Lightweight tufted flame-retardant composite carpet and preparation method thereof

Abstract

The invention belongs to the technical field of flame-retardant carpets, and particularly discloses a light tufted flame-retardant composite carpet and a preparation method thereof.The carpet comprises a three-layer composite structure including a tufted surface layer, a flame-retardant bonding layer and an anti-skid bottom layer, the tufted surface layer comprises polypropylene fiber multifilaments and polypropylene fiber non-woven base cloth, the flame-retardant bonding layer takes waterborne polyurethane as a base material, and the anti-skid bottom layer is a non-skid bottom layer; the anti-skid bottom layer is prepared from styrene butadiene rubber emulsion, modified polytetrafluoroethylene micro powder, a waterborne polyurethane binder and an anti-aging agent. According to the light tufted flame-retardant composite carpet and the preparation method thereof, the flame-retardant safety and the light comfort of a product are synergistically improved through multi-layer flame-retardant structural design and process optimization aiming at a scene with a high flame-retardant property requirement.

Description

Technical Field

[0001] This invention relates to the field of flame-retardant carpet technology, and in particular to a lightweight tufted flame-retardant composite carpet and its preparation method. Background Technology

[0002] Existing carpet materials have many limitations: wool carpets are expensive and require high maintenance; nylon carpets are prone to static electricity and have poor environmental performance; polyester carpets have poor wear resistance and insufficient comfort; and traditional polypropylene tufted carpets have problems such as poor flame retardancy, hard pile surface, insufficient bonding between tuft and base fabric, and excessive weight.

[0003] Existing tufted composite carpets often use heavy base fabrics to ensure wear resistance, increasing the difficulty of handling and installation, and limiting their application in light-duty buildings or frequently changing environments. From a cost perspective, high-performance tufted carpets often rely on imported fibers or complex post-processing, resulting in high prices, while affordable products struggle to balance safety and durability. Furthermore, existing tufted carpets have significant shortcomings in flame retardancy, especially polypropylene carpets. Polypropylene fibers have a limiting oxygen index of only about 20% (classified as flammable), and the loose structure of the tufted fibers easily creates a "chimney effect," accelerating flame spread. Traditional flame retardant improvements often involve a single coating or simple addition of flame retardants, which suffer from the following problems: low flame retardant efficiency: only a flame retardant layer is formed on the carpet surface, allowing flames to easily penetrate the surface and ignite the internal tufted fibers. Poor combustion safety: combustion produces a large number of molten droplets (polypropylene has a melting temperature of about 160°C, easily dripping and igniting items below), and releases toxic gases such as CO and formaldehyde, posing a serious threat to human safety. Insufficient flame retardant durability: After washing or long-term use, the surface flame retardant is easily detached, and the flame retardant performance is degraded. Summary of the Invention

[0004] The purpose of this invention is to provide a lightweight tufted flame-retardant composite carpet and its preparation method. Targeting scenarios with high flame-retardant performance requirements, the invention achieves a synergistic improvement in flame-retardant safety and lightweight comfort through multi-layer flame-retardant structure design and process optimization.

[0005] To achieve the above objectives, the present invention provides a lightweight tufted flame-retardant composite carpet, comprising a three-layer composite structure of a tufted surface layer, a flame-retardant adhesive layer, and an anti-slip bottom layer. The tufted surface layer comprises polypropylene multifilament and polypropylene nonwoven base fabric. The flame-retardant adhesive layer uses water-based polyurethane as the base material and is compounded with a phosphorus-nitrogen intumescent flame retardant. The anti-slip bottom layer is composed of styrene-butadiene rubber latex, modified polytetrafluoroethylene micro powder, water-based polyurethane adhesive, and an anti-aging agent.

[0006] Preferably, the linear density of the polypropylene multifilament is 2.0-3.0 denier.

[0007] Preferably, the flame-retardant adhesive layer further includes nano-silica, silane coupling agent, and antioxidant.

[0008] Preferably, the anti-slip bottom layer also contains magnesium hydroxide micro-powder to assist in flame retardancy.

[0009] Preferably, the phosphorus-nitrogen intumescent flame retardant is a compound system of ammonium polyphosphate, melamine, and pentaerythritol, with a mass ratio of ammonium polyphosphate:melamine:pentaerythritol of 3:2:1.

