不同木材和竹材比例对木竹层积复合材机械性能的影响

张洋++李文定

中图分类号:TS653 文献标识码:A DOI编码:10.3969/j.issn.1006-6500.2014.03.013

摘 要:由于木竹复合材料的性能与原料的类型、施胶量、工艺参数、木材和竹材的比例等许多因素有关,本文研究了不同木材和竹材的比例对木竹层积复合材的性能影响,采用的酚醛胶固含量为45%,板材尺寸800 mm× 800 mm× 10 mm,热压时间15 min ,热压温度,热压压力2.5 MPa。试验结果表明:木材和竹材的比例对木竹复合材料的静曲强度、弹性模量和胶合强度有显著影响,对其含水率影响较小。当木材比例从20%到60%时,木竹复合材料的静曲强度、弹性模量和胶合强度逐渐增加。

关键词:木竹层积复合材;材料比例;机械性能

INTRODUCTION

Bamboo is one kind of important bio-resource, with a series of advantages such as short growth cycle, the air of respirable particulate[1], quick growing into useful timber, easy renew, and powerful capacity. Moreover, the genomic DNA of bamboo was also investigated by some scientists[2]. However, there are also some drawbacks such as vulnerable deep fungal, hollow, structure and physical properties, mechanical uneven, small diameter, etc. In order to improve the product quality, increasing the resources of raw materials, and decrease the production cost, some scientists have focused on the research of bamboo and wood composite materials processing in some Asian countries[3-5]; Two-layered bamboo mat board, corrugated roofing sheets, and bamboo strip board have been manufactured in Vietnam[6-7]. Although many studies have been conducted on bamboo mat board, extensive literature search did not reveal any information about the manufacturing of layered laminate bamboo-wood composites from bamboo and wood to evaluate its properties. In order to ensure the proper utilization of this valuable resource and to reduce the excess pressure on wood, this study was carried out to manufacture layered laminate bamboo-wood and determining the effect of material ratios on mechanical properties of the layered laminate composite made from bamboo (Dendrocalamus membranaceus Munro) and wood (Styrax tonkinensis Pierre) a hardwood species, which is commonly used for manufacturing of commercial plywood and paper in Vietnam. But the question is that bamboo and wood are two material structure characteristics of properties, chemical composition and other advantages and disadvantages. Therefore, the design structure of the layered laminate composite is an issue that needs to be studied. There are many papers about layered laminate composites [7-9] .

Both bamboo mats and wood veneers were used to make four types of 11-ply layered laminate composite(Fig.1).

Influence from types of layered laminate composite

In the tab.1, it can be observed that the density, mechanical properties are changed when the material ratios change. MOR and MOE of the layered laminate bamboo-wood composite were higher than that of the plywood made from Styrax tonkinensis Pierre (R4). But bonding ability between bamboo and wood is less than bonding ability between wood and wood. MOR and MOE of the layered laminate bamboo-wood composite depend on mechanical properties of bamboo and wood; and depend on bonding quality between the bamboo mats and wood veneers. Although bamboo has a higher mechanical strength of wood, bonding quality between bamboo and wood is smaller.

Effect of ratios for wood and bamboo

Samples for bending strength testing were 10 for each series. Figure 2, 3, 4, 5 show the effect of material ratios (wood and bamboo) on bearing capacity of bamboo-wood composite, and a comparatively between four types of structure. The highest bearing capacity was obtained in series R3 (wood: 60% and bamboo: 40%). And the lowest bearing capacity was in series R4 (wood: 100%).

The samples in series R1 and series R2, when under load, glue line separated before destruction; deflection of samples are small when bending.

The lowest standard deviation of the testing samples was in series R4, and the highest standard deviation of the testing samples was in series R1 because the hardness value of bamboo is higher than the hardness value of wood; therefore, the possibility of contact between bamboo and wood is less than the possibility of contact between wood and wood.

CONCLUSION

This study investigated the potentiality of using bamboo mat and wood veneer in manufacturing of layered laminate bamboo-wood composite and its basic mechanical properties. The specific conclusions of the study are that differences in the mechanical properties among the products are due to the raw material characteristics. Therefore, the properties of product depend on the ratio of materials in products. Through the study results, we have recommended that optimal material ratios (bamboo/wood) of the layered laminate bamboo-wood composite: volume of bamboo mats are about 40% and volume of wood veneers are about 60%.

