PVC wood-plastic material having strong smoke suppression and flame retardancy, and preparation method therefor
By adding a molybdenum compound and a composition of ferrocene and oxalate dihydrate to PVC wood-plastic composite materials, and modifying the wood flour with a silane coupling agent, the problem of poor smoke suppression performance of existing PVC wood-plastic composite materials has been solved, achieving excellent smoke suppression effect and improved safety.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- ANHUI KOJO NEW MATERIAL TECH CO LTD
- Filing Date
- 2024-12-31
- Publication Date
- 2026-07-02
AI Technical Summary
Existing PVC wood-plastic composite materials have poor smoke suppression performance, posing a safety hazard.
The smoke suppression performance of PVC wood-plastic composites is improved by adding molybdenum compounds, or a combination of molybdenum compounds and ferrocene and oxalate dihydrate to the PVC wood-plastic composite material as a smoke suppressant, and by end-capping the wood flour with a silane coupling agent.
It significantly improves the smoke suppression performance of PVC wood-plastic composite materials, enhances their safety, and avoids the problem of decreased smoke suppression effect during the middle of combustion.
Smart Images
Figure PCTCN2024144379-FTAPPB-I100001 
Figure PCTCN2024144379-FTAPPB-I100002
Abstract
Description
Strong smoke-suppressing and flame-retardant PVC wood-plastic composite materials and their preparation methods Technical Field
[0001] This invention relates to the field of wood-plastic composite materials technology, specifically to a strong smoke-suppressing and flame-retardant PVC wood-plastic material and its preparation method. Background Technology
[0002] Wood-plastic composite profiles are a new type of composite material that has flourished in recent years both domestically and internationally. They refer to boards or profiles produced by mixing polyethylene, polypropylene, and polyvinyl chloride (PVC) with waste plant fibers such as wood flour, rice husks, and straw, instead of traditional resin adhesives, to create a new wood-based material. This material is then processed through plastics processing techniques such as extrusion, molding, and injection molding. It is mainly used in the building materials, furniture, and logistics packaging industries. Extruded wood-plastic composite boards are made by hot-extruding a mixture of plastic and wood powder in a certain proportion. PVC wood-plastic composite materials are a major type of wood-plastic composite material, formed by melt blending polyvinyl chloride (PVC) with plant fiber materials (usually wood flour). It is environmentally friendly and combines the excellent properties of both wood and plastic.
[0003] PVC wood-plastic composites possess outstanding advantages such as waterproofing, moisture resistance, corrosion and insect resistance, and excellent mechanical properties. In the early stages of production and application, it was generally believed that by encapsulating wood flour fillers in a plastic matrix, even without adding flame retardants to the composite material, the inherent flame retardancy of the plastic matrix itself could prevent flame attack, providing sufficient flame retardancy for the material. However, when the temperature rises further, the plastic matrix decomposes and becomes the first material to produce smoke. The plastic matrix first undergoes a dehydrochlorination reaction, followed by a series of reactions such as cross-linking, cyclization, and chain scission, ultimately generating carbon monoxide, carbon dioxide, benzene-containing compounds, and soot. Existing solutions typically involve adding flame retardants to the PVC wood-plastic composite system; however, the smoke suppression effect of flame retardants is limited, and it still poses a threat to public safety.
[0004] Based on this, the present invention discloses a strong smoke-suppressing and flame-retardant PVC wood-plastic material and its preparation method. This material not only has excellent flame-retardant properties, but also outstanding smoke-suppressing properties, which greatly improves the safety of use. Summary of the Invention
[0005] (a) Technical problems to be solved
[0006] To address the shortcomings of existing technologies, this invention provides a strong smoke-suppressing and flame-retardant PVC wood-plastic composite material and its preparation method, solving the technical problem of poor smoke suppression performance of existing PVC wood-plastic composite materials.
[0007] (II) Technical Solution
[0008] To achieve the above objectives, the present invention provides the following technical solution:
[0009] The strong smoke-suppressing and flame-retardant PVC wood-plastic composite material comprises the following components in parts by weight: 70-100 parts PVC resin, 20-30 parts wood flour, 20-30 parts calcium carbonate, 15-20 parts smoke-suppressing material, 10-15 parts flame retardant, 1-6 parts foaming agent, 5-10 parts stabilizer, 1-2 parts coupling agent, 5-10 parts processing aid, and 1-4 parts lubricant; wherein, the smoke-suppressing material comprises molybdenum compound, ferrocene, and oxalate dihydrate in a mass ratio of 1:(0.5-1.5):(5-10).
