When making enameled wire, it is very important to choose paint with high solvent resistance. Common paints include polyurethane paint, phenolic paint, acetate paint, etc. These paints have good solvent resistance and can maintain good insulating properties when exposed to solvents.
Next, we will have a test for Resistance to solvents.
This test is applicable to enamelled round wire with a nominal conductor diameter over 0,250 mm and to enamelled rectangular wire.
The test is not suitable for round wires with a nominal conductor diameter up to and including 0,250 mm.
Resistance to solvents is expressed by the pencil hardness of the wire after solvent treatment.
Equipment
The following solvents shall be used:
Standard solvent as specified below, or solvent as agreed between purchaser and supplier.
The standard solvent shall be a mixture of:
60 % by volume white spirit with maximum aromatic content of 1 8 %; 30 % by volume xylene; 1 0 % by volume butanol.
The pencil to be used shall be a lead pencil of the hardness specified in the relevant standard. Before each test, the point of the pencil shall be sharpened with a smooth-cut file to form an angle of 60° symmetrical about the axis of the lead.
Key
1.Winding wire specimen
2.Pencil
3.Test surface
NOTE Angle tolerances ±5°
Pencil and specimen for solvent test
Procedure
A straight piece of wire, approximately 1 50 mm in length, shall be preconditioned for (1 0 ± 1 ) min at (1 30 ± 3) °C in an oven with forced air circulation. A substantial length of the wire shall then be immersed in standard solvent contained in a glass cylinder and shall be maintained therein at a temperature of (60 ± 3) °C for a period of (30 ± 3) min. The wire shall then be removed from the solvent. The hardness of the wire surface shall then be determined in the following manner within a period of 30 s after removal from the solvent.
The specimen to be tested shall be laid on a smooth hard surface. In the case of rectangular wires, the test shall be carried out on the largest side of the wire. The pencil shall be placed on the surface of the wire at an angle of approximately (60 ± 5) and the sharpened edge shall be pressed slowly along the surface of the wire with a force of approximately (5 ± 0,5) N.
Three tests shall be made. It shall be reported if the coating is removed with exposure of the bare conductor.
NOTE 1 This method can also be used for testing resistance to other fluids, for example oil.
NOTE 2 Where it is desired to determine the hardness of the insulation, the hardness of the lead pencil which just fails to remove the coating from the surface of the conductor is considered to be the hardness of the wire surface, expressed by the pencil hardness.
Why Choose This Type Experiments?
Evaluate the solvent resistance of enameled wires: Through experiments, you can determine the resistance of enameled wires when exposed to solvents and understand whether their insulation layer will be corroded by solvents, resulting in performance degradation.
Verify the chemical resistance of enameled wires: Enameled wires may be exposed to chemicals such as acids and alkalis during use. The resistance of enameled wires to these chemicals can be evaluated through experiments.
Ensure the stability of enameled wires in specific environments: Through experiments, the ability of enameled wires to withstand special environmental conditions such as high temperature and high humidity can be verified to ensure their stability and reliability in various usage environments.
Relevant Experiments To Test The Solvent Resistance Of Enameled Wires Have The Following Functions:
Assess the stability of the insulation: The insulation of enameled wire may be corroded or dissolved when exposed to solvents. Experiments can be used to evaluate whether the insulating layer can remain stable under solvent contact to avoid damage and performance degradation of the insulating layer due to solvent erosion.
Ensure safety performance: Enameled wire is widely used in electrical equipment and circuits, and the solvent resistance of its insulation layer is directly related to the safety performance of the wire. Through experiments, it can be ensured that the enameled wire will not cause circuit short circuits, leakage and other problems when exposed to solvents, ensuring the normal operation of electrical equipment and the safety of users.
Select appropriate materials and processes: Experimentally evaluating the solvent resistance of enameled wires can provide manufacturers with a basis for selecting appropriate insulation materials and manufacturing processes. Different paints and processes have different effects on solvent resistance. Through experimental results, material selection and production processes can be optimized to improve the solvent resistance of enameled wires.
Verify product compliance with standards and requirements: In the wire and cable industry, there are various national and industry standards that include requirements for the solvent resistance of enameled wire. Through experiments, it can be verified whether the enameled wire meets the solvent resistance performance requirements of the corresponding standards and specifications, ensuring product quality and compliance.
Provide technical reference and data support: The data and results obtained through experiments can be used as technical reference and data support for technical exchanges and cooperation between manufacturers, suppliers and users. At the same time, the experimental results can also be used as a basis for product publicity and promotion, demonstrating the advantages and performance characteristics of enameled wires.
In summary, experiments to test the solvent resistance in enameled wires play an important role, including evaluating the stability of the insulation layer, ensuring safety performance, guiding material and process selection, verifying that products comply with standards and requirements, and providing technical references and data support. These experiments help ensure that the enameled wire has good solvent resistance in actual use and meets relevant technical and safety requirements.
