PVC decorative sheet is widely used in the fields of architecture and interior decoration, and its fireproof performance has attracted much attention. The following is the relevant content about its fireproof performance improvement and detection.
First of all, starting from the material formula is the key to improving the fireproof performance. Adding an appropriate amount of flame retardants, such as inorganic flame retardants such as aluminum hydroxide and magnesium hydroxide, they will decompose and absorb heat when heated, and release water vapor to dilute the concentration of combustible gases in the combustion area, thereby playing a flame retardant role. At the same time, some organic phosphorus or halogen flame retardants can be used in combination to prevent the spread of flames by interrupting the free radical reaction chain of combustion, but it should be noted that halogen flame retardants may produce harmful gases, and environmental factors should be considered comprehensively when using them.
Secondly, optimizing the degree of polymerization and molecular structure of PVC resin can also help fire prevention. PVC resins with higher degrees of polymerization usually have better thermal stability and mechanical properties, and can form a denser carbon layer when burning, blocking the transfer of heat and oxygen and delaying the combustion process.
Furthermore, during the production process, controlling the processing temperature and time has an impact on the fireproof performance. Excessive processing temperature or long processing time may cause PVC to decompose and reduce its fire resistance. Therefore, accurately setting the parameters of processing processes such as extrusion and injection molding to ensure that the PVC decorative sheet is molded under good processing conditions can maintain its inherent fire resistance.
There are many common methods for testing fire resistance. Among them, the oxygen index test is one of the important means. The PVC decorative sheet sample is placed in a specific combustion environment, and the oxygen concentration is gradually increased until the sample can continue to burn. The oxygen concentration at this time is the oxygen index. The higher the oxygen index, the more difficult the material is to burn and the better the fire resistance. Generally speaking, the oxygen index of PVC decorative sheet with good fire resistance should reach more than 30%.
Vertical burning test is also common. Place the sample vertically, ignite its lower end with a specified flame for a certain period of time, and then observe the flame spread speed, burning time, and whether there are drips, and rate it according to relevant standards. For example, in the UL-94 standard, V-0 grade materials have the best vertical burning performance, the flame is extinguished in a short time and there is no dripping to ignite the cotton below.
In addition, the cone calorimeter test can provide more comprehensive fire resistance data. It can measure parameters such as heat release rate, smoke release, and carbon monoxide generation during the combustion process of the material, evaluate the fire resistance of PVC decorative sheet from multiple dimensions, and provide a basis for its safety assessment in different application scenarios.
Through reasonable material formula design, optimized production process, and comprehensive evaluation using multiple testing methods, the fire resistance of PVC decorative sheet can be effectively improved and accurately determined.
