共查询到20条相似文献,搜索用时 265 毫秒
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木材纤维-铜丝网复合MDF的研究 总被引:3,自引:0,他引:3
笔者重点研究了不同目数的铜丝网和木材纤维压制具有电磁屏蔽效能的复合MDF的生产工艺。结果表明,采用异氰酸酯涂刷铜丝网,可显著改善复合MDF的胶合性能,其胶合强度可以达到国家标准的要求。铜丝网的层数对复合MDF的电磁屏蔽效能影响显著,铜丝网在MDF中的复合位置对电磁屏蔽效能影响较显著,在MDF双表面复合铜丝网,当铜丝网的目数大于60目时,在9kHz到1.5GHz频率范围内其电磁屏蔽效能可达到60dB以上。 相似文献
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UV光固化数码喷绘技术是一种高效便捷的表面打印技术,用于家居板材表面装饰可满足环保与个性化的高分辨图案定制的需求。选取木质家具常用的中密度纤维板(MDF)为对象,研究最佳的基材表面预处理,优化UV喷绘涂层的涂刷效果。首先,通过测量不同目数砂纸预处理后MDF表面的粗糙度、表面接触角,分析表面机械处理对其性能的影响;通过表征UV喷绘后涂层的性能,确定MDF表面机械处理的最佳砂纸目数。然后,采用4种不同种类的PU与PE底漆预处理MDF,再进行UV数码喷绘;通过表征喷绘涂层的光泽度、附着力、耐磨性、硬度以及板材吸水率性能,获得MDF最佳的底漆涂刷工艺。研究结果表明,经过400#砂纸打磨后,MDF表面粗糙度较低,润湿性较好,此时涂层的光泽度与附着力最好。比较不同的底漆种类与涂刷次数发现,由于UV喷绘涂层较薄,底漆性能对喷绘涂层影响较大,通过刷涂2~3道白色PU底漆预处理基材,可较好地提升UV喷绘涂层的附着力、表现力,并降低MDF基材的吸水性。 相似文献
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Physical and mechanical properties of medium density fiberboards (MDF) made from various mixtures of wood fibers and stone pine (Pinus pinea L.) cones were evaluated using European standards. MDF panels were manufactured using standardized procedures that simulated industrial production at the laboratory. Six panel types were made from mixtures of wood fiber/cone flour, 100/0, 90/10, 80/20, 70/30, 60/40, and 50/50 percents, respectively. Addition of the cone flour into the MDF significantly reduced formaldehyde emission from the panel. In addition, the addition of 10% cone flour also improved water resistance of the MDF panels made using urea–formaldehyde (UF) resin. However, further addition of the cone flour into the panel negatively influenced their water resistance. Flexural properties and internal bond strength decreased with the increase of cone flour content in the panel. The UF resin is the main source of formaldehyde emission from the UF-bonded wood-based panels. Depending on addition of the cone flour in the panels, the formaldehyde emission values ranged from 2.6% to 55.3% lower than the panels made from 100% wood fiber. Based on the findings obtained from this study, pine cone can be used as a renewable biological formaldehyde catcher as an alternative to the traditional formaldehyde catchers for E1 Class MDF manufacture. 相似文献
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一种脲醛树脂胶粘剂的设计 总被引:7,自引:2,他引:7
鉴于对文献的分析和实验验证,本文提出一种脲醛树脂胶粘剂的设计原则。即:1)脲醛树脂最终摩尔比应取1.40~1.20:1,这样可以使制成的板材具有足够的胶接强度;2)为了使人造板的甲醛释放量达到10mg/100g(穿孔法)以下,树脂中的游离尿素应在10%以上;3)在脲醛树脂的分子中引入尿素的环状衍生物,如三嗪环或Uron。环状化合物含量最好在10%左右。按此原则合成了三种树脂,在试验室按标准刨花板和中密度纤维板工艺制成板材,其甲醛释放量在10mg/100g左右,板材物理力学性能均超过国家标准和企业标准。 相似文献
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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。 相似文献
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低甲醛释放蔗渣中密度纤维板用脲醛树脂 总被引:6,自引:0,他引:6
以脲醛树脂结构形成特征为基础,研制了一种甲醛释放量低、内结合强度高的适用于蔗渣中密度纤维板生产的脲醛树脂胶粘剂。使用结果表明,所压制的蔗渣中密度纤维板物理力学性能达到国家标准要求,甲醛释放量可控制在20mg/100g左右。 相似文献
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利用ET03助剂对UF树脂进行改性处理,并将改性前、后的UF树脂分别用于中密度纤维板生产.试验结果表明:改性后的UF树脂在降低10%施胶量的情况下,板材的物理力学性能指标、甲醛释放量仍可达到GB/T 1718-1999<中密度纤维板>E1级标准;每m3的中纤板可降低成本4%~5%. 相似文献
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Saim Ates Hasimet R. Kara Cag˘ri Olgun Osman E. Ozkan 《Wood material science & engineering》2017,12(3):158-164
