Flame-retardant glass fiber composite material and preparation method thereof

Abstract

The present invention belongs to the technical field of composite materials, and in particular relates to a flame-retardant glass fiber composite material and a preparation method thereof. The composite material comprises the following components in parts by weight: 60-70 parts of nylon 610, 5-15 parts of nylon 66 powder, 1-4 parts of pentaerythritol and its derivatives, 20-30 parts of glass fiber, 5-10 parts of alkyl phosphinate, 0.1-5 parts of coupling agent, 0.1-5 parts of antioxidant, and 0.1-5 parts of processing aid; wherein, the particle size of nylon 66 powder is 1-10 μm. The present invention adds nylon 66 powder of a certain size to the nylon 610-glass fiber-alkyl phosphinate flame retardant system. Nylon 66 powder plays the role of rigid particle reinforcement, which can improve the impact resistance of nylon 610 without losing its tensile strength. Pentaerythritol not only has the function of a carbon forming agent, but also can improve the melt strength and mechanical properties of the composite material, thereby preparing a composite material with both flame retardancy and high mechanical properties.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite materials, and in particular relates to a flame-retardant glass fiber composite material and a preparation method thereof. Background Art

[0002] Polymer materials offer numerous advantages and are widely used in various fields, including human life and production. However, most polymer materials are flammable and do not self-extinguish when exposed to fire. To reduce the risk and harmfulness of fires, flame-retardant treatment of polymer materials is becoming increasingly important. Some countries have mandated the use of flame-retardant polymer materials in certain areas. Therefore, reducing the flammability of polymer materials and preparing flame-retardant polymer materials remain key challenges.

[0003] Polyamide (nylon) is a widely used engineering plastic. It was first developed for fiber production by DuPont in the United States in the 1930s, with industrial production achieved in 1939. In the 1950s, nylon injection molding began to be developed and produced to replace metal, meeting the demands for lightweighting and cost-reducing industrial products. Currently, nylon has become the largest, most widely used, and most diverse of the five major engineering plastics. Its diverse varieties include nylon 6, nylon 66, nylon 11, nylon 12, nylon 46, nylon 610, nylon 612, and nylon 1010, as well as more recently developed semi-aromatic and specialty nylons. Nylon 610 is a widely used variety, offering both strength and toughness. Nylon 610 has excellent overall properties, including excellent mechanical and electrical properties, oil resistance, heat resistance, wear resistance, electrical insulation, chemical resistance, weather resistance, and self-lubrication. It also has a low coefficient of friction and is easy to process. It is also suitable for reinforcement and modification with glass fiber and other fillers to improve material properties and expand its application range. Currently, nylon 610 and reinforced nylon 610 are mainly used in industries such as transportation, electronics, and machinery.

[0004] Nylon 610 is a combustible material that generates high heat during combustion, producing large amounts of thick smoke and flaming droplets, which can easily spread flames. The typical combustion process for nylon 610 is as follows: it first melts and softens under flame heating. Further heating to a certain temperature causes the surface nylon to thermally decompose and break its molecular chains. During combustion, nylon 610 exhibits significant melt dripping, producing a large number of flaming droplets. These droplets carry away a significant amount of the combustion heat, causing the burning nylon 610 to self-extinguish. Although its inherent flame retardancy has reached UL94V-2, it is still a combustible material, and the generation of flaming droplets can cause flames to spread.

[0005] With the rapid development of flame retardant research in polymer materials, additive flame retardants have become the second most popular plastic additive in terms of production volume, second only to plasticizers. Flame retardants suitable for flame-retardant nylon 610 and glass fiber-reinforced nylon 610 primarily include halogen-based, nitrogen-based, phosphorus-based, and phosphorus-nitrogen composite flame retardants. Different types of flame retardants exhibit significant differences in their effects on the flame retardant mechanism, flame retardant effect, and material properties of nylon 610 and glass fiber-reinforced nylon 610. Among these, alkyl phosphinates are the most widely used flame retardants. However, alkyl phosphinates have poor compatibility with nylon 610. In particular, the addition of alkyl phosphinate flame retardants significantly reduces the mechanical properties of nylon 610 composites. While existing technologies improve the mechanical strength of nylon 610 composites through the use of glass fibers, these improvements in toughness are limited. Therefore, there is an urgent need to develop nylon 610 composites that meet both flame retardancy requirements and exhibit high mechanical properties. Summary of the Invention

[0006] In order to solve the technical problem of reduced mechanical properties of nylon 610 composite materials caused by the addition of alkyl phosphinates, the present invention provides a flame retardant glass fiber composite material and a preparation method thereof.

