107] This comparative example provides a method for preparing a composite artificial board of rock wool fibers and phenolic resin. The specific steps are the same as those of comparative example 3. The only difference is that the 100 parts of rock wool long fibers (the cutting length set by the cotton cutter is 3 cm) in comparative example 3 are replaced by 60 parts of rock wool long fibers (the cutting length set by the cotton cutter is 3 cm) and 40 parts of rock wool short fibers (the cutting length set by the cotton cutter is 1 cm).

[0108] Comparative Example 7

[0109] This comparative example provides a method for preparing a composite artificial board of rock wool fibers and phenolic resin. The specific steps are the same as those in Comparative Example 3. The only difference is that the 100 parts of rock wool long fibers (the cutting length set by the cotton cutter is 3 cm) in Comparative Example 3 are replaced by 60 parts of rock wool medium and long fibers (the cutting length set by the cotton cutter is 2 cm) and 40 parts of rock wool short fibers (the cutting length set by the cotton cutter is 1 cm).

[0110] Comparative Example 8

[0111] This comparative example provides a method for preparing a composite artificial board of rock wool fibers and phenolic resin. The specific steps are the same as those of comparative example 3. The only difference is that the 100 parts of rock wool long fibers (the cutting length set by the cotton cutter is 3 cm) in comparative example 3 are replaced by 60 parts of rock wool long fibers (the cutting length set by the cotton cutter is 3 cm) and 40 parts of rock wool medium and long fibers (the cutting length set by the cotton cutter is 2 cm).

[0112] Comparative Example 9

[0113] This comparative example provides a method for preparing a composite artificial board of rock wool fibers and phenolic resin with different length ratios without modification by a silane coupling agent and a water repellent agent, and the specific steps are as follows:

[0114] Step S1: Weigh 30 parts of rock wool long fibers (the cutting length of the cotton cutter is set to 3 cm), 30 parts of rock wool medium and long fibers (the cutting length of the cotton cutter is set to 2 cm), and 40 parts of rock wool short fibers (the cutting length of the cotton cutter is set to 1 cm), and place the three rock wool fibers of different lengths in a cotton disintegrating device to ensure that the three fibers are fully mixed.

[0115] Step S2: Transfer the rock wool fibers to a mixer, add 10 parts of phenolic resin (with a particle size of 200 mesh), and mix them for 10 minutes by mechanical mixing to ensure that the fibers and the resin are fully mixed.

[0116] Step S3: spray 0.2 parts of release agent evenly on the surface of the hot pressing mold.

[0117] Step S4: Weigh 100 parts of the uniformly mixed rock wool fiber-phenolic resin raw material and spread it evenly into a customized mold.

[0118] Step S5: Put the mixture together with the mold into a flat vulcanizer for pre-pressing. Pre-pressing pressure: 1.5 MPa; pre-pressing temperature: 20° C.; pre-pressing time: 2 min. The fiber-resin mixture in the mold is preliminarily compacted into a man-made board embryo.

[0119] Step S6: Put the pre-pressed sample together with the mold into a flat vulcanizer for hot pressing. Hot pressing pressure: 8MPa, hot pressing temperature: 190°C, hot pressing time: 10min, and hot pressing the mixture into an artificial board under these hot pressing process parameters.

[0120] Step S7: Put the hot pressed sample together with the mold into a flat vulcanizer for cold pressing. Cold pressing pressure: 8MPa, cold pressing temperature: 20°C, cold pressing time: 5min, and the composite material artificial board is cooled under these cold pressing process parameters.

[0121] Step S8: releasing the pressure and demoulding the product from the mold.

[0122] Step S9: After the finished product is allowed to stand at room temperature for 2 hours, the composite artificial board is cut to remove the burrs around the edges, thereby obtaining a composite artificial board of rock wool fiber and phenolic resin with a long, medium and short fiber ratio of 30:30:40.

[0123] Comparative Example 10

[0124] This comparative example provides a method for preparing a composite artificial board of rock wool fibers and phenolic resin with different length ratios without modification by silane coupling agent and water repellent agent. The specific steps are the same as those of comparative example 9, the only difference being that the ratio of long, medium and short fibers is 40:40:20.

[0125] Comparative Example 11

[0126] This comparative example provides a method for preparing a composite artificial board of rock wool fibers and phenolic resin with different length ratios without modification by silane coupling agent and water repellent agent. The specific steps are the same as those of comparative example 9, the only difference being that the ratio of long, medium and short fibers is 10:10:80.

