Halogen-free cable and process thereof

Abstract

The invention discloses a halogen-free cable, and particularly relates to the technical field of cable processing, and a halogen-free sheath comprises the following raw materials by weight: 50-80% of polyethylene (PE), 10-30% of a halogen-free flame retardant, 5-15% of a filling material, 5-10% of a plasticizer, and 1-5% of nano clay. According to the halogen-free cable disclosed by the invention, the nano clay is added in the implementation scheme, so that the thermal stability of the material can be improved, the thermal decomposition temperature is reduced, and the service life of the cable is prolonged. Due to excellent thermal conductivity and high-temperature barrier property, the nano-clay can effectively slow down the propagation of heat in the cable and prevent performance reduction caused by overheating, so that good electrical performance is maintained in a high-temperature environment, and the added nano-clay can significantly improve the aging resistance of the material and delay performance degradation caused by oxidation and illumination. The existence of the nano clay can effectively block the invasion of moisture and oxygen, and reduce the influence of environmental factors on the performance of the cable, thereby ensuring the stability of the cable in long-term use.

Description

Technical Field

[0001] The invention relates to the technical field of cable processing, and in particular to a halogen-free cable and a process thereof. Background Art

[0002] Halogen-free cables are cables that do not release halogens (such as chlorine, bromine, etc.) and their compounds during production and use. This type of cable has the advantages of low smoke, non-toxicity, and fire resistance, and is particularly suitable for occasions with high safety requirements, such as public buildings, subways, airplanes, etc.

[0003] Chinese patent announcement number CN117089133B discloses a low-smoke halogen-free flame-retardant cable and its processing technology. The low-smoke halogen-free flame-retardant cable includes a cable core, a winding layer, a filler, and a sheath layer; the sheath layer is formed by extruding a polyolefin low-smoke halogen-free flame-retardant material; the polyolefin low-smoke halogen-free flame-retardant material is mainly made of the following raw materials: polyolefin resin, linear low-density polyethylene, tri(2-methoxyethoxy)vinyl silane, oleyl amide propyl betaine, peroxide cross-linking agent, ethylene-vinyl acetate copolymer, calcium sulfate whisker, magnesium hydroxide, modified montmorillonite; the modified montmorillonite is montmorillonite treated with tri(2-methoxyethoxy)vinyl silane, 3-butylene acid ethyl ester, and diethanolamine. The polyolefin low-smoke halogen-free flame-retardant material has the advantages of high flame retardancy, high tensile strength, and high heat aging resistance. When applied to the outer jacket layer, it can adapt to the harsh environment in the field and meet market demand;

[0004] The above documents still have the following defects in the implementation process:

[0005] Although the above patent documents have good processing performance, their heat resistance and antioxidant capabilities need to be improved during implementation. Summary of the invention

[0006] The main purpose of the present invention is to provide a halogen-free cable and a process thereof, which can effectively solve the problem that its heat resistance and oxidation resistance need to be improved during the implementation process.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] A halogen-free cable, the cable consists of a halogen-free sheath and a core, the halogen-free sheath is wrapped around the outside of the core, and the raw materials of the halogen-free sheath include, by weight, polyethylene (PE): 50-80%, halogen-free flame retardant: 10-30%, filling material: 5-15%, plasticizer: 5-10%, and nano clay: 1-5%.

[0009] Preferably, the polyethylene (PE) is an insulating layer, and the weight proportion of the polyethylene (PE) is 50%.

[0010] Preferably, the halogen-free flame retardant comprises aluminum hydroxide (ATH), and the weight proportion of the aluminum hydroxide (ATH) is 20%.

[0011] Preferably, the filling material includes calcium carbonate and talcum powder, and the weight ratio of the calcium carbonate to the talcum powder is 1:10.

[0012] Preferably, the plasticizer includes phthalates, alcohols and bio-based plasticizers, and the weight ratio of the phthalates, alcohols and bio-based plasticizers is 1:2:3.

[0013] Preferably, the nanoclay includes montmorillonite and kaolin, and the weight ratio of the montmorillonite to kaolin is 4:5.

[0014] Preferably, the phthalates are diethyl phthalate, the alcohols are butanediol, and the bio-based plasticizer is polyester derived from plant oil.