[0007] A flame-retardant glass fiber composite material comprising the following components in parts by weight:

[0008] 60-70 parts of nylon 610, 5-15 parts of nylon 66 powder, 1-4 parts of pentaerythritol and its derivatives, 20-30 parts of glass fiber, 5-10 parts of alkyl phosphinate, 0.1-5 parts of coupling agent, 0.1-5 parts of antioxidant, and 0.1-5 parts of processing aid; wherein the particle size of the nylon 66 powder is 1-10 μm.

[0009] Nylon 610, an important engineering plastic, is often used as structural components in electronics, machinery, and other fields. However, the low strength of nylon 610 limits its application. Furthermore, its products are often used in harsh environments, such as high temperatures and heat, necessitating flame retardant modification. Alkyl phosphinates are the most widely used flame retardants. However, alkyl phosphinates have poor compatibility with nylon 610, resulting in a significant decrease in the mechanical properties of nylon composites. While the addition of glass fiber can significantly improve the mechanical properties and heat distortion temperature of the material, the low melt viscosity of nylon 610 allows the melt to soak into the glass fiber surface, causing a candle-like effect. This effect, called the candle-like wick effect, makes the nylon more flammable and the flame burns vigorously, unable to self-extinguish. This makes flame retardancy more difficult. Furthermore, the presence of glass fiber impedes the flow of the molten polymer, preventing it from dripping, thus preventing the material from being flame-retarded by the heat of combustion through the droplets. Therefore, the amount of glass fiber in nylon 610 composites should be limited.

[0010] To further enhance the mechanical properties of nylon 610, the present invention incorporates nylon 66 powder of a specific size. Nylon 66 has a relatively high melting point, much higher than that of nylon 610, and exhibits high mechanical strength. During the melt processing of nylon 610 composites (typically at 210-230°C), the nylon 66 powder does not melt, but instead acts as a reinforcing agent, similar to rigid particles. Compared to common inorganic fillers, nylon 66 powder presents no compatibility issues with nylon 610, improving the impact resistance of nylon 610 without sacrificing tensile strength. Furthermore, as organic rigid particles, their size is similar to that of glass fibers, both in the micron range. The presence of nylon 66 powder improves the dispersion of glass fibers, helping to address the problem of floating fibers and enhancing the mechanical properties of the composite. The types of nylon 610 and nylon 66 are not particularly limited; any commonly used materials in the field can be used. The melting point of nylon 66 is generally 255-270°C, while that of nylon 610 is generally 210-215°C. Specifically, the melting point of nylon 66 used in the specific embodiment of the present invention is 260°C, and the melting point of nylon 610 is 215°C.

[0011] In a specific embodiment of the present invention, the pentaerythritol and its derivatives are one or more of monopentaerythritol, dipentaerythritol and tripentaerythritol. As a small molecule additive, pentaerythritol not only has the function of a carbon forming agent and improves flame retardancy, but more importantly, as a small molecule compound, it can improve the dispersibility of nylon 66 powder and improve the mechanical properties of the composite material. In addition, due to its polyhydroxy structure, it can form stronger hydrogen bonds with the softened parts of nylon 610 and nylon 66 surfaces during melt processing, forming a cross-linked structure, improving melt strength and composite material mechanical properties. However, as a small molecule additive, its consumption cannot be too much, otherwise it may cause excessive cross-linking and cause the composite material toughness to decrease.

[0012] In a specific embodiment of the present invention, the glass fiber is an alkali-free glass fiber. The glass fiber size is not particularly limited. Common glass fibers generally have a length of 3-40 mm and a diameter of 1-20 μm. The glass fiber used in this embodiment of the present invention has a diameter of 10 μm and a fiber length of 3 mm.

