Rock wool fibrils with a size mismatch and phenol formaldehyde resin composite wood-based panels and methods of making

Abstract

The application discloses a size-mismatched rock wool fiber and phenolic resin composite artificial board and a preparation method thereof. According to the weight percentage, the rock wool fiber is 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 fiber, and the hydrophobic agent accounts for 3-5 wt% of the total amount of the rock wool fiber. The rock wool fiber is mainly composed of 2.5-3.5 cm long rock wool fiber, 1.5-2.5 cm medium-length rock wool fiber and 0.6-1.5 cm short rock wool fiber. The 2.5-3.5 cm long rock wool fiber accounts for 20-30% of the total amount of the fiber, the 1.5-2.5 cm medium-length rock wool fiber accounts for 20-30% of the total amount of the fiber, and the 0.6-1.5 cm short rock wool fiber accounts for 40-60% of the total amount of the fiber. The length and respective proportion of the rock wool fiber and the use of the silane coupling agent and other auxiliaries are controlled and adjusted, so that the prepared rock wool fiber and phenolic resin composite artificial board has the high strength, high toughness and low water absorption rate of the artificial board and the A-grade non-combustible performance of the inorganic board.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of artificial board manufacturing, in particular to a size-mismatched rock wool fiber and phenolic resin composite artificial board and a preparation method thereof. BACKGROUND

[0002] Artificial board generally refers to various types of boards formed by hot pressing wood (wood fiber) as a base material with an organic binder. Artificial board materials include shaving board, density board, joinery board (large core board), plywood, etc., and are widely used in home furnishing (furniture, wooden doors, floors), building wallboards, partitions, and composite floors, etc. The outstanding problem of artificial board materials is their poor flame retardant performance, which can cause indoor fires. In the Notice on Issuing the National Key Industrial Product Quality and Safety Supervision Directory (2024 Edition) (Guoshang Anquan Fa

[2023] No. 5) issued by the General Administration of Market Supervision, artificial board for furniture and building decoration is included in the national key industrial product quality and safety supervision directory.

[0003] In order to avoid the risk of burning artificial board, fiber-reinforced inorganic board (inorganic board) has been developed on the market, mainly including cement fiber board, calcium silicate board, etc. Inorganic board can achieve A-level non-combustion, but it is relatively brittle, has high water absorption, and insufficient freeze-thaw resistance, and is mainly used in indoor dry environment for partition walls and decorative boards. SUMMARY

[0004] In view of the deficiencies in the existing artificial board and inorganic board technologies, the present application 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 present application discloses a size-mismatched rock wool fiber and phenolic resin composite artificial board, which comprises rock wool fiber, phenolic resin, silane coupling agent, and hydrophobic agent.

[0006] The rock wool fiber accounts for 82-93wt%, the solid content of the phenolic resin accounts for 18-7wt%, the silane coupling agent accounts for 2-4wt% of the total amount of rock wool fiber, and the hydrophobic agent accounts for 3-5wt% of the total amount of rock wool fiber.

[0007] The rock wool fiber is mainly composed of 2.5-3.5cm long rock wool fiber, 1.5-2.5cm medium-length rock wool fiber, and 0.6-1.5cm short rock wool fiber. The 2-3cm long rock wool fiber accounts for 20-30% of the total amount of fiber, the 1.5-2.5cm medium-length rock wool fiber accounts for 20-30% of the total amount of fiber, the 0.6-1.5cm short rock wool fiber accounts for 40-60% of the total amount of fiber, and the rock wool fiber shorter than 0.6cm and the rock wool fiber longer than 3.5cm account for no more than 15% of the total amount of fiber.

[0008] The rock wool long fiber (2.5-3.5 cm) mainly plays a reinforcing role of the composite material, and improves the tensile strength of the material; however, the dispersibility of the long fiber is poor, and the long fiber is easily entangled in the mixing process, leading to uneven distribution and affecting the performance consistency of the wood-based panel. The rock wool medium-length fiber (1.5-2.5 cm) has moderate length, can provide a certain reinforcing effect, has good dispersibility, and plays a balancing role between the rock wool long fiber and the rock wool short fiber; however, compared with the rock wool long fiber, the rock wool medium-length fiber has a weak mechanical property reinforcing effect. The rock wool short fiber (0.6-1.5 cm) has good dispersibility, is easy to be uniformly mixed, can effectively fill the gaps in the material, and improves the static bending strength and screw holding force of the wood-based panel; however, the wood-based panel prepared by using the single rock wool short fiber has a high density, does not meet the actual demand of light weight and high strength of the wood-based panel, and has problems such as too large brittleness and poor plastic toughness. By reasonably adjusting the proportion of the long, medium-length and short fibers in the rock wool raw fiber, the density, static bending strength, elastic modulus, screw holding force, brittleness and toughness and water resistance of the wood-based panel can be considered, the dispersibility of the fiber can be improved, the advantages of the fibers with different lengths can be fully utilized, and the comprehensive performance of the wood-based panel is optimized.

[0009] As a further improvement of the present application, the material of the rock wool raw fiber meets the standard requirements of “Rock wool thermal insulation products for building 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 application, the phenolic resin is a powdered solid phenolic resin with a particle size of not more than 200 mesh or a liquid phenolic resin with a number average molecular weight of not more than 1200 g / mol.

