Limiting Oxygen Index (LOI) is a parameter used to evaluate the fire resistance of materials. The LOI value may vary depending on a number of factors. Here are five factors that influence the LOI of materials.
1. Material Composition: The chemical composition of the material is an important factor that influences the LOI. Different chemical compositions of materials lead to different burning characteristics. For example, materials containing fluorine compounds generally have lower LOI values than materials without fluorine.
2. Material Density: The density of the material can influence the LOI. Materials with greater density typically have higher LOI values than materials with lower density, provided they have the same chemical compositions.
3. Material Form: The form of the material can also influence the LOI. The particle size, fiber density, and surface form of the material, for example, all influence the burning characteristics.
4. Oxygen Concentration: LOI is defined as the minimum concentration of oxygen in an oxygen/nitrogen mixture that is required for the material to begin self-igniting. As a result, the oxygen concentration is a significant factor that affects LOI. Typically, higher oxygen concentrations lead to lower LOI values.
5. Thermal Stability: Another factor that can influence LOI is the material's thermal stability. Materials with high thermal stability usually have higher LOI values because they are more difficult to ignite and can withstand high temperatures.
In short, these factors can all influence the LOI of materials, and as a result, they need to be considered holistically when evaluating the combustion characteristics of materials. For different application scenarios, the material with appropriate combustion properties must be chosen to enhance the safety and fire prevention performance of the product.