High-insulativity and high-wear-resistance circuit breaker housing

Abstract

The present invention provides a high-insulativity and high-wear-resistance circuit breaker housing. A sodium dimethyldithiocarbamate aqueous solution is sprayed in a mold, the mold is dried to remove moisture, so that a sodium dimethyldithiocarbamate thin layer is formed in the mold, injection molding is performed, and then the outer layer of the circuit breaker housing is compounded with the sodium dimethyldithiocarbamate thin layer. The insulativity, the hardness, and the wear resistance of the circuit breaker housing are effectively improved by means of the vulcanization promotion effect and the dimerization effect of sodium dimethyldithiocarbamate.

Description

A circuit breaker housing with high insulation and high wear resistance Technical Field

[0001] The invention relates to a preparation process of a circuit breaker housing, and in particular to a circuit breaker housing with high insulation and high wear resistance. Background Art

[0002] A circuit breaker generally consists of a housing, operating mechanism, magnetic system, thermal system, terminals, and an arc extinguishing chamber. Currently, circuit breaker housings are generally made of thermoplastics or thermosetting plastics through injection molding or compression molding. Thermoplastics have the following advantages over thermosetting plastics: (1) They are elastic and less prone to cracking; (2) They are more environmentally friendly, as thermosetting plastics require additives that pollute the environment; and (3) Production control is simpler, with the main process being injection molding or compression molding, which requires no curing time.

[0003] However, the current circuit breaker casings made of thermoplastics have the following problems that need to be improved: (1) The insulation needs to be further improved to enhance the safety of the circuit breaker; (2) The hardness and wear resistance of the circuit breaker casing are poor, and surface defects are easily formed due to scratches during production, storage, transportation, assembly, and other links. Summary of the Invention

[0004] The present invention develops a circuit breaker housing with high insulation and high wear resistance. The method comprises spraying a sodium furam aqueous solution in a mold, drying the moisture to form a thin layer of sodium furam in the mold, and then compounding the outer layer of the circuit breaker housing with the sodium furam thin layer after injection molding. The vulcanization promotion and dimerization of sodium furam effectively improve the insulation, hardness and wear resistance of the circuit breaker housing.

[0005] A circuit breaker housing with high insulation and high wear resistance, the preparation process of which is as follows:

[0006] (1) Preparation of injection molding materials

[0007] Heat the thermoplastic plastic particles at 120-140°C for 30-40 minutes to remove water, and then heat to 270-290°C to melt;

[0008] (2) Mold pretreatment

[0009] Dissolve sodium furam in pure water to prepare a sodium furam aqueous solution with a mass fraction of 0.6% to 1.0%, spray it into the mold, and then heat the mold to 115℃ to 120℃ to remove moisture;

[0010] (3) Injection molding

[0011] The mold is quickly heated to 130°C to 135°C, and then molten PA66 is injected. When the mold is cooled to 115°C to 120°C, it is kept warm for 20 to 30 seconds and then demolded to obtain the circuit breaker housing.

[0012] Furthermore, the thermoplastic plastic particles are PA66.

[0013] Furthermore, the circuit breaker housing obtained in step (3) is post-processed:

[0014] The demolded circuit breaker housing is placed in a post-processing box, and an ozone atmosphere with a volume fraction of 0.1% is maintained in the post-processing box until the circuit breaker housing is cooled to room temperature, thereby obtaining a circuit breaker housing.

[0015] Advantages of the present invention:

[0016] 1. The present invention sprays a sodium furam aqueous solution in a mold, dries the water, and forms a sodium furam thin layer in the mold. After injection molding, the outer layer of the circuit breaker housing is composited with the sodium furam thin layer. The vulcanization-promoting effect and dimerization effect of sodium furam effectively improve the insulation, hardness, and wear resistance of the circuit breaker housing.