[0011] As a further improvement of the present application, the silane coupling agent is one or more than one of an amino silane coupling agent, an epoxy silane coupling agent, a vinyl silane coupling agent, an acrylic silane coupling agent and a methyl silane coupling agent which are soluble in water; when used, the silane coupling agent is mixed with water in a weight ratio of 1:(8-10) to form a coupling agent diluent.

[0012] As a further improvement of the present application, the hydrophobic agent is one or more than one of a silicon-based hydrophobic agent which is mixed with water in a weight ratio of 1:(2-4) to form a hydrophobic agent diluent.

[0013] The present application also discloses a preparation method of the wood-based panel with the size-mismatched rock wool raw fiber and the phenolic resin.

[0014] S1, directly feeding the rock wool melt into a centrifuge to form the rock wool raw fiber through the centrifuge;

[0015] S2, cutting the rock wool raw fiber into the raw fiber with a required length through a cotton cutting machine to obtain the required rock wool raw fiber;

[0016] S3, the cut rock wool fiber is passed through 2-4 opening machines, and a coupling agent diluent is sprayed on the last opening machine to mix uniformly;

[0017] S4, the rock wool fiber with the coupling agent is 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 fiber with the coupling agent by a spraying device, and is mixed uniformly;

[0018] S5, a water-repellent agent diluent is sprayed on the rock wool fiber with the coupling agent and the phenolic resin, and after mixing uniformly, is transferred to a forming machine;

[0019] S6, the material transferred to the forming machine is pre-pressed, hot-pressed, and cold-pressed to form a rock wool fiber and phenolic resin composite artificial board blank;

[0020] S7, the blank is dried and maintained, cut, and sanded to form a rock wool fiber and phenolic resin composite artificial board.

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

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

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

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

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

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

[0027] The present application controls and adjusts the length and respective ratio of the rock wool fiber, and uses the silane coupling agent and other additives, so that the prepared rock wool fiber and phenolic resin composite artificial board has high strength, high toughness, and low water absorption rate, and has A-grade non-combustible performance of inorganic board, so as to improve the comprehensive performance of the composite board. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 The flow chart of the rock wool fiber and phenolic resin composite artificial board preparation method disclosed in the present application is shown. DETAILED DESCRIPTION

[0029] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0030] The present application provides a kind of rock wool fiber and phenolic resin composite artificial board, comprising: rock wool fiber, phenolic resin, silane coupling agent and hydrophobic agent. Wherein, according to weight percentage, rock wool fiber is 82~93wt%, the solid content of phenolic resin is 18~7wt%;Silane coupling agent accounts for 2~4wt% of the total amount of rock wool fiber, and hydrophobic agent accounts for 3~5wt% of the total amount of 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 length 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 amount of fiber, 1.5~2.5cm rock wool medium length fiber accounts for 20~30% of the total amount of fiber, 0.6~1.5cm rock wool short fiber accounts for 40~60% of the total amount of 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 amount of fiber.

[0031] The rock wool fiber used in the present application is the fiber formed by blowing through a centrifuge during the manufacture of rock wool products. At the same time of blowing the fiber, phenolic resin for bonding the fiber is applied, silane coupling agent for increasing the bonding performance of the fiber and resin glue is applied, and hydrophobic agent for realizing hydrophobic performance is applied. The above-mentioned rock wool fiber and phenolic resin, silane coupling agent, hydrophobic agent, etc. form an intermediate product in the process of preparing rock wool products, which is called glue spraying cotton. The glue spraying cotton is formed into semi-hard rock wool product rock wool board through cotton collecting, laying, rolling and curing. The fiber obtained by blowing without applying resin glue, coupling agent, hydrophobic agent, etc. is called rock wool fiber.

[0032] The rock wool fiber required for the rock wool fiber and phenolic resin composite artificial board can be obtained from the production line without glue spraying cotton.

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

[0034] The proportion of rock wool fiber and phenolic resin as the main material of composite wood-based panel has a great influence on the performance of the panel. The higher the content of phenolic resin, the higher the strength performance of the panel, and the higher the heat release rate and total heat release during combustion. As an optimal balance between strength performance and combustion performance, the proportion of rock wool fiber is 82-93wt%, and the solid content of phenolic resin is 18-7wt%.

[0035] It is found that the fiber length has an influence on the performance and preparation process of the 0.5cm-5cm fiber. When the fiber length is too long, such as more than 3.5cm, the difficulty of mixing phenolic resin with the fiber increases significantly, and the strength and screw holding force performance of the wood-based panel decrease; when the fiber length is too short, such as less than 0.6cm, the phenolic resin is easy to mix with the fiber, but the fibers are not fully entangled, and the strength and screw holding force of the wood-based panel also decrease, and the brittleness increases. For different length intervals of the fiber, the performance and mixing uniformity are optimized, and when the 2.5-3.5cm(>2.5 and ≤3.5) rock wool long fiber accounts for 20-30% of the total fiber, the 1.5-2.5cm(>1.5 and ≤2.5) rock wool medium-length fiber accounts for 20-30% of the total fiber, and the 0.6-1.5cm(≥0.6 and ≤1.5) rock wool short fiber accounts for 40-60% of the total fiber, a good balance can be achieved. However, in the actual preparation process of different length fibers(such as S2), it is difficult to control the fiber length within a fixed range, and as an acceptable requirement, the rock wool short fiber less than 0.6cm and greater than 3.5cm accounts for no more than 15% of the total fiber.

