GB/T 3 2788.1 - 2016 is a standard for the determination of gel time of prepregs. The standard details how to select representative prepreg samples, specifies the accuracy requirements of required test instruments, such as temperature control accuracy of heating equipment. The operation steps are also strictly standardized, including temperature setting, stirring Frequency during testing, etc. According to this standard, the gel time of prepregs can be accurately measured, providing a key basis for determining the best forming time during composite processing, helping to ensure product mass and improve production efficiency.