[0127] The performance of the rock wool fiber-phenolic resin composite artificial board provided in the above embodiments and comparative examples was tested, and the performance test included density, static bending strength, elastic modulus, combustion grade, screw holding force, and water absorption rate. The specific test method is as follows:

[0128] Density: Test according to the requirements of GB / T 17657-2022 Test methods for physical and chemical properties of wood-based panels and veneered wood-based panels.

[0129] Static bending strength: Tested in accordance with the requirements of GB / T 17657-2022 Test methods for physical and chemical properties of wood-based panels and veneered wood-based panels.

[0130] Elastic modulus: Tested in accordance with the requirements of GB / T 17657-2022 Test methods for physical and chemical properties of wood-based panels and veneered wood-based panels.

[0131] Combustion grade: Refer to the requirements of "GB 8624-2012 Classification of Combustion Performance of Building Materials and Products" as the classification criteria.

[0132] Screw holding force: Test according to the requirements of GB / T 17657-2022 Test methods for physical and chemical properties of wood-based panels and veneered wood-based panels.

[0133] Water absorption rate: Test according to the requirements of GB / T 17657-2022 Test methods for physical and chemical properties of wood-based panels and veneered wood-based panels.

[0134] The above performance test data is shown in Table 1

[0135] Table 1 Performance test results

[0136]

[0137]

[0138] According to the experimental data of the present invention, the mechanical properties of the rock wool fiber / phenolic resin composite artificial board were successfully optimized by adjusting the ratio of rock wool fibers of different lengths and using a silane coupling agent to modify the surface of the rock wool fibers. The specific results are as follows:

[0139] In different embodiments and comparative examples, the amount of phenolic resin added did not change, the difference was the use of different lengths of rock wool fiber ratios and whether or not silane coupling agent was used for modification, so the combustion grade of the artificial board reached A2 grade.

[0140] Example 1: A man-made board prepared by combining rock wool fibers modified by coupling agent (KH550) with phenolic resin in a ratio of 30:30:40 for long, medium and short fibers, with a density of 1.326 g / cm 3 , the static bending strength is 33.456MPa, the elastic modulus is 5775MPa, the screw holding force is 1187N, and the water absorption rate is 6.44%.

[0141] Example 2: A man-made board prepared by combining rock wool fibers modified by coupling agent (KH550) with phenolic resin in a ratio of 20:20:60 for long, medium and short fibers, with a density of 1.324 g / cm 3, the static bending strength is 33.788MPa, the elastic modulus is 5696MPa, the screw holding force is 1142N, and the water absorption rate is 6.33%.

[0142] Example 3: A man-made board prepared by combining rock wool fibers modified by coupling agent (KH560) with phenolic resin in a ratio of 30:30:40 for long, medium and short fibers, with a density of 1.329 g / cm 3 , the static bending strength is 33.011MPa, the elastic modulus is 5633MPa, the screw holding force is 1138N, and the water absorption rate is 5.68%.

[0143] Compared with Example 1, Example 2 has similar density, slightly higher static bending strength, slightly lower elastic modulus, screw holding force and water absorption rate, and the overall difference is not significant.

[0144] Compared with Example 1, Example 3 has similar density, static bending strength, elastic modulus and screw holding force, and its water absorption rate decreases by 11.8%.

[0145] Comparative Example 1 and Comparative Example 2: Using different ratios of long, medium and short fibers from Example 1 and Example 2, the results show that the performance is reduced compared with Example 1 and Example 2. The specific data are as follows:

[0146] Compared with Example 1, Comparative Example 1 has: density reduced by 0.5%, static bending strength reduced by 4.7%, elastic modulus reduced by 3.4%, screw holding force reduced by 11.9%, and water absorption rate increased by 6.8%; compared with Example 2, density reduced by 0.4%, static bending strength reduced by 5.7%, elastic modulus reduced by 2.3%, screw holding force reduced by 8.4%, and water absorption rate increased by 8.7%.

[0147] Compared with Example 1, Comparative Example 2 has: density increased by 1.1%, static bending strength increased by 1.4%, elastic modulus decreased by 0.2%, screw holding force increased by 0.7%, and water absorption rate decreased by 0.2%; compared with Example 2: density increased by 1.3%, static bending strength increased by 0.4%, elastic modulus increased by 1.2%, screw holding force increased by 4.7%, and water absorption rate decreased by 0.3%.

