Thermal-insulation flame-retardant material prepared from waste spinning regenerated fibers and cement and preparation method of thermal-insulation flame-retardant material

Abstract

The invention relates to the technical field of recycling of solid waste renewable resources, in particular to a thermal-insulation flame-retardant material prepared from waste spinning regenerated fibers and cement and a preparation method thereof.The thermal-insulation flame-retardant material is prepared from the waste spinning regenerated fibers, the cement, vinyl acetate-ethylene copolymer emulsion and a cement foaming agent through high-pressure collision mixing; compared with the prior art, the waste spinning does not need to be added according to different proportions after being classified, components such as PVA materials, gravel, fly ash, latex powder, lime putty and a water reducing agent are omitted, and the heat-preservation flame-retardant material with uniform and independent closed air holes is obtained through a specific formula and proportion and a specific preparation method. And when the average temperature is not higher than 350 DEG C, the heat conductivity coefficient is reduced to 0.03-0.04 W / (mK), the combustion performance reaches the B1-A2 level, and the volume weight is 100-150 kg / m < 3 >.

Description

Technical Field

[0001] This invention relates to the field of solid waste recycling technology, and in particular to a heat-insulating and flame-retardant material made from recycled waste textile fibers and cement, and its preparation method. Background Technology

[0002] land

[0003] Textiles are indispensable in daily life. We need textiles for clothing, housing, and transportation. At the same time, a large amount of textile waste is generated, which is simply called waste textiles or waste used textiles.

[0004] From the perspective of energy conservation and carbon reduction, improving the resource utilization and harmless treatment of waste textiles and promoting their efficient use is of great significance. A 2008 study by the Bureau of International Recycling at the University of Copenhagen, Sweden, concluded that recycling 1 kg of waste textiles can reduce carbon dioxide emissions by 3.6 kg, save 6000 liters of water, and reduce pesticide use by 0.2 kg. However, if waste textiles are not fully utilized, it will lead to the waste of natural fibers such as cotton, wool, silk, and hemp, as well as synthetic fibers made from petroleum, and energy waste in spinning, dyeing, and finishing processes. Furthermore, because waste textiles are difficult to degrade in nature, landfilling or other methods of disposal will cause long-term environmental pollution. However, due to technological and cost limitations, the efficient utilization of waste textiles remains a challenge. Therefore, the utilization of waste textiles is not only a resource reuse issue but also a major environmental issue. Currently, waste textile recycling faces two main problems: (1) The problem of flammability of recycled waste textiles: Recycled waste textile products are flammable, which limits the application fields and application scenarios of recycled products; (2) The problem of recycling waste textiles not being utilized at a high value: The recycled waste textiles are mixed. In particular, the recycled waste clothing is sorted out and sold directly as second-hand clothing abroad. The remaining part, which accounts for about 50-60% of the waste clothing, is mixed with waste clothing. A very small part is used as insulation blankets for vegetable greenhouses. The utilization rate is less than 1-2%. The rest cannot be disposed of because it is not allowed to be landfilled or burned.

[0005] Cement is a powdered hydraulic inorganic binder. Concrete made by binding crushed stone with cement not only has high strength after hardening but also resists erosion from fresh or salt water. For a long time, it has been widely used as an important binder in civil engineering, water conservancy, and national defense projects. However, cement products still have the following drawbacks in current technology: (1) Crack problem of cement products: Under long-term natural environment, fine cracks will appear in the internal structure of cement products, resulting in unstable performance; (2) Powdering of cement products: Under long-term natural environment, cement products are prone to powdering, which reduces the anti-aging performance and performance of the products. (3) Problem of density of cement products: Cement products are generally heavy. In some application fields and application scenarios, under the premise of the same performance, lighter products are chosen, which is what we call lightweight products. However, the cost of lightweight products in the existing technology is higher than that of cement products.

[0006] (4) Cement products themselves do not have thermal insulation function: General buildings also need to have thermal insulation function. However, existing technologies often use a combination of cement products and thermal insulation materials, which not only increases the difficulty of construction, but also has poor compatibility between the two materials, increasing the later maintenance cost.

[0007] CN109575357A discloses a method for treating textile waste, including the following steps: (1) separating and extracting solid textiles and desizing waste from textile waste; (2) identifying and sorting the textiles to obtain waste polyester fibers, cellulose fibers, protein fibers, and blended fibers; (3) separating the desizing waste into slurry; (4) concentrating the product of the slurry separation to obtain PVA material; and (5) making the PVA material into industrial-grade slurry. The building reinforcement fiber can be made into reinforced wood-plastic composite materials, modified waterproof membranes, and modified shock-absorbing cement additives. In other words, waste textiles need to undergo a series of complex treatments to be made into modified shock-absorbing cement additives from fibers, which increases the treatment cost of waste textiles, limits their application scope, and is not conducive to promotion and use.