[0015] Preferably, the melt index of the halogen-free flame retardant is 10 to 100 g / 10 min.

[0016] Preferably, the melt index of the plasticizer is 20 to 100 g / 10 min;

[0017] The present invention also discloses a process for preparing a halogen-free cable, which is carried out according to the following steps:

[0018] (I) Preparation of halogen-free outer skin:

[0019] S11: Raw material preparation

[0020] According to the formula ratio, polyethylene (PE), flame retardant, filling material and auxiliary additives are accurately weighed;

[0021] S12 Hybrid:

[0022] Premixing: Preliminary mixing of the weighed ingredients in a mixer to ensure uniform distribution of the materials;

[0023] High shear mixing: Use a high shear mixer for further mixing to improve the homogeneity of the material;

[0024] S13 Extrusion:

[0025] Heating extrusion: The mixed materials are fed into the extruder and formed into an insulating layer through heating and extrusion process;

[0026] Cooling: The extruded cable insulation is cooled by a cooling system to ensure that it maintains a stable shape after molding;

[0027] S14 crosslinking:

[0028] Cross-linking treatment: For polyethylene (PE), cross-linking treatment is carried out after extrusion, using chemical cross-linking or physical cross-linking methods;

[0029] S15 Insulation Molding:

[0030] Molding: The cooled insulation layer is passed through a mold to form the desired cable shape to ensure that the cable specifications meet the design requirements;

[0031] (II) Assembling halogen-free cable sheath and core:

[0032] S21 core twisting:

[0033] Twisting process: The cable cores are twisted to ensure good contact between the conductors and to improve their mechanical strength. The cooled and formed insulation layer is then placed on the surface of the twisted cores.

[0034] S22 outer sheath extrusion: a protective outer sheath is extruded outside the formed insulation layer.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1. The addition of nanoclay in the embodiments of the present invention can significantly enhance the mechanical strength and toughness of the cable material. The microstructure of nanoclay forms a reinforcement network in the matrix, which makes the material show higher fracture resistance under loads such as tension and compression. This improved mechanical property makes the cable more durable in application and adaptable to harsh environments.

[0037] 2. The addition of nanoclay in the embodiment of the present invention can improve the thermal stability of the material, reduce the thermal decomposition temperature, and extend the service life of the cable. Due to its excellent thermal conductivity and high temperature barrier, nanoclay can effectively slow down the spread of heat inside the cable, prevent performance degradation caused by overheating, and thus maintain good electrical performance in a high temperature environment. The addition of nanoclay can significantly improve the aging resistance of the material and delay the performance degradation caused by oxidation and light. The presence of nanoclay can effectively block the intrusion of moisture and oxygen, reduce the impact of environmental factors on the performance of the cable, and thus ensure its stability and reliability in long-term use. DETAILED DESCRIPTION

[0038] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0039] The present application prepares a halogen-free cable in the following manner;

[0040] (I) Preparation of halogen-free outer skin:

[0041] S11: Raw material preparation

[0042] According to the formula ratio, polyethylene (PE), flame retardant, filling material and auxiliary additives are accurately weighed;

[0043] S12 Hybrid:

[0044] Premixing: Preliminary mixing of the weighed ingredients in a mixer to ensure uniform distribution of the materials;

[0045] High shear mixing: Use a high shear mixer for further mixing to improve the homogeneity of the material;

[0046] S13 Extrusion:

[0047] Heating extrusion: The mixed materials are fed into the extruder and formed into an insulating layer through heating and extrusion process;

[0048] Cooling: The extruded cable insulation is cooled by a cooling system to ensure that it maintains a stable shape after molding;

[0049] S14 crosslinking:

[0050] Cross-linking treatment: For polyethylene (PE), cross-linking treatment is carried out after extrusion, using chemical cross-linking or physical cross-linking methods;

[0051] S15 Insulation Molding:

[0052] Molding: The cooled insulation layer is passed through a mold to form the desired cable shape to ensure that the cable specifications meet the design requirements;

[0053] (II) Assembling halogen-free cable sheath and core:

[0054] S21 core twisting:

[0055] Twisting process: The cable cores are twisted to ensure good contact between the conductors and to improve their mechanical strength. The cooled and formed insulation layer is then placed on the surface of the twisted cores.