[0010] This invention also provides a method for preparing a lightweight tufted flame-retardant composite carpet, comprising the following steps: Step 1, raw material processing: flame retardant impregnation treatment of polypropylene multifilament; premixing phosphorus-nitrogen intumescent flame retardant with nano-silica to form uniform flame retardant composite powder; Step 2, tufting: The pretreated polypropylene multifilament is loaded into the tufting machine and tufted evenly onto the surface of the polypropylene nonwoven base fabric. Step 3, preparation of adhesive liquid: heat the water-based polyurethane base material, add flame retardant composite powder, silane coupling agent and antioxidant in sequence, disperse at high speed, add deionized water in batches during the process, coat the adhesive liquid evenly on the tufted surface layer, ensure that the adhesive liquid penetrates to the root of the pile 2-3mm, send the coated semi-finished product into a segmented hot air oven for segmented curing, and cool to room temperature. Step 4, preparation of anti-slip liquid: Styrene-butadiene rubber latex, modified polytetrafluoroethylene micro powder, water-based polyurethane binder, magnesium hydroxide micro powder, and anti-aging agent are dispersed at high speed, and deionized water is added to adjust the viscosity; the anti-slip liquid is coated on the back of the tufted surface layer, and then sent to an oven to dry to form a textured anti-slip structure; Step 5: Trim the pile of the laminated carpet with a shearing machine to remove loose fibers, cut it to the preset specifications, and treat the edges with a hot melt edge sealing machine to prevent frayed edges.

[0011] Preferably, in step 1, the flame retardant impregnation operation is as follows: prepare a 10-15wt% polyphosphate flame retardant masterbatch emulsion with a phosphorus content of 25-30% and a bath ratio of 1:20. Immerse the cleaned polypropylene multifilament into the emulsion and ultrasonically impregnate it at 40-50℃ for 20-30 minutes to ensure uniform penetration of the flame retardant.

[0012] Preferably, in step 2, the polypropylene nonwoven base fabric needs to be treated by a plasma treatment machine with a power of 300-400W and a treatment time of 3-5 seconds before use, to increase the surface tension to 45-48mN / m and enhance the bonding force with the adhesive layer.

[0013] Preferably, in step 3, the segmented curing is performed at 60-70℃ for 5 minutes for dehydration and shaping; at 90-100℃ for 10 minutes for melting and dispersing of the flame retardant; and at 120-130℃ for 5 minutes for the formation of the char layer precursor.

[0014] The advantages and beneficial effects of the present invention using the above-mentioned lightweight tufted flame-retardant composite carpet and its preparation method are as follows: 1. This invention forms a full-dimensional flame-retardant barrier from surface pretreatment, core flame retardant adhesive layer, and auxiliary flame retardant anti-slip layer, overcoming the industry problem of easy penetration of flame retardant on the surface of tufted carpets and difficulty in controlling internal combustion, thereby reducing the speed of flame spread.

[0015] 2. This invention achieves a synergistic effect of high-efficiency flame retardancy, no dripping, and low toxicity release: The combination of phosphorus-nitrogen intumescent flame retardant and nano-reinforcing components ensures high flame retardancy efficiency and avoids dripping by wrapping the fiber with an expanded carbon layer; the addition of nano-magnesium hydroxide further inhibits the release of toxic gases and improves the safety of personnel escaping in a fire.

[0016] 3. This invention optimizes the compounding ratio of phosphorus-nitrogen flame retardants, nano-modification technology, and segmented curing process, providing a replicable high flame retardant solution for the tufted carpet industry. This drives technological advancements in upstream and downstream flame retardant additives, polypropylene modified fibers, and tufting equipment, forming a complete industrial chain for high flame retardant tufted carpets.

[0017] The technical solution of the present invention will be further described in detail below through embodiments. Detailed Implementation

[0018] The technical solution of the present invention will be further described below through embodiments.