[0008] CN102276200A discloses a method for preparing masonry mortar using waste textile fibers. The initial materials are: cement, medium sand, fly ash, waste fibers, vitrified microspheres, renewable dispersible latex powder, lime paste, water-reducing agent, and water. The initial formula is: cement:lime paste:medium sand = 1:0.44:4. The waste fiber volume accounts for 0.1%-0.5% of the total volume of the premixed mortar, and the insulation material, vitrified microspheres, accounts for 80%-120% of the total volume of the premixed mortar. This technical solution discloses the ability to combine waste textiles with cement to prepare masonry mortar. However, the mortar produced by this technical solution still has disadvantages such as high density and the need to add additional insulation material. Furthermore, since the fiber volume only accounts for 0.1%-0.5% of the total volume of the premixed mortar, the utilization rate still cannot meet the goal of fully recycling waste textiles.

[0009] Based on the above-mentioned existing technologies, there are several technical problems that urgently need to be solved, such as low recycling rate of waste textiles, high bulk density of the mixed material after being combined with cement, and inability to meet the requirements of having thermal insulation, fireproof and flame-retardant properties. Summary of the Invention

[0010] To solve the above technical problems, the present invention provides a thermal insulation and flame retardant material prepared from waste textile recycled fibers and cement. The raw materials for preparing the thermal insulation and flame retardant material include waste textile recycled fibers, cement, vinyl acetate-ethylene copolymer emulsion (VAE emulsion), and cement foaming agent. The materials are mixed by high-pressure collision to obtain a thermal insulation and flame retardant material with uniform, independent, closed pores. The thermal conductivity of the heat-insulating and flame-retardant material is 0.03-0.04 W / (m•K), the combustion performance is B1-A2 grade, and the bulk density is 100-150 kg / m³. Among them, B1 grade is a flame-retardant insulation material with good flame-retardant properties. It is difficult to ignite when exposed to open flames or high temperatures in the air, and it is not easy to spread quickly. Moreover, the combustion stops immediately when the fire source is removed. A2 grade is a non-combustible insulation material that does not burn at all.

[0011] Furthermore, the proportions of each component in the preparation of the thermal insulation and flame retardant material, based on parts by weight, are as follows: Waste textile recycled fiber: 25-35 parts by weight; Cement: 100 parts by weight; Vinyl acetate-ethylene copolymer emulsion (VAE emulsion): 15-16 parts by weight; Cement foaming agent: 8-9 parts by weight.

[0012] Furthermore, the length of the recycled waste textile fibers is 1-8 mm.

[0013] Furthermore, the cement is silicate cement.

[0014] Furthermore, the cement is Silicate cement PII42.5.

[0015] Furthermore, the vinyl acetate-ethylene copolymer emulsion (VAE emulsion) is designated as VAE emulsion 707.

[0016] Furthermore, the type of cement foaming agent is cement foaming agent AD-300.

[0017] Furthermore, the cement foaming agent also includes a foam stabilizing and reinforcing agent.

[0018] Furthermore, the pressure of the high pressure is 16-19 PMa.

[0019] The present invention also provides a method for preparing the above-mentioned thermal insulation and flame retardant material made from recycled waste textile fibers and cement, comprising the following steps: Step 1: Preparation of recycled waste textile fibers; The waste textile is broken down and then loosened into single fibers to obtain recycled waste textile fibers; Step 2: The waste textile recycled fibers from Step 1 are allowed to fall freely onto the cement surface in a loose state, mixed and further dispersed to obtain waste textile recycled fiber cement slurry. Step 3: Add vinyl acetate-ethylene copolymer emulsion (VAE emulsion) and cement foaming agent to the waste textile recycled fiber cement slurry prepared in Step 2, and mix them under high pressure to obtain waste textile recycled fiber cement foaming slurry. Step 4: The waste textile recycled fiber cement foaming slurry obtained in Step 3 is subjected to injection molding and curing to obtain the thermal insulation and flame retardant material prepared by the waste textile recycled fiber and cement.

[0020] Furthermore, the equipment used to break up the waste textiles in step 1 includes, but is not limited to, a fiber unpacking machine; the equipment used for loosening includes, but is not limited to, a fiber loosening machine.

[0021] Furthermore, in step 2, water is added to dilute the cement before it is mixed with the recycled waste textile fibers.