[0056] S22 outer sheath extrusion: a protective outer sheath is extruded outside the formed insulation layer.

[0057] Embodiment 1

[0058] The raw materials of the halogen-free cable prepared in this embodiment include, by weight:

[0059] Polyethylene (PE): 50%, halogen-free flame retardant: 10%, filler: 5%, plasticizer: 5%, nanoclay: 1%.

[0060] Embodiment 2

[0061] A halogen-free cable, the raw materials of which include, by weight:

[0062] Polyethylene (PE): 55%, halogen-free flame retardant: 15%, filler: 7%, plasticizer: 6%, nanoclay: 2%.

[0063] Embodiment 3

[0064] A halogen-free cable, the raw materials of which include, by weight:

[0065] Polyethylene (PE): 56%, halogen-free flame retardant: 17%, filler: 7%, plasticizer: 6%, nanoclay: 2%.

[0066] Embodiment 4

[0067] A halogen-free cable, the raw materials of which include, by weight:

[0068] Polyethylene (PE): 65%, halogen-free flame retardant: 20%, filler: 10%, plasticizer: 7.5%, nanoclay: 3%.

[0069] Embodiment 5

[0070] A halogen-free cable, the raw materials of which include, by weight:

[0071] Polyethylene (PE): 70%, halogen-free flame retardant: 25%, filler: 12%, plasticizer: 8%, nanoclay: 4%.

[0072] Embodiment 6

[0073] A halogen-free cable, the raw materials of which include, by weight:

[0074] Polyethylene (PE): 80%, halogen-free flame retardant: 30%, filler: 15%, plasticizer: 10%, nanoclay: 5%.

[0075] Comparative Example 1

[0076] A halogen-free cable, the raw materials of which include, by weight:

[0077] Polyethylene (PE): 65%, halogen-free flame retardant: 20%, filler: 10%, plasticizer: 7.5%, nanoclay: 3%.

[0078] The polyethylene (PE) is an insulating layer, and the weight share of the polyethylene (PE) is 50%;

[0079] The halogen-free flame retardant comprises aluminum hydroxide (ATH), and the weight proportion of the aluminum hydroxide (ATH) is 20%.

[0080] The filling material includes calcium carbonate and talcum powder, and the weight ratio of the calcium carbonate to the talcum powder is 1:10.

[0081] The plasticizers include phthalates, alcohols and bio-based plasticizers, and the weight ratio of the phthalates, alcohols and bio-based plasticizers is 1:2:3.

[0082] The nano clay includes montmorillonite and kaolin, and the weight ratio of the montmorillonite to kaolin is 4:5.

[0083] The phthalates are diethyl phthalate, the alcohols are butanediol, and the bio-based plasticizer is polyester derived from plant oil.

[0084] The melt index of the halogen-free flame retardant is 10 to 100 g / 10 min.

[0085] The melt index of the plasticizer is 20 to 100 g / 10 min.

[0086] Comparative Example 2

[0087] A halogen-free cable, the raw materials of which include, by weight:

[0088] Polyethylene (PE): 65%, halogen-free flame retardant: 20%, filling material: 10%, plasticizer: 7.5%.

[0089] The polyethylene (PE) is an insulating layer, and the weight share of the polyethylene (PE) is 50%;

[0090] The halogen-free flame retardant comprises aluminum hydroxide (ATH), and the weight proportion of the aluminum hydroxide (ATH) is 20%.

[0091] The filling material includes calcium carbonate and talcum powder, and the weight ratio of the calcium carbonate to the talcum powder is 1:10.

[0092] The plasticizers include phthalates, alcohols and bio-based plasticizers, and the weight ratio of the phthalates, alcohols and bio-based plasticizers is 1:2:3.

[0093] The phthalates are diethyl phthalate, the alcohols are butanediol, and the bio-based plasticizer is polyester derived from plant oil.

[0094] The melt index of the halogen-free flame retardant is 10 to 100 g / 10 min.

[0095] The melt index of the plasticizer is 20 to 100 g / 10 min.

