Is the bulk density of ceramic fiber more higher, the more durable?

Bulk density of ceramic fiber board is between 280kg/m3 and 550kg/m3. When ceramic fiber boards are used at insulation layer, the bulk density is generally 280kg/m3 -350kg/m3, as it is not used at working layer, it has no high requirement to strength. And it shows the best insulation performance at this bulk density, or insulation performance will decrease. When ceramic fiber boards are used in refractory layer,

bulk desnity shoule be appropriately increased with the temperature requirements, which will increase the service life. However, it is not necessary to choose too high density. On the one hand, the density is too high, which will increase the thermal conductivity, resulting to a decrease in thermal insulation performance. On the other hand, if the density is too high, the hardness of the ceramic fiber boards will increase, and it will be more likely to crack, so the density of the ceramic fiber boards should be selected according to the usage conditions.