[0036] The rock wool fiber is mainly composed of SiO2, Al2O3, CaO, MgO, Fe m O n (Fe2O3, FeO), and the melt is rapidly cooled by air blowing to form a fiber with ionic covalent bond as the main glass state, while the phenolic resin has typical covalent bond properties. The alkoxyl 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 improving the bonding strength of the rock wool fiber and the phenolic resin. Therefore, the coupling agent is an interfacial agent, and theoretically, a single molecular layer of the coupling agent can achieve bridging effect, and the proportion of the coupling agent in the fiber can well describe this interfacial characteristic. As an optimization result of 1-6wt% of the fiber, 2-4wt% of the silane coupling agent in the total rock wool fiber can achieve the effect of coupling enhancement, and too much coupling agent will increase the cost.

[0037] The phenol-formaldehyde resin in the continuous phase has better hydrophobicity than cement and calcium silicate due to its covalent bond properties. The purpose of the hydrophobic agent is to disperse in the material to form a low surface energy hydrophobic layer. When the optimal amount of hydrophobic agent is 1-10wt% of the total amount of rock wool fibers, and the amount of hydrophobic agent is 3-5wt% of the total amount of rock wool fibers, the hydrophobic purpose can be achieved. Too much hydrophobic agent not only increases the cost, but also is not beneficial to the strength of the board.

[0038] Further, the material of the rock wool fibers of the present application meets the standard requirements of "Rock wool thermal insulation products for building GB / T 19686" 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 the material of the original fiber has different requirements. Corresponding to different standards, their main difference lies 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 that the acidity coefficient be not less than 1.8. "Rock wool thermal insulation products for building GB / T 19686" requires that the acidity coefficient be not less than 1.6. Rock wool fibers and phenolic resin composite wood-based panels do not produce original fibers alone, but use intermediate products in the rock wool industry, which is technically and economically feasible. As a recommendation, indoor dry occasions can use original fibers that meet GB / T 19686, and outdoor and humid occasions can use original fibers that meet GB / T 25975.

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

[0041] The rock wool fibers and the phenolic resin are fully mixed, which is a basic condition for preparing the composite wood-based panel. As an optimized test result, the powdered solid phenolic resin with a particle size of not more than 200 mesh can make the powdered resin uniformly adhere to the surface of the fiber, which can reduce the amount of resin while achieving uniform dispersion. Spraying can make the liquid phenolic resin fully wrap the surface of the fiber. As an optimized number average molecular weight of not more than 1200 g / mol liquid phenolic resin, it is not easy to block the spray gun. The number average molecular weight is the average value of the molecular weight of each polymer, and the commonly used test methods include gel permeation chromatography (GPC) and other methods.

[0042] Further, the silane coupling agent is one or more than one of an amino silane coupling agent, an epoxy silane coupling agent, a vinyl silane coupling agent, an acrylic silane coupling agent, and a methyl silane coupling agent, which are soluble in water; when used, the silane coupling agent is mixed with water in a weight ratio of 1:(8-10) to form a coupling agent diluent.

[0043] Rock wool fiber belongs to ion covalent bond fiber obtained by glass melt blowing, and amino silane coupling agent, epoxy silane coupling agent, vinyl silane coupling agent, acrylic silane coupling agent and methyl silane coupling agent can form coupling force between the fiber and phenolic resin. One or more than one of them can be selected and used to enhance the effect of rock wool fiber and phenolic resin composite artificial board. As a surface treatment agent, a single molecular layer of coupling agent can obtain bridging effect in theory. The beneficial effect of mixing silane coupling agent and water in a weight ratio of 1:(8-10) is to make it uniformly distributed during spraying. The water-soluble coupling agent is easy to dry and does not produce volatile organic compounds.

[0044] Further, the water-repellent agent is one or more than one of water-soluble silicon-based water-repellent agents; when used, the water-repellent agent is mixed with water in a weight ratio of 1:(2-4) to form a water-repellent agent diluent.

[0045] There are many types of water-repellent agents, such as low surface energy water-repellent agents, biodegradable water-repellent agents, polymer water-repellent agents, etc. Silicon-based water-repellent agents have performance and price advantages and are widely used. Mixing water-soluble silicon-based water-repellent agents with water in a weight ratio of 1:(2-4) improves the uniformity of spraying and does not produce volatile organic compounds.

[0046] The present application provides a preparation method of size mismatched rock wool fiber and phenolic resin composite artificial board, comprising:

[0047] S1, the rock wool melt is directly introduced into a centrifuge to form rock wool fiber through the centrifuge.

[0048] In the preparation of rock wool fiber meeting the requirements of "Building Rock Wool Insulation Products GB / T 19686" or "Building External Wall Rock Wool Insulation Products GB / T 25975", no auxiliary agent such as resin glue, water-repellent agent, coupling agent, etc. is applied, and the fiber is directly formed through the centrifuge.

[0049] S2, the rock wool fiber is cut into fibers of desired length by a cotton cutting machine to obtain the desired rock wool fiber.

