Sugarcane fiber reinforced flame-retardant A-type polyvinyl chloride sheath material and preparation method thereof

Abstract

The invention discloses a sugarcane fiber reinforced flame-retardant A-type polyvinyl chloride sheath material and a preparation method thereof. The material comprises the following raw materials in parts by weight: 100 parts of polyvinyl chloride resin, 25-45 parts of a plasticizer, 3-8 parts of a calcium-zinc stabilizer, 20-35 parts of sugarcane fibers and 10-25 parts of a halogen-free flame retardant, and the sugarcane fibers are obtained through pretreatment. According to the present invention, the A-type flame retardation standard (the bundle combustion carbonization height is less than or equal to 2.5 m) of GB / T 19666-2019 is met, and the sugarcane fiber reinforcement is provided, such that the structure is simplified, the production cost is reduced, and the environmental protection property and the processing efficiency are improved. Compared with the prior art, redundant processes such as an oxygen barrier layer are omitted, and the material is light and suitable for cable sheaths.

Description

Technical Field

[0001] This invention relates to the field of cable sheathing materials, specifically to a sugarcane fiber reinforced flame-retardant Class A polyvinyl chloride sheathing material and its preparation method. Background Technology

[0002] With the popularization of green and environmentally friendly concepts, cable sheath materials need to balance flame retardancy, high temperature resistance, and environmental friendliness. Currently, flame-retardant Class A polyvinyl chloride (PVC) sheath materials are widely used in cables, but traditional solutions have several drawbacks: First, the materials rely on halogenated flame retardants (such as bromine-containing compounds), leading to decreased mechanical properties and environmental risks. They are also prone to releasing toxic fumes during fires, which does not comply with green design principles. Second, while existing flame-retardant Class A sheath materials (such as Type I 90℃ soft PVC) can withstand a 90℃ operating temperature, their flame-retardant performance is unstable, requiring the addition of an oxygen barrier layer or outer wrapping layer to meet bundled burning tests (char height ≤ 2.5m). This increases production processes and costs, and the high material density affects cable portability and installation efficiency. Furthermore, the application of natural fiber reinforcement materials (such as sugarcane fiber) in PVC is not yet mature. Existing technologies mostly use synthetic fibers or inorganic fillers, which have poor dispersibility and easily reduce material toughness and flame-retardant efficiency. Sugarcane fiber, as an agricultural waste, is lightweight and has a high cellulose content (>60%), making it a suitable substitute for synthetic reinforcing materials. However, existing technologies have not solved the problems of its dispersibility and flame retardant synergy in polyvinyl chloride. Summary of the Invention

[0003] Therefore, this invention provides a sugarcane fiber reinforced flame-retardant Class A polyvinyl chloride sheathing material and its preparation method, in order to solve the problem that existing technologies mostly use synthetic fibers or inorganic fillers, which have poor dispersibility and easily reduce the toughness and flame-retardant efficiency of the material.

[0004] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions: According to a first aspect of the present invention, the present invention provides a sugarcane fiber reinforced flame-retardant Class A polyvinyl chloride sheathing material, the material comprising the following raw materials in parts by weight: 100 parts polyvinyl chloride resin, 25-45 parts plasticizer, 3-8 parts calcium zinc stabilizer, 20-35 parts sugarcane fiber, and 10-25 parts halogen-free flame retardant, wherein the sugarcane fiber is obtained through pretreatment.

[0005] Furthermore, it is made from the following raw materials in parts by weight: 100 parts polyvinyl chloride resin, 38 parts plasticizer, 6 parts calcium-zinc stabilizer, 32 parts pretreated sugarcane fiber, and 12 parts phosphorus-nitrogen flame retardant.

[0006] Furthermore, the polyvinyl chloride resin used is SG-5 type polyvinyl chloride resin.

[0007] Furthermore, the halogen-free flame retardant is a phosphorus-nitrogen complex.

[0008] Furthermore, the plasticizer is epoxidized soybean oil.

[0009] Furthermore, the sugarcane fiber is obtained by alkali treatment, and the fiber length is 0.5-2 mm.

[0010] According to a second aspect of the present invention, an embodiment of the present invention provides a method for preparing a sugarcane fiber reinforced flame-retardant Class A polyvinyl chloride sheathing material, the preparation method comprising: Pretreatment of sugarcane fiber raw materials; Pretreated sugarcane fiber, polyvinyl chloride resin, plasticizer, and stabilizer are added to a mixer for mixing, then halogen-free flame retardant is added and mixed again, and finally the finished product is obtained by extrusion granulation.