[0148] Comparative Examples 3, 4 and 5: Instead of using different lengths of rock wool fibers, single long rock wool fibers, single medium-long rock wool fibers and single short rock wool fibers were used to manufacture artificial boards with phenolic resin. The results showed that the performance was reduced compared with Examples 1 and 2. The specific data are as follows:

[0149] Compared with Example 1, Comparative Example 3 has the following characteristics: density reduced by 1.1%, static bending strength reduced by 10.8%, elastic modulus reduced by 9.5%, screw holding force reduced by 10.1%, and water absorption rate increased by 10.7%; compared with Example 2, density reduced by 1.0%, static bending strength reduced by 11.6%, elastic modulus reduced by 8.2%, screw holding force reduced by 6.6%, and water absorption rate increased by 12.6%.

[0150] Compared with Example 1, Comparative Example 4 has: density reduced by 0.4%, static bending strength reduced by 9.6%, elastic modulus reduced by 7.7%, screw holding force reduced by 6.0%, and water absorption rate increased by 1.2%; compared with Example 2: density reduced by 0.2%, static bending strength reduced by 10.5%, elastic modulus reduced by 6.4%, screw holding force reduced by 2.3%, and water absorption rate increased by 3.0%.

[0151] Compared with Example 1, Comparative Example 5 has: density increased by 1.4%, static bending strength decreased by 7.1%, elastic modulus decreased by 5.5%, screw holding force increased by 1.0%, and water absorption rate decreased by 4.2%; compared with Example 2: density increased by 1.6%, static bending strength decreased by 8.0%, elastic modulus decreased by 4.2%, screw holding force increased by 5.0%, and water absorption rate decreased by 2.5%.

[0152] Comparative Examples 6, 7 and 8: Instead of using three different lengths of rock wool fibers, two types of rock wool long fibers, medium-long rock wool fibers and short rock wool fibers were used to compound phenolic resin to manufacture artificial boards. The results showed that the performance was reduced compared with Examples 1 and 2. The specific data are as follows:

[0153] Compared with Example 1, Comparative Example 6 has the following characteristics: the density is similar, the static bending strength decreases by 2.2%, the elastic modulus decreases by 3.5%, the screw holding force decreases by 2.9%, and the water absorption rate increases by 2.3%; compared with Example 2, the density is similar, the static bending strength decreases by 3.2%, the elastic modulus decreases by 2.1%, the screw holding force increases by 0.9%, and the water absorption rate increases by 4.1%.

[0154] Compared with Example 1, Comparative Example 7 has the following characteristics: the density is similar, the static bending strength decreases by 7.3%, the elastic modulus decreases by 6.0%, the screw holding force decreases by 7.7%, and the water absorption rate decreases by 0.9%; compared with Example 2, the density is similar, the static bending strength decreases by 8.2%, the elastic modulus decreases by 4.7%, the screw holding force decreases by 4.0%, and the water absorption rate increases by 0.8%.

[0155] Compared with Example 1, Comparative Example 8 has the following: density reduced by 1.1%, static bending strength reduced by 10.7%, elastic modulus reduced by 8.5%, screw holding force reduced by 11.1%, and water absorption rate increased by 9.0%; compared with Example 2, the density reduced by 1.0%, static bending strength reduced by 11.5%, elastic modulus reduced by 7.2%, screw holding force increased by 7.6%, and water absorption rate increased by 10.9%.

[0156] Comparative Examples 9, 10 and 11: No coupling agent was used to modify the surface of rock wool fibers with different length ratios, resulting in a significant decrease in mechanical properties. The specific data are as follows:

[0157] Compared with Example 1, Comparative Example 9 has similar densities, a 11.4% decrease in static bending strength, a 11.9% decrease in elastic modulus, a 9.1% decrease in screw holding force, and a 33.7% increase in water absorption; compared with Example 2, the densities are similar, the static bending strength is reduced by 12.3%, the elastic modulus is reduced by 10.7%, the screw holding force is reduced by 5.5%, and the water absorption is increased by 36.0%; compared with Example 3, the densities are similar, the static bending strength is reduced by 10.2%, the elastic modulus is reduced by 9.8%, the screw holding force is reduced by 5.2%, and the water absorption is increased by 51.6%.

[0158] Compared with Comparative Example 1, Comparative Example 10 has similar density, static bending strength decreases by 14.0%, elastic modulus decreases by 12.0%, screw holding force decreases by 1.8%, and water absorption increases by 27.8%.

[0159] Compared with Comparative Example 2, Comparative Example 11 has similar density, static bending strength decreases by 13.8%, elastic modulus decreases by 11.5%, screw holding force decreases by 7.3%, and water absorption increases by 36.1%.