[0013] In a specific embodiment of the present invention, the alkyl phosphinate is a metal diethylphosphinate. Metal diethylphosphinates have low toxicity, smoke generation, and corrosiveness. They primarily function in the condensed phase, producing phosphoric acid and polyphosphoric acid during combustion, which promote polymer dehydration and char formation. They also form a glassy or liquid protective layer, inhibiting char oxidation and reducing combustion heat, thereby achieving flame retardancy in nylon materials.

[0014] Furthermore, the volume average particle size D50 of nylon 66 powder is 1-10 μm. Specifically, it can be in the specific ranges of 2-8 μm, 3-7 μm, 4-6 μm, 4-5 μm, etc. The appropriate particle size of nylon 66 powder can have both the technical effects of reinforcement and toughening. If the particle size is too large, it cannot play the role of filling rigid particles. If the particle size is too small, excessive softening will occur during the processing and stable rigid particles cannot be formed. The amount of nylon 66 powder used is 5-15 parts. Specifically, it can be in the specific ranges of 6-14 parts, 8-12 parts, 9-11 parts, etc. An appropriate amount of nylon 66 powder can give full play to its enhanced technical effect and avoid the problem of reduced melt fluidity caused by its addition.

[0015] In a specific embodiment of the present invention, the coupling agent is one or more of KH550, KH551, KH560, and KH570.

[0016] In a specific embodiment of the present invention, the antioxidant is one or more of hindered phenol antioxidants, phosphite antioxidants, and thioester antioxidants.

[0017] In a specific embodiment of the present invention, the processing aid is one or more of a lubricant, a colorant, an antistatic agent, an anti-hydrolysis agent, a flow modifier, a plasticizer, and a nucleating agent.

[0018] In a specific embodiment of the present invention, the lubricant is one or more of stearate, silicone powder, paraffin, amide wax, ethylene bis stearamide, talc, and silicone oil.

[0019] On the other hand, the present invention also provides a method for preparing a flame retardant glass fiber composite material, comprising the following steps:

[0020] (1) Nylon 610, nylon 66 powder, pentaerythritol and its derivatives, alkyl phosphinate, coupling agent, antioxidant, and processing aid are mixed to obtain a premix;

[0021] (2) The premix is ​​fed into a twin-screw extruder from a main feed port, and glass fiber is fed into the twin-screw extruder from a side feed port, and the mixture is extruded and granulated to obtain a flame-retardant glass fiber composite material.

[0022] In a specific embodiment of the present invention, the screw speed of the twin-screw extruder is 300-600 r / min, and the extrusion temperature is 215-230°C.

[0023] Beneficial effects:

[0024] The present invention adds a certain size of nylon 66 powder to the nylon 610-glass fiber-alkylphosphinic acid flame retardant system. Nylon 66 has a higher melting point and plays a role similar to that of rigid particles in the nylon 610 composite material melt processing. Relative to common inorganic fillers, there is no compatibility problem between it and nylon 610, and it can improve the impact resistance of nylon 610 without losing its tensile strength. On the other hand, as an organic rigid particle, the presence of nylon 66 powder can improve the dispersion of glass fiber and help solve the floating fiber phenomenon. Pentaerythritol not only has the function of a carbonizing agent, but more importantly, its polyhydroxy structure can form stronger hydrogen bonds with the softened parts of nylon 610 and nylon 66 surfaces during the melt processing, forming a cross-linked structure, thereby improving melt strength and composite material mechanical properties. DETAILED DESCRIPTION

[0025] Below in conjunction with the embodiment of the present application, the technical scheme in the embodiment of the present application is clearly and completely described. Obviously, the embodiment described is only a part of the embodiment of the present application, rather than all the embodiments. Based on the embodiment in the application, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of this application. Unless otherwise specified, the following examples and comparative examples are all consistent in raw material type.

