Mechanical properties assessment of Cunninghamia lanceolata plantation wood with three acoustic-based nondestructive methods

Using Cunninghamia lanceolata as a substrate, the thermochromic ink was added to the waterborne finish to test the optical properties and mechanical properties of the finish film. The results showed that the discoloration performance of the finish film with 15.0% and 30.0% of the thermochromic ink was better. The gloss of the finish film changes irregularly when the concentration increases. The finish film with a thermochromic ink concentration of 10.0% has the highest gloss, and with a concentration of 30.0% has the lowest gloss. When the thermochromic ink concentration exceeds 15.0%, the impact resistance of the finish film is slightly enhanced. The concentration is not related to the liquid resistance of the finish film. When the thermochromic ink concentration was 0–15.0%, the particle distribution uniform reunion was not much. The discoloration mechanism of discolored finish film can be considered to be as follows. After adding thermochromic ink, when the finish film temperature rises, it fades from red to colorless. When the temperature is lowered, the thermochromic ink changes to its original colour again, and the thermochromic effect is stable and sustainable. On the basis of the above results, when the thermochromic ink concentration is 15.0%, the general performance of the waterborne finish film on the Cunninghamia lanceolata surface is the best. This study provides new prospects in using thermochromic ink for waterborne finish film.

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Influence of Microfibril angle on within-tree variations in the Mechanical properties of chinese fir (Cunninghamia Lanceolata)

IAWA Journal ◽

10.1163/22941932-90000069 ◽

2011 ◽

Vol 32 (4) ◽

pp. 431-442 ◽

Cited By ~ 8

Author(s):

Yafang Yin ◽

Mingming Bian ◽

Kunlin Song ◽

Fuming Xiao ◽

Jiang Xiaomei

Keyword(s):

Mechanical Properties ◽

Bending Strength ◽

Juvenile Wood ◽

Microfibril Angle ◽

Basic Density ◽

Chinese Fir ◽

Cunninghamia Lanceolata ◽

Effective Utilization ◽

Longitudinal Modulus

Radial variations in microfibril angle (MFA) and their effect on the mechanical properties of plantation-grown Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) were investigated with the aim of achieving an effective utilization of the wood. Correlations between MFA and mechanical properties, including longitudinal modulus of elasticity (MOEL), static bending strength (MOR) and compression strength parallel-to-the-grain (CS), were analyzed for predicting the quality of timber. The results indicated that MFA had a greater variation in juvenile wood than in mature wood. The biggest change occurred close to the pith in Chinese fir. The outer-rings (rings 9–30 from the pith) have a relatively low MFA, together with high mechanical properties and high density, when compared with the inner-rings (rings 1–8 from the pith). The MFA had significant negative curvilinear correlations with all the mechanical properties (MOEL, MOR and CS) of Chinese fir, with the value of r2 being 0.88, 0.69 and 0.74 respectively. The correlation between the MFA and basic density (BD) was strong in certain consecutive rings (rings 5–30 from the pith), but this did not apply across the whole billet, i.e. from the pith to the bark.

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