[0022] Furthermore, in step 2, the mixing equipment is a cement mixer. The waste textile recycled fibers fall onto the cement surface in a loose state using a loose roller, and the mixing shaft blades carry them into the cement for mixing, in order to prevent the waste textile recycled fibers from clumping together during the mixing process and affecting the dispersion.

[0023] Furthermore, before adding the vinyl acetate-ethylene copolymer emulsion (VAE emulsion) in step 3, the vinyl acetate-ethylene copolymer emulsion (VAE emulsion) is diluted with water.

[0024] Further, in step 3, the waste textile recycled fiber cement slurry is pumped into the high-pressure mixer inside the cement foaming machine, and then the vinyl acetate-ethylene copolymer emulsion (VAE emulsion) is pumped into the high-pressure mixer inside the cement foaming machine. At the same time, the cement foaming agent and water are mixed and foamed to form foam, which is sent to the high-pressure mixer of the cement foaming machine and mixed with the waste textile recycled fiber cement slurry under high pressure to obtain a waste textile recycled fiber cement foaming slurry with uniform independent closed pores.

[0025] Further, in step 4, the waste textile recycled fiber cement foaming slurry is injected into the mold, left to stand for 24-72 hours for curing, then the mold is removed, and after curing for another 3-7 days, a heat-insulating and flame-retardant material prepared from waste textile recycled fiber and cement is obtained.

[0026] Furthermore, the curing temperature in step 4 is room temperature.

[0027] Furthermore, the water used for dilution or foaming is at a temperature of 40-55°C, and the total mass of the water used is 65-68% of the mass of the cement.

[0028] The present invention also provides a foamed thermal insulation product, wherein the foamed thermal insulation product is a thermal insulation and flame retardant material prepared from the above-mentioned waste textile recycled fibers and cement, or is made from the above-mentioned waste textile recycled fibers and cement, or includes the above-mentioned waste textile recycled fibers and cement.

[0029] The present invention also provides a foamed insulation board, wherein the foamed insulation board is a heat-insulating and flame-retardant material prepared from the above-mentioned waste textile recycled fibers and cement, or is made from the above-mentioned heat-insulating and flame-retardant material prepared from the above-mentioned waste textile recycled fibers and cement, or includes the above-mentioned heat-insulating and flame-retardant material prepared from the above-mentioned waste textile recycled fibers and cement.