[0026] Example 1

[0027] A flame-retardant glass fiber composite material comprising the following components in parts by weight:

[0028] 60 parts of nylon 610, 8 parts of nylon 66 powder, 1 part of dipentaerythritol, 20 parts of alkali-free glass fiber, 5 parts of aluminum diethylphosphinate, 0.5 parts of coupling agent, 3 parts of antioxidant, and 0.5 parts of lubricant; wherein the volume average particle size of the nylon 66 powder is 1 μm; the coupling agent is KH550; the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1; and the lubricant is calcium stearate.

[0029] Example 2

[0030] A flame-retardant glass fiber composite material comprising the following components in parts by weight:

[0031] 70 parts of nylon 610, 12 parts of nylon 66 powder, 4 parts of dipentaerythritol, 30 parts of alkali-free glass fiber, 10 parts of aluminum diethylphosphinate, 3 parts of coupling agent, 0.5 parts of antioxidant, and 1 part of lubricant; wherein the volume average particle size of the nylon 66 powder is 5 μm; the coupling agent is KH560; the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:4; and the lubricant is zinc stearate.

[0032] Example 3

[0033] A flame-retardant glass fiber composite material comprising the following components in parts by weight:

[0034] 66 parts of nylon 610, 5 parts of nylon 66 powder, 2.5 parts of dipentaerythritol, 25 parts of alkali-free glass fiber, 7 parts of aluminum diethylphosphinate, 1 part of coupling agent, 1 part of antioxidant, and 2 parts of lubricant; wherein the volume average particle size of the nylon 66 powder is 3 μm; the coupling agent is KH550; the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:2; and the lubricant is talc.

[0035] Example 4

[0036] A flame-retardant glass fiber composite material comprising the following components in parts by weight:

[0037] 60 parts of nylon 610, 12 parts of nylon 66 powder, 1 part of dipentaerythritol, 30 parts of alkali-free glass fiber, 5 parts of aluminum diethylphosphinate, 3 parts of coupling agent, 0.8 parts of antioxidant, and 3 parts of lubricant; wherein the volume average particle size of the nylon 66 powder is 3.5 μm; the coupling agent is KH550; the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:3; and the lubricant is talc.

[0038] Example 5

[0039] A flame-retardant glass fiber composite material comprising the following components in parts by weight:

[0040] 66 parts of nylon 610, 15 parts of nylon 66 powder, 2.5 parts of dipentaerythritol, 25 parts of alkali-free glass fiber, 7 parts of aluminum diethylphosphinate, 1 part of coupling agent, 1 part of antioxidant, and 2 parts of lubricant; wherein, the volume average particle size of the nylon 66 powder is 3 μm; the coupling agent is KH550; the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:2; and the lubricant is talc.

[0041] Example 6

[0042] A flame-retardant glass fiber composite material comprising the following components in parts by weight:

[0043] 62 parts of nylon 610, 9 parts of nylon 66 powder, 1.8 parts of dipentaerythritol, 23 parts of alkali-free glass fiber, 7 parts of aluminum diethylphosphinate, 1.1 parts of a coupling agent, 1.2 parts of an antioxidant, and 1 part of a lubricant; wherein the volume average particle size of the nylon 66 powder is 2 μm; the coupling agent is KH560; the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:3; and the lubricant is calcium stearate.

[0044] Example 7

[0045] A flame-retardant glass fiber composite material comprising the following components in parts by weight:

[0046] 66 parts of nylon 610, 10 parts of nylon 66 powder, 2.5 parts of dipentaerythritol, 25 parts of alkali-free glass fiber, 7 parts of aluminum diethylphosphinate, 1 part of coupling agent, 1 part of antioxidant, and 2 parts of lubricant; wherein, the volume average particle size of the nylon 66 powder is 10 μm; the coupling agent is KH550; the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:2; and the lubricant is talc.

[0047] Example 8

[0048] A flame-retardant glass fiber composite material comprising the following components in parts by weight:

[0049] 68 parts of nylon 610, 11 parts of nylon 66 powder, 3 parts of dipentaerythritol, 27 parts of alkali-free glass fiber, 9 parts of aluminum diethylphosphinate, 2.5 parts of a coupling agent, 2.2 parts of an antioxidant, and 2 parts of a lubricant; wherein the volume average particle size of the nylon 66 powder is 4 μm; the coupling agent is KH560; the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1; and the lubricant is calcium stearate.

