The Cone calorimeter is a versatile fire-testing device for testing a diversity of materials to determine combustion characteristics. These can be solids like plastics, metals, and composites or also building materials. In this regard, it is able to quantify heat release rates from materials like polystyrene, an extremely flammable plastic, as well as mineral-based products such as cement, which is commonly used due to its fire-resistant qualities. It can also assess wood and wood-based composites such as plywood and medium-density fibreboard (MDF), all widely used across construction.
The cone calorimeter can be used to assess flammability, and a study carried out in 2022 by Fire Protection Research Foundation investigated the flammability of various construction materials; the results show that the polymer construction materials, such as polyethylene foam, exhibit a tendency to yield a heat release rate of over 800 kW/m², whereas non-combustible materials such as steel show a negligible heat release. These measurements play a vital role in evaluating the performance of different materials in fire scenarios, which ultimately affects their application in building projects.
The cone calorimeter has proven to be particularly useful in insulation materials testing. An example of this would be fiberglass insulation (typically found in homes and businesses), which can have its heat release and smoke-generation properties tested. According to a report filed by the International Code Council (ICC), fiberglass insulation had a relatively low heat release rate, and its burning produced far less heat and toxic gases than materials used for insulating, such as polyurethane foam, which releases dramatically more heat and toxic smoke during combustion.
The device also plays an instrumental role in assessing textiles, which are commonly exposed to fire hazards in applications like automotive interiors, home furnishings and protective wear. In a 2021 study conducted by the American Society for Testing and Materials (ASTM), the cone calorimeter was used to measure the heat release rate from various fabrics, and the researchers found, not surprisingly, that natural flame-retardant wool had a much lower heat release rate in comparison to polyester, a synthetic material known to promote fire spread rapidly.
Others types of materials employed in electronics like, circuit boards, cables, and batteries can also used for fire testing. As an example, the cone calorimeter test on lithium-ion batteries showed that when batteries are subjected to extreme conditions, some type of battery may release heat in excess of 1500 kW/m², a potential source of fire hazards from overheating in high-capacity batteries. These results have spurred developments in battery safety standards, especially for sectors such as electric vehicles and consumer electronics.
Only by testing materials in realistic fire scenarios can you hope to understand their behaviour, as the authorities — the venerable fire safety expert Dr. William Harris — have been saying since at least 1979. This underscores the necessity of instruments such as the cone calorimeter to properly vet materials for safety prior to general use.
To find out more about the Cone Calorimeter, and its fire safety testing capabilities for an array of materials.