[0010] Preferably, the molybdenum compound is any one of ammonium octamolate, molybdenum trioxide, melamine octamolate, and ammonium phosphomolybdate; and the oxalate dihydrate is any one of manganese oxalate dihydrate, ferrous oxalate dihydrate, cobalt oxalate dihydrate, nickel oxalate dihydrate, and copper oxalate dihydrate.
[0011] Preferably, the smoke-suppressing material comprises ammonium phosphomolybdate, ferrocene, and ferrous oxalate dihydrate in a mass ratio of 1:(0.5-1):(5-8).
[0012] Preferably, the flame retardant comprises ammonium polyphosphate, aluminum hydroxide, zinc borate, and melamine cyanurate in a mass ratio of 1:(2.5-5):(0.1-1):(1-4).
[0013] Preferably, it also includes 10-20 parts of ABS resin.
[0014] Preferably, the foaming agent is one or a mixture of two of azodicarbonamide and calcium bicarbonate.
[0015] Preferably, the stabilizer is any one of calcium-zinc stabilizer, zeolite, or silica gel.
[0016] Preferably, the coupling agent is a titanate or an aluminate.
[0017] The preparation method of highly smoke-suppressing and flame-retardant PVC wood-plastic composite material specifically includes the following steps:
[0018] S1. Wood flour end-capping modification:
[0019] Weigh out the wood flour and add it to 8% wt of triethoxysilane;
[0020] Add vinyltris(β-methoxyethoxy)silane until the liquid completely covers the wood flour;
[0021] After standing for 2-3 days, remove the mixture of vinyltris(β-methoxyethoxy)silane and triethoxysilane, and wash with anhydrous ethanol 4-6 times.
[0022] The wood powder obtained by vacuum filtration is heated in a water bath at a temperature of 30–50°C for 1–2 hours, and then dried to obtain modified wood powder.
[0023] S2. Preparation of PVC wood-plastic composite materials:
[0024] First, heat the PVC resin to a molten state, stir it evenly, then add wood flour, calcium carbonate, smoke suppressant, and flame retardant, and mix the above components evenly.
[0025] Then add foaming agent, stabilizer, coupling agent, processing aid, and lubricant to the mixture and stir to allow it to react;
[0026] After the reaction is complete, the material is melted, extruded, pressed, pulverized, and sieved to obtain the finished PVC wood-plastic composite material.
[0027] Preferably, in step S2, the ABS resin is first heated to a molten state, then PVC resin is added, and after the two are stirred and mixed evenly, the mixture is cooled down and then wood flour, calcium carbonate, smoke suppressant, and flame retardant are added.
[0028] (III) Beneficial Effects
[0029] This invention provides a highly smoke-suppressing and flame-retardant PVC wood-plastic composite material and its preparation method. Compared with the prior art, it has the following advantages:
[0030] 1. The PVC wood-plastic composite material system disclosed in this invention incorporates a smoke-suppressing material, which is a composition of molybdenum compound, ferrocene, and oxalate dihydrate. The molybdenum compound mainly functions in the solid phase of the PVC wood-plastic composite material, promoting the formation of a char layer and reducing smoke through Lewis acid. In other words, the molybdenum compound can produce a smoke-suppressing effect at the beginning of combustion. In the chlorine-containing PVC system, ferrocene mainly plays a smoke-suppressing role in the condensed phase. When combustion progresses to a certain extent (usually the middle stage), that is, when a certain amount of gas is produced, ferrocene can play a maximum role, avoiding the problem of the smoke-suppressing effect of PVC wood-plastic composite material decreasing in the middle stage of combustion. Oxalate dihydrate itself produces a smoke-suppressing effect by cross-linking with PVC and promoting the formation of a char layer. At the same time, during the smoke-suppressing process, it can work synergistically with molybdenum compound and oxalate dihydrate to play a role in enhancing the smoke-suppressing effect.
[0031] 2. Before preparing PVC wood-plastic composite materials, the present invention first uses two silane coupling agents to end-cap and modify the wood powder. The two silane coupling agents work synergistically to improve the flame retardancy of the wood powder, the interfacial bonding force with organic matter, and the stability of the system. Detailed Implementation
[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0033] This application provides a strong smoke-suppressing and flame-retardant PVC wood-plastic composite material and its preparation method, which solves the technical problem of poor smoke suppression performance of existing PVC wood-plastic composite materials. The prepared PVC wood-plastic composite material not only has excellent flame-retardant properties, but also outstanding smoke suppression performance, and its safety in use is greatly improved.
