The melamine cyanurate fire retardant and its flame retardant nylon must have good thermal stability at its processing temperature (nylon 6≥220 ℃, nylon 6≥260 ℃). Most flame retardants reduce the stability of nylon. In the process, instability can make the product color, and its degradation will reduce the melt viscosity and deteriorate its performance. Therefore, the first step in the development of flame retardant nylon is to estimate the thermal stability of additives and nylon formulations. A common method for evaluating thermal stability is thermal analysis, such as thermal weight loss (TG), differential thermal analysis (DTA), and differential scanning calorimetry (DSC) .The thermal analysis can obtain the melting point or volatility of Related information such as oxidation reaction.For injection molding, melamine cyanurate fire retardant nylon has lower operating stability than pure nylon. Some flame retardant formulations with poor thermal stability have silver streaks due to local degradation during the molding process. Excessive molding temperature will cause discoloration of the product.Table 4-16 lists the applicable temperature ranges for some flame retardant nylon 66 systems.