[0050] Example 9

[0051] A flame-retardant glass fiber composite material comprising the following components in parts by weight:

[0052] 64 parts of nylon 610, 10 parts of nylon 66 powder, 3.5 parts of dipentaerythritol, 26 parts of alkali-free glass fiber, 8 parts of aluminum diethylphosphinate, 1.6 parts of a coupling agent, 1.8 parts of an antioxidant, and 2.2 parts of a lubricant; wherein the volume average particle size of the nylon 66 powder is 3 μm; the coupling agent is KH550; the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:2; and the lubricant is zinc stearate.

[0053] Example 10

[0054] A flame-retardant glass fiber composite material comprising the following components in parts by weight:

[0055] 64 parts of nylon 610, 9.5 parts of nylon 66 powder, 1.8 parts of dipentaerythritol, 29 parts of alkali-free glass fiber, 8.5 parts of aluminum diethylphosphinate, 1 part of coupling agent, 2 parts of antioxidant, and 1 part of lubricant; wherein, the volume average particle size of the nylon 66 powder is 4 μm; the coupling agent is KH560; the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1; and the lubricant is talc.

[0056] Example 11

[0057] A flame-retardant glass fiber composite material comprising the following components in parts by weight:

[0058] 66 parts of nylon 610, 10 parts of nylon 66 powder, 2.5 parts of dipentaerythritol, 25 parts of alkali-free glass fiber, 7 parts of aluminum diethylphosphinate, 1 part of coupling agent, 1 part of antioxidant, and 2 parts of lubricant; wherein, the volume average particle size of the nylon 66 powder is 3 μm; the coupling agent is KH550; the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:2; and the lubricant is talc.

[0059] Comparative Example 1

[0060] A flame-retardant glass fiber composite material comprising the following components in parts by weight:

[0061] 66 parts of nylon 610, 10 parts of nylon 66 powder, 2.5 parts of dipentaerythritol, 25 parts of alkali-free glass fiber, 7 parts of aluminum diethylphosphinate, 1 part of coupling agent, 1 part of antioxidant, and 2 parts of lubricant; wherein, the volume average particle size of the nylon 66 powder is 0.5 μm; the coupling agent is KH550; the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:2; and the lubricant is talc.

[0062] Comparative Example 2

[0063] A flame-retardant glass fiber composite material comprising the following components in parts by weight:

[0064] 66 parts of nylon 610, 10 parts of nylon 66 powder, 7 parts of dipentaerythritol, 25 parts of alkali-free glass fiber, 7 parts of aluminum diethylphosphinate, 1 part of coupling agent, 1 part of antioxidant, and 2 parts of lubricant; wherein the volume average particle size of the nylon 66 powder is 3 μm; the coupling agent is KH550; the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:2; and the lubricant is talc.

[0065] The preparation method of the flame-retardant glass fiber composite materials of Examples 1-11 and Comparative Examples 1-2 comprises the following steps:

[0066] (1) Nylon 610, nylon 66 powder, pentaerythritol and its derivatives, alkyl phosphinate, coupling agent, antioxidant, and processing aid are mixed to obtain a premix;

[0067] (2) The premix is ​​fed into a twin-screw extruder from a main feed port, and glass fiber is fed into the twin-screw extruder from a side feed port, and extrusion is performed to form pellets, thereby obtaining a flame-retardant glass fiber composite material. The twin-screw extruder has a screw speed of 400 r / min and an extrusion temperature of 227°C.

[0068] Performance testing: The tensile strength (ISO 527-2), flexural strength (ISO 178), notched impact strength (ISO 179), and flame retardancy (UL94) of the flame retardant glass fiber composites prepared in Examples 1-11 and Comparative Examples 1-2 were tested, as shown in Tables 1 and 2.