[0034] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.
[0035] All raw materials used in this invention were purchased from our partner manufacturers.
[0036] Example 1:
[0037] The strong smoke-suppressing and flame-retardant PVC wood-plastic material comprises the following components in parts by weight: 70 parts PVC resin, 20 parts wood flour, 20 parts calcium carbonate, 15 parts smoke-suppressing material, 10 parts flame retardant, 1 part azodicarbonamide, 5 parts zeolite, 1 part titanate, 5 parts processing aid, and 1 part silicone oil.
[0038] The smoke-suppressing materials include ammonium octamolate, ferrocene, and manganese oxalate dihydrate in a mass ratio of 1:0.5:5.
[0039] The flame retardant includes ammonium polyphosphate, aluminum hydroxide, zinc borate, and melamine cyanurate in a mass ratio of 1:2.5:0.1:1.
[0040] The preparation method of highly smoke-suppressing and flame-retardant PVC wood-plastic composite material specifically includes the following steps:
[0041] S1. Wood flour end-capping modification:
[0042] Weigh out the wood flour and add it to 8% wt vinyltriethoxysilane;
[0043] Add vinyltris(β-methoxyethoxy)silane until the liquid completely covers the wood flour;
[0044] After 3 days of standing, the mixture of vinyltris(β-methoxyethoxy)silane and vinyltriethoxysilane was removed, and the mixture was washed 4 times with anhydrous ethanol.
[0045] The wood powder obtained by vacuum filtration was heated in a water bath at 30°C for 2 hours, and then dried to obtain modified wood powder.
[0046] S2. Preparation of PVC wood-plastic composite materials:
[0047] Sift the modified wood powder and dry it in an oven for 8 hours. First, heat the PVC resin to a molten state, stir it evenly, and then add wood powder, calcium carbonate, smoke suppressant, and flame retardant. Mix the above components evenly.
[0048] Then add azodicarbonamide, zeolite, titanate, processing aid, and silicone oil to the mixture and stir to allow it to react.
[0049] After the reaction is complete, the material is melted, extruded, pressed, pulverized, and sieved to obtain the finished PVC wood-plastic composite material.
[0050] Example 2:
[0051] The strong smoke-suppressing and flame-retardant PVC wood-plastic composite material comprises the following components by weight: 90 parts PVC resin, 25 parts wood flour, 25 parts calcium carbonate, 18 parts smoke-suppressing material, 12 parts flame retardant, 3 parts calcium bicarbonate, 7 parts calcium-zinc stabilizer, 1.5 parts aluminate, 7 parts processing aids, and 3 parts silicone oil.
[0052] The smoke-suppressing materials include ammonium phosphomolybdate, ferrocene, and ferrous oxalate dihydrate in a mass ratio of 1:0.75:6.
[0053] The flame retardant includes ammonium polyphosphate, aluminum hydroxide, zinc borate, and melamine cyanurate in a mass ratio of 1:3.5:0.5:3.
[0054] The preparation method of highly smoke-suppressing and flame-retardant PVC wood-plastic composite material specifically includes the following steps:
[0055] S1. Wood flour end-capping modification:
[0056] Weigh out the wood flour and add it to 8% wt vinyltriethoxysilane;
[0057] Add vinyltris(β-methoxyethoxy)silane until the liquid completely covers the wood flour;
[0058] After 3 days of standing, the mixture of vinyltris(β-methoxyethoxy)silane and vinyltriethoxysilane was removed, and the mixture was washed 5 times with anhydrous ethanol.
[0059] The wood powder obtained by vacuum filtration was heated in a water bath at 40°C for 1 hour, and then dried to obtain modified wood powder.
[0060] S2. Preparation of PVC wood-plastic composite materials:
[0061] First, heat the PVC resin to a molten state, stir it evenly, then add wood flour, calcium carbonate, smoke suppressant, and flame retardant, and mix the above components evenly.
[0062] Then add calcium bicarbonate, calcium-zinc stabilizer, aluminate, processing aid, and silicone oil to the mixture and stir to allow it to react.
[0063] After the reaction is complete, the material is melted, extruded, pressed, pulverized, and sieved to obtain the finished PVC wood-plastic composite material.
