About retardant MDF B1 class A, B and C that you know about?

About retardant MDF B1 class A, B and C that you know about? Customers often receive a phone call saying to buy B1 retardant MDF, whenever this time I'm going to explain to customers that the market is not fire-retardant MDF B1 grade sold only B grade or C grade barrier Burning MDF. Why do you say? B1 level has become history, B1 level is GB8624-1997 "burning of construction materials classification method performance" in the statement. According to GB8624-1997 "burning of construction materials classification method performance" testing standards, divided into A-grade building materials (non-combustible materials), B1 level (flame retardant materials), B2 level (combustible materials), B3 level (flammable material). B1 content detected are: a) according to GB / T8626 test, the combustion performance should reach the target set in the GB / T8626, and does not allow burning paper ignited drip phenomenon; b) according to GB / T8625 test The average remaining length of each set of specimens ≥15cm (where the remaining length of any specimen> 0cm), and the average flue gas temperature for each test peak ≤200 ℃; c) according to GB / T8627 test, the smoke density Ratings (SDR) ≤75. Under the new standards GB8624-2006 "building materials and products of combustion classification" testing standards, building materials are divided into A1, A2, B, C, D, E, F seven levels. Contents Grade B and C testing is: a) Press GB / T8626 to the continuous ignition internal tests conducted 30S 60S Fs (burn length) ≤150mm; b) according to GB / T20284 test, FIGRA (burn growth rate) ≤120W / s and LFS (lateral spread of flame length)