[0019] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0020] The following examples are not intended to limit the invention, but are only for illustration. Unless otherwise specified, the experimental methods used in the following examples are generally performed under conventional conditions. Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0021] Example 1 A lightweight tufted flame-retardant composite carpet comprises a three-layer composite structure: a tufted surface layer, a flame-retardant adhesive layer, and an anti-slip bottom layer. The tufted surface layer consists of polypropylene multifilament and a polypropylene nonwoven base fabric. The flame-retardant adhesive layer uses waterborne polyurethane as the base material and is compounded with a phosphorus-nitrogen intumescent flame retardant (phosphorus content 12-15%, nitrogen content 20-22%), nano-silica (particle size 10-20nm, modified with a silane coupling agent), a silane coupling agent, and an antioxidant. The anti-slip bottom layer is composed of styrene-butadiene rubber latex, modified polytetrafluoroethylene micropowder, waterborne polyurethane adhesive, and an anti-aging agent, and magnesium hydroxide micropowder (particle size 50-100nm) is added to assist in flame retardancy.

[0022] Phosphorus-nitrogen intumescent flame retardant: Ammonium polyphosphate (APP, degree of polymerization ≥1000, water solubility ≤0.5%), melamine (Mel), and pentaerythritol (PER) are preferably compounded in a ratio of 3:2:1. Under this ratio, the thickness of the intumescent char layer reaches 5-8mm, the char layer strength is ≥0.8MPa, and it can withstand the erosion of flames without cracking.

[0023] Nano silica: Modified with KH-550 silane coupling agent, the surface hydroxyl content is reduced by 30%, improving compatibility with water-based polyurethane base material. It can be uniformly dispersed in the adhesive layer and play a role in reinforcing the carbon layer skeleton.

[0024] Flame retardant pretreatment of polypropylene multifilament: using polyphosphate flame retardant masterbatch (phosphorus content 25-30%), emulsion concentration 10-15wt%, ultrasonic impregnation to ensure that the flame retardant is evenly attached to the fiber surface, and after drying, the limiting oxygen index of the fiber is improved, laying the foundation for subsequent overall flame retardancy.

[0025] Antioxidants and anti-aging agents: The hindered phenolic antioxidant 1010 and phosphite antioxidant 168 are compounded (mass ratio 1:1) to prevent the flame retardant from oxidizing and failing during high-temperature processing and to extend the durability of flame retardant performance.

[0026] First layer: Flame retardant pretreatment of the tufted surface layer. Polypropylene multifilament is impregnated with phosphorus-based flame retardant masterbatch emulsion, forming a "microcapsule flame retardant layer" on the fiber surface. When the surface layer is exposed to fire, the microcapsules rupture and release the flame retardant, initially inhibiting fiber combustion. At the same time, the multifilament linear density is controlled at 2.0-3.0 denier, and the tuft density is 300-400 tufts / 10cm. 2 This avoids excessively sparse structures that allow flames to penetrate quickly.

[0027] The second layer: The core flame retardant of the adhesive layer (accounting for 70-75% of the total flame retardant) uses high-solids waterborne polyurethane as a carrier, compounded with 25-30wt% of phosphorus-nitrogen intumescent flame retardant (ammonium polyphosphate-melamine-pentaerythritol system, with a mass ratio of ammonium polyphosphate:melamine:pentaerythritol of 3:2:1). When heated, this system undergoes an esterification reaction to generate polyphosphate ester (acid source), melamine decomposes to release ammonia (gas source), and pentaerythritol dehydrates to form a carbon skeleton (carbon source). The three work together to form a 20-30 times expanded carbon layer. The addition of 3-5wt% nano silica (which improves compatibility with flame retardants by 40% after modification) can enhance the density of the carbon layer (porosity ≤15%), preventing the carbon layer from cracking and causing flame penetration. During coating, it penetrates to the pile root 2-3mm, bonding the pile to the base fabric as a "flame retardant whole", solving the problem of "easy ignition of the pile root" in traditional carpets.

[0028] The third layer: anti-slip bottom layer with flame retardant assistance - adding 0.5-1wt% nano magnesium hydroxide (smoke suppressant), which releases water of crystallization to absorb heat during combustion, while inhibiting CO generation (CO release is reduced by 15-20%). Modified polytetrafluoroethylene micro powder not only improves anti-slip properties, but its high temperature resistance (decomposition temperature ≥320℃) can also reduce the participation of the bottom layer in combustion.