[0069] Table 1 Properties of flame retardant glass fiber composite materials prepared in Examples 1-6

[0070]

[0071] Table 2 Properties of flame-retardant glass fiber composites prepared in Examples 7-11 and Comparative Examples 1-2

[0072]

[0073] As can be seen from Table 1 and Table 2, the present invention has added a certain size of nylon 66 powder in the nylon 610-glass fiber-alkylphosphinic acid flame retardant system. Nylon 66 has a higher melting point and has played a role in strengthening similar rigid particles in the nylon 610 composite material melt processing process. With respect to common inorganic fillers, there is no compatibility problem between itself and nylon 610, and while improving the impact resistance of nylon 610, it does not lose its tensile strength. On the other hand, as organic rigid particles, its size is close to the glass fiber diameter and belongs to micron level. The presence of nylon 66 powder can improve the dispersion properties of glass fiber and improve the mechanical properties of composite materials. Pentaerythritol not only has the function of carbonizing agent, but more importantly, it can improve the dispersion properties of nylon 66 and improve melt strength, thereby further improving its mechanical properties on the basis of improving the flame retardant properties of composite materials.

[0074] Specifically, compared to Example 11, the nylon 66 powder used in Comparative Example 1 had a volume average particle size of 0.5 μm. This particle size was too small, resulting in excessive softening during processing, failing to form stable, rigid particles. This inability to serve as stress dispersion points and enhance toughness was ineffective. Compared to Example 11, the excessive addition of pentaerythritol in Comparative Example 2 resulted in a significant decrease in impact properties, despite minimal changes in mechanical properties such as tensile strength and flexural strength. This suggests that as a small molecule, pentaerythritol is prone to precipitation and can also cause excessive crosslinking, leading to reduced toughness in the composite material.

[0075] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications to equivalent embodiments using the technical contents disclosed above. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A flame retardant glass fiber composite material, characterized in that: The composition comprises the following components in parts by weight: The invention comprises 60-70 parts of nylon 610, 5-15 parts of nylon 66 powder, 1-4 parts of pentaerythritol and its derivatives, 20-30 parts of glass fiber, 5-10 parts of alkyl phosphinate, 0.1-5 parts of coupling agent, 0.1-5 parts of antioxidant, and 0.1-5 parts of processing aid. The particle size of the nylon 66 powder is 1-10 μm. The alkyl phosphinate is a metal salt of diethylphosphinate. The processing aid is one or more of a lubricant, a colorant, an antistatic agent, an anti-hydrolysis agent, a flow modifier, a plasticizer, and a nucleating agent. The glass fiber has a length of 3-40 mm and a diameter of 1-20 μm.

2. The flame-retardant glass fiber composite material according to claim 1, characterized in that: The pentaerythritol and its derivatives are one or more of monopentaerythritol, dipentaerythritol and tripentaerythritol.

3. The flame-retardant glass fiber composite material according to claim 1, characterized in that: The glass fiber is alkali-free glass fiber.

4. The flame-retardant glass fiber composite material according to claim 1, characterized in that: The coupling agent is one or more of KH550, KH551, KH560, and KH570.

5. The flame-retardant glass fiber composite material according to claim 1, characterized in that: The antioxidant is one or more of hindered phenol antioxidants, phosphite antioxidants, and thioester antioxidants.

6. The flame-retardant glass fiber composite material according to claim 1, characterized in that: The lubricant is one or more of stearate, silicone powder, paraffin, amide wax, ethylene bis stearamide, talc, and silicone oil.

7. The method for preparing a flame-retardant glass fiber composite material according to any one of claims 1 to 6, characterized in that: The following steps are involved: (1) Nylon 610, nylon 66 powder, pentaerythritol and its derivatives, alkyl phosphinate, coupling agent, antioxidant, and processing aid are mixed to obtain a premix; (2) The premix is ​​fed into a twin-screw extruder from a main feed port, and glass fiber is fed into the twin-screw extruder from a side feed port, and the mixture is extruded and granulated to obtain a flame-retardant glass fiber composite material.

8. The method for preparing a flame-retardant glass fiber composite material according to claim 7, wherein: The twin-screw extruder has a screw speed of 300-600 r / min and an extrusion temperature of 215-230°C.

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