Glow-Wire Test

The glow-wire test is a safety-relevant material and component test from electrical engineering. It evaluates whether materials and assemblies ignite, continue to burn, or self-extinguish when they come into contact with a heated test body. For KKC Koffer GmbH in Stemwede-Levern, this test principle is relevant in many projects: enclosures of cases, aluminium cases and plastic cases, interior builds with foam inlays as well as modular transport containers for technology often serve as carriers for measurement, control, and power technology. Wherever electrical or thermal sources operate in or around a case, the glow-wire test helps classify material and design risks—from demo cases and equipment cases to industrial cases and specialized solutions such as the Mobile Work Table in a Case or the X-PCK backpack case.

Definition: What is meant by the glow-wire test?

The glow-wire test is a standardized glow-wire testing method in which a heated wire (the test glow wire) with defined temperature, force, and duration is applied to a test specimen. The goal is to assess whether the tested material or component ignites due to this thermal load, how long any afterflame or afterglow lasts, and whether burning particles drip. The test is performed on insulating materials, enclosures, fasteners, and interior builds that could come into contact with hot parts during operation. The results feed into material selection, risk assessment, and design decisions, for example with enclosures for presentation cases, transport cases, and professional machinery cases that house components with self-heating.

How the glow-wire test works and key metrics

In the glow-wire test, the specimen is exposed to a heated wire at specified temperature levels. The assessment includes, among other things:

• Ignition behavior: Does a flame develop or only afterglow? Does the material self-extinguish after the wire is removed?
• Afterflame and afterglow time: Time until extinction without additional influence.
• Dripping behavior: Do burning droplets fall and ignite underlying paper (as an indicator)?
• Temperature limits and indices: Material characteristics indicating up to which glow-wire temperature no ignition or no sustained flame occurs.

In practice, this means materials for enclosures, brackets, covers, cable pass-throughs, and foam inlays can be selected specifically for their robustness against localized heat sources. In project phases with integrated power supplies, charging electronics, resistors, preheating or desoldering technology, this set of metrics is particularly relevant.

Relevance for cases, transport containers, and interior builds

The products and configurations of KKC Koffer GmbH are used in technical B2B environments—from sample cases for electronic components to equipment cases with permanently integrated measuring devices. Wherever components can become hot, the glow-wire test helps identify the right combination of enclosure material, interior build, and cable management.

Enclosure selection: aluminium cases or plastic cases

Aluminium cases for technical applications conduct heat and offer mechanical stability. They can serve as thermally robust outer shells when there are heat sources inside. Plastic cases enable complex geometries and low weight; here, the glow-wire test is central to selecting suitable materials, especially around terminals, switch-mode power supplies, and charging electronics.

Interior build with foam inlays

Foam inlays secure devices but dissipate heat less effectively. Precisely fitted foam inlays for devices support defined guidance and fixation. For built-in configurations in demo cases, cases for measuring instruments, or cases for electrical engineering, it must be verified whether spacing, ventilation, or thermal barriers are required. Materials with favorable afterglow times and without burning drip are advantageous.

X-PCK backpack case

In compact mobile applications with high packing density—such as the X-PCK backpack case—air paths are short and thermal buffering is lower. Glow-wire test results support decisions for heat-resistant cover elements, cable holders, and device mounts.

Mobile Work Table in a Case

In the Mobile Work Table in a Case, mobile power supply, cabling, and tools come together. For testing companies, IT service providers, service tradespeople, mobile trades, measurement technology manufacturers, HVAC, presenters, consultants, exhibition outfitters, electrical plant engineering, electrical installation, and mechanical engineering, this results in increased requirements for material selection, cable pass-throughs, and the placement of heat-generating devices. Glow-wire test results underpin robust decisions here.

Branding

Branding such as printing, embossing, or engraving does not change the glow-wire characteristics of the base material but should be implemented to be heat-resistant. This is especially important near power-supply openings, fans, or charging sockets.

Typical application scenarios relevant to the glow-wire test

The need increases wherever electrical energy is converted, stored, or distributed:

• Equipment cases with integrated power supplies, chargers, or controllers.
• Cases for medical technology and cases for measuring instruments with sensitive electronic assemblies.
• Professional cases for tradespeople and professional machinery cases with tools and testers that heat up in operation.
• Demo cases and presentation cases in which samples are demonstrated under power.
• Industrial cases and special cases used in electrotechnical environments.
• Transport containers with integrated charging bays or buffer batteries.

Material selection and design: practical guidance

The glow-wire test provides metrics that can flow directly into the design:

1. Consider material characteristics: For enclosures and built-in parts, favor materials that do not ignite or that extinguish quickly at the required temperature levels.
2. Thermal separation: Do not embed heat sources directly in foam inlays; plan intermediate layers made of temperature-resistant material.
3. Clearances and airflow: Provide sufficient distance between hotspots and walls; plan air channels, openings, or heat spreaders in cases—especially in compact solutions such as the X-PCK backpack case.
4. Cable and component holders: Use holders and pass-throughs made of materials with suitable glow-wire metrics; ensure low-stress routing and proper strain relief.
5. Electrical interfaces: Place charging sockets, distribution units, and switches so that surrounding surfaces are not stressed by local heating.
6. Surfaces and branding: Implement markings to be heat-stable; avoid coatings near potential hotspots that soften or drip under heat.

Test planning within the project workflow

A systematic approach increases safety:

• Requirements analysis: Is there potential contact between hot components and enclosure/interior materials?
• Preselection of materials: Choose materials with documented glow-wire and other fire-test metrics.
• Prototyping: Build initial functional prototypes of aluminium cases, plastic cases, or transport containers with real components.
• Validation: Schedule testing by qualified bodies; feed results back into the design.
• Series release: Document changes and adapt production documentation for repeatable quality.

Legal and normative requirements may vary depending on the application. Statements in this article are general in nature and do not replace individual testing or binding interpretation.

Distinction from other fire and material tests

The glow-wire test evaluates behavior against a heated wire. Other established tests examine flame spread, flammability ratings (e.g., HB, V-2, V-0, 5VA), needle flame, or dripping behavior under different conditions. In many projects, a combination is sensible to realistically cover both localized heat sources and open flames.

Documentation and labeling

For robust results, clear documentation is recommended: materials used, metrics, test reports, installation locations, clearances, airflow paths, as well as notes on maximum power consumption. Branding and functional markings should be temperature- and solvent-resistant and remain legible even at elevated surface temperatures.

Common pitfalls in practice

• Heat-generating components embedded directly in dense foam inlays without thermal barriers.
• Clearances too small between hot spots and enclosure walls in plastic cases.
• Unsuitable cable ties or holders that soften or drip under heat.
• Missing airflow in compact solutions such as the X-PCK backpack case.
• Insufficient documentation of material characteristics in transport containers with electrical equipment.
• Branding placed immediately next to power supplies or power resistors without temperature assessment.