[0029] Example 2 A method for preparing a lightweight tufted flame-retardant composite carpet includes the following steps: 1. Raw material pretreatment (1) Pretreatment of polypropylene multifilament Cleaning and degreasing: Place the polypropylene multifilament into a 40kHz ultrasonic cleaner, add 5wt% neutral detergent, water temperature 40-50℃, clean for 10-15 minutes to remove surface oil.

[0030] Flame retardant impregnation: Prepare a 10-15wt% polyphosphate flame retardant masterbatch emulsion (phosphorus content 25-30%), with a liquor ratio of 1:20. Immerse the cleaned multifilaments in the emulsion and ultrasonically impregnate at 40-50℃ for 20-30 minutes to ensure uniform penetration of the flame retardant.

[0031] Drying and curing: Take out the multifilament and put it into an 80-90℃ oven to dry for 30-40 minutes, controlling the moisture content to ≤0.3% and the flame retardant adhesion amount to 0.5-1wt%.

[0032] (2) Base fabric pretreatment Plasma modification: The polypropylene nonwoven base fabric is treated with a plasma treatment machine with a power of 300-400W and a treatment time of 3-5 seconds to increase the surface tension to 45-48mN / m and enhance the bonding force with the adhesive layer.

[0033] (3) Pretreatment of powder additives Premixing and dispersion: Add phosphorus-nitrogen intumescent flame retardant and nano-silica to a high-speed mixer and premix at 1500-1800 r / min for 15-20 minutes to form a uniform composite powder and avoid uneven dispersion in the later stage.

[0034] 2. Tufting molding Tufting operation: The pretreated polypropylene multifilament is loaded into the tufting machine and tufted evenly on the surface of the plasma-treated base fabric, ensuring that there are no missing tufts, broken tufts, or flattened tufts. After forming, it is left to stand for 5 minutes to release the internal stress during the tufting process.

[0035] 3. Flame-retardant adhesive layer coating and curing (1) Preparation of adhesive liquid Base material preheating: Heat the water-based polyurethane base material to 40-50℃, stir evenly, and improve its fluidity.

[0036] Component mixing: Add the premixed flame retardant composite powder, silane coupling agent and antioxidant in sequence, and disperse with a high-speed disperser at 1200-1500 r / min for 20-30 minutes. During this period, add a small amount of deionized water in batches to adjust the viscosity to 1500-2000 mPa·s.

[0037] Coating operation: Use a doctor blade coater with a coating pressure of 0.3-0.5MPa to evenly coat the back of the tufted pile with an adhesive thickness of 0.5-0.8mm, ensuring that the adhesive penetrates to the pile root 2-3mm.

[0038] Segmented curing: The coated semi-finished product is sent into a segmented hot air oven and cured in the following process: 60-70℃ / 5min (dehydration and shaping) → 90-100℃ / 10min (flame retardant melting and dispersion) → 120-130℃ / 5min (carbon layer precursor formation). After cooling to room temperature, the bonding strength is tested to be ≥3.0N / 25mm.

[0039] 4. Anti-slip base coat coating and curing Preparation of anti-slip liquid: Styrene-butadiene rubber latex, modified polytetrafluoroethylene micro powder, water-based polyurethane binder, nano magnesium hydroxide, and anti-aging agent are added to a high-speed disperser and dispersed at 1800-2000 r / min for 25-30 minutes. Deionized water is added to adjust the viscosity to 800-1000 mPa·s.

[0040] Coating and curing: Using a comma-shaped scraper coating machine, the anti-slip liquid is applied to the back of the tufted surface layer with a coating thickness of 0.3-0.5mm. Then, it is placed in an 80-90℃ oven to dry for 15-20 minutes to form a textured anti-slip structure with a dry friction coefficient ≥0.85.

[0041] 6. Post-processing Heat setting: The pile of the laminated carpet is trimmed using a shearing machine to trim the pile height to 8-10mm and remove loose fibers; for products that need to be printed, rotary screen printing is used, and the carpet is dried at 100-110℃ for 10 minutes.

[0042] Inspection and cutting: Sampling tests are conducted on key indicators such as limiting oxygen index, abrasion resistance, and flame retardancy. After passing the tests, the material is cut to the preset specifications, and the edges are treated with a hot melt edge sealing machine to prevent fraying.