[0011] Furthermore, the sugarcane fiber raw materials undergo pretreatment, specifically including: Alkali treatment is applied to sugarcane fiber raw materials.

[0012] Furthermore, the sugarcane fiber raw material undergoes alkali treatment, specifically including: Sugarcane fiber raw materials are cut into short fibers with a length of 0.5-2 mm, soaked in 5% NaOH solution for 2 hours to remove lignin, washed with water and dried until the moisture content is <1%.

[0013] Further, pretreated sugarcane fiber, polyvinyl chloride resin, plasticizer, and stabilizer are first mixed in a high-speed mixer, then a halogen-free flame retardant is added and mixed again, and finally the finished product is obtained by extrusion granulation, specifically including: Pretreated sugarcane fiber, polyvinyl chloride resin, plasticizer, and stabilizer are first mixed at low speed at 80℃ for 10 minutes, then halogen-free flame retardant is added and mixed at high speed at 110℃ for 15 minutes. Finally, the product is obtained by extrusion granulation at 110-150℃ using a polyvinyl chloride two-stage granulation extruder.

[0014] Compared with existing technologies, the present invention provides a sugarcane fiber reinforced flame-retardant Class A polyvinyl chloride sheath material and its preparation method, which not only meets the Class A flame-retardant standard of GB / T 19666-2019 (char height ≤ 2.5m during bundled combustion), but also simplifies the structure, reduces production costs, and improves environmental friendliness and processing efficiency through sugarcane fiber reinforcement. Compared with existing technologies, redundant processes such as oxygen barrier layers are omitted, the material is lightweight, and it is suitable for cable sheaths. Specific beneficial effects are as follows: 1) Excellent flame retardant performance: Sugarcane fiber and halogen-free flame retardant work synergistically to improve char formation rate and oxygen index (≥35), pass Class A bundle burning test (char height ≤1.0m), no oxygen barrier layer required, simplifying the structure; 2) Low cost and environmentally friendly: Sugarcane fiber is a renewable resource that can replace synthetic fillers, reducing material density by 20% and production costs by 15%; the halogen-free formula reduces toxic fumes and complies with green design. 3) Easy processing: The material has good flexibility, the extrusion process is simple, the bending performance of the sheath is improved, it is suitable for soft cables (such as ZA-KVVR), and the installation efficiency is improved; 4) High temperature resistance: Operating temperature 90℃, short circuit resistance 250℃, meets the Class A performance standard of Type I 90℃ sheath-grade soft polyvinyl chloride plastic. Detailed Implementation

[0015] The present invention will now be described in detail with reference to embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present invention can be combined with each other.

[0016] The following detailed description is exemplary and intended to provide further detailed explanation of the invention. Unless otherwise specified, all technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this invention is for describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention.

[0017] Example 1 A sugarcane fiber reinforced flame-retardant Class A polyvinyl chloride sheathing material is made from the following raw materials in parts by weight: 100 parts polyvinyl chloride resin, 38 parts plasticizer, 6 parts calcium-zinc stabilizer, 32 parts pretreated sugarcane fiber, and 12 parts phosphorus-nitrogen flame retardant.

[0018] in: The polyvinyl chloride resin used is SG-5 type polyvinyl chloride resin. Its function is as a matrix material, providing heat resistance. The plasticizer used is epoxidized soybean oil, an environmentally friendly plasticizer made by epoxidizing soybean oil. Its function is to improve processing fluidity and enhance the plasticity, flame retardancy, and heat resistance of materials. Calcium and zinc stabilizers, function: to prevent decomposition at high temperatures; Sugarcane fiber is obtained through alkali treatment. The fiber length is 0.5-2mm. Its function is as a reinforcing phase, which improves mechanical strength, tensile strength and flame retardancy. The halogen-free flame retardant uses a phosphorus-nitrogen complex with an oxygen index ≥32. Its function is to work synergistically with sugarcane fiber to increase char formation and inhibit flame spread.

[0019] The specific steps for preparing the above-mentioned sugarcane fiber reinforced flame-retardant Class A polyvinyl chloride sheath material are as follows: (1) Cut the sugarcane fiber raw material into short fibers with a length of 0.5-2 mm, soak them in 5% NaOH solution for 2 hours to remove lignin, wash them with water and dry them until the moisture content is <1%.