[0050] The cotton cutting machine is a fiber cutting device that cuts fibers into fibers of a certain length. It has a pair of rollers with regularly arranged teeth. By controlling the distribution density, shape and rotation speed of the teeth, the dispersion and cutting of the fibers are completed. The greater the density and speed of the teeth, the more short fibers; on the contrary, the smaller the density and speed of the teeth, the less short fibers. The device is commonly used in the preparation of granular cotton in rock wool products, and engineering and technical personnel should know how to adjust the device to control the distribution of fiber length.

[0051] S3, the rock wool fiber is passed through 2-4 cotton opening machines to open the cotton, and the coupling agent diluent is sprayed on the last cotton opening machine to mix uniformly.

[0052] The opener is a device for dispersing fibers into a fluffy state, and is a common device in the textile industry. The purpose of multi-pass opening is to completely disperse the fibers to facilitate uniform application of coupling agents, resins, and water-adding agents in subsequent processes. 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 fibers. In order to prevent dilution and carry-out of the coupling agent by the subsequent applied liquid resin, a drying process is provided. The test method for water content is carried out in accordance with the standard "Granular Cotton for Absorbing Panels JC / T 903". As a recommended method, the coupling agent application step is completed by a uniformly distributed spray device provided on the opener box.

[0053] S4, the rock wool fibrils with coupling agent enter the 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 by a spray device and mixed evenly.

[0054] The resin mixer is actually also an opener, and a uniformly distributed spray device is provided on the box to complete the fluffy glue spraying. As a recommendation, the spray device can also be provided in a pair of hollow rollers to spray glue in the radial direction. For powdered solid phenolic resin, "wet cotton" with coupling agent dilution liquid in S3 process is beneficial to the uniform adhesion of powdered solid phenolic resin on the surface of the fibers.

[0055] When liquid phenolic resin is used, hot air is introduced for drying, so that the water content is not more than 10%; among them, the air hole is a key index affecting the mechanical strength of the composite panel, and the low water content of the liquid resin can effectively control the porosity rate in the forming process of the composite panel.

[0056] S5, spraying a water-repellent agent dilution liquid on the rock wool fibers with coupling agent and phenolic resin, and after mixing evenly, transferring to a forming machine.

[0057] As a recommendation, spraying a water-repellent agent dilution liquid can be continued in the mixer of S4, and a set of water-repellent agent spray devices are provided on the box for uniform distribution.

[0058] S6, the material transferred to the forming machine is formed into a rock wool fibril and phenolic resin composite panel blank after pre-pressing, hot pressing, and cold pressing.

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

[0060] The main process parameters of hot pressing include temperature, pressure and time. Among them, the hot pressing process is through temperature to make the phenolic resin crosslinking reaction to form a composite material of bonded fibers. The optimum reaction temperature is different for different phenolic resins, and differential scanning calorimetry (DSC) is one of the methods, and those skilled in the art know how to determine the curing temperature of phenolic resin. The reaction curing time is directly related to the thickness of the plate in addition to the type of phenolic resin. The thicker the plate, the longer the time required. By observing the reaction color and testing the performance of the phenolic resin, it can be judged whether the reaction curing is completed. The pressure is the main control of the density of the plate. The density is closely related to the performance of the plate, but there is a saturation value. The increase in density does not correspondingly increase the comprehensive performance. The hot pressing pressure of 5-10 MPa is the result of performance optimization of the parameters.

[0061] S7, the blank plate is dried and maintained, cut and sanded to form a rock wool primary fiber and phenolic resin composite artificial plate.

[0062] As a process engineering, the same as phenolic resin and urea-formaldehyde resin wood-based artificial plate, the blank plate is maintained after standing to release the stress formed by the curing of the resin. The uneven surface is sanded and polished to provide a flat condition for the veneer.

[0063] The specific implementation is as follows:

[0064] Some components in the examples and comparative examples are as follows:

[0065] Rock wool fiber: rock wool fiber (purchased from Beijing Jinju Energy-saving 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: hexamethylene tetramine (purchased from Jinan Shengquan Group Co., Ltd.)

[0068] Example 1

[0069] This example provides a preparation method of a rock wool primary fiber and phenolic resin composite artificial plate with different length ratios, and the specific steps are as follows:

[0070] Step S1: weigh 30 parts of rock wool long fiber (cutting length set by cutting machine is 3 cm), 30 parts of rock wool medium length fiber (cutting length set by cutting machine is 2 cm), and 40 parts of rock wool short fiber (cutting length set by cutting machine is 1 cm). The three different lengths of rock wool primary fibers are placed in the opening device to ensure that the three fibers are fully mixed and uniform.

[0071] Step S2: 3 parts of γ-aminopropyl triethoxysilane (KH550) were weighed and mixed with deionized water in a ratio of 1:10 to prepare a coupling agent solution. The coupling agent solution was uniformly sprayed onto the surface of the rock wool fiber using a vacuum pump for pressurized atomization to obtain a coupling agent modified rock wool fiber.

[0072] Step S3: The rock wool fiber was transferred to a mixer, 10 parts of phenolic resin (particle size 200 mesh) were added, and mechanical mixing was used for 10 min to fully mix the fiber and resin uniformly.