[0043] Flame-retardant adhesive layer premixing process: Flame retardant and nano silica are first premixed at high speed of 1500-1800r / min for 15-20 minutes to form "flame-retardant-reinforced composite powder", and then water-based polyurethane base material is added to avoid uneven dispersion caused by single addition.

[0044] The three-stage curing process is as follows: the low-temperature stage (60-70℃) removes moisture from the adhesive to avoid surface crusting caused by direct drying at high temperatures; the medium-temperature stage (90-100℃) promotes the melting and dispersion of the flame retardant to ensure full bonding with the base material; and the high-temperature stage (120-130℃) induces the flame retardant to undergo a pre-crosslinking reaction to form a char layer precursor, thereby improving the flame retardant efficiency of the adhesive layer after curing.

[0045] Example 3 Preparation of raw materials for a lightweight tufted flame-retardant composite carpet: Polypropylene multifilament: linear density 2.5 denier, ultrasonically impregnated with polyphosphate flame retardant masterbatch emulsion (phosphorus content 28%) for 25 minutes, dried at 85℃ for 35 minutes, flame retardant adhesion amount 1.8wt%.

[0046] Flame-retardant adhesive layer: waterborne polyurethane base material (65% solid content), phosphorus-nitrogen flame retardant (APP:Mel:PER=3:2:1), modified nano silica (KH-550 treatment), silane coupling agent KH-550, antioxidant 1010 / 168 (1:1).

[0047] Anti-slip bottom layer: styrene-butadiene rubber latex, modified polytetrafluoroethylene micro powder, water-based polyurethane adhesive, anti-aging agent 264, magnesium hydroxide micro powder.

[0048] A method for preparing a lightweight tufted flame-retardant composite carpet includes the following steps: Step 1, raw material processing: flame retardant impregnation treatment of polypropylene multifilament; premixing phosphorus-nitrogen intumescent flame retardant with nano-silica to form a uniform flame retardant composite powder; flame retardant impregnation operation: prepare 10-15wt% polyphosphate flame retardant masterbatch emulsion, phosphorus content 25-30%, bath ratio 1:20, immerse the cleaned polypropylene multifilament in the emulsion, ultrasonically impregnate at 40-50℃ for 20-30 minutes to ensure uniform penetration of flame retardant.

[0049] Step 2, tufting: The pretreated polypropylene multifilament is loaded into the tufting machine and tufted evenly onto the surface of the polypropylene nonwoven base fabric. Before use, the polypropylene nonwoven base fabric needs to be treated by a plasma treatment machine with a power of 300-400W and a treatment time of 3-5 seconds to increase the surface tension to 45-48mN / m and enhance the bonding force with the adhesive layer.

[0050] Step 3: Adhesive preparation. Heat the water-based polyurethane base material, then sequentially add flame-retardant composite powder, silane coupling agent, and antioxidant, dispersing at high speed. During this process, add small amounts of deionized water in stages. Evenly coat the tufted surface with the adhesive, ensuring penetration to the root of the tuft 2-3 mm. Place the coated semi-finished product into a segmented hot air oven for segmented curing: 65℃ / 5min for dehydration and shaping; 95℃ / 10min for melting and dispersing the flame retardant; and 125℃ / 5min for the formation of the char layer precursor. Cool to room temperature.

[0051] Step 4, preparation of anti-slip liquid: high-speed dispersion of styrene-butadiene rubber latex, modified polytetrafluoroethylene micro powder, water-based polyurethane binder, magnesium hydroxide micro powder, and anti-aging agent; addition of deionized water to adjust viscosity; coating the anti-slip liquid on the back of the tufted surface layer, and then sending it into an oven to dry, forming a textured anti-slip structure.

[0052] Step 5: Trim the pile of the laminated carpet with a shearing machine to remove loose fibers, cut it to the preset specifications, and treat the edges with a hot melt edge sealing machine to prevent frayed edges.

[0053] Example 4 Preparation of raw materials for a lightweight tufted flame-retardant composite carpet: Polypropylene multifilament: linear density 2.0 denier, ultrasonically impregnated with 15wt% polyphosphate flame retardant masterbatch emulsion (phosphorus content 30%) for 30 minutes, dried at 90℃ for 40 minutes, flame retardant adhesion amount 1.0wt%.