[0020] (2) The pretreated sugarcane fiber, polyvinyl chloride resin, plasticizer and stabilizer are first mixed at low speed at 80°C for 10 min, then halogen-free flame retardant is added and mixed at high speed at 110°C for 15 min, and finally extruded and granulated at 130°C by a polyvinyl chloride two-stage granulation extruder to obtain the finished product.

[0021] Application of the above-mentioned sugarcane fiber reinforced flame-retardant Class A PVC sheath material: The particles are used for extruding cable sheaths with a sheath thickness of 1.0-2.0mm and a bending radius ≥12 times the cable diameter. It is suitable for ZA-KVV and ZA-KVVR series flame-retardant Class A control cables.

[0022] Example 2 A sugarcane fiber reinforced flame-retardant Class A polyvinyl chloride sheathing material is made from the following raw materials in parts by weight: 100 parts polyvinyl chloride resin, 25 parts plasticizer, 3 parts calcium-zinc stabilizer, 20 parts pretreated sugarcane fiber, and 10 parts phosphorus-nitrogen flame retardant.

[0023] in: The polyvinyl chloride resin used is SG-5 type polyvinyl chloride resin. Its function is as a matrix material, providing heat resistance. The plasticizer used is epoxidized soybean oil, an environmentally friendly plasticizer made by epoxidizing soybean oil. Its function is to improve processing fluidity and enhance the plasticity, flame retardancy, and heat resistance of materials. Calcium and zinc stabilizers, function: to prevent decomposition at high temperatures; Sugarcane fiber is obtained through alkali treatment. The fiber length is 0.5-2mm. Its function is as a reinforcing phase, which improves mechanical strength, tensile strength and flame retardancy. The halogen-free flame retardant uses a phosphorus-nitrogen complex with an oxygen index ≥32. Its function is to work synergistically with sugarcane fiber to increase char formation and inhibit flame spread.

[0024] The specific steps for preparing the above-mentioned sugarcane fiber reinforced flame-retardant Class A polyvinyl chloride sheath material are as follows: (1) Cut the sugarcane fiber raw material into short fibers with a length of 0.5-2 mm, soak them in 5% NaOH solution for 2 hours to remove lignin, wash them with water and dry them until the moisture content is <1%.

[0025] (2) The pretreated sugarcane fiber, polyvinyl chloride resin, plasticizer and stabilizer are first mixed at low speed at 80°C for 10 min, then halogen-free flame retardant is added and mixed at high speed at 110°C for 15 min, and finally extruded and granulated at 130°C by a polyvinyl chloride two-stage granulation extruder to obtain the finished product.

[0026] Application of the above-mentioned sugarcane fiber reinforced flame-retardant Class A PVC sheath material: The particles are used for extruding cable sheaths with a sheath thickness of 1.0-2.0mm and a bending radius ≥12 times the cable diameter. It is suitable for ZA-KVV and ZA-KVVR series flame-retardant Class A control cables.

[0027] Example 3 A sugarcane fiber reinforced flame-retardant Class A polyvinyl chloride sheathing material is made from the following raw materials in parts by weight: 100 parts polyvinyl chloride resin, 45 parts plasticizer, 8 parts calcium-zinc stabilizer, 35 parts pretreated sugarcane fiber, and 25 parts phosphorus-nitrogen flame retardant.

[0028] in: The polyvinyl chloride resin used is SG-5 type polyvinyl chloride resin. Its function is as a matrix material, providing heat resistance. The plasticizer used is epoxidized soybean oil, an environmentally friendly plasticizer made by epoxidizing soybean oil. Its function is to improve processing fluidity and enhance the plasticity, flame retardancy, and heat resistance of materials. Calcium and zinc stabilizers, function: to prevent decomposition at high temperatures; Sugarcane fiber is obtained through alkali treatment. The fiber length is 0.5-2mm. Its function is as a reinforcing phase, which improves mechanical strength, tensile strength and flame retardancy. The halogen-free flame retardant uses a phosphorus-nitrogen complex with an oxygen index ≥32. Its function is to work synergistically with sugarcane fiber to increase char formation and inhibit flame spread.

[0029] The specific steps for preparing the above-mentioned sugarcane fiber reinforced flame-retardant Class A polyvinyl chloride sheath material are as follows: (1) Cut the sugarcane fiber raw material into short fibers with a length of 0.5-2 mm, soak them in 5% NaOH solution for 2 hours to remove lignin, wash them with water and dry them until the moisture content is <1%.