[0064] Example 3
[0065] The strong smoke-suppressing and flame-retardant PVC wood-plastic material comprises the following components in parts by weight: 100 parts PVC resin, 30 parts wood flour, 30 parts calcium carbonate, 20 parts smoke-suppressing material, 15 parts flame retardant, 6 parts calcium bicarbonate, 10 parts silica gel, 2 parts titanate, 10 parts processing aid, and 4 parts silicone oil.
[0066] The smoke-suppressing material includes molybdenum trioxide, ferrocene, and nickel oxalate dihydrate in a mass ratio of 1:1.5:10.
[0067] The flame retardant includes ammonium polyphosphate, aluminum hydroxide, zinc borate, and melamine cyanurate in a mass ratio of 1:5:1:4.
[0068] The preparation method of highly smoke-suppressing and flame-retardant PVC wood-plastic composite material specifically includes the following steps:
[0069] S1. Wood flour end-capping modification:
[0070] Weigh out the wood flour and add it to 8% wt vinyltriethoxysilane;
[0071] Add vinyltris(β-methoxyethoxy)silane until the liquid completely covers the wood flour;
[0072] After 3 days of standing, the mixture of vinyltris(β-methoxyethoxy)silane and vinyltriethoxysilane was removed, and the mixture was washed 6 times with anhydrous ethanol.
[0073] The wood powder obtained by vacuum filtration was heated in a water bath at 50°C for 1 hour, and then dried to obtain modified wood powder.
[0074] S2. Preparation of PVC wood-plastic composite materials:
[0075] First, heat the PVC resin to a molten state, stir it evenly, then add wood flour, calcium carbonate, smoke suppressant, and flame retardant, and mix the above components evenly.
[0076] Then add calcium bicarbonate, silica gel, titanate, processing aid, and silicone oil to the mixture and stir to allow it to react.
[0077] After the reaction is complete, the material is melted, extruded, pressed, pulverized, and sieved to obtain the finished PVC wood-plastic composite material.
[0078] Example 4 differs from Example 2 in that:
[0079] The smoke-suppressing material includes ammonium phosphomolybdate, ferrocene, and ferrous oxalate dihydrate in a mass ratio of 1:1:8.
[0080] Example 5 differs from Example 2 in that:
[0081] The strong smoke-suppressing and flame-retardant PVC wood-plastic composite material also includes 15 parts of ABS resin.
[0082] When preparing PVC wood-plastic composite materials, ABS resin is first heated to a molten state, then PVC resin is added. After the two are stirred and mixed evenly, the temperature is lowered to 160℃, and then wood flour, calcium carbonate, smoke suppressant, and flame retardant are added.
[0083] Comparative Example 1 differs from Example 5 in that:
[0084] Remove ferrous oxalate dihydrate from the smoke-suppressing material.
[0085] Comparative Example 2 differs from Example 5 in that:
[0086] Remove ferrocene from the smoke-suppressing material.
[0087] The difference between Comparative Example 3 and Example 5 is as follows:
[0088] The smoke-suppressing material includes a magnesium-zinc composite, ferrocene, and ferrous oxalate dihydrate in a mass ratio of 1:0.75:6.
[0089] The difference between Comparative Example 4 and Example 5 is that:
[0090] The smoke-suppressing material includes ammonium phosphomolybdate, magnesium-zinc composite, and ferrous oxalate dihydrate in a mass ratio of 1:0.75:6.
[0091] Comparative Example 5 differs from Example 5 in that:
[0092] Do not add smoke-suppressing materials to PVC wood-plastic composite material systems.
[0093] Comparative Example 6 differs from Example 5 in that:
[0094] The smoke-suppressing material includes ammonium phosphomolybdate, ferrocene, and ferrous oxalate dihydrate in a mass ratio of 1:1.2:12.
[0095] Comparative Example 7 differs from Example 5 in that:
[0096] The smoke-suppressing material includes ammonium phosphomolybdate, ferrocene, and ferrous oxalate dihydrate in a mass ratio of 1:0.3:3.
[0097] Comparative Example 8 differs from Example 5 in that:
[0098] Remove ammonium polyphosphate from the flame retardant.
[0099] Comparative Example 9 differs from Example 5 in that:
[0100] Remove zinc borate from the flame retardant.
[0101] Comparative Example 10 differs from Example 5 in that:
[0102] Remove zinc borate and melamine cyanurate from the flame retardant.