References:

[1] CUI Hui-ping, ZHANG Jian-guo, XU Wen-jun.Variations of air PM10 concentrationin of 5 kinds of bamboo community in Lin'an City Zhejiang Province[J]. Tianjin Agricultural Sciences,2013,19(2):50-52.

[2] YANG Qing, SU Guang-rong, HAN Lei, et al. Study on genomic DNA extraction method and AFLP amplification reaction system of D.hamiltonii Nees et Arn.ex Munro[J]. Acta Agriculturae Boreali-Sinica,2010,25 (S) : 32 -37.

[3] China National Bamboo Research Center. Cultivation & integrated utilization on bamboo in china[M]. Hangzhou, China: China National Bamboo Research Center, 2011:143-148.

[4] Jiang Shen-xue. On structure, production, and market of bamboo-based panels in China[J].Journal of Forestry Research, 13(2): 151-156.

[5] Zhao Ren-jie. Some views on developing bamboo-based panel Industry[J].Forestry Products Industry, 2001,28 (2):6-8.

[6] van Chuong P. Research on the technology of making multy-layers composite from bamboo and wood[J]. Journal of Agriculture and Rural Development,2009(10):89-93.

[7] ZANG Yang, MA Yan,YANG Chun-mei. Mechanism of the structure and elastic modulus calculation of the sliced veneer laminated timber cervical splint[J]. Scientia Silvae Sinicae, 2013, 49( 8 ):103-107.

[8] DONG Guo-qing,WANG Jia-hang. Experimental study on the structural performance of poplar laminated veneer lumber beams[J]. Journal of Huaiyin Institute of Technology, 2010, 19(1):84-88.

[9] LYU Bin, FU Yue-jin, WU Sheng-fu, et al. Trial production and mechanical property of LVL made from plantation wood[J]. China Forest Products Industry,2004, 31(3):13-17.

Effect of ratios for wood and bamboo

Samples for bending strength testing were 10 for each series. Figure 2, 3, 4, 5 show the effect of material ratios (wood and bamboo) on bearing capacity of bamboo-wood composite, and a comparatively between four types of structure. The highest bearing capacity was obtained in series R3 (wood: 60% and bamboo: 40%). And the lowest bearing capacity was in series R4 (wood: 100%).

The samples in series R1 and series R2, when under load, glue line separated before destruction; deflection of samples are small when bending.

The lowest standard deviation of the testing samples was in series R4, and the highest standard deviation of the testing samples was in series R1 because the hardness value of bamboo is higher than the hardness value of wood; therefore, the possibility of contact between bamboo and wood is less than the possibility of contact between wood and wood.

CONCLUSION

This study investigated the potentiality of using bamboo mat and wood veneer in manufacturing of layered laminate bamboo-wood composite and its basic mechanical properties. The specific conclusions of the study are that differences in the mechanical properties among the products are due to the raw material characteristics. Therefore, the properties of product depend on the ratio of materials in products. Through the study results, we have recommended that optimal material ratios (bamboo/wood) of the layered laminate bamboo-wood composite: volume of bamboo mats are about 40% and volume of wood veneers are about 60%.

References:

[1] CUI Hui-ping, ZHANG Jian-guo, XU Wen-jun.Variations of air PM10 concentrationin of 5 kinds of bamboo community in Lin'an City Zhejiang Province[J]. Tianjin Agricultural Sciences,2013,19(2):50-52.

[2] YANG Qing, SU Guang-rong, HAN Lei, et al. Study on genomic DNA extraction method and AFLP amplification reaction system of D.hamiltonii Nees et Arn.ex Munro[J]. Acta Agriculturae Boreali-Sinica,2010,25 (S) : 32 -37.

[3] China National Bamboo Research Center. Cultivation & integrated utilization on bamboo in china[M]. Hangzhou, China: China National Bamboo Research Center, 2011:143-148.

[4] Jiang Shen-xue. On structure, production, and market of bamboo-based panels in China[J].Journal of Forestry Research, 13(2): 151-156.

