As we all know, the UL flame retardant grade increases step by step from HB, V-2, V-1, V-0, 5VB to 5VA. The UL flame retardant standard is a popular standard for daily inspection of whether materials are flame retardant. However, because it is an American standard, usually after translation, Chinese people have a variety of understandings of the standard. Each factory has its own set of "V0" grades. It brings great inconvenience to upstream and downstream manufacturers.
Misunderstanding 1: It only reaches V0 level when it is self-extinguishing away from the fire
This is the understanding of some small injection molding factories. They have only one standard for judging whether the material is flame retardant: self-extinguishing away from fire, that is, "the material cannot be ignited", and once it burns, they will be rated as "not enough flame retardant". The reason for this misunderstanding is that you don't understand the standard at all, only hearsay can't be ignited for 10 seconds, and no matter how you explain it, you only recognize your own standards.
Misunderstanding 2: HB grade is not a flame retardant grade
HB grade is not a flame retardant grade, so any material without flame retardant treatment can be marked with HB, which is also wrong. The actual HB grade is the lowest flame retardant grade in the UL94 standard, commonly referred to as the "retarding grade", which requires a burning rate of less than 40 mm per minute for samples with a thickness of 3 to 13 mm; and a burning rate of less than 3 mm thick for samples. less than 70mm per minute; or go out before the 100mm mark. In order to make HB grade, color masterbatch manufacturers once added flame retardant to the natural ABS (HB grade) after adding color masterbatch to achieve HB grade.
Misunderstanding 3: The higher the flame retardant grade, the better
Different uses have different requirements for flame retardancy. Generally speaking, people always hope that the flame retardancy level of materials is higher. But in fact, various flame retardant test methods have their limitations, and their conclusions are relative. Therefore, it is not that the higher the flame retardant level, the better. For example, it is generally considered that the material with the UL94 V-0 level is better than the V-2 level. However, some electrical products require materials to have arc ignition resistance, and V-2 grade is better than V-0 grade at this time. Because 94V-2 grade plastic will not form conductive and coke under the action of electricity, thus greatly reducing the possibility of fire, and 94V-0 grade plastic is the opposite.
Misunderstanding 4: UL yellow card certification is only V0 level
UL yellow card certification only has V0 grade for its natural color, so the products given to customers can declare V0 grade no matter what color it is; this is caused by the inaccurate interpretation of the UL standard - although it is possible that the natural color material can reach the V0 level and Other color products can also be achieved, but this is only possible, not all; different materials, different flame retardant systems, and different color effects, such as iron red has a considerable impact on flame retardant, a friend is making UL yellow When the whole series of cards are certified, the natural color, white and black all pass the V0 level, but the card is only on red. The reason for the investigation turned out to be iron red doing something strange, and it is OK to switch to organic dyes.
The flame retardant misunderstanding is analyzed. How many have you won?
Source: Suzhou Dongtuo Chemical Co., Ltd.
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