E_0级地板用MUF胶应用性能研究

推广E_0级地板用MUF胶过程中,进行补充试验发现:用NH_4Cl(0.5%~1.0%)和H_3PO_4(0.3%~0.5%)复合固化剂的MUF胶压制的胶合板甲醛释放量比用单一NH_4Cl(0.8%~1.0%)或单一H_3PO_4(0.5%)为固化剂的MUF胶低,均符合E_0级;采用复合固化剂的MUF胶涂胶预压后,陈放1~24h均可生产胶合强度符合要求的E_0级胶合板;用F/U m.r.1.40,F/(U+M)m.r.1.11、M/MUF 14.2%的MUF胶生产的实木地板基材胶合板3d送检甲醛释放量0.3mg/L,11d送检甲醛释放量0.1mg/L,胶合强度、浸渍剥离合格。     

SiO_2浸渍杨木单板/低密度聚乙烯复合胶合板的制备工艺

采用SiO2水性分散液浸渍处理的杨木单板,以低密度聚乙烯(LDPE)薄膜为胶黏剂,制备热塑性树脂胶合板,分析其制备工艺因子对板材性能的影响。结果表明:塑料加入量、热压温度、偶联剂种类等因素对热塑性树脂胶合板的性能有非常显著影响,优化工艺条件制备板材的胶合强度可达到GB/T 9846.3-2004中II类胶合板的要求,表面硬度比未处理板材有所提高,游离甲醛释放量更低。     

卫浴用树脂浸渍单板重组材的尺寸稳定性

为满足卫浴装饰装修用木材的需求,以速生桦木为原料,开发出一种树脂浸渍单板重组材。通过分析浸渍三聚氰胺-甲醛(MF)树脂固体含量、浸渍方法、热压压力等因子对板材尺寸稳定性的影响,结果表明:当MF树脂固体含量45%、热压压力1.0MPa,采用辊压浸渍(压榨率50%～70%)时,板材的极限体积膨胀率为6.2%,低于水曲柳、栎木等实木试件,尺寸稳定性大大改善。     

实木复合地板的表层改性工艺

将表层橡木单板浸渍三聚氰胺树脂后,与桉木单板、三聚氰胺浸渍纸一次热压成型制作多层实木复合地板。采用正交试验方法,探讨橡木单板浸渍工艺及热压工艺对多层实木复合地板表面耐磨性等理化性能指标的影响。试验结果表明:浸渍温度对橡木单板浸渍质量增加率影响显著,浸渍浓度对橡木单板浸渍质量增加率影响一般显著,热压温度对多层实木复合地板的表面耐磨性能影响显著。在试验条件下,以浸渍时间20 min、浸渍浓度40%、浸渍温度45℃、热压温度145℃、热压时间0.8 min/mm、热压压力1.8 MPa和施胶量240 g/m2为较优工艺,压制所得多层实木复合地板的表面耐磨性能等理化性能较佳。     

三种三聚氰胺改性脲醛树脂胶结构与性能关系的研究

用IR、~(13)C-NMR、TG等仪器分析手段结合化学分析对三种三聚氰胺含量不同和F/(U+M)摩尔比不同的MUF树脂的化学结构和性能之间的关系进行研究。发现MUF树脂的固化时间与其羟甲基含量有关。用MUF树脂压制的杨木胶合板的强度与其三聚氰胺量和羟甲基含量有关。杨木胶合板的甲醛释放量与MUF树脂的羟甲基含量和亚甲基醚键含量有关。     

杨木基电气绝缘板的制备

电气绝缘材料是制造电气设备的关键,在一定程度上决定了电气产品的寿命。以杨木单板为原料,采用酚醛树脂对单板浸渍等技术手段制备电气绝缘板,系统研究了单板厚度、树脂浸渍时间、热压成型压力以及与玻纤或绝缘纸复合、Si O2改性酚醛树脂等对绝缘板力学强度和电气性能的影响。结果表明,厚度为1.1 mm、树脂浸渍时间为60 min、热压压力为5.0 MPa时,电气绝缘板的综合性能较佳,各性能指标分别为:密度1.24 g/cm3、弯曲强度137.05 MPa、击穿电压46.76 k V、电气强度14.3 k V/mm。采用改性酚醛树脂与纺织玻纤布复合可以制得强度和电气性能优良的复合电气绝缘板。     

工艺参数对防潮刨花板性能的影响

采用三聚氰胺-尿素-甲醛(MUF)树脂胶制备防潮刨花板,讨论密度、施胶量、热压温度、热压时间等工艺因素对板材性能的影响。结果表明:密度和施胶量是影响刨花板防潮性能的主要因素;采用优化的制板工艺参数,试板性能可达到GB/T 4897-2015中"P7型潮湿状态下使用的承载型刨花板"及"P9型高潮湿状态下使用的普通型刨花板"的要求,甲醛释放量达到日本JIS A 5908:2003中F☆☆☆☆要求。     