[5] Zhao Ren-jie. Some views on developing bamboo-based panel Industry[J].Forestry Products Industry, 2001,28 (2):6-8.

[6] van Chuong P. Research on the technology of making multy-layers composite from bamboo and wood[J]. Journal of Agriculture and Rural Development,2009(10):89-93.

[7] ZANG Yang, MA Yan,YANG Chun-mei. Mechanism of the structure and elastic modulus calculation of the sliced veneer laminated timber cervical splint[J]. Scientia Silvae Sinicae, 2013, 49( 8 ):103-107.

[8] DONG Guo-qing,WANG Jia-hang. Experimental study on the structural performance of poplar laminated veneer lumber beams[J]. Journal of Huaiyin Institute of Technology, 2010, 19(1):84-88.

[9] LYU Bin, FU Yue-jin, WU Sheng-fu, et al. Trial production and mechanical property of LVL made from plantation wood[J]. China Forest Products Industry,2004, 31(3):13-17.

Effect of ratios for wood and bamboo

Samples for bending strength testing were 10 for each series. Figure 2, 3, 4, 5 show the effect of material ratios (wood and bamboo) on bearing capacity of bamboo-wood composite, and a comparatively between four types of structure. The highest bearing capacity was obtained in series R3 (wood: 60% and bamboo: 40%). And the lowest bearing capacity was in series R4 (wood: 100%).

The samples in series R1 and series R2, when under load, glue line separated before destruction; deflection of samples are small when bending.

The lowest standard deviation of the testing samples was in series R4, and the highest standard deviation of the testing samples was in series R1 because the hardness value of bamboo is higher than the hardness value of wood; therefore, the possibility of contact between bamboo and wood is less than the possibility of contact between wood and wood.

CONCLUSION

This study investigated the potentiality of using bamboo mat and wood veneer in manufacturing of layered laminate bamboo-wood composite and its basic mechanical properties. The specific conclusions of the study are that differences in the mechanical properties among the products are due to the raw material characteristics. Therefore, the properties of product depend on the ratio of materials in products. Through the study results, we have recommended that optimal material ratios (bamboo/wood) of the layered laminate bamboo-wood composite: volume of bamboo mats are about 40% and volume of wood veneers are about 60%.

References:

[1] CUI Hui-ping, ZHANG Jian-guo, XU Wen-jun.Variations of air PM10 concentrationin of 5 kinds of bamboo community in Lin'an City Zhejiang Province[J]. Tianjin Agricultural Sciences,2013,19(2):50-52.

[2] YANG Qing, SU Guang-rong, HAN Lei, et al. Study on genomic DNA extraction method and AFLP amplification reaction system of D.hamiltonii Nees et Arn.ex Munro[J]. Acta Agriculturae Boreali-Sinica,2010,25 (S) : 32 -37.

[3] China National Bamboo Research Center. Cultivation & integrated utilization on bamboo in china[M]. Hangzhou, China: China National Bamboo Research Center, 2011:143-148.

[4] Jiang Shen-xue. On structure, production, and market of bamboo-based panels in China[J].Journal of Forestry Research, 13(2): 151-156.

[5] Zhao Ren-jie. Some views on developing bamboo-based panel Industry[J].Forestry Products Industry, 2001,28 (2):6-8.

[6] van Chuong P. Research on the technology of making multy-layers composite from bamboo and wood[J]. Journal of Agriculture and Rural Development,2009(10):89-93.

[7] ZANG Yang, MA Yan,YANG Chun-mei. Mechanism of the structure and elastic modulus calculation of the sliced veneer laminated timber cervical splint[J]. Scientia Silvae Sinicae, 2013, 49( 8 ):103-107.

[8] DONG Guo-qing,WANG Jia-hang. Experimental study on the structural performance of poplar laminated veneer lumber beams[J]. Journal of Huaiyin Institute of Technology, 2010, 19(1):84-88.

[9] LYU Bin, FU Yue-jin, WU Sheng-fu, et al. Trial production and mechanical property of LVL made from plantation wood[J]. China Forest Products Industry,2004, 31(3):13-17.