不同纤维制备中密度纤维板及其力学性能研究

研究了由橡木纤维和回收的废旧瓦楞纸纤维混合制备的中密度纤维板(MDF)的阻燃性能,讨论了阻燃剂氢氧化铝(ATH)对MDF的内结合强度(IB)、膨胀率和吸水性等力学性能的影响。试验结果表明:随着ATH用量的增加,MDF的极限氧指数(LOI)增大,表明加入适量的ATH能提高MDF的阻燃性能。当MDF中不含树脂时,其IB值会随ATH用量增加而增大,并随回收的废旧瓦楞纸纤维用量的增加呈递增趋势;树脂的加入,提高了MDF的粘接强度,降低了MDF的膨胀率和吸水率;但当回收的废旧瓦楞纸纤维用量增大时,MDF面板的膨胀率也增大。     

水玻璃胶黏剂在芦苇中密度纤维板中的应用研究

为了探索水玻璃胶黏剂在纤维板中的应用效果,以芦苇纤维和水玻璃胶黏剂为主要原料,制备了芦苇中密度纤维板,综合考察了密度、施胶量、活化剂用量对纤维板性能的影响。试验结果确定了芦苇中密度纤维板的较佳制备工艺为板材密度0.80 g/cm~3,施胶量为25.00%,活化剂量为5.00%,由此制备的芦苇中密度纤维板的各项物理力学性能达到GB/T 11718—2009规定的指标要求。     

单宁改性双组份豆粕胶制备中密度纤维板的工艺优化

采用单宁基固化交联剂改性的双组份豆粕胶制备中密度纤维板(MDF)。结果显示,MDF的力学性能随热压时间、热压温度、板坯含水率及密度的提高而逐渐升高,24 h吸水厚度膨胀率(TS)呈相反的趋势。在热压时间330s、热压温度190～200℃,板坯含水率7%～9%,密度750～840 kg/m~3的条件下,制备的MDF性能指标满足GB/T 11718—2009《中密度纤维板》中普通型中密度纤维板的要求。     

密度对异氰酸酯胶高密度纤维板性能的影响

以桉木纤维和异氰酸酯胶为原料制备高密度纤维板,探索密度变化对高密度纤维板吸水厚度膨胀率和力学性能的影响。结果表明:高密度纤维板的主要力学性能随板材密度的增大而大幅度提高,而吸水厚度膨胀率则大幅度下降。异氰酸酯胶高密度纤维板的成功制备,对开发新型纤维板产品意义重大。     

无胶纤维板生产工艺的研究

研究密度为1.0g/cm~3、厚度为8mm的无胶纤维板制造工艺,结果表明其较优工艺为:板坯含水率10%,热压压力3.0MPa,热压温度200℃,板坯芯层温度140℃。以此工艺在MDF生产线上进行的试验结果表明:板材的物理力学性能达到LY/T1611—2003普通型地板基材用纤维板指标要求。     

工艺因素对中密度纤维板（MDF）板性的影响

MDF主要物理性能如：密度与剖面密度梯度、吸湿（水）性与尺寸稳定性等都直接影响到MDF的应用，而这些性能主要取决于制板时相关工艺因素和参数的制定。因此，研究物理性能与工艺之间的关系，对MDF的生产非常重要。合理选择工艺参数是改善MDF性能的重要手段。1密度与剖面密度梯度纤维板按密度分为三类：高密度（≥800kg／m3）、中密度（500～800kg／m3）、低密度（＜500kg／m3）。纤维板的密度影响其所有物理力学性能及机械加工性能，因此，它是纤维板的主要指标之一。人们喜欢密度低、强度高、加工性能又好的纤维板，MDF的性能与这种…     

大豆蛋白胶黏剂用于竹柳中密度纤维板试验

以大豆蛋白胶为胶黏剂,分别采用剥皮和未剥皮的竹柳枝桠材制备中密度纤维板.探讨了枝桠材树皮与木质部的比例和纤维得浆率,研究了树皮含量、施胶量和板材密度对竹柳纤维板物理力学性能的影响,优化了板材的制备工艺参数,并与脲醛树脂胶制备的剥皮竹柳中密度纤维板进行性能对比分析.结果表明:竹柳枝桠材的树皮含量这30.5％,其纤维得浆率比剥皮枝桠材低约4％;纤维板的性能随着密度和施胶量的增加而明显提高;剥皮竹柳所制纤维板的性能优于未剥皮的,未剥皮竹柳所制纤维板在密度为0.80 g/cm3,施胶量为16％时,其物理力学性能可满足GB/T 11718-2009的要求;而剥皮竹柳所制纤维板在密度为0.75 g/cm3,施胶量为14％时即可达到国标要求;大豆蛋白胶所制纤维极性能略低于脲醛树脂所制纤维板,但基本可以满足国标要求.     