[0030] The beneficial effects of this invention are as follows: 1. The thermal insulation and flame retardant material prepared by this invention using waste textiles and cement, compared with the prior art, does not require the waste textiles to be sorted and added in different proportions, and also eliminates components such as PVA material, sand, fly ash, latex powder, lime paste, and water-reducing agent. Through a specific formula and ratio combined with a specific preparation method, its thermal conductivity is reduced to 0.03-0.04 W / (m•K) at an average temperature not exceeding 350℃. According to the national standard (GB / T10295-2008), materials with a thermal conductivity not greater than 0.12 W / (m•K) at an average temperature not exceeding 350℃ are called thermal insulation materials, and materials with a thermal conductivity below 0.05 W / (m•K) are called high-efficiency thermal insulation materials. That is, the thermal insulation and flame retardant material of this invention is a high-efficiency thermal insulation material. The combustion performance is rated B1-A2. According to the requirements of the 2020 edition of the National Code for Fire Protection Design of Buildings, the combustion performance of the thermal insulation and flame retardant material of this invention meets the GB8624-2012 standard. With a density of 100-150 kg / m³, it belongs to lightweight building materials and meets the requirements of lightweight building materials standards (such as GB / T23451-2023 or JG / T567-2019). Furthermore, the waste textile recycled fiber prepared by this invention and the thermal insulation and flame retardant material prepared by cement combine waste textiles and silicate cement. While playing a role in gelling and flame retardancy, it can also ensure that the mixed thermal insulation and flame retardant material is odorless, formaldehyde-free, has good stability, anti-aging, and is green and environmentally friendly. Its thermal insulation performance and environmental protection performance are superior to current thermal insulation materials such as rock wool, glass wool, polyurethane, and phenolic resin. 2. This invention makes full use of waste textiles, and the waste textiles account for as much as 25-35 parts by weight in the raw materials. Compared with the existing technology where waste textiles can only be reused in small or trace amounts, the technical solution of this invention can effectively save resources, reduce carbon dioxide emissions, turn waste into treasure, improve the environment, and realize the high-value recycling of renewable resources. After being processed through a specific process, waste textiles are recycled into fibers with a single fiber length of 1-8 mm. When combined with specific silicate cement, these fibers give the thermal insulation and flame-retardant material a gelling effect. The synergistic effect of the two includes physical adsorption, such as the adsorption of ions or molecules from cement on the surface of the recycled textile fibers to form a physical adsorption layer, and chemical bonding, such as the chemical reaction between the functional groups on the surface of the waste textile fibers and cement to form chemical bonds and generate stable gel hydrates (such as calcium silicate hydrate). The above synergistic effect, combined with the specific size of the recycled textile fibers and the loose state of the recycled textile fibers falling freely onto the cement surface, allows for sufficient adsorption, dispersion, or reaction. This effectively prevents the fine cracking phenomenon in the internal structure of cement in existing technologies, thus expanding the application fields and scenarios. Furthermore, the waste textile recycled fibers selected in this invention, compared to ordinary waste textile fibers that are directly broken down, can form stable, uniform, and non-dissipating pores in the system after being mixed with cement. Through optimization of the broken waste textile fibers, it was unexpectedly discovered that only by selecting single fibers of a specific size, namely the waste textile recycled fibers of the present invention with a specific length of 1-8mm, can the final heat-insulating and flame-retardant material simultaneously possess multiple properties. These are all excellent effects that ordinary waste textile fibers in the prior art cannot achieve. Meanwhile, after mixing waste textiles and cement, a specific proportion of vinyl acetate-ethylene copolymer emulsion (VAE emulsion) is added. After mixing with the waste textile recycled fiber cement slurry, the adhesion between cement and waste textile recycled fibers is further strengthened. It can also counteract the brittleness of silicate cement after curing, improve its water resistance, and prevent water penetration and erosion. 3. In the process of preparing thermal insulation and flame retardant materials, the present invention uses ethylene as an internal plasticizer in the VAE emulsion, which gives the polymer in the vinyl acetate-ethylene copolymer emulsion internal plasticizing properties. Moreover, the internal plasticizer does not migrate during the preparation of thermal insulation and flame retardant materials, thereby avoiding polymer performance aging. It modifies cement, effectively solving the problems of adhesion performance, weather resistance performance, and preventing surface cement powdering. By adding a specific ratio of VAE emulsion and cement foaming agent, it was unexpectedly discovered that their interaction can also innovatively increase the thermal insulation and flame retardant properties of cement itself, further strengthening and improving the properties of cement itself, increasing the adhesion performance of thermal insulation and flame retardant materials, preventing surface powdering, increasing the affinity between thermal insulation and flame retardant materials and the main structure, and also reducing the density of thermal insulation and flame retardant materials, reducing weight, improving thermal insulation performance, and reducing thermal conductivity. Meanwhile, in the preparation of the thermal insulation and flame retardant material, the present invention incorporates a high-pressure collision mixing process to maintain a high pressure in the pores. Therefore, during the static curing period, the pores in the slurry prepared in the early stage can still exist stably, maintaining the excellent thermal insulation and flame retardant performance of the final product. 4. The thermal insulation and flame retardant material prepared by the waste textile recycled fiber and cement of the present invention can also be made into various thermal insulation products of different shapes, specifications and densities, such as foamed thermal insulation boards, depending on the application scenario, and has a wide range of applications. Detailed Implementation

[0031] Example 1 This embodiment provides a thermal insulation and flame retardant material prepared from waste textile recycled fibers and cement. The raw materials for preparing the thermal insulation and flame retardant material include waste textile recycled fibers with a length range of 1-8mm, silicate cement PII42.5, vinyl acetate-ethylene copolymer emulsion (VAE emulsion) model VAE emulsion 707, cement foaming agent AD-300 and water, which are mixed by high pressure collision to obtain a thermal insulation and flame retardant material with uniform independent closed pores. The proportions of each component in the preparation of the thermal insulation and flame retardant material, by weight, are as follows: Waste textile recycled fiber: 35 parts by weight; Cement: 100 parts by weight; Vinyl acetate-ethylene copolymer emulsion (VAE emulsion): 15 parts by weight; Cement foaming agent: 8 parts by weight; Water: 65 parts by weight.

[0032] The thermal conductivity of the heat-insulating and flame-retardant material is 0.03 W / (m•K), the combustion performance is A2 grade, and the bulk density is 120 kg / m³.