[0103] Comparative Example 11 differs from Example 5 in that:
[0104] The flame retardants include red phosphorus, aluminum hydroxide, zinc borate, and melamine cyanurate in a mass ratio of 1:3.5:0.5:3.
[0105] Comparative Example 12 differs from Example 5 in that:
[0106] The flame retardant includes red phosphorus, aluminum hydroxide, magnesium hydroxide, and melamine cyanurate in a mass ratio of 1:3.5:0.5:3.
[0107] Comparative Example 13 differs from Example 5 in that:
[0108] When end-capping wood flour, vinyltris(β-methoxyethoxy)silane is replaced with vinyltrimethoxysilane.
[0109] Comparative Example 14 differs from Example 5 in that:
[0110] No end-capping modification is performed on the wood flour.
[0111] Performance testing
[0112] The smoke suppression and flame retardant properties of the PVC wood-plastic composite materials prepared by Examples 1-5 and Comparative Examples 1-14 were tested, and the test results are recorded in Table 1.
[0113] Limiting Oxygen Index (LOI) determination: The limiting oxygen index (LOI) of wood-plastic composites was measured using an oxygen index meter according to GB / T 2406.2-2009 to characterize the flame retardant properties of the material. A higher limiting oxygen index indicates that the material is more difficult to burn.
[0114] Cone calorimetry: The sample size was 100mm × 100mm × 5mm, and the test was conducted according to ISO 5660-1 "Test for heat release rate of combustion". The thermal radiation power was 50kW / m². 2The heat release rate is a fundamental parameter reflecting the development of a fire, determining indoor temperature and smoke production. The smaller the value, the less heat is released and the slower the flame spreads.
[0115] Smoke density: Used to characterize the smoke suppression performance of materials, tested according to ASTM D2843 standard. Based on the test results, it is divided into three levels: A, B, and C, with level A representing the lowest smoke density and level C representing the highest smoke density.
[0116] Table 1 - Smoke suppression and flame retardant performance data of materials prepared in Examples 1-5 and Comparative Examples 1-14
[0117] As can be seen from Table 1,
[0118] 1. As can be seen from the test data of Examples 1-5, the PVC wood-plastic material prepared by the present invention has excellent flame retardant and smoke suppression properties, especially after adding ABS resin to the system. This should be because ABS resin and ferrocene smoke suppression material have a synergistic effect. The addition of ABS resin changes the active phase of ferrocene, allowing it to continuously exert a smoke suppression effect in the gas phase, thereby improving the smoke suppression effect.
[0119] 2. As can be seen from the test data of Example 5 and Comparative Examples 1-7, the smoke-suppressing material of the present invention has excellent smoke-suppressing and flame-retardant properties, and the three components of ammonium phosphomolybdate, ferrocene, and ferrous oxalate dihydrate have a synergistic effect. By controlling the three components within a reasonable ratio range, their smoke-suppressing effect can be maximized.
[0120] 3. As can be seen from the test data of Example 5 and Comparative Examples 8-12, the ammonium polyphosphate, aluminum hydroxide, zinc borate and melamine cyanurate used in the flame retardant of the present invention have a synergistic effect, which can significantly improve the flame retardant performance of PVC wood-plastic composite materials.
[0121] 4. As can be seen from the test data of Example 5 and Comparative Examples 13-14, end-capping modification of wood flour can affect the flame retardant and smoke-suppressing properties of PVC wood-plastic composite materials to a certain extent, and vinyltris(β-methoxyethoxy)silane and vinyltriethoxysilane have a certain synergistic effect.
[0122] In summary, compared with existing technologies, it has the following beneficial effects:
[0123] 1. The PVC wood-plastic composite material system disclosed in this invention incorporates a smoke-suppressing material, which is a composition of molybdenum compound, ferrocene, and oxalate dihydrate. The molybdenum compound mainly functions in the solid phase of the PVC wood-plastic composite material, promoting the formation of a char layer and reducing smoke through Lewis acid. In other words, the molybdenum compound can produce a smoke-suppressing effect at the beginning of combustion. In the chlorine-containing PVC system, ferrocene mainly plays a smoke-suppressing role in the condensed phase. When combustion progresses to a certain extent (usually the middle stage), that is, when a certain amount of gas is produced, ferrocene can play a maximum role, avoiding the problem of the smoke-suppressing effect of PVC wood-plastic composite material decreasing in the middle stage of combustion. Oxalate dihydrate itself produces a smoke-suppressing effect by cross-linking with PVC and promoting the formation of a char layer. At the same time, during the smoke-suppressing process, it can work synergistically with molybdenum compound and oxalate dihydrate to play a role in enhancing the smoke-suppressing effect.
