Evaluating Flammability of Plastics Using Glow Wire Test Machine

Flammability testing is a critical step in assessing the safety of materials used in electrical and electronic products. The glow wire test machine, such as the LISUN ZRS-3H Glow-wire Test Apparatus, is a specialized tool designed to simulate the effects of thermal overload and assess the combustibility of plastics. This article delves into the mechanics, applications, and testing procedures of glow wire testing, focusing on how it ensures the safety of solid insulating materials in preventing fire hazards.

ZRS-3H Glow-wire Test Apparatus

Importance of Glow Wire Testing
The glow wire test is a physical thermal test designed to measure the ignition resistance and self-extinguishing properties of plastics under specific high-temperature conditions. It is widely used to evaluate the safety of insulating materials in electrical components, ensuring that such materials do not propagate fire in the event of overheating or short circuits.

By subjecting a sample to a controlled, glowing hot wire, this test simulates conditions where components could come into contact with overheated metal parts or electrical faults. The LISUN ZRS-3H Glow-wire Test Apparatus ensures that materials meet strict international safety standards such as IEC 60695-2-10, making it an indispensable tool in the electrical and electronics industries.

Structure and Features of the Glow Wire Test Machine
The LISUN ZRS-3H Glow-wire Test Apparatus is engineered for precision, offering a reliable and repeatable method for flammability testing.

Key features include:
• Nickel-Chromium Wire: The device uses a specially designed nickel/chromium alloy wire that can be heated to temperatures up to 960°C, ensuring consistent testing conditions.
• Force Application System: A standardized force of 1N is applied to ensure uniform contact between the heated wire and the test sample.
• Temperature Control: Equipped with a precise temperature regulation system to maintain the desired glow wire temperature.
• Automatic Timing: The machine records the exposure time, ensuring that the sample is tested within the required time window.
• Safety Features: The device includes automatic shutdown mechanisms and fireproof construction to protect users during operation.
These features enable manufacturers and laboratories to conduct thorough tests while maintaining operator safety and test accuracy.

Glow Wire Test Procedure
The glow wire test involves the following steps:
Preparation of Test Sample:
The material sample is cut into the required size, typically a flat piece or a component representing the end-use application.
Setting Parameters:
The glow wire is pre-heated to a specified temperature, often 750°C, 850°C, or 960°C, depending on the test requirements.
Application of Force:
The heated wire is pressed against the test sample with a force of 1N.
Observation Period:
The sample is exposed to the glowing wire for a maximum of 30 seconds or until ignition occurs.
Data Recording:
The time to ignition, flame duration, and any material drips are recorded.
Evaluation:
The material passes the test if it does not ignite or self-extinguishes within 30 seconds and does not produce flaming drips that ignite tissue paper placed below.

Table 1 summarizes typical parameters and evaluation criteria for different test scenarios.

Applications of Glow Wire Test Machine
The glow wire test machine is widely used across industries where fire safety is a concern. Typical applications include:
• Electrical Insulation Materials: Ensures that materials used in circuit boards, connectors, and enclosures resist ignition and do not propagate flames.
• Household Appliances: Verifies the safety of plastic components in devices such as washing machines, refrigerators, and toasters.
• Lighting Equipment: Evaluates the combustibility of materials in lighting fixtures and their ability to withstand overheating.
• Automotive Components: Tests insulating materials used in wiring systems and electronic control units for fire resistance.
• Industrial Products: Assesses the flammability of materials used in machinery and safety equipment.

Case Study: Glow Wire Testing of an Insulating Material
To illustrate the practical application of glow wire testing, a standard test was conducted using the LISUN ZRS-3H Glow-wire Test Apparatus. The sample, a plastic sheet used in electrical insulators, was tested at 850°C.

The test demonstrated the material’s ability to self-extinguish and resist flaming drips, meeting the safety standards for electrical insulation.

Advantages of LISUN ZRS-3H Glow-wire Test Apparatus
• Compliance with Standards: Fully adheres to IEC 60695-2-10, ensuring globally accepted results.
• User-Friendly Operation: Simplifies complex procedures, making it suitable for routine testing.
• High Precision: Guarantees accurate temperature control and consistent force application.
• Versatility: Can be used for a variety of materials and applications.

Conclusion
The glow wire test machine is an essential tool for evaluating the flammability of plastics and other insulating materials. By simulating high-temperature conditions, it helps manufacturers ensure product safety, reduce fire risks, and comply with international standards. The LISUN ZRS-3H Glow-wire Test Apparatus stands out as a reliable and efficient solution for conducting these tests, making it an invaluable asset for industries prioritizing fire safety.