This work investigated some mechanical, physical and free formaldehyde emission properties of heat-treated MDF. For this purpose, MDF panels were subjected to varying heat treatment temperatures (155°C, 165°C and 175°C), durations (2.5?h., 3.5?h. and 4.5?h.) and waiting times after hot pressing (30?min., 120?min. and 600?min). Thickness swelling (TS), water absorption (WA), free formaldehyde emission (FFE), bending strength (BS), modulus of elasticity (MOE), tensile strength perpendicular to fibers (TSPF) for treated and untreated samples were tested and evaluated statistically. Consequently, after the heat treatment values of tensile strength, bending strength and modulus of elasticity were almost negatively affected relatively, but the thickness swelling and water absorption and quantities of free formaldehyde were improved positively of MDF samples. 相似文献
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Ayoub Salari Taghi Tabarsa Abolghasem Khazaeian Ahmadreza Saraeian 《Journal of Wood Science》2012,58(6):513-524
In this study, the effect of nanoclay on some applied properties of oriented strand board (OSB) made from underutilized low quality paulownia wood was investigated. Organo-modified montmorillonite (MMT) at four levels (0, 1, 3 and 5?%) was added to urea formaldehyde (UF) resin. Some chemical properties of paulownia wood (holocellulose, cellulose, lignin and ash contents, pH value and hot and cold water solubility), mechanical [modulus of rupture (MOR), modulus of elasticity (MOE), internal bond strength, screw and nail withdrawal strengths], physical (water absorption and thickness swelling) properties and formaldehyde emission of the strand boards were evaluated. Mechanical properties of all panels complied with the general-purpose OSB minimum property requirements of European Norm. With increasing 5?% nanoclay to UF resin, mechanical and physical properties of the resulting panels improved and formaldehyde emission decreased. However, none of the panels satisfied the thickness swelling and water absorption requirement. The results of X-ray diffraction and transmission electron microscope analysis confirmed the good dispersion of nanoclay in the resulting OSBs. Using paulownia as a fast-growing underutilized species not only can sustain the forests but also can supply raw material to countries facing shortage of wood. 相似文献
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清除人造板中甲醛的后处理试验结果表明,喷涂甲醛清除触媒后的人造板物理力学性能没有明显变化,甲醛清除触媒对不同种类人造板释放出的甲醛清除效果相同,E3级胶合板喷涂甲醛清除触媒后的甲醛释放量小于(等于)0.12mg/L,清除率大于99.08%。 相似文献
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改性脲醛树脂胶低密度稻壳-木材复合材料制造工艺的研究 总被引:4,自引:0,他引:4
采用异氰酸酯(ISO)改性的脲醛树脂胶制造低密度稻壳-木材复合材料。稻壳与木质刨花的混合比例为1:1,施胶量为7%,试验结果表明,异氰酸酯改性的脲醛树脂胶黏剂适用于低密度稻壳-木材复合材料,其物理力学性能明显优于使用传统的脲醛树脂胶黏剂。低密度稻壳-木材复合材料的物理力学性能随着改性剂异氰酸酯用量的增加而提高。密度是稻壳-木材复合材料物理力学性能的重要影响因素,低密度稻壳-木材复合材料的物理力学性能随着密度的增加而提高。在设定密度为0.45g/m~3和0.5g/cm~3的条件下,3:4的ISO/UF的稻壳-木材复合材料的物理力学性能均达到日本刨花板工业标准(JIS A5908)的要求。 相似文献
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Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) were used to study ambient-aged wood
fibers and their effects on the mechanical properties of medium-density fiberboard (MDF). It was found that MDF made with
ambient-aged fibers had poorer mechanical properties than MDF made with fresh fibers; this difference resulted from the alterations
of surface characteristics of wood fibers after ambient aging, which led to poor wettability of the urea–formaldehyde (UF)
resin applied to the aged wood fibers. After 6 months of ambient aging, the concentration of carbonyl groups in the fibers
increased by 144%, while the pH value of wood fiber decreased from 5.2 to 4.7. SEM showed that much more UF resin agglomerated
on the surface of ambient-aged fibers and the breakage of MDF made with aged fiber frequently occurred at the resin-fiber
interfaces, indicated the poorer wettability of UF resin to fibers due to the decrease in surface energy after aging. 相似文献