[0124] 2. Before preparing PVC wood-plastic composite materials, the present invention first uses two silane coupling agents to end-cap and modify the wood powder. The two silane coupling agents work synergistically to improve the flame retardancy of the wood powder, the interfacial bonding force with organic matter, and the stability of the system.
[0125] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0126] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A strong smoke suppression flame retardant PVC wood plastic material, characterized in that, It includes the following components in parts by weight: 70-100 parts PVC resin, 20-30 parts wood flour, 20-30 parts calcium carbonate, 15-20 parts smoke suppressant, 10-15 parts flame retardant, 1-6 parts foaming agent, 5-10 parts stabilizer, 1-2 parts coupling agent, 5-10 parts processing aid, and 1-4 parts lubricant; wherein, the smoke suppressant includes molybdenum compound, ferrocene, and oxalate dihydrate in a mass ratio of 1:(0.5-1.5):(5-10).
2. The strong smoke suppression flame retardant PVC wood plastic material according to claim 1, characterized in that, The molybdenum compound is any one of ammonium octamolybdate, molybdenum trioxide, melamine octamolybdate, and ammonium phosphomolybdate; the oxalate dihydrate is any one of manganese oxalate dihydrate, ferrous oxalate dihydrate, cobalt oxalate dihydrate, nickel oxalate dihydrate, and copper oxalate dihydrate.
3. The strong smoke suppression flame-retardant PVC wood plastic material according to claim 2, characterized in that, The smoke-suppressing material comprises ammonium phosphomolybdate, ferrocene, and ferrous oxalate dihydrate in a mass ratio of 1:(0.5-1):(5-8).
4. The strong smoke suppression flame-retardant PVC wood plastic material according to claim 3, characterized in that, The flame retardant comprises ammonium polyphosphate, aluminum hydroxide, zinc borate, and melamine cyanurate in a mass ratio of 1:(2.5-5):(0.1-1):(1-4).
5. The PVC wood-plastic composite material with strong smoke suppression and flame retardancy as described in claim 1, characterized in that, It also includes 10-20 parts of ABS resin.
6. The strong smoke suppression flame retardant PVC wood plastic material according to claim 1, wherein, The foaming agent is one or a mixture of two of azodicarbonamide and calcium bicarbonate.
7. The PVC wood-plastic composite material with strong smoke suppression and flame retardancy as described in claim 1, characterized in that, The stabilizer is any one of calcium-zinc stabilizer, zeolite, or silica gel.
8. The strong smoke suppression flame retardant PVC wood plastic material of claim 1, wherein, The coupling agent is a titanate or an aluminate.
9. The process for the preparation of strong smoke suppressing flame retardant PVC wood plastic material according to any one of claims 1-8, characterized in that, Specifically, the following steps are included: S1. Wood flour end-capping modification: Weigh out the wood flour and add it to 8% wt of triethoxysilane; Add vinyltris(β-methoxyethoxy)silane until the liquid completely covers the wood flour; After standing for 2-3 days, remove the mixture of vinyltris(β-methoxyethoxy)silane and triethoxysilane, and wash with anhydrous ethanol 4-6 times. The wood powder obtained by vacuum filtration is heated in a water bath at a temperature of 30–50°C for 1–2 hours, and then dried to obtain modified wood powder. S2. Preparation of PVC wood-plastic composite materials: First, heat the PVC resin to a molten state, stir it evenly, then add wood flour, calcium carbonate, smoke suppressant, and flame retardant, and mix the above components evenly. Then add foaming agent, stabilizer, coupling agent, processing aid, and lubricant to the mixture and stir to allow it to react; After the reaction is complete, the material is melted, extruded, pressed, pulverized, and sieved to obtain the finished PVC wood-plastic composite material.
10. The process for the preparation of strong smoke suppressant flame retardant PVC wood plastic material as claimed in any one of the claims 9, wherein, In step S2, ABS resin is first heated to a molten state, then PVC resin is added. After the two are stirred and mixed evenly, the mixture is cooled down and then wood flour, calcium carbonate, smoke suppressant, and flame retardant are added.