[0033] The preparation method of the above-mentioned thermal insulation and flame retardant material made from recycled waste textile fibers and cement includes the following steps: Step 1: Preparation of recycled waste textile fibers; The waste textiles are broken up using a fiber unpacking machine, and then the broken waste textiles are broken up into single fibers using a fiber loosening machine to obtain recycled waste textile fibers with a length range of 1-8mm. Step 2: First, dilute the cement with water before mixing it with the waste textile recycled fibers. Then, use a loosening roller to let the waste textile recycled fibers from Step 1 fall freely into the cement mixer in a loose state onto the surface of the cement. The mixing shaft blades carry the fibers into the cement for mixing and further dispersing to prevent the waste textile recycled fibers from clumping together during the mixing process, which would affect the dispersion, and thus obtain waste textile recycled fiber cement slurry. Step 3: First, dilute the vinyl acetate-ethylene copolymer emulsion (VAE emulsion) with water, and mix the cement foaming agent with water to form foam. Then, add the diluted vinyl acetate-ethylene copolymer emulsion (VAE emulsion) and the foamed cement foaming agent to a high-pressure mixer containing the waste textile recycled fiber cement slurry prepared in Step 2. Mix the waste textile recycled fiber cement slurry under high pressure at a pressure of 18 MPa to obtain a waste textile recycled fiber cement foam slurry with uniform, independent, closed pores. Among them, the waste textile recycled fiber cement foaming slurry was stored for less than or equal to 3 hours. Step 4: Perform injection molding and curing on the waste textile recycled fiber cement foaming slurry obtained in Step 3. Specifically, inject the waste textile recycled fiber cement foaming slurry into a mold (specification: 0.94*0.94*0.33 meters), let it stand for curing for 24-72 hours, remove the mold, cut and trim, and then cure for another 3-7 days to obtain a thermal insulation and flame retardant material made of waste textile recycled fiber and cement with a volume of 0.291588 cubic meters. The curing conditions are the same as those for concrete in the prior art; The water used for dilution or foaming is at a temperature of 45°C.

[0034] Taking a market share of 500 million cubic meters as an example, this embodiment calculates based on 120 kg / cubic meter of product. Each cubic meter requires 48 kg of waste textile recycled fiber. 500 million cubic meters would require 200 million kg of waste textile recycled fiber, or 200,000 tons, which can reduce carbon dioxide emissions by 720 million kg, or 720,000 tons, and save 12 billion tons of water.

[0035] Comparative Example 1 This comparative example provides a material whose raw materials include recycled waste textile fibers with a length ranging from 1-8 mm and silicate cement PII42.5. The proportions of each component in the material prepared in this comparative example, by weight, are as follows: Waste textile recycled fiber: 35 parts by weight; Cement: 100 parts by weight; Water: 35 parts by weight.

[0036] The thermal conductivity of the heat-insulating and flame-retardant material is 0.31 W / (m•K), the combustion performance is B2 grade, and the bulk density is 267 kg / m³.

[0037] The preparation method of the above material includes the following steps: Step 1: Preparation of recycled waste textile fibers; The waste textiles are broken up using a fiber unpacking machine, and then the broken waste textiles are broken up into single fibers using a fiber loosening machine to obtain recycled waste textile fibers with a length range of 1-8mm. Step 2: First, dilute the cement with water before mixing it with the waste textile recycled fibers. Then, use a loosening roller to let the waste textile recycled fibers from Step 1 fall freely into the cement mixer in a loose state onto the surface of the cement. The mixing shaft blades carry the fibers into the cement for mixing and further dispersing to prevent the waste textile recycled fibers from clumping together during the mixing process, which would affect the dispersion, and thus obtain waste textile recycled fiber cement slurry. Step 3: Perform injection molding and curing on the waste textile recycled fiber cement slurry obtained in Step 2. Specifically, inject the waste textile recycled fiber cement slurry into a mold (specification: 0.94*0.94*0.33 meters), let it stand for 24-72 hours, remove the mold, cut and trim it, and then cure it for another 3-7 days to obtain the material in this comparative example.

[0038] Compared with Example 1, it was found that simply mixing and curing waste textile recycled fibers and cement can produce the waste textile reuse material in the prior art. However, this material has a high thermal conductivity and high density, and cannot achieve the function of flame retardancy. Furthermore, it was found that the material prepared in this comparative example is also unstable, such as being brittle and prone to cracking, which is not conducive to its widespread application.

[0039] Comparative Example 2 This comparative example provides a material whose raw materials include recycled waste textile fibers with a length range of 1-8 mm, silicate cement PII42.5, and vinyl acetate-ethylene copolymer emulsion (VAE emulsion) model VAE emulsion 707. The proportions of each component in the material of this comparative example, by weight, are as follows: Waste textile recycled fiber: 35 parts by weight; Cement: 100 parts by weight; Vinyl acetate-ethylene copolymer emulsion (VAE emulsion): 15 parts by weight; Water: 50 parts by weight.

[0040] The thermal conductivity of the heat-insulating and flame-retardant material is 0.30 W / (m•K), the combustion performance is B1 grade, and the bulk density is 242 kg / m³.