[0054] Flame-retardant adhesive layer: waterborne polyurethane base material (70% solid content), phosphorus-nitrogen flame retardant (APP:Mel:PER=3:2:1), modified nano silica, silane coupling agent KH-560, antioxidant 1076 / 168 (1:1).

[0055] Anti-slip bottom layer: styrene-butadiene rubber latex, modified polytetrafluoroethylene micro powder, water-based polyurethane adhesive, anti-aging agent 2246, magnesium hydroxide micro powder.

[0056] The preparation method of a lightweight tufted flame-retardant composite carpet differs from that of Example 3 in that the segmented curing in step 3 is 70℃ / 5min→100℃ / 10min→130℃ / 5min, while the rest is the same as in Example 3.

[0057] Comparative Example 1 Unlike Example 3, step 2 of the preparation method does not involve plasma treatment of the polypropylene nonwoven base fabric; the rest of the steps are the same as in Example 3.

[0058] Comparative Example 2 Preparation of raw materials for a lightweight tufted flame-retardant composite carpet: Polypropylene multifilament: linear density 2.5 denier.

[0059] Flame-retardant adhesive layer: water-based polyurethane base material (65% solid content), phosphorus-nitrogen flame retardant (APP:Mel:PER=3:2:1).

[0060] Anti-slip bottom layer: styrene-butadiene rubber latex, water-based polyurethane adhesive, anti-aging agent 264.

[0061] A method for preparing a lightweight tufted flame-retardant composite carpet includes the following steps: Step 1, tufting: The polypropylene multifilament is loaded into the tufting machine and tufted evenly onto the surface of the polypropylene nonwoven base fabric.

[0062] Step 3, preparation of adhesive liquid: heat the water-based polyurethane base material, add phosphorus-nitrogen flame retardant, disperse at high speed, add a small amount of deionized water in batches during the process, coat the adhesive liquid evenly on the tufted surface, send the coated semi-finished product into a hot air oven for curing, and cool to room temperature.

[0063] Step 4, preparation of anti-slip liquid: high-speed dispersion of styrene-butadiene rubber latex, water-based polyurethane binder and anti-aging agent, and addition of deionized water to adjust viscosity; coating the anti-slip liquid on the back of the tufted surface layer, and then sending it into an oven to dry, forming a textured anti-slip structure.

[0064] Step 5: Trim the pile of the laminated carpet with a shearing machine to remove loose fibers, cut it to the preset specifications, and treat the edges with a hot melt edge sealing machine to prevent frayed edges.

[0065] Comparative Example 3 Unlike Example 3, the polypropylene multifilament is not subjected to flame-retardant impregnation treatment in step 1 of the preparation method; the rest is the same as in Example 3.

[0066] Comparative Example 4 Unlike Example 3, the anti-slip bottom layer includes styrene-butadiene rubber latex (75 wt%), waterborne polyurethane adhesive (8 wt%), and anti-aging agent 264 (0.3 wt%). In step 4 of the preparation method, modified polytetrafluoroethylene powder and magnesium hydroxide powder are not added; the rest of the steps are the same as in Example 3.

[0067] Performance tests were conducted on the carpets of Examples 3-4 and Comparative Examples 1-4, and the test results are shown in Table 1.

[0068] Table 1 Test Results

[0069] Through the design of a three-dimensional flame retardant system, it far surpasses the comparative products 1-4 in key indicators such as limiting oxygen index, vertical combustion performance, and toxic gas release. It also significantly improves flame retardant durability, completely solving the pain points of traditional polypropylene carpets such as poor flame retardancy, unsafe combustion, and rapid performance degradation. In particular, it meets the stringent safety requirements of special scenarios in terms of no dripping and low toxicity release.

