CAJ | 학술논문

以人工林杉木为试材,分别用空气和菜子油为介质,在温度为180,200和220 ℃对其分别热处理1,3和5 h,研究试材的抗弯强度(MOR)、抗弯弹性模量(MOE)、顺纹抗压强度、表面硬度对高温热处理条件变化的响应,同时对处理材的主要化学成分进行分析,用扫描电镜对处理材横切面微观结构进行观察.结果表明:人工林杉木试材的4种主要力学性质对不同条件热处理的响应程度不同.无论是空气热处理还是油热处理,试材的MOR,MOE,顺纹抗压强度与对照比有不同程度的降低,且随处理温度升高、时间延长,下降幅度增大,相比于时间,温度的影响更显著;180 ℃热处理1,3和5 h时,试材的MOR,MOE与对照比未发生明显变化(降幅在3%以内),而顺纹抗压强度则明显低于对照,两介质中降低幅度分别在3.29%～9.58%和3.89%～7.18%;200 ℃以上处理时,不同时间处理的3种主要力学性质不仅显著或极显著低于对照,且各性质问的差异也达显著或极显著水平;对硬度的测试结果表明:180 ℃热处理时,试件的径面硬度和弦面硬度均随时间的延长而增大;200 ℃热处理3 h时,试件的硬度达最大,与对照差异达显著水平;随后热处理试件的硬度开始降低,220 ℃热处理5 h后试件的硬度又明显低于对照.在隔氧的油介质中进行热处理,4种主要力学性质的变化程度低于空气介质处理材,当温度高于200 ℃时,两介质处理间的差异达显著水平.而热处理过程中木材主要化学组成与横切面微观结构变化的差异,反映了4种主要力学性质对不同条件热处理时表现出的响应差异.
이인공림삼목위시재,분별용공기화채자유위개질,재온도위180,200화220 ℃대기분별열처리1,3화5 h,연구시재적항만강도(MOR)、항만탄성모량(MOE)、순문항압강도、표면경도대고온열처리조건변화적향응,동시대처리재적주요화학성분진행분석,용소묘전경대처리재횡절면미관결구진행관찰.결과표명:인공림삼목시재적4충주요역학성질대불동조건열처리적향응정도불동.무론시공기열처리환시유열처리,시재적MOR,MOE,순문항압강도여대조비유불동정도적강저,차수처리온도승고、시간연장,하강폭도증대,상비우시간,온도적영향경현저;180 ℃열처리1,3화5 h시,시재적MOR,MOE여대조비미발생명현변화(강폭재3%이내),이순문항압강도칙명현저우대조,량개질중강저폭도분별재3.29%～9.58%화3.89%～7.18%;200 ℃이상처리시,불동시간처리적3충주요역학성질불부현저혹겁현저저우대조,차각성질문적차이야체현저혹겁현저수평;대경도적측시결과표명:180 ℃열처리시,시건적경면경도화현면경도균수시간적연장이증대;200 ℃열처리3 h시,시건적경도체최대,여대조차이체현저수평;수후열처리시건적경도개시강저,220 ℃열처리5 h후시건적경도우명현저우대조.재격양적유개질중진행열처리,4충주요역학성질적변화정도저우공기개질처리재,당온도고우200 ℃시,량개질처리간적차이체현저수평.이열처리과정중목재주요화학조성여횡절면미관결구변화적차이,반영료4충주요역학성질대불동조건열처리시표현출적향응차이.
This paper focuses on the response of main wood mechanical properties of the Cunninghamia lanceolata plantation wood treated in hot air and hot vegetable oil respectively for different processing temperatures and times, so the M0R(modulus of rupture), M0E(modulus of elasticity), compression strength parallel to grain and hardness of wood were studied, also, the differences of main chemical components of heat treated samples were analyzed, and the cross section of treated samples were observed by scanning electron microscope to acquire information on changes of heat treated wood internal structure. The results showed that the MOR, MOE, compression strength parallel to grain and hardness of wood had different responses to different heat treatment process, the MOR, MOE, compression strength parallel to grain of samples which was treated in hot oil or hot air all had a decreasing trend compared to reference samples, and their difference vary much when processing temperature was increased and times was lengthened during the heat treatment, in comparison with processing times, the processing temperatures showed remarkable effects. When samples were heated for 1,3 and 5 h at a temperature of 180 ℃ in air or oil, the changes of MOR and MOE were both within the scope of 3 % and compression strength parallel to grain of samples decreased by 3.29% ～ 9.58 % and 3.89% ～7.18% respectively, there were obvious differences in the compression strength parallel to grain but no obvious ones in the MOR and MOE, while samples were treated at 200 ℃ or above for 1,3 and 5 h, they all were significantly lower than those of the control, however, the differences were significant. The results of hardness showed that both of the hardness in the tangential direction and in the radial direction of treated samples tended to increase when the heating treatment time from 1 to 5 h at the temperature of 180 ℃, when samples were treated at 200 ℃ for 3 h, the hardness were the highest, while samples were treated at 200 ℃ for 5 h or above 200 ℃ , the hardness tended to decrease, the hardness of samples treated at 220 ℃ for 5 h were significantly lower than those of the control. In addition, the effect of heat medium on the main wood mechanical properties of treated samples were significant, the variations of the main wood mechanical properties of the samples when the treatment of hot oil appeared to be slightly lower than that of samples when the treatment of hot air under the same condition. The differences in main chemical components and the cross section of samples in responses to the different processing condition reflected the response difference of main wood mechanical properties in Chinese Fir plantation.