[0041] The preparation method of the above material includes the following steps: Step 1: Preparation of recycled waste textile fibers; The waste textiles are broken up using a fiber unpacking machine, and then the broken waste textiles are broken up into single fibers using a fiber loosening machine to obtain recycled waste textile fibers with a length range of 1-8mm. Step 2: First, dilute the cement with water before mixing it with the waste textile recycled fibers. Then, use a loosening roller to let the waste textile recycled fibers from Step 1 fall freely into the cement mixer in a loose state onto the surface of the cement. The mixing shaft blades carry the fibers into the cement for mixing and further dispersing to prevent the waste textile recycled fibers from clumping together during the mixing process, which would affect the dispersion, and thus obtain waste textile recycled fiber cement slurry. Step 3: First, dilute the vinyl acetate-ethylene copolymer emulsion (VAE emulsion) with water, then add the diluted vinyl acetate-ethylene copolymer emulsion (VAE emulsion) to a high-pressure mixer containing the waste textile recycled fiber cement slurry prepared in Step 2, and mix it with the waste textile recycled fiber cement slurry under high pressure. The pressure of the high pressure is 18 MPa, and the slurry is obtained. Step 4: Perform molding and curing on the slurry obtained in Step 3. Specifically, inject the slurry into the mold (specifications: 0.94*0.94*0.33 meters), let it stand for 24-72 hours, remove the mold, cut and trim, and then cure for another 3-7 days to obtain the material in this comparative example.

[0042] Compared with Example 1, it was found that even with the addition of VAE emulsion and the inclusion of high-pressure collision mixing in the production process, the resulting material still had a high thermal conductivity and high density, making it unable to achieve flame retardant properties and thus unsuitable for widespread application.

[0043] Comparative Example 3 This comparative example provides a material whose raw materials include recycled waste textile fibers with a length range of 1-8 mm, silicate cement PII42.5, and cement foaming agent AD-300. The proportions of each component in the material of this comparative example, by weight, are as follows: Waste textile recycled fiber: 35 parts by weight; Cement: 100 parts by weight; Vinyl acetate-ethylene copolymer emulsion (VAE emulsion): 15 parts by weight; Water: 50 parts by weight.

[0044] The thermal conductivity of the heat-insulating and flame-retardant material is 0.27 W / (m•K), the combustion performance is B2 grade, and the bulk density is 184 kg / m³.

[0045] The preparation method of the above material includes the following steps: Step 1: Preparation of recycled waste textile fibers; The waste textiles are broken up using a fiber unpacking machine, and then the broken waste textiles are broken up into single fibers using a fiber loosening machine to obtain recycled waste textile fibers with a length range of 1-8mm. Step 2: First, dilute the cement with water before mixing it with the waste textile recycled fibers. Then, use a loosening roller to let the waste textile recycled fibers from Step 1 fall freely into the cement mixer in a loose state onto the surface of the cement. The mixing shaft blades carry the fibers into the cement for mixing and further dispersing to prevent the waste textile recycled fibers from clumping together during the mixing process, which would affect the dispersion, and thus obtain waste textile recycled fiber cement slurry. Step 3: Mix cement foaming agent and water to form foam, then add the foamed cement foaming agent to a high-pressure mixer containing the waste textile recycled fiber cement slurry prepared in step 2, and mix it with the waste textile recycled fiber cement slurry under high pressure. The pressure of the high pressure is 18PMa, and waste textile slurry with non-uniform pores is obtained. The slurry was stored for less than or equal to 40 minutes, and the pores formed therein gradually broke down and disappeared after 40 minutes. Step 4: Perform injection molding and curing on the slurry obtained in Step 3. Specifically, inject the waste textile recycled fiber cement foaming slurry into the mold (specification: 0.94*0.94*0.33 meters), let it stand for curing for 24-72 hours, remove the mold, cut and trim, and then cure for another 3-7 days to obtain the material in this comparative example.

[0046] Compared with Example 1, it was found that even with the addition of cement foaming agent and the addition of high-pressure collision mixing in the production process, although the slurry contained a small amount of non-uniform bubbles, the bubbles disappeared and collapsed too quickly. Even if the thermal conductivity and density of the obtained material were reduced, it still could not achieve the flame-retardant function, which was also not conducive to its widespread application.

[0047] Comparative Example 4 This embodiment provides a material, the raw materials for which include waste recycled fibers with a length range of 1-8 mm, silicate cement PII42.5, vinyl acetate-ethylene copolymer emulsion (VAE emulsion) model VAE emulsion 707, cement foaming agent AD-300 and water are mixed by high pressure collision to obtain the material; The proportions of each component in the prepared material, by weight, are as follows: Waste textile recycled fiber: 35 parts by weight; Cement: 100 parts by weight; Vinyl acetate-ethylene copolymer emulsion (VAE emulsion): 15 parts by weight; Cement foaming agent: 8 parts by weight; Water: 65 parts by weight.