[0160] In summary, the present invention adjusts the ratio of rock wool fibers of different lengths and uses a silane coupling agent to perform surface modification on the rock wool fibers. While ensuring that the density of the artificial boards is close, the comprehensive performance of the rock wool fiber-phenolic resin composite artificial boards is effectively optimized, the static bending strength, elastic modulus and screw holding force of the artificial boards are significantly improved, the water absorption rate of the artificial boards is reduced, and the artificial boards are ensured to meet the A2 combustion performance standard requirements.

[0161] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A composite artificial board of rock wool fibers and phenolic resin with mismatched sizes, characterized in that: include: Rock wool fiber, phenolic resin, silane coupling agent and water repellent; In terms of weight percentage, the rock wool fibers are 82-93 wt%, the solid content of the phenolic resin is 18-7 wt%; the silane coupling agent accounts for 2-4 wt% of the total amount of the rock wool fibers, and the water repellent accounts for 3-5 wt% of the total amount of the rock wool fibers; The rock wool raw fibers are mainly composed of 2.5-3.5 cm rock wool long fibers, 1.5-2.5 cm rock wool medium-long fibers and 0.6-1.5 cm rock wool short fibers, 2.5-3.5 cm rock wool long fibers account for 20-30% of the total fiber amount, 1.5-2.5 cm rock wool medium-long fibers account for 20-30% of the total fiber amount, 0.6-1.5 cm rock wool short fibers account for 40-60% of the total fiber amount, and rock wool short fibers below 0.6 cm and rock wool long fibers greater than 3.5 cm account for no more than 15% of the total fiber amount.

2. The size-mismatched rock wool fiber and phenolic resin composite artificial board according to claim 1, characterized in that: The material of the rock wool raw fiber meets the standard requirements of "Rock wool insulation products for construction GB / T 19686" or "Rock wool products for external thermal insulation of building exterior walls GB / T 25975".

3. The size-mismatched rock wool fiber and phenolic resin composite artificial board according to claim 1, characterized in that: The phenolic resin is a powdered solid phenolic resin with a particle size of no more than 200 meshes or a liquid phenolic resin with a number average molecular weight of no more than 1200 g / mol.

4. The size-mismatched rock wool fiber and phenolic resin composite artificial board according to claim 1, characterized in that: The silane coupling agent is one or more of water-soluble aminosilane coupling agents, epoxysilane coupling agents, vinylsilane coupling agents, acrylic silane coupling agents and methylsilane coupling agents used in combination; when used, the silane coupling agent is miscible with water in a weight ratio of 1:(8-10) to form a coupling agent diluent.

5. The size-mismatched rock wool fiber and phenolic resin composite artificial board according to claim 1, characterized in that: The water repellent is one or more silicon-based water repellents used in combination; when used, the water repellent is mixed with water in a weight ratio of 1:(2-4) to form a water repellent dilution solution.

6. A method for preparing a composite artificial board of rock wool fibers and phenolic resin with mismatched sizes as claimed in any one of claims 1 to 5, characterized in that: include: S1. Directly feed the rock wool melt into a centrifuge to form rock wool fibers; S2, cutting the rock wool fibers into fibers of a desired length using a cotton cutter to obtain the desired rock wool fibers; S3. The cut rock wool fibers are unraveled by 2 to 4 unraveling machines, and the coupling agent dilution liquid is sprayed on the last unraveling machine to mix evenly; S4, the rock wool fiber with coupling agent enters into a mixer containing powdered solid phenolic resin, or the powdered solid phenolic resin or liquid phenolic resin is sprayed on the rock wool fiber with coupling agent through a spray device and mixed evenly; S5. Spray the water-repellent agent dilution on the rock wool fiber with coupling agent and phenolic resin, mix them evenly, and then transfer them to the molding machine; S6, the material transferred to the molding machine is subjected to pre-pressing, hot pressing, and cold pressing to form a composite artificial slab of rock wool fiber and phenolic resin; S7, drying and curing the blank, cutting and sanding the blank to form a rock wool fiber and phenolic resin composite artificial board original board.

7. The preparation method according to claim 6, characterized in that: When liquid phenolic resin is used, hot air is passed through to dry it so that its moisture content is no more than 10%.

8. The preparation method according to claim 6, characterized in that: In S6: The pre-pressing pressure is 0.4-3MPa, the pre-pressing temperature is room temperature, and the pre-pressing time is 1-3min; The hot pressing pressure is 5-10 MPa, the hot pressing temperature is 180-260°C, and the hot pressing time is 7-15 min; The cold pressing pressure is 5-10MPa, the cold pressing temperature is 15-35°C, and the cold pressing time is 3-8min.

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