UL94 is the most widely used flame retardant performance evaluation standard for plastic materials, with a total of 12 classifications: HB, V-0, V-1, V-2, 5VA, 5VB, VTM-0, VTM-1, VTM-2, HBF , HF-1, HF-2. UL94 covers tests for flammability of polymeric materials used for parts in devices and appliances, it is applied to measure and describe the flammability properties of materials ( burning rate, after glow time, after flame tim e, damage length of the specimen , drip particles, particles ignited the cotton indicator ). Many values can be obtained for each tested material based on color or thickness. When selecting the material of a product, its UL rating should meet the thickness requirements of the wall part of the plastic part. The UL rating must be reported with the thickness value. Commonly UL94 test method 1. Horizontal Burning Test (HB) HB is the lowest flame retardant grade in the UL94 standard . The test procedure is to clamp the specimen at the en...