[0048] The thermal conductivity of the heat-insulating and flame-retardant material is 0.23 W / (m•K), the combustion performance is B2 grade, and the bulk density is 219 kg / m³.

[0049] The preparation method of the above material includes the following steps: Step 1: Preparation of recycled waste textile fibers; The waste textiles are broken up using a fiber unpacking machine, and then the broken waste textiles are broken up into single fibers using a fiber loosening machine to obtain recycled waste textile fibers with a length range of 1-8mm. Step 2: First, dilute the cement with water before mixing it with the waste textile recycled fibers. Then, use a loosening roller to let the waste textile recycled fibers from Step 1 fall freely into the cement mixer in a loose state onto the surface of the cement. The mixing shaft blades carry the fibers into the cement for mixing and further dispersing to prevent the waste textile recycled fibers from clumping together during the mixing process, which would affect the dispersion, and thus obtain waste textile recycled fiber cement slurry. Step 3: First, dilute the vinyl acetate-ethylene copolymer emulsion (VAE emulsion) with water, and mix the cement foaming agent with water to form foam. Then, add the diluted vinyl acetate-ethylene copolymer emulsion (VAE emulsion) and the foamed cement foaming agent to the waste textile recycled fiber cement slurry prepared in Step 2, and mix with the waste textile recycled fiber cement slurry under normal pressure to obtain a waste textile recycled fiber cement foaming slurry with non-uniform pores. Among them, the storage time of the obtained waste textile recycled fiber cement foaming slurry is less than or equal to 1.5 hours; Step 4: Perform injection molding and curing on the waste textile recycled fiber cement foaming slurry obtained in Step 3. Specifically, inject the waste textile recycled fiber cement foaming slurry into a mold (specification: 0.94*0.94*0.33 meters), let it stand for 24-72 hours, remove the mold, cut and trim, and then cure for another 3-7 days to obtain the material in this comparative example.

[0050] Compared with Example 1, when atmospheric pressure mixing was selected during the preparation process, it was found that even with the same formula and ratio, the slurry contained only a small amount of non-uniform bubbles, and the bubbles disappeared and collapsed too quickly. The resulting material had a high thermal conductivity and bulk density. Although it had some flame-retardant properties, it was still not conducive to widespread application.

[0051] Comparative Example 5 This comparative example provides a material, the raw materials for which include broken waste textile fibers, silicate cement PII42.5, vinyl acetate-ethylene copolymer emulsion (VAE emulsion) model VAE emulsion 707, cement foaming agent AD-300 and water are mixed by high-pressure collision to obtain the material; The proportions of each component in the prepared material, by weight, are as follows: Disassembled waste textile fibers: 35 parts by weight; Cement: 100 parts by weight; Vinyl acetate-ethylene copolymer emulsion (VAE emulsion): 15 parts by weight; Cement foaming agent: 8 parts by weight; Water: 65 parts by weight.

[0052] The material has a thermal conductivity of 0.18 W / (m•K), a combustion performance rating of B2, and a bulk density of 243 kg / m³.

[0053] The preparation method of the above-mentioned broken-up waste textile fibers and cement-based materials includes the following steps: Step 1: Preparation of broken-up waste textile fibers; Use a fiber unpacking machine to break up the waste textile fibers to obtain broken-up waste textile fibers; Step 2: First, dilute the cement with water before mixing it with the broken waste textile fibers. Then, use a loosening roller to let the broken waste textile fibers from Step 1 fall freely into the cement mixer in a loose state onto the surface of the cement. The mixing shaft blades carry the cement in for mixing and further breaking it up to obtain waste textile fiber cement slurry. Step 3: First, dilute the vinyl acetate-ethylene copolymer emulsion (VAE emulsion) with water, and mix the cement foaming agent with water to form foam. Then, add the diluted vinyl acetate-ethylene copolymer emulsion (VAE emulsion) and the foamed cement foaming agent to a high-pressure mixer containing the waste textile fiber cement slurry prepared in Step 2, and mix it with the waste textile fiber cement slurry under high pressure. The pressure of the high pressure is 18 PPa, to obtain the waste textile fiber cement foamed slurry. The waste textile fiber cement foaming slurry was stored for only 0.5 hours. Step 4: Perform injection molding and curing on the waste textile fiber cement foaming slurry obtained in Step 3. Specifically, inject the waste textile fiber cement foaming slurry into a mold (specification: 0.94*0.94*0.33 meters), let it stand for curing for 24-72 hours, remove the mold, cut and trim, and then cure for another 3-7 days to obtain the material. The curing conditions are the same as those for concrete in the prior art; The water used for dilution or foaming is at a temperature of 45°C.