[0096] According to the method provided in the specific implementation manner and the material ratios provided in Examples 1 to 6, cables are made using an extruder, a wire drawing machine and a braiding machine to obtain six different halogen-free cable samples;

[0097] The data were obtained after heat resistance test and oxidation resistance test were carried out on the above six cable samples according to GB / T 19666;

[0098] The test results are shown in the following table:

[0099] Serial number Heat resistance(℃) <![CDATA[Antioxidant strength (cc / m 2 ·day)]]> Example 1 90 1.2 Example 2 103 1.3 Example 3 107 1.4 Example 4 112 1.5 Example 5 110 1.6 Example 6 117 1.1 Comparative Example 1 112 1.5 Comparative Example 2 108 1.1

[0100] It can be seen from the above table:

[0101] 1. By comparing the data in Examples 1 to 6 and Comparative Examples 1 to 2, it can be seen that the addition of nanoclay materials in halogen-free cables has excellent heat resistance and oxidation resistance, which indicates that the halogen-free circuit of this scheme has good heat resistance and high oxidation resistance;

[0102] 2. By comparing the data in Example 4 and Comparative Example 2, it can be seen that after removing the nanoclay material, the data values ​​of the heat resistance and oxidation resistance of the halogen-free cable are significantly reduced, and the product quality deteriorates. This shows that the nanoclay material plays a significant role in the material.

[0103] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A halogen-free cable, the cable consisting of a halogen-free sheath and a core, the halogen-free sheath is wrapped around the outside of the core, characterized in that: The halogen-free outer skin raw materials include, by weight: polyethylene (PE): 50-80%, halogen-free flame retardant: 10-30%, filling material: 5-15%, plasticizer: 5-10%, and nano clay: 1-5%.

2. A halogen-free cable according to claim 1, characterized in that: The polyethylene (PE) is an insulating layer, and the weight proportion of the polyethylene (PE) is 50%.

3. The halogen-free cable according to claim 1, characterized in that: The halogen-free flame retardant comprises aluminum hydroxide (ATH), and the weight proportion of the aluminum hydroxide (ATH) is 20%.

4. The halogen-free cable according to claim 1, characterized in that: The filling material includes calcium carbonate and talcum powder, and the weight ratio of the calcium carbonate to the talcum powder is 1:

10.

5. The halogen-free cable according to claim 1, characterized in that: The plasticizers include phthalates, alcohols and bio-based plasticizers, and the weight ratio of the phthalates, alcohols and bio-based plasticizers is 1:2:

3.

6. The halogen-free cable according to claim 1, characterized in that: The nano clay includes montmorillonite and kaolin, and the weight ratio of the montmorillonite to kaolin is 4:

5.

7. The halogen-free cable according to claim 5, characterized in that: The phthalates are diethyl phthalate, the alcohols are butanediol, and the bio-based plasticizer is polyester derived from plant oil.

8. The halogen-free cable according to claim 3, characterized in that: The melt index of the halogen-free flame retardant is 10 to 100 g / 10 min.

9. The halogen-free cable according to claim 5, characterized in that: The melt index of the plasticizer is 20 to 100 g / 10 min.

10. A process for preparing the halogen-free cable using any one of claims 1 to 9, characterized in that: Follow these steps: (I) Preparation of halogen-free outer skin: S11: Raw material preparation According to the formula ratio, polyethylene (PE), flame retardant, filling material and auxiliary additives are accurately weighed; S12 Hybrid: Premixing: Preliminary mixing of the weighed ingredients in a mixer to ensure uniform distribution of the materials; High shear mixing: Use a high shear mixer for further mixing to improve the homogeneity of the material; S13 Extrusion: Heating extrusion: The mixed materials are fed into the extruder and formed into an insulating layer through heating and extrusion process; Cooling: The extruded cable insulation is cooled by a cooling system to ensure that it maintains a stable shape after molding; S14 crosslinking: Cross-linking treatment: For polyethylene (PE), cross-linking treatment is carried out after extrusion, using chemical cross-linking or physical cross-linking methods; S15 Insulation Molding: Molding: The cooled insulation layer is passed through a mold to form the desired cable shape to ensure that the cable specifications meet the design requirements; (II) Assembling halogen-free cable sheath and core: S21 core twisting: Twisting process: The cable cores are twisted to ensure good contact between the conductors and to improve their mechanical strength. The cooled and formed insulation layer is then placed on the surface of the twisted cores. S22 outer sheath extrusion: a protective outer sheath is extruded outside the formed insulation layer.