工艺参数对脲基超支化聚合物改性效果的影响

以一种新型脲基超支化聚合物为改性剂,对低摩尔比三聚氰胺-尿素-甲醛（MUF）树脂进行改性,并对热压工艺参数进行优化,探讨脲基超支化聚合物改性剂添加量、热压温度、热压因子、板材密度、施胶量等因素对中密度纤维板性能的影响。结果表明：当改性剂添加量为2%,热压温度为185℃,热压因子为20 s/mm,施胶量为14%,板材密度为850 kg/mm³时,纤维板的性能较佳。该工艺条件下中密度纤维板的结合强度及耐水性能改善效果显著,与对照组相比,内结合强度提升109%,表面结合强度提升93%,24 h吸水厚度膨胀率下降30%。     

添加阻燃剂对三层实木复合地板生产工艺的影响

以三层实木复合地板为对象,探讨阻燃剂对其生产工艺的影响,结果表明:芯板、背板浸渍阻燃剂时,单板的增重率随着浸渍时间的延长而增加,当浸渍时间超过30 min后,增重率增加不明显;随着阻燃剂施加量增加氧指数增大,含水率、静曲强度随着施加量增加而降低;含水率、静曲强度、甲醛释放量和氧指数随着涂胶量的增加而增大;热压温度和热压时间对含水率、静曲强度、甲醛释放量和氧指数影响不明显。最佳热压工艺条件为:阻燃剂施加量8%,涂胶量360g·m-2,热压温度120℃,热压时间12 min。     

杨木单板条层积材的制备工艺及性能评价

为了更好地利用单板加工剩余物,采用三聚氰胺改性脲醛树脂胶制备杨木单板条层积材(PSL),探讨涂胶量、热压工艺及板材密度等工艺因子对板材性能的影响。在本试验条件下,较优工艺参数为:涂胶量(双面)300g/m~2、热压温度130℃、热压时间75 s/mm、板材密度0.60 g/cm~3,制备的PSL物理力学性能优良,甲醛释放量低于GB 18580-2001中E1限量值(≤1.5 mg/L),可用作室内装饰装修用材。     

Influence of the melamine content in melamine-urea-formaldehyde resins on formaldehyde emission and cured resin structure

The effect of melamine content in melamine-urea-formaldehyde (MUF) resins on the formaldehyde emission and resin structure was investigated using six MUF resins synthesized with different F/(M + U) and M/U molar ratios. The formaldehyde emission from the plywood decreased as the F/(M + U) molar ratio decreased and the M/ U molar ratio increased. In addition, the bond performance was enhanced as the M/U molar ratio increased in the MUF resins with a fixed F/(M + U) molar ratio. Quantitative solution¹³C-NMR spectra of MUF resins revealed that the MUF resins with a high melamine content consisted of more highly branched crosslinkage structure and free melamine compared to the resins with low melamine contents. Furthermore, solid-state¹³C CP-MAS NMR spectra of cured MUF resins proved that more methylol groups, dimethylene ether, and branched methylene structures were present in the MUF resins with a higher F/(M + U) molar ratio, leading to increased bond strength and formaldehyde emission. There is no significant difference in the linkage structure of the cured resins with the same F/(M + U) and different M/U molar ratios except the ratios of carbonyl carbon of urea and triazine carbon of melamine. Therefore, the lower formaldehyde emission from cured MUF resins with a higher M/U molar ratio might be ascribed to the stronger linkages between triazine carbons of melamine than those of urea carbons. Consequently, the melamine contributed to strong crosslinking linkages in the cured resin structures, leading to lower formaldehyde emission and better bond performance.Part of this work was presented at the 48th Annual Meeting of the Japan Wood Research Society, Shizuoka, April 1998     

三聚氰胺脲醛树脂改性酚醛树脂胶粘剂的研究

采用常规合成的脲醛(UF)或酚醛(PF)树脂胶对多层胶合板贴面时，很容易出现开胶或透胶现象。本研究采用三聚氰胺脲醛(MUF)树脂对PF树脂进行改性，生产浅色改性PF胶粘剂，探讨了MUF与PF树脂摩尔比、混合比、热压条件等对胶液的粘度、缩合度、稳定性、胶层颜色及胶合质量的影响。结果表明，改性后的浅色酚醛树脂胶粘剂筘存性好、固化后胶层近似木材本色、高强耐水、耐候，用来压制的多层实木复合地板可达到GB9846．1～12-88Ⅰ类胶合板要求。     

The fire-retardant properties of the melamine-modified urea–formaldehyde resins mixed with ammonium polyphosphate

Fire retardancy of melamine-modified urea–formaldehyde resin (MUF) containing intumescent fire-retardant ammonium polyphosphate (APP) (MUF/APP) was conducted by cone calorimeter with surface treatment of medium density fiberboard (MDF). The results showed that the six MUF resins synthesized with different F/(M + U) and M/U molar ratios containing APP significantly improved the fire retardancy of the MDF by prolonging ignition time, reducing heat release rate and total heat release, and decreasing mass loss rate. The fire-retardant properties of the six synthesized MUF/APP acted differently even though each MUF resin containing the same mass ratio of APP. The melamine content in the MUF should not be too high, otherwise it would decrease the fire-retardant properties of MUF/APP. Based on this study, the higher the APP amounts, the better the fire-retardant performance of the resin was. The fire retardancy of MUF/APP increased with the increase in the amount of glue that spread on the material surface. However, only the amount of glue spread exceeded 250 g/m², whereas the ability of MUF/APP in inhibiting heat release did not increase significantly any longer.     

