Moisture migration analysis of laminated veneer lumber based on low field nuclear magnetic resonance

Figures (9) Tables (1)

Figure 1.
Experimental laminated veneer lumber samples (40 mm × 40 mm × 35 mm). Left, physical picture; right, schematic diagram.
Figure 2.
Effect of water absorption time on sample weight. Note: Means with standard error are indicated, different letters represent significant differences (p < 0.05) in each treatment (n = 10).
Figure 3.
Changes in T₂ relaxation spectra during water absorption.
Figure 4.
Relaxation times and peak area ratios of water in laminated veneer lumber sample after water absorption. Note: Means with standard error are indicated, different letters represent significant differences (p < 0.05) in each treatment (n = 10).
Figure 5.
T₂-weighted MRI images of laminated veneer lumber sample of different water absorption time.
Figure 6.
Changes of weight in laminated veneer lumber sample after water absorption. Note: Means with standard error are indicated, different letters represent significant differences (p < 0.05) in each treatment (n = 10).
Figure 7.
Changes in T₂ relaxation spectra during drying process. (a) Dried at 105 °C, (b) dried at 60 °C.
Figure 8.
Standard curves of water quality and nuclear magnetic signal quantity.
Figure 9.
Comparison of water content by the nuclear magnetic predicted method and weighing method. (a) Dried at 105 °C, (b) dried at 60 °C.

Water absorption time	A₂₁	A₂₂	A₂
Control	160.41 ± 11.39^f	7.48 ± 1.00^f	168.37 ± 11.99^e
0.5	318.31 ± 42.43^e	135.93 ± 60.31^e	455.56 ± 100.71^d
1	381.52 ± 36.28^d	171.29 ± 65.32^de	554.56 ± 98.67^d
2	441.11 ± 38.18^c	209.57 ± 73.62^de	652.67 ± 108.44^c
3	470.18 ± 32.41^bc	238.79 ± 77.29^cd	711.00 ± 105.75^c
6	513.33 ± 18.04^ab	302.35 ± 82.23^c	817.64 ± 82.08^b
12	518.82 ± 68.02^a	384.47 ± 81.43^b	904.74 ± 28.58^a
24	432.31 ± 65.19^c	523.85 ± 130.30^a	913.49 ± 26.70^a
48	351.22 ± 81.30^de	580.79 ± 120.04^a	897.33 ± 21.79^a
96	341.68 ± 62.32^de	552.65 ± 117.83^a	860.42 ± 16.26^ab
Different letters of superscripts in each column represent significant differences (p < 0.05) in each treatment (n = 10).

Table 1.

Peak area of laminated veneer lumber sample of different water absorption time.