[0030] (2) The pretreated sugarcane fiber, polyvinyl chloride resin, plasticizer and stabilizer are first mixed at low speed at 80°C for 10 min, then halogen-free flame retardant is added and mixed at high speed at 110°C for 15 min, and finally extruded and granulated at 130°C by a polyvinyl chloride two-stage granulation extruder to obtain the finished product.

[0031] Application of the above-mentioned sugarcane fiber reinforced flame-retardant Class A PVC sheath material: The particles are used for extruding cable sheaths with a sheath thickness of 1.0-2.0mm and a bending radius ≥12 times the cable diameter. It is suitable for ZA-KVV and ZA-KVVR series flame-retardant Class A control cables.

[0032] Example 4 A sugarcane fiber reinforced flame-retardant Class A polyvinyl chloride sheathing material is made from the following raw materials in parts by weight: 100 parts polyvinyl chloride resin, 30 parts plasticizer, 7 parts calcium-zinc stabilizer, 28 parts pretreated sugarcane fiber, and 18 parts phosphorus-nitrogen flame retardant.

[0033] in: The polyvinyl chloride resin used is SG-5 type polyvinyl chloride resin. Its function is as a matrix material, providing heat resistance. The plasticizer used is epoxidized soybean oil, an environmentally friendly plasticizer made by epoxidizing soybean oil. Its function is to improve processing fluidity and enhance the plasticity, flame retardancy, and heat resistance of materials. Calcium and zinc stabilizers, function: to prevent decomposition at high temperatures; Sugarcane fiber is obtained through alkali treatment. The fiber length is 0.5-2mm. Its function is as a reinforcing phase, which improves mechanical strength, tensile strength and flame retardancy. The halogen-free flame retardant uses a phosphorus-nitrogen complex with an oxygen index ≥32. Its function is to work synergistically with sugarcane fiber to increase char formation and inhibit flame spread.

[0034] The specific steps for preparing the above-mentioned sugarcane fiber reinforced flame-retardant Class A polyvinyl chloride sheath material are as follows: (1) Cut the sugarcane fiber raw material into short fibers with a length of 0.5-2 mm, soak them in 5% NaOH solution for 2 hours to remove lignin, wash them with water and dry them until the moisture content is <1%.

[0035] (2) The pretreated sugarcane fiber, polyvinyl chloride resin, plasticizer and stabilizer are first mixed at low speed at 80°C for 10 min, then halogen-free flame retardant is added and mixed at high speed at 110°C for 15 min, and finally extruded and granulated at 130°C by a polyvinyl chloride two-stage granulation extruder to obtain the finished product.

[0036] Application of the above-mentioned sugarcane fiber reinforced flame-retardant Class A PVC sheath material: The particles are used for extruding cable sheaths with a sheath thickness of 1.0-2.0mm and a bending radius ≥12 times the cable diameter. It is suitable for ZA-KVV and ZA-KVVR series flame-retardant Class A control cables.

[0037] Example 5 A sugarcane fiber reinforced flame-retardant Class A polyvinyl chloride sheathing material is made from the following raw materials in parts by weight: 100 parts polyvinyl chloride resin, 40 parts plasticizer, 5 parts calcium-zinc stabilizer, 30 parts pretreated sugarcane fiber, and 20 parts phosphorus-nitrogen flame retardant.

[0038] in: The polyvinyl chloride resin used is SG-5 type polyvinyl chloride resin. Its function is as a matrix material, providing heat resistance. The plasticizer used is epoxidized soybean oil, an environmentally friendly plasticizer made by epoxidizing soybean oil. Its function is to improve processing fluidity and enhance the plasticity, flame retardancy, and heat resistance of materials. Calcium and zinc stabilizers, function: to prevent decomposition at high temperatures; Sugarcane fiber is obtained through alkali treatment. The fiber length is 0.5-2mm. Its function is as a reinforcing phase, which improves mechanical strength, tensile strength and flame retardancy. The halogen-free flame retardant uses a phosphorus-nitrogen complex with an oxygen index ≥32. Its function is to work synergistically with sugarcane fiber to increase char formation and inhibit flame spread.

[0039] The specific steps for preparing the above-mentioned sugarcane fiber reinforced flame-retardant Class A polyvinyl chloride sheath material are as follows: (1) Cut the sugarcane fiber raw material into short fibers with a length of 0.5-2 mm, soak them in 5% NaOH solution for 2 hours to remove lignin, wash them with water and dry them until the moisture content is <1%.