落叶松单宁胶在中密度纤维板生产中的应用

以粉状落叶松单宁胶与传统的酚醛树脂胶制成的中密度纤维板 (MDF)作对比实验 ,证明了落叶松单宁胶制成的板的主要物理力学性能接近于或优于酚醛树脂胶制成的板 ,落叶松单宁胶可基本替代酚醛树脂胶     

制板因素对FRW阻燃中密度纤维板性能的影响

制板因素对阻燃中密度纤维板(MDF)各项性能的影响至关重要.根据前期试验,选取阻燃剂施加量和热压温度两个主要的制板影响因素,分别探讨了该因素对FRW阻燃中密度纤维板物理力学性能和阻燃性能的影响.研究结果表明:阻燃剂施加量对FRW阻燃中密度纤维板的物理力学性能影响较小,并且所有物理力学性能指标均达到并超过了中密度纤维板国家标准GB/T11718-1999的要求;而阻燃剂施加量对FRW阻燃中密度纤维板的阻燃性能影响较大,氧指数与阻燃剂施加量之间具有显著的相关性.热压温度除对FRW阻燃中密度纤维板的几个指标略有影响外,对其他的物理力学性能指标和氧指数几乎无影响.     

圆棒榫与刨花板接合抗拉强度的研究

本报告探讨了圆棒榫与不同物理力学性能的A类刨花板,通过分别采用PVAC、UF和混合胶胶粘剂接合,对抗拉强度的影响。结果表明：圆棒榫接合抗拉强度,随刨花板密度及静曲强度的增大而增大,影响程度,UF胶＞混合胶＞PVAC胶;随刨花板吸水厚度膨胀的增大而减少,影响程度,混合胶＞UF胶＞PVAC胶。     

Development of high-performance UF-bonded reed and wheat straw medium-density fiberboard

Urea formaldehyde resin-bonded reed and wheat straw fiberboards were produced from the fibers made under different steam cooking conditions in refining processes at densities of 500 and 700kg/m³. The effect of steam cooking conditions on the board properties was examined. The steam pressure and cooking time for reed and wheat straws were 0.4MPa/10min and 0.4MPa/5min, respectively, and 0.6MPa/3min and 0.6MPa/10min for both straws. The effect of steam cooking treatment before the fiber refining process on the wettability and weight losses of the straws was also investigated. The results indicated that the mechanical properties and linear expansion of the straw medium-density fiberboard (MDF) were improved with increasing steam cooking pressure and time during the refining process, whereas the thickness swelling (TS) did not vary much. The wettability of the straws was improved by cooking treatment. The steam cooking conditions had little effect on the wettability of the straw surfaces. For reed and wheat straws, the weight losses increased with increasing steam pressure and cooking time. In addition, it was found that the properties of MDF were significantly higher than those of particleboard, especially the internal bond (IB), where the IB values of MDF were more than 10 times higher than those of particleboard. All the properties of the straw MDF, except the TS of wheat board, can meet the requirement of JIS fiberboard standard. The high performances of MDF could be due to the improved wettability and the removal of extractives during the refining process.     

火炬松制造中密度纤维板工艺的研究

通过对火炬松制造中纤维板制板工艺条件的研究,探索降低中密度纤维板制造过程中纤维施胶量的可能性。结果表明,火炬松制造中密度纤维板是可行的;采用８％的施胶量制板;板材的主要物理力学性能可达到美国ＭＤＦ国家标准ＡＮＳＴＡ２０８．２－１９９４和我国ＭＤＦ国家标准７０型及８０型特级品的要求。     

湿地松制造中密度纤维板工艺的研究

以湿地松（Ｐｉｎｕｓｅｌｉｏｔｉ）为原料制造中密度纤维板工艺的研究,采用正交试验方法,分析了施胶量、板坯含水率、热压温度及热压时间对中密度纤维板物理力学性能的影响。试验结果表明：板坯含水率及热压时间对试验板质量影响较大,热压温度及施胶量的影响较小。采用适宜的工艺,即板坯含水率在１０％、热压温度１６５℃、热压时间５ｍｉｎ,施胶量可以降至８％～９％,试验板的各项物理力学性能可以达到国标特级品的要求。     

用异氰酸酯胶生产中密度纤维板的尝试

以异氰酸酯为胶黏剂,进行了2种原料的中密度纤维板(MDF)生产试验,分析其生产工艺的特点,并根据我国国标及日本相关标准,对板材的性能与甲醛释放量等指标进行检测。结果表明:用异氰酸酯制造的MDF,其各项指标均优于UF胶的MDF,是一种应用前景广阔的环保板材。     

15mm厚中密度纤维板不同装饰后耐老化性能研究

研究了加速老化试验对经不同装饰后的脲醛胶中纤板物理力学性能的影响.结果表明,未经装饰的中纤板经加速老化处理后力学强度降低较快,吸水厚度膨胀率明显增大.选用的4种装饰中纤板中,三聚氰胺板的力学性能降低最大,油漆板耐久性能最好.     