[0073] Step S4: 3 parts of silicone hydrophobic agent were weighed and mixed with deionized water in a ratio of 1:3 to prepare a silicone hydrophobic agent solution. The hydrophobic agent solution was uniformly sprayed onto the surface of the rock wool fiber with the coupling agent and phenolic resin.

[0074] Step S5: 0.2 parts of a release agent was uniformly sprayed on the surface of the hot-pressing mold.

[0075] Step S6: 100 parts of the mixed rock wool fiber-phenolic resin raw material were weighed and evenly laid into the customized mold.

[0076] Step S7: The mixture was placed together with the mold on a flat vulcanizing machine for pre-pressing. The pre-pressing pressure was 1.5 MPa, the pre-pressing temperature was 20°C, and the pre-pressing time was 2 min. The fiber-resin mixture in the mold was preliminarily compacted into a wood-based panel blank.

[0077] Step S8: The pre-pressed sample was placed together with the mold on a flat vulcanizing machine for hot pressing. The hot pressing pressure was 8 MPa, the hot pressing temperature was 190°C, and the hot pressing time was 10 min. The mixture was hot pressed into a wood-based panel under these hot pressing process parameters.

[0078] Step S9: The hot-pressed sample was placed together with the mold on a flat vulcanizing machine for cold pressing. The cold pressing pressure was 8 MPa, the cold pressing temperature was 20°C, and the cold pressing time was 5 min. The composite wood-based panel was cooled under these cold pressing process parameters.

[0079] Step S10: The pressure was removed and the product was demolded from the mold.

[0080] Step S11: After standing at room temperature for 2 hours, the composite wood-based panel was cut and the surrounding edges were removed. A rock wool fiber-phenolic resin composite wood-based panel modified by a coupling agent (KH550) was obtained, with a long, medium and short fiber ratio of 30:30:40.

[0081] Example 2

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

[0083] Embodiment 3

[0084] The embodiment provides a preparation method of rock wool raw fiber and phenolic resin composite artificial board with different length ratios, and the difference from the embodiment 1 is that an amino silane coupling agent (KH550) used in the embodiment is replaced by an epoxy silane coupling agent (KH560), and the rest of steps are the same as those of the embodiment 1.

[0085] Comparative example 1

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

[0087] Comparative example 2

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

[0089] Comparative example 3

[0090] The comparative example provides a preparation method of rock wool raw fiber and phenolic resin composite artificial board with a single length, and specific steps are as follows.

[0091] Step S1: 100 parts of rock wool long fibers (the cutting length set by a cotton cutting machine is 3 cm) are weighed and placed in a cotton opening device to be uniformly dispersed.

[0092] Step S2: 3 parts of gamma-aminopropyl triethoxysilane (KH550) are weighed, and a coupling agent solution is prepared by mixing the gamma-aminopropyl triethoxysilane (KH550) with deionized water at a ratio of 1:10, and the coupling agent solution is uniformly sprayed onto the surface of the rock wool fibers by using a vacuum pump to pressurize and atomize, so that the coupling agent modified rock wool fibers are obtained.

[0093] Step S3: the rock wool fibers are transferred into a mixer, 10 parts of phenolic resin (the particle size is 200 meshes) are added, and the fibers and the resin are fully mixed and uniformly mixed by using mechanical mixing for 10 minutes.

[0094] Step S4: 3 parts of an organic silicon hydrophobic agent are weighed, and an organic silicon hydrophobic agent solution is prepared by mixing the organic silicon hydrophobic agent with deionized water at a ratio of 1:3, and the hydrophobic agent solution is uniformly sprayed onto the surface of the rock wool fibers by using a vacuum pump to pressurize and atomize.

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

[0096] Step S6: 100 parts of the mixed and uniform rock wool fiber-phenolic resin raw material is evenly laid in the customized mold.

[0097] Step S7: The mixed material is placed in the flat vulcanizing machine together with the mold for pre-pressing. The pre-pressing pressure is 1.5 MPa, the pre-pressing temperature is 20°C, and the pre-pressing time is 2 min. The fiber-resin mixed material in the mold is preliminarily compacted into a wood-based board blank.

[0098] Step S8: The pre-pressed sample is placed in the flat vulcanizing machine together with the mold for hot-pressing. The hot-pressing pressure is 8 MPa, the hot-pressing temperature is 190°C, and the hot-pressing time is 10 min. The mixed material is hot-pressed into a wood-based board under the hot-pressing process parameters.

[0099] Step S9: The hot-pressed sample is placed in the flat vulcanizing machine together with the mold for cold-pressing. The cold-pressing pressure is 8 MPa, the cold-pressing temperature is 20°C, and the cold-pressing time is 5 min. The composite wood-based board is cooled under the cold-pressing process parameters.

[0100] Step S10: The pressure is released, and the product is demolded from the mold.

[0101] Step S11: After the finished product is placed at room temperature for 2 hours, the composite wood-based board is cut and treated, and the peripheral burrs are removed. A rock wool primary fiber-phenolic resin composite wood-based board modified by a coupling agent (KH550) and composed of long fibers is obtained.

[0102] Comparative Example 4

[0103] The present comparative example provides a preparation method of a single-length rock wool primary fiber-phenolic resin composite wood-based board. The specific steps are the same as those of Comparative Example 3, and the only difference is that 100 parts of the rock wool long fiber (the cutting length set by the cotton cutting machine is 3 cm) in Comparative Example 3 is replaced by 100 parts of the rock wool medium-length fiber (the cutting length set by the cotton cutting machine is 2 cm).