复合地板无醛饰面材料加工工艺研究

为实现复合地板的无醛饰面,采用水性丙烯酸树脂对花梨木、樟子松薄木和原纸进行浸渍,研究丙烯酸树脂浓度对黏度、浸胶量的影响及浸渍时间对丙烯酸树脂浸胶量的影响。结果表明:随着水性丙烯酸树脂浓度的降低,其黏度也随之降低,当树脂浓度降至84%,其黏度呈现明显下降的趋势,随后趋于相对稳定;结合水性丙烯酸树脂浓度对浸胶量和挥发物含量的影响,优选浸渍纸的树脂浓度为68%,浸渍花梨木、樟子松薄木的树脂浓度为80%;实验室优选薄木与原纸的浸渍时间均为1 min。     

低成本E_0级地板用UMF胶的研制

采用碱-酸-碱传统工艺,Fo(U+M)摩尔比1.15,三聚氰胺用量13%制得Eo级地板用UMF树脂胶.该胶制备工艺简单,三聚氰胺和尿素分三批添加反应平稳易控制,再现性好,游离甲醛低,贮存期达15d以上.用该胶压制的胶合板,胶合强度符合Ⅱ类板国家标准,甲醛释放量<0.5mg/L,该胶的三聚氰胺用量比市售的地板胶降低2%～5%,成本较低.     

轻质豆秸刨花板工艺的研究

从UF胶制造轻质豆秸刨花板的初步研究,分析了板的密度、施胶量、热压时间等工艺因子对板性能的影响。试验结果表明,利用豆秸制造轻质刨花板是完全可行的,其产品主要物理力学性能为:密度0.483 g/cm 3、吸水厚度膨胀率11.2 % 、内结合强度0.303 MPa、静曲强度8.98 MPa,均达到日本JISA 5908 的技术指标。     

Manufacturing of LVL using cost-effective resin impregnation and layup technologies

The purpose of this study was to develop a cost-effective method to manufacture high-performance laminated veneer lumber (LVL) from mountain pine beetle (MPB)-affected veneers through partial resin impregnation and optimum board layup. Dry MPB-affected veneer sheets were segregated into two stress grades based on dynamic modulus of elasticity (MOE). A new phenol formaldehyde resin with a 30% solids content was formulated for resin impregnation. To reduce resin consumption, only veneer sheets used as outer layers were dipped in the resin for 5?min and then dried to manufacture 13-ply LVL. The bending properties, shear strength and dimensional stability of these LVL billets were examined and compared to those from the controls made from entirely untreated veneers. The results demonstrated that high-grade (E1) MPB-affected veneers had lower resin solids uptake than low-grade (E2) counterparts based on a 5?min dipping. Compared with the controls, the LVL billets made from resin-impregnated veneers for outer layers yielded increased surface hardness, significantly improved dimensional stability, shear strength and modulus of rupture on both edgewise and flatwise as well as better appearance with no cosmetic concerns. However, the improvement in LVL bending MOE was dependent on initial veneer stress grade. For high-grade (or density) E1 veneers, the use of impregnated veneers resulted in insignificant improvement in bending MOE. The optimum product layup was to place one ply of impregnated E1 grade veneer each for product face and back. By contrast, for low-grade (or density) E2 veneers, the use of impregnated veneers yielded a significantly higher flatwise bending MOE compared to the controls. The recommended product layup was the placement of two plies of impregnated E2 grade veneer sheets each for product face and back.     

竹木复合单板层积材制备工艺

以浸渍酚醛树脂的杨木单板和竹帘为原料制备竹木复合单板层积材, 探讨制造工艺对复合材料性能的影响.结果表明,竹木复合材料的MOE及MOR均达到或超过了日本JAS标准的相关规定,尺寸稳定性良好; 单板厚度、树脂浓度、压缩率对MOE和MOR有显著影响;组坏方式对MOR影响显著;而吸水厚度膨胀率的影响作用比较复杂.     

C NMR 定量分析

按酚醛(PF)树脂的制备工艺,采用CaO和NaOH为复合催化剂,在碱性条件下制备了95%～200%的系列尿素改性酚醛(PUF)树脂,贮存期达30 d以上。该系列PUF树脂压制的杨木三合板,胶合强度符合Ⅱ类胶合板要求,甲醛释放量<0.5 mg/L,符合E0级。其中选用尿素/苯酚(U/P)质量比为1.5∶1,甲醛与尿素-苯酚(F/(U+P))物质的量的比值为0.97的配方制胶,结合13C NMR分析手段,监控投料甲醛在反应过程中形成的亚甲基、羟甲基和亚甲基醚键的含量变化,以及最终PUF树脂的亚甲基(32.4%)、羟甲基(57%)和亚甲基醚键(10%)的结构比例。