[0054] Compared with Example 1, in the preparation process, the waste textile fibers were selected after being broken down, but the fibers were not further loosened into single fibers. It was found that even with the same formula and ratio, the bubbles in the resulting slurry were uneven, and the large bubbles disappeared and collapsed too quickly. The remaining small bubbles resulted in high thermal conductivity and bulk density of the material. There were significant unstable factors in the preparation process. Although it has some flame-retardant function, it is also not conducive to industrial promotion.

[0055] It should be understood that the present invention is not limited to the content already described above, and various modifications and changes can be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. A thermal insulation and flame retardant material prepared from recycled waste textile fibers and cement, characterized in that, The raw materials for preparing the thermal insulation and flame retardant material include waste recycled fibers, cement, vinyl acetate-ethylene copolymer emulsion, and cement foaming agent, which are mixed by high-pressure collision to obtain a thermal insulation and flame retardant material with uniform, independent, and closed pores. The thermal conductivity of the heat-insulating and flame-retardant material is 0.03-0.04 W / (m•K), the combustion performance is B1-A2 grade, and the bulk density is 100-150 kg / m³.

2. The thermal insulation and flame retardant material prepared from recycled waste textile fibers and cement according to claim 1, characterized in that, The proportions of each component in the preparation of the thermal insulation and flame retardant material, by weight, are as follows: Waste textile recycled fiber: 25-35 parts by weight; Cement: 100 parts by weight; Vinyl acetate-ethylene copolymer emulsion: 15-16 parts by weight; Cement foaming agent: 8-9 parts by weight.

3. The thermal insulation and flame retardant material prepared from recycled waste textile fibers and cement according to claim 2, characterized in that, The length of the recycled waste textile fibers is 1-8 mm.

4. The thermal insulation and flame retardant material prepared from recycled waste textile fibers and cement according to claim 2, characterized in that, The cement is silicate cement.

5. The thermal insulation and flame retardant material prepared from recycled waste textile fibers and cement according to claim 1, characterized in that, The pressure of the high pressure is 16-19 PMa.

6. A method for preparing a thermal insulation and flame retardant material made from recycled waste textile fibers and cement according to any one of claims 1-5, characterized in that, Includes the following steps: Step 1: Preparation of recycled waste textile fibers; The waste textile is broken down and then loosened into single fibers to obtain recycled waste textile fibers; Step 2: The waste textile recycled fibers from Step 1 are allowed to fall freely onto the cement surface in a loose state, mixed and further dispersed to obtain waste textile recycled fiber cement slurry. Step 3: Add vinyl acetate-ethylene copolymer emulsion and cement foaming agent to the waste textile recycled fiber cement slurry prepared in Step 2, and mix under high pressure to obtain waste textile recycled fiber cement foaming slurry. Step 4: The waste textile recycled fiber cement foaming slurry obtained in Step 3 is subjected to injection molding and curing to obtain the thermal insulation and flame retardant material prepared by the waste textile recycled fiber and cement.

7. The method for preparing the thermal insulation and flame retardant material made from recycled waste textile fibers and cement according to claim 6, characterized in that, In step 2, water is added to dilute the cement before it is mixed with the recycled waste textile fibers; Before adding the vinyl acetate-ethylene copolymer emulsion in step 3, dilute the vinyl acetate-ethylene copolymer emulsion with water; Cement foaming agent is mixed with water to form foam.

8. The method for preparing the thermal insulation and flame retardant material made from recycled waste textile fibers and cement according to claim 7, characterized in that, The water used for dilution or foaming is at a temperature of 40-55℃, and the total mass of the water used is 65-68% of the mass of the cement.

9. A foamed thermal insulation product, characterized in that, The foamed thermal insulation product is a thermal insulation and flame retardant material prepared from waste textile recycled fibers and cement according to any one of claims 1-5, or is prepared from a thermal insulation and flame retardant material prepared from waste textile recycled fibers and cement according to any one of claims 1-5, or includes a thermal insulation and flame retardant material prepared from waste textile recycled fibers and cement according to any one of claims 1-5.

10. A foamed insulation board, characterized in that, The foamed insulation board is a heat-insulating and flame-retardant material prepared from waste textile recycled fibers and cement according to any one of claims 1-5, or is made from a heat-insulating and flame-retardant material prepared from waste textile recycled fibers and cement according to any one of claims 1-5, or includes a heat-insulating and flame-retardant material prepared from waste textile recycled fibers and cement according to any one of claims 1-5.