LLM型UF树脂制造橡胶木和赤桉中密度纤维板

通过使用ＬＬＭ型ＵＦ树脂制造橡胶木和赤桉中密度纤维板的研究,评价用该树脂制造橡胶木和赤桉中密度纤维板的适应性。橡胶木和赤桉各５０％比例温和后施以ＬＬＭ型ＵＦ树脂,按照ＭＤＦ常规工艺压制９,１２,１６ｍｍ的试验板。结果表明：板材物理力学性能及甲醛释放量指标均达到ＧＢ１１７１８．２－８９标准规定的要求。     

湿地松制造中密度纤维板中试报告

在湿地松制造中密纤维板小型工艺试验的基础上,为进一步完善和考核生产工艺参数,在年产１．５万ｍ＾３中密度纤维板生产线上进行了中间试验。中试结果表明,用１０％ＵＦ旋施胶量生产的湿地松中密度纤维板,其物理力学性能达到国家标准ＧＢ１１７１８．２－８规定的８０型一级品规格的要求和美国ＭＤＦ标准规定的要求,因此,中间试验所采用的工艺参数是可行和适宜的。     

A global model for the hot-pressing of MDF

The hot-pressing operation is the final stage in medium-density fiberboard (MDF) manufacture, where the mattress of fibers is compressed and heated to promote the cure of the resin. In MDF hot-pressing, many physical, chemical and mechanical processes are involved; the complexity of this operation arises from the fact that they are coupled. A global model is presented for this operation that integrates all mechanisms involved in the panel formation (heat and mass transfer, chemical reaction and mechanical behavior). This approach results in a two-dimensional unsteady state problem, which involves the knowledge of the polymerization kinetics of the resin, the transport properties and material properties, which are position and time dependent. This dynamic model was used to predict the evolution of the variables relating to heat and mass transfer (temperature, moisture content, gas pressure and relative humidity), as well as the variables relating to mechanical behavior (pressing pressure, strain, modulus of elasticity and density). The model performance was analyzed using the typical operating conditions for the hot-pressing of MDF and the results were compared to the experimental data from an industrial MDF press. We concluded that the model could predict in an acceptable way the behavior of the key variables for the control of the pressing cycle, as well as some physico–mechanical properties of the final product. The improvement of this model will permit the scheduling of the press cycle to fulfill objectives of minimization of energy consumption, better quality of the board and increased process flexibility.     

热磨条件对麦秸中密度纤维板性能的影响

在不同的热磨条件下(蒸汽压力为0.4、0.6、0.8、1.0MPa,磨盘转数为2 500r/min和3 000r/min),将麦秸原料分离成纤维,并试制了相应的麦秸中密度纤维板,对比分析了不同的热磨条件对麦秸中密度纤维板的内结合强度、弯曲性能、吸水性能、表面硬度和边部握螺钉力的影响。结果表明,不同的热磨条件下分离得到的麦秸纤维形态存在差异,纤维的强度和形态对麦秸中密度纤维板的物理力学性能影响较大。当蒸汽压力为0.8MPa,磨盘转数为3 000r/min,麦秸中密度纤维板的各项性能得刮改善。     

Upgrading of urea formaldehyde-bonded reed and wheat straw particleboards using silane coupling agents

Reed and wheat straw particleboards bonded with urea formaldehyde (UF) resin were manufactured from two different material configurations (i.e., fine and coarse particles). The board densities were in the range of 0.550–.90g/cm³. The effects of particle size and board density on the board properties were examined. The properties of particleboard produced from fine particles were better than those made from coarse particles. An increase in board density resulted in a corresponding improvement in the board properties. The properties of OF bonded reed and wheat straw particleboards were relatively lower than those of commercial particleboards. Three silane coupling agents were used to improve the bondability between the reed and wheat particles and OF resin. Results of this study indicate that all the board properties were improved by the addition of silane coupling agent. The degree of improvement achieved from each coupling agent was different; epoxide silane was found to be more effective for reed straw particleboard, and amino silane was better for wheat straw particleboard.