Abstract:

The bamboo test pieces could be scanned by the X-ray densitometer to get the successive profile on radial variation in density.The profile on radial variation in density of bamboo timber might be accordance with the equation of y=ax²-bx +c(x≤1),x is relative distance from bamboo green to yellow,moreover the regression coefficient beyond 0.8～0.9.It is possible to classify the bamboo slivers from different parts for improving value of the bamboo slivers.With age changing density of bamboo pulp change distinctly while density of bamboo green keep little variation.Density of bamboo pulp is the main factor to bamboo average density.With the height of culms increasing the density components and density grades(density gap/distance)in the radial direction also increase.The bamboo average density has excellent correlation with its middle density.The bamboo density grades have good correlation with its maximum density.As for the bamboo at the same height the minimum density is the main factor to its density grades while as for the bamboo at the different heights the culms thickness is the key effect on the density grades.The density grades of bamboo culm in the radial direction are normally 3 or 4 times bigger than that of wood.Because that characteristic might lead to an uneven shrinkage to produce the surface crack of bamboo,some protections should be done to reduce the effect.

Key words: X-ray scanning, Radial variation in bamboo density, Density grades