[0070] Therefore, this invention employs the aforementioned lightweight tufted flame-retardant composite carpet and its preparation method. Targeting scenarios requiring high flame-retardant performance, it achieves a synergistic improvement in flame-retardant safety and lightweight comfort through multi-layer flame-retardant structural design and process optimization. From surface pretreatment, core flame-retardant bonding layer, and auxiliary flame-retardant anti-slip layer, a multi-dimensional flame-retardant barrier is formed, overcoming the industry challenge of easy penetration of surface flame retardancy and difficulty in controlling internal combustion in tufted carpets. This achieves a synergistic effect of highly efficient flame retardancy, no dripping, and low toxicity release.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A lightweight tufted flame-retardant composite carpet, characterized in that: It consists of a three-layer composite structure, including a tufted surface layer, a flame-retardant adhesive layer, and an anti-slip bottom layer. The tufted surface layer includes polypropylene multifilament and polypropylene nonwoven base fabric. The flame-retardant adhesive layer uses water-based polyurethane as the base material and is compounded with phosphorus-nitrogen intumescent flame retardant. The anti-slip bottom layer is composed of styrene-butadiene rubber latex, modified polytetrafluoroethylene micro powder, water-based polyurethane adhesive, and anti-aging agent.

2. The lightweight tufted flame-retardant composite carpet according to claim 1, characterized in that: The linear density of polypropylene multifilament is 2.0-3.0 denier.

3. The lightweight tufted flame-retardant composite carpet according to claim 1, characterized in that: The flame-retardant adhesive layer also includes nano-silica, silane coupling agents, and antioxidants.

4. The lightweight tufted flame-retardant composite carpet according to claim 1, characterized in that: The non-slip bottom layer also contains magnesium hydroxide micro-powder to assist in flame retardancy.

5. The lightweight tufted flame-retardant composite carpet according to claim 1, characterized in that: The phosphorus-nitrogen intumescent flame retardant is a compound system of ammonium polyphosphate, melamine, and pentaerythritol, with a mass ratio of ammonium polyphosphate:melamine:pentaerythritol of 3:2:

1.

6. A method for preparing a lightweight tufted flame-retardant composite carpet according to any one of claims 1-5, characterized in that, Includes the following steps: Step 1, raw material processing: flame retardant impregnation treatment of polypropylene multifilament; premixing phosphorus-nitrogen intumescent flame retardant with nano-silica to form uniform flame retardant composite powder; Step 2, tufting: The pretreated polypropylene multifilament is loaded into the tufting machine and tufted evenly onto the surface of the polypropylene nonwoven base fabric. Step 3, preparation of adhesive liquid: heat the water-based polyurethane base material, add flame retardant composite powder, silane coupling agent and antioxidant in sequence, disperse at high speed, add deionized water in batches during the process, coat the adhesive liquid evenly on the tufted surface layer, ensure that the adhesive liquid penetrates to the root of the pile 2-3mm, send the coated semi-finished product into a segmented hot air oven for segmented curing, and cool to room temperature. Step 4, preparation of anti-slip liquid: high-speed dispersion of styrene-butadiene rubber latex, modified polytetrafluoroethylene micro powder, water-based polyurethane binder, magnesium hydroxide micro powder, and anti-aging agent, followed by addition of deionized water to adjust viscosity; Anti-slip liquid is applied to the back of the tufted surface layer, and then it is dried in an oven to form a textured anti-slip structure. Step 5: Trim the pile of the laminated carpet with a shearing machine to remove loose fibers, cut it to the preset specifications, and treat the edges with a hot melt edge sealing machine to prevent frayed edges.

7. The method for preparing a lightweight tufted flame-retardant composite carpet according to claim 6, characterized in that, In step 1, the flame retardant impregnation operation is as follows: prepare a 10-15wt% polyphosphate flame retardant masterbatch emulsion with a phosphorus content of 25-30% and a bath ratio of 1:

20. Immerse the cleaned polypropylene multifilament into the emulsion and ultrasonically impregnate at 40-50℃ for 20-30 minutes to ensure uniform penetration of the flame retardant.

8. The method for preparing a lightweight tufted flame-retardant composite carpet according to claim 6, characterized in that: In step 2, the polypropylene nonwoven base fabric needs to be treated with a plasma treatment machine before use. The power is 300-400W and the treatment time is 3-5 seconds to increase the surface tension to 45-48mN / m and enhance the bonding force with the adhesive layer.

9. The method for preparing a lightweight tufted flame-retardant composite carpet according to claim 6, characterized in that: In step 3, the segmented curing process is carried out at 60-70℃ for 5 minutes for dehydration and shaping; at 90-100℃ for 10 minutes for melting and dispersion of the flame retardant; and at 120-130℃ for 5 minutes for the formation of the char layer precursor.

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