[0104] Comparative Example 5

[0105] The present comparative example provides a preparation method of a single-length rock wool primary fiber-phenolic resin composite wood-based board. The specific steps are the same as those of Comparative Example 3, and the only difference is that 100 parts of the rock wool long fiber (the cutting length set by the cotton cutting machine is 3 cm) in Comparative Example 3 is replaced by 100 parts of the rock wool short fiber (the cutting length set by the cotton cutting machine is 1 cm).

[0106] Comparative Example 6

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

[0108] Comparative example 7

[0109] The comparative example provides a preparation method of rock wool raw fiber and phenolic resin composite artificial board, and the specific steps are the same as those of comparative example 3, and the only difference is that 100 parts of rock wool long fibers (the cutting length set by the cotton cutting machine is 3 cm) in comparative example 3 are replaced by 60 parts of rock wool long fibers (the cutting length set by the cotton cutting machine is 3 cm) and 40 parts of rock wool short fibers (the cutting length set by the cotton cutting machine is 1 cm).

[0110] Comparative example 8

[0111] The comparative example provides a preparation method of rock wool raw fiber and phenolic resin composite artificial board, and the specific steps are the same as those of comparative example 3, and the only difference is that 100 parts of rock wool long fibers (the cutting length set by the cotton cutting machine is 3 cm) in comparative example 3 are replaced by 60 parts of rock wool long fibers (the cutting length set by the cotton cutting machine is 3 cm) and 40 parts of rock wool short fibers (the cutting length set by the cotton cutting machine is 1 cm).

[0112] Comparative example 9

[0113] The comparative example provides a preparation method of rock wool raw fiber and phenolic resin composite artificial board, and the specific steps are the same as those of comparative example 3, and the only difference is that 100 parts of rock wool long fibers (the cutting length set by the cotton cutting machine is 3 cm) in comparative example 3 are replaced by 60 parts of rock wool long fibers (the cutting length set by the cotton cutting machine is 3 cm) and 40 parts of rock wool short fibers (the cutting length set by the cotton cutting machine is 1 cm).

[0114] Step S1: 30 parts of rock wool long fibers (the cutting length set by the cotton cutting machine is 3 cm), 30 parts of rock wool medium-length fibers (the cutting length set by the cotton cutting machine is 2 cm), and 40 parts of rock wool short fibers (the cutting length set by the cotton cutting machine is 1 cm) are weighed, and the three different lengths of rock wool raw fibers are placed in the cotton opening device to ensure that the three fibers are fully mixed and uniform.

[0115] Step S2: The rock wool raw fibers are transferred to the mixer, 10 parts of phenolic resin (the particle size is 200 meshes) are added, and the fibers and the resin are fully mixed and uniform by mechanical mixing for 10 minutes.

[0116] Step S3: 0.2 parts of the release agent are uniformly sprayed on the surface of the hot-pressing mold.

[0117] Step S4: 100 parts of the mixed and uniform rock wool fiber-phenolic resin raw material is weighed and evenly laid into the customized mold.

[0118] Step S5: Put the mixture together with the mold on the flat vulcanizing machine for pre-pressing. Pre-pressing pressure: 1.5 MPa; pre-pressing temperature: 20℃; pre-pressing time 2 min. The fiber-resin mixture in the mold is initially compacted into a wood-based panel blank.

[0119] Step S6: Put the pre-pressed sample together with the mold on the flat vulcanizing machine for hot pressing. Hot pressing pressure: 8 MPa, hot pressing temperature: 190℃, hot pressing time: 10 min. The mixture is hot pressed into a wood-based panel under the above hot pressing process parameters.

[0120] Step S7: Put the hot-pressed sample together with the mold on the flat vulcanizing machine for cold pressing. Cold pressing pressure: 8 MPa, cold pressing temperature: 20℃, cold pressing time: 5 min. The composite wood-based panel is cooled under the above cold pressing process parameters.

[0121] Step S8: Remove the pressure and demold the product from the mold.

[0122] Step S9: After the finished product is placed at room temperature for 2 hours, the composite wood-based panel is cut and the surrounding edges are removed to obtain a rock wool fiber-phenolic resin composite wood-based panel with a long, medium and short fiber ratio of 30:30:40.

[0123] Comparative Example 10

[0124] This comparative example provides a preparation method of a rock wool fiber-phenolic resin composite wood-based panel with different length ratios without modification by silane coupling agent and hydrophobic agent. The specific steps are the same as those of Comparative Example 9, and the only difference is that the ratio of long, medium and short fibers is 40:40:20.

[0125] Comparative Example 11

[0126] This comparative example provides a preparation method of a rock wool fiber-phenolic resin composite wood-based panel with different length ratios without modification by silane coupling agent and hydrophobic agent. The specific steps are the same as those of Comparative Example 9, and the only difference is that the ratio of long, medium and short fibers is 10:10:80.

[0127] The properties of the rock wool fiber-phenolic resin composite wood-based panels provided in the above examples and comparative examples are tested, and the property tests include density, static bending strength, elastic modulus, combustion grade, screw holding force, and water absorption rate. The specific test methods are as follows:

[0128] Density: tested according to the requirements of GB / T 17657-2022 Wood-based panels and veneered wood-based panels-Determination of physical and mechanical properties.