[0040] (2) The pretreated sugarcane fiber, polyvinyl chloride resin, plasticizer and stabilizer are first mixed at low speed at 80°C for 10 min, then halogen-free flame retardant is added and mixed at high speed at 110°C for 15 min, and finally extruded and granulated at 130°C by a polyvinyl chloride two-stage granulation extruder to obtain the finished product.

[0041] Application of the above-mentioned sugarcane fiber reinforced flame-retardant Class A PVC sheath material: The particles are used for extruding cable sheaths with a sheath thickness of 1.0-2.0mm and a bending radius ≥12 times the cable diameter. It is suitable for ZA-KVV and ZA-KVVR series flame-retardant Class A control cables.

[0042] 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 it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A sugarcane fiber reinforced flame-retardant Class A polyvinyl chloride sheathing material, characterized in that, The material comprises the following raw materials in parts by weight: 100 parts polyvinyl chloride resin, 25-45 parts plasticizer, 3-8 parts calcium-zinc stabilizer, 20-35 parts sugarcane fiber, and 10-25 parts halogen-free flame retardant, wherein the sugarcane fiber is obtained through pretreatment.

2. The sugarcane fiber reinforced flame-retardant Class A polyvinyl chloride sheathing material according to claim 1, characterized in that, It is made from the following raw materials in parts by weight: 100 parts polyvinyl chloride resin, 38 parts plasticizer, 6 parts calcium-zinc stabilizer, 32 parts pretreated sugarcane fiber, and 12 parts phosphorus-nitrogen flame retardant.

3. The sugarcane fiber reinforced flame-retardant Class A polyvinyl chloride sheathing material according to claim 1, characterized in that, The polyvinyl chloride resin used is SG-5 type polyvinyl chloride resin.

4. The sugarcane fiber reinforced flame-retardant Class A polyvinyl chloride sheathing material according to claim 1, characterized in that, The halogen-free flame retardant is a phosphorus-nitrogen complex.

5. The sugarcane fiber reinforced flame-retardant Class A polyvinyl chloride sheathing material according to claim 1, characterized in that, The plasticizer used is epoxidized soybean oil.

6. The sugarcane fiber reinforced flame-retardant Class A polyvinyl chloride sheathing material according to claim 1, characterized in that, The sugarcane fiber is obtained through alkali treatment and has a fiber length of 0.5-2 mm.

7. A method for preparing a sugarcane fiber reinforced flame-retardant Class A polyvinyl chloride sheathing material according to any one of claims 1-6, characterized in that, The preparation method includes: Pretreatment of sugarcane fiber raw materials; Pretreated sugarcane fiber, polyvinyl chloride resin, plasticizer, and stabilizer are added to a mixer for mixing, then halogen-free flame retardant is added and mixed again, and finally the finished product is obtained by extrusion granulation.

8. The method for preparing a sugarcane fiber reinforced flame-retardant Class A polyvinyl chloride sheathing material according to claim 7, characterized in that, Pretreatment of sugarcane fiber raw materials specifically includes: Alkali treatment is applied to sugarcane fiber raw materials.

9. The method for preparing a sugarcane fiber reinforced flame-retardant Class A polyvinyl chloride sheathing material according to claim 8, characterized in that, Alkali treatment of sugarcane fiber raw materials specifically includes: Sugarcane fiber raw materials are cut into short fibers with a length of 0.5-2 mm, soaked in 5% NaOH solution for 2 hours to remove lignin, washed with water and dried until the moisture content is <1%.

10. The method for preparing a sugarcane fiber reinforced flame-retardant Class A polyvinyl chloride sheathing material according to claim 7, characterized in that, Pretreated sugarcane fiber, polyvinyl chloride resin, plasticizer, and stabilizer are first mixed in a high-speed mixer, then a halogen-free flame retardant is added and mixed again. Finally, the finished product is obtained by extrusion granulation. Specifically, the process includes: Pretreated sugarcane fiber, polyvinyl chloride resin, plasticizer, and stabilizer are first mixed at low speed at 80℃ for 10 minutes, then halogen-free flame retardant is added and mixed at high speed at 110℃ for 15 minutes. Finally, the product is obtained by extrusion granulation at 110-150℃ using a polyvinyl chloride two-stage granulation extruder.