[0017] 2. The mold needs to be temperature controlled: first, heat and dehydrate to prevent bubbling; then quickly heat up to melt the thin layer of sodium fumei, and then inject; finally, keep warm to improve the composite effect between the outer layer of the circuit breaker shell and the thin layer of sodium fumei. Implementation Method Example

[0018] A circuit breaker housing with high insulation and high wear resistance, the preparation process of which is as follows:

[0019] (1) Preparation of injection molding materials

[0020] PA66 particles were first heated at 125°C for 30 min to remove water, and then heated to 280°C to melt;

[0021] (2) Mold pretreatment

[0022] Sodium fumarate was dissolved in pure water to prepare a 0.8% sodium fumarate aqueous solution, which was sprayed into the mold, and then the mold was heated to 120°C to remove moisture;

[0023] (3) Injection molding

[0024] The mold is quickly heated to 135°C, and then molten PA66 is injected. When the mold is cooled to 115°C, it is kept warm for 30 seconds and then demolded to obtain the intermediate product.

[0025] (4) Post-processing:

[0026] The demolded intermediate product is placed in a post-processing box, and an ozone atmosphere with a volume fraction of 0.1% is maintained in the post-processing box until the circuit breaker housing cools to room temperature, thereby obtaining a circuit breaker housing. Example

[0027] A circuit breaker housing with high insulation and high wear resistance, wherein the intermediate product obtained in step (3) of the preparation process is not post-processed but directly cooled in air, and the remaining processes are the same as those in Example 1.

[0028] Comparative Example 1

[0029] A circuit breaker housing is prepared by injection molding molten PA66 without mold pretreatment in step (2). The circuit breaker housing is directly prepared, and the remaining processes are the same as those in Example 1.

[0030] Comparative Example 2

[0031] A circuit breaker housing, wherein during the injection molding step (3) in its preparation process, the temperature is not rapidly increased, but is maintained at 120°C before injection molding begins, and the remaining processes are the same as those in Example 1.

[0032] Comparative Example 3

[0033] A circuit breaker housing, wherein in the preparation process, during the injection molding step (3), the mold is directly demoulded when the mold temperature drops to 115°C, and the remaining processes are the same as those in Example 1.

[0034] Detection and analysis:

[0035] 1. The dielectric constant of the circuit breaker housings prepared in each embodiment and comparative example was tested according to the test method of IEC 60250 (23°C, 60% RH, 50 Hz);

[0036] 2. The Rockwell hardness (R scale, 23°C) of the circuit breaker housings prepared in each embodiment and comparative example was tested according to the test method of ISO 2039-2;

[0037] 3. The Taber wear resistance (1000 cycles) of the circuit breaker housings prepared in the examples and comparative examples was tested according to the test method of ISO 9352.

[0038]

[0039] Among them, the circuit breaker shell prepared in Comparative Example 2 has surface defects and has sand holes.

[0040] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A circuit breaker housing with high insulation and high wear resistance, characterized in that: The preparation process of the circuit breaker housing is as follows: (1) Preparation of injection molding materials The thermoplastic plastic particles are first heated at 120°C to 140°C for 30min to 40min to remove water, and then heated to 270°C to 290°C to melt; (2) Mold pretreatment Dissolve sodium furam in pure water to prepare a sodium furam aqueous solution with a mass fraction of 0.6% to 1.0%, spray it into the mold, and then heat the mold to 115°C to 120°C to remove moisture; (3) Injection molding The mold is quickly heated to 130°C to 135°C, and then molten PA66 is injected. When the mold is cooled to 115°C to 120°C, it is kept warm for 20 to 30 seconds and then demolded to obtain the circuit breaker housing.

2. The circuit breaker housing with high insulation and high wear resistance according to claim 1, characterized in that: The thermoplastic plastic particles are PA66.

3. The circuit breaker housing with high insulation and high wear resistance according to claim 1, characterized in that: The circuit breaker housing obtained in step (3) is post-processed: The demoulded circuit breaker housing is placed in a post-processing box, and an ozone atmosphere with a volume fraction of 0.1% is maintained in the post-processing box until the circuit breaker housing is cooled to room temperature, thereby obtaining the circuit breaker housing.

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