[0129] Modulus of rupture: tested according to the requirements of GB / T 17657-2022 Test methods of physical and mechanical properties of wood-based panels and sandwich panels.

[0130] Modulus of elasticity: tested according to the requirements of GB / T 17657-2022 Test methods of physical and mechanical properties of wood-based panels and sandwich panels.

[0131] Burning classification: tested according to the requirements of GB 8624-2012 Classification of building materials and products according to their burning behavior.

[0132] Screw holding capacity: tested according to the requirements of GB / T 17657-2022 Test methods of physical and mechanical properties of wood-based panels and sandwich panels.

[0133] Water absorption: tested according to the requirements of GB / T 17657-2022 Test methods of physical and mechanical properties of wood-based panels and sandwich panels.

[0134] The performance test data are shown in Table 1.

[0135] Table 1 Performance test results

[0136]

[0137]

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

[0139] In different embodiments and comparative examples, the amount of phenolic resin added does not change, the difference is the use of different length rock wool fiber ratio and whether to use silane coupling agent modification, therefore the burning classification of artificial board all reaches A2 level.

[0140] Example 1: the artificial board prepared by using long, medium and short fiber ratio of 30:30:40 and rock wool fiber modified by coupling agent (KH550) and phenolic resin composite, its density is 1.326 g / cm 3 , the modulus of rupture is 33.456 MPa, the modulus of elasticity is 5775 MPa, the screw holding capacity is 1187 N, and the water absorption is 6.44%.

[0141] Example 2: the artificial board prepared by using long, medium and short fiber ratio of 20:20:60 and rock wool fiber modified by coupling agent (KH550) and phenolic resin composite, its density is 1.324 g / cm 3, the static bending strength is 33.788 MPa, the elastic modulus is 5696 MPa, the screw clamping force is 1142 N, and the water absorption rate is 6.33%.

[0142] Example 3: The artificial board is prepared by compounding the rock wool fiber with a length-to-medium-to-short ratio of 30:30:40 and modified by a coupling agent (KH560) with phenolic resin. The density is 1.329 g / cm 3 , the static bending strength is 33.011 MPa, the elastic modulus is 5633 MPa, the screw clamping force is 1138 N, and the water absorption rate is 5.68%.

[0143] Example 2 and Example 1: The density is close, the static bending strength is slightly higher, the elastic modulus, the screw clamping force and the water absorption rate are slightly lower, and the overall difference is not large.

[0144] Example 3 and Example 1: The density, static bending strength, elastic modulus and screw clamping force are close, and the water absorption rate decreases by 11.8%.

[0145] Comparative Example 1 and Comparative Example 2: Different length-to-medium-to-short fiber ratios are used compared with Example 1 and Example 2. The results show that the performance decreases compared with Example 1 and Example 2, and the specific data are as follows:

[0146] Comparative Example 1 and Example 1: The density decreases by 0.5%, the static bending strength decreases by 4.7%, the elastic modulus decreases by 3.4%, the screw clamping force decreases by 11.9%, and the water absorption rate increases by 6.8%; compared with Example 2: The density decreases by 0.4%, the static bending strength decreases by 5.7%, the elastic modulus decreases by 2.3%, the screw clamping force decreases by 8.4%, and the water absorption rate increases by 8.7%.

[0147] Comparative Example 2 and Example 1: The density increases by 1.1%, the static bending strength increases by 1.4%, the elastic modulus decreases by 0.2%, the screw clamping force increases by 0.7%, and the water absorption rate decreases by 0.2%; compared with Example 2: The density increases by 1.3%, the static bending strength increases by 0.4%, the elastic modulus increases by 1.2%, the screw clamping force increases by 4.7%, and the water absorption rate decreases by 0.3%.

[0148] Comparative Example 3, Comparative Example 4 and Comparative Example 5: Different length-to-medium-to-short fiber ratios are not used, but single rock wool long fiber, single rock wool medium-long fiber and single rock wool short fiber are respectively used to manufacture artificial boards with phenolic resin. The results show that the performance decreases compared with Example 1 and Example 2. The specific data are as follows:

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

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

[0151] Comparative Example 5 compared with Example 1: 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%, water absorption 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%, water absorption decreased by 2.5%.

[0152] Comparative Example 6, Comparative Example 7 and Comparative Example 8: instead of using three different lengths of rock wool fiber ratio, two fibers of rock wool long fiber, rock wool medium long fiber and rock wool short fiber were respectively used to manufacture artificial board with phenolic resin. The results show that compared with Example 1 and Example 2, the performance has decreased. The specific data are as follows:

[0153] Comparative Example 6 compared with Example 1: density is close, static bending strength decreased by 2.2%, elastic modulus decreased by 3.5%, screw holding force decreased by 2.9%, water absorption increased by 2.3%; compared with Example 2: density is close, static bending strength decreased by 3.2%, elastic modulus decreased by 2.1%, screw holding force increased by 0.9%, water absorption increased by 4.1%.

