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Development of Tobacco Stem Particle Board

Author: XunMi
Tutor: XuJianYing
School: Central South University of Forestry Science and Technology
Course: Wood Science and Technology
Keywords: tobacco stem wood structure and quality DSC analysis technical parameters binderless particleboard bonding mechanism
CLC: TS653
Type: Master's thesis
Year: 2009
Downloads: 29
Quote: 1
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Abstract

Nowadays, marerials, energy and information technology are recognized to be the three pillars of modern civilization by the international community. China has also attached importance to these three pillars increasingly. However, contradiction between wood supply and demand is getting more and more obvious in China as we are one of countries lacking of forest resource, thus saving existing wood, developing new wood and exploring replacements of wooden products will be long-term main trend for China's wood industry. Tobacco stems is a new raw material. As an agricultural residues, using tobacco stems to product wood-based panel will not only resolve the environmental problems from burning of stems, but also relieve the difficulties of getting flakeboard raw materials. Besides, making use of tobacco stems will increase the income of the farmers. Therefore, it has good social benefits, economic benefits and ecological benefits.In this paper, the study of materials through the wooden structure on Tobacco stems observation, fiber morphology and chemical composition determination, comparison between other non-wood plant and tobacco stems, and considered tobacco stems 'feasibility of flakeboard as a raw material. The test of the average length of fiber is 0.8 to 1.2mm, the average width of the fiber is 25 to 35μm, so it is suited to be wood-based panel material in non-wood plant . The results showed that Tobacco stems chemical composition of the ashy substance content 5.01 percent, cold-water extract content 10.52 percent, hot-water extract content 14.17 percent, 1 percent sodium hydroxide extract content 38.19 percent, benzyl extract content 3.21 percent, lignin content 18.63 percent, poly-pen-tose content 17.92 percent, and comprehensive cellulose content 78.2 percent. Considering all the various angles, Tobacco stems is more suitable for the production of flakeboard compared with other common non-wood plant raw materials.By differential scanning calorimetry (DSC) to study the amount of curing agent for urea-formaldehyde resin (UF) curing process, as well as tobacco stems and wood fiber mixing ratio of the urea-formaldehyde resin on the impact of curing. In this experiment, the use of adhesive, by adding NH4Cl and not for the reinforcement of the UF compared to thermal response curve significantly different. The reason is that the accession NH4Cl, with the UF in the hydroxymethyl response form-hexamine, hydrochloric acid and water, thereby reducing the PH value of the UF resin to cure faster. When the chlorid content of 1.5%, the lowest temperature curing. When tobacco stems / wood fiber mixed at 1:3 ratio, UF resin became greatest change, followed by the ratio of 4:0,0 : 4,3:1 situation, and when the tobacco stem / wood fiber mixed at 1:1, UF resin changed the least.Using orthogonal design of the tobacco stem and wood shaving particleboard pressing the main process parameters to conduct studies on the various process parameters on the physical and mechanical properties of sheet impact. According to orthogonal test, tobacco stem and wood shaving particleboard optimum process parameters as follows: pressing time 5min; sizing volume 11%; density 0.85 g/cm3; adding wood shaving ratio 75% . The results showed that the particleboard under the optimum process parameters can obtain national standards in MOR and IB, in addition to TS.Using multi-level single-factor test to explore the better tobacco stem binderless particleboard process parameters and analyze the effects of board density, hot pressing temperature, moisture content of the raw materials, and pre-treatment methods on the particleboard properties. The result showed that the tobacco stem binderless particleboard with 6mm thickness and density of 0.85g/cm, produced under the conditions of particle moisture content (MC) 25%, hot-pressing temperature 190 ℃, pressure 5 MPa and hot-pressing time 7 minutes, can meet the requirements of JIS A 5908 standards at the aspects of modulus of rupture (MOR), internal bonding strength (IB ) and thickness swelling rate of water absorption (TS). Compared with other binderless particleboard, tobacco stem binderless particleboard has high internal bonding strength. Besides, the result show that high temperature steam and steam injection treatment can improve the performance of binderless particleboard.

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