[0154] Comparative Example 7 compared with Example 1: density is close, static bending strength decreased by 7.3%, elastic modulus decreased by 6.0%, screw holding force decreased by 7.7%, water absorption decreased by 0.9%; compared with Example 2: density is close, static bending strength decreased by 8.2%, elastic modulus decreased by 4.7%, screw holding force decreased by 4.0%, water absorption increased by 0.8%.

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

[0156] Comparative Example 9, Comparative Example 10 and Comparative Example 11: the surface modification treatment is not carried out on the rock wool fibers of different length ratios by using a coupling agent, resulting in a significant decrease in mechanical properties.

[0157] Comparative Example 9 compared with Example 1: the density is close, the static bending strength decreases by 11.4%, the elastic modulus decreases by 11.9%, the screw holding force decreases by 9.1%, and the water absorption increases by 33.7%; compared with Example 2, the density is close, the static bending strength decreases by 12.3%, the elastic modulus decreases by 10.7%, the screw holding force decreases by 5.5%, and the water absorption increases by 36.0%; compared with Example 3, the density is close, the static bending strength decreases by 10.2%, the elastic modulus decreases by 9.8%, the screw holding force decreases by 5.2%, and the water absorption increases by 51.6%.

[0158] Comparative Example 10 compared with Comparative Example 1: the density is close, the static bending strength decreases by 14.0%, the elastic modulus decreases by 12.0%, the screw holding force decreases by 1.8%, and the water absorption increases by 27.8%.

[0159] Comparative Example 11 compared with Comparative Example 2: the density is close, the static bending strength decreases by 13.8%, the elastic modulus decreases by 11.5%, the screw holding force decreases by 7.3%, and the water absorption increases by 36.1%.

[0160] In summary, 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 comprehensive performance of the rock wool fiber-phenolic resin composite plywood is effectively optimized, the static bending strength, elastic modulus and screw holding force of the plywood are significantly improved, the water absorption of the plywood is reduced, and the plywood meets the A2 level combustion performance standard requirements.

[0161] The above is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A composite engineered wood panel made of mismatched rock wool fibers and phenolic resin, characterized in that, include: Rock wool fibers, phenolic resin, silane coupling agent, and water-repellent agent; By weight percentage, rock wool fibers account for 82-93 wt%, phenolic resin solids account for 18-7 wt%, silane coupling agent accounts for 2-4 wt% of the total rock wool fibers, and water-repellent agent accounts for 3-5 wt% of the total rock wool fibers. The rock wool fibers are mainly composed of 2.5-3.5cm long rock wool fibers, 1.5-2.5cm medium-length rock wool fibers, and 0.6-1.5cm short rock wool fibers. The 2.5-3.5cm long rock wool fibers account for 20-30% of the total fiber volume, the 1.5-2.5cm medium-length rock wool fibers account for 20-30% of the total fiber volume, the 0.6-1.5cm short rock wool fibers account for 40-60% of the total fiber volume, and the rock wool short fibers shorter than 0.6cm and the rock wool long fibers longer than 3.5cm account for no more than 15% of the total fiber volume.

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 conforms to the requirements of the standards GB / T 19686 "Rock Wool Insulation Products for Buildings" or GB / T 25975 "Rock Wool Products for External Thermal Insulation of Building Walls".

3. The size-mismatched rock wool fiber and phenolic resin composite engineered wood panel 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 mesh 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 engineered wood panel according to claim 1, characterized in that, The silane coupling agent is one or more of the following: water-soluble aminosilane coupling agent, epoxysilane coupling agent, vinylsilane coupling agent, acrylic silane coupling agent, and methylsilane coupling agent, used in combination. When used, the silane coupling agent is miscible with water at a weight ratio of 1:(8-10) to form a coupling agent dilution solution.

5. The size-mismatched rock wool fiber and phenolic resin composite engineered wood panel according to claim 1, characterized in that, The hydrophobic agent is one or more of the silicon-based hydrophobic agents used in combination; when used, the hydrophobic agent is mixed with water at a weight ratio of 1:(2-4) to form a hydrophobic agent dilution.

6. A method for preparing a composite artificial board of rock wool fibers and phenolic resin with size mismatch as described in any one of claims 1 to 5, characterized in that, include: S1. Rock wool melt is directly fed into a centrifuge, where it is processed into rock wool fibers. S2. The rock wool raw fibers are cut into the required lengths using a cotton cutter to obtain the required rock wool raw fibers; S3. The cut rock wool fibers are unwound by 2 to 4 unwound machines, and a coupling agent dilution is sprayed on the last unwound machine to mix them evenly. S4. Rock wool fibers with coupling agent are fed into a mixer containing powdered solid phenolic resin, or powdered solid phenolic resin or liquid phenolic resin is sprayed onto rock wool fibers with coupling agent through a spraying device and mixed evenly. S5. Spray a water-repellent agent dilution onto the rock wool fiber containing coupling agent and phenolic resin, mix evenly, and then transfer it to the molding machine. S6. The material transferred to the molding machine is pre-pressed, hot-pressed, and cold-pressed to form a composite artificial board blank of rock wool fiber and phenolic resin. S7. The blank board is dried and cured, then cut and sanded to form the original board of rock wool fiber and phenolic resin composite artificial board.

7. The preparation method according to claim 6, characterized in that, When using liquid phenolic resin, hot air should be introduced for drying to ensure that its moisture content is no more than 10%.

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

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