大豆蛋白胶稻草碎料板制备关键工艺参数研究

采用自制大豆蛋白胶,通过热压法对稻草碎料板的制备工艺参数进行了系列试验的结果表明：稻草碎料板的静曲强度（MOR）在施胶量为71%时（相当于粗蛋白添加量为12%）最强,接近GB/T 21723-2008的要求;稻草碎料板的内结合强度（IB）随着施胶量的增大而增强,在施胶量为82%时（相当于粗蛋白添加量为18%）,内结合强度接近GB/T 21723-2008的要求;稻草碎料粒径对稻草板的静曲强度和内结合强度影响不显著,稻草碎料板的静曲强度和内结合强度随板材表观密度增大而显著增强。     

稻草刨花板制造工艺的初步研究

探讨了以腺醛(UF)胶和以异氰酸酯(PMDI)改性的UF胶制造稻草刨花板的可行性。结果表明,用UF胶很难制造出较高强度的刨花板,以PMDI改性可明显提高UF胶对稻草的胶着力。通过对改性胶的施胶方式、固化利用量与板判性能关系的研究,以及对制板主要工艺参数的正交试俭,提出了制造稻草刨花阪的工艺条件。     

稻草-木纤维复合材料制造工艺研究

将稻草与木纤维均混后制板,采用单因素分析法,探讨原料配比、施胶量、板密度及热压工艺等因子对复合板性能的影响,并简单分析了此种板材的经济效益。结果表明:热压温度160℃,热压时间30s／mm,稻草施胶量6％(MDI)、木纤维施胶量11％(UF),密度不小于0.85g／cm3,木纤维与稻草的配比小于3:7时板的各项性能完全达到GB／T11718-1999的要求。生产草木复合板能有效提高稻草板企业的经济效益。     

水泥对稻草碎料板性能影响的分析研究

主要研究了不同水泥添加量对异氰酸脂(MDI)、脲醛树脂(UF)稻草碎料板性能的影响,尤其是对板材吸水厚度膨胀率的影响。结果表明,随着水泥添加量的增加,板材的吸水厚度膨胀率减小,当水泥的添加量达到10%或以上时,用脲醛树脂胶粘剂制成的稻草秸秆碎料板其吸水厚度膨胀率可达到国标要求。     

MDI-UF复合胶黏剂生产稻草碎料板的研究

本研究的着眼点在于采用MDI—UF复合胶生产稻草碎料板,施胶时先施加MDI胶,后施加UF胶,从而解决UF与稻草表面无法接合的问题。实验结果证明此方法不仅成功制造出稻草碎料板,同时由于减少MDI胶的使用量,大大降低了生产成本,具有非常可观的经济效益。而实验制成的板材各项力学性能均符合国家优等品的标准,只有IB与国标还有些差距,但已通过研究发现了造成IB较低的原因,并制订出相关的解决方案。另外板材的游离甲醛释放量只有2．2mg／100g,完全符合国家E1级标准。     

双氧水和固化剂对稻草碎料板性能影响的比较

分析比较用双氧水处理稻草、板材表芯层固化剂的添加量对稻草碎料板性能影响的结果表明,用浓度为10%、pH值为10~11的双氧水处理稻草,会降低稻草板的综合性能;而将稻草板的表芯层分开添加不同量的固化剂,压制的稻草板可达到国标要求。     

芦苇-稻草原料球磨处理生产刨花板

选择芦苇和稻草为原料,以脲醛树脂为黏结剂制备了芦苇-稻草刨花板。在芦苇碎料中加入一定量的矿物材料,然后采用机械球磨进行处理,应用正交设计对施胶量、热压压力、碎料球磨处理3个因素对板材各项性能的影响进行了研究。实验结果表明,球磨处理可以明显改善芦苇／树脂的结合强度,提高刨花板的各项性能。在施胶量16％,热压压力3．4MPa,对碎料进行球磨处理后制板,除内结合力较低外,板的静曲强度、弹性模量和握钉力都可以达到GBT 4897．3-2003对在干燥状态下使用的家具及室内装修用板的性能要求。     

稻草中密度纤维板用改性脲醛树脂的研究

对比三聚氰胺、二甲基硅油、硅树脂和偶联剂KH-550四种改性剂改性的脲醛(UF)树脂性能的差别及其对稻草中密度纤维板性能的影响,并进行经济评价,最终确定适用于稻草纤维板的改性UF树脂的工艺条件,同时借助于红外光谱(FT-IR)和差热扫描分析(DSC)研究最佳改性UF树脂的结构和固化特性.结果表明,三聚氰胺改性脲醛(MUF)树脂不论是对树脂性能、板性能改善还是从成本分析方面均为稻草纤维板最佳的胶黏剂,FT-IR显示出与未加三聚氰胺相比,加入三聚氰胺后树脂的羟甲基含量降低了10 %,DSC分析则表明其峰值温度有较大幅度的提高,但放出的热量较少.加入三聚氰胺改性的UF树脂其表面张力变小.     

原状粉煤灰在水泥刨花板中应用的研究

主要论述了原状粉煤灰（Ⅲ级灰）在水泥刨花极中应用的情况。分析了在其它工艺条件（密度、水灰比、木灰比）确定情况下,粉煤灰替代量、外加剂种类和用量等因素对板各项性能指标的影响。结果表明：（１）粉煤灰替代量是影响极材性能的主要因素,外加剂种类和用量对极性能也有影响;（２）粉煤灰替代量３０％为强度转折点,但４０％替代量制板,板各性能指标仍然能达到国家行业标准要求;（３）以粉煤灰替代部分水泥生产水泥刨花板。不但可以降低生产成本,而且可以改善板的某些性能。     

漆酶/碳源系统预处理对稻草碎料板性能的影响

利用添加少量碳源与漆酶组成的体系对稻草进行预处理,以改善其压板性能,研究了漆酶预处理的最佳工艺条件、漆酶／碳源系统(LCS)与漆酶／介体系统(LMS)预处理结果比较及酶处理对稻草碎料板性能的影响。结果表明:LCS完全可以代替昂贵的LMS来降解稻草中木质素;预处理最适条件为pH值5.0,温度45℃,液比1:7,时间4-6h,酶用量20-30IU／g;当酶用量为20IU/g,时间4h条件下预处理稻草碎料板的各项力学性能均有显著改善,与粗碎料板相比,酶处理对细碎料板的性能改善效果更是明显:内结合强度(IB)增加20％,静曲强度(MOR)增加21％,弹性模量(MOE)增加31％,吸水厚度膨胀率(TS)降低35％,甲醛释放量可达到F1级标准。     

脲醛树脂胶稻草中密度纤维板的性能

通过用稻草代替木材制造脲醛树脂胶稻草中密度纤维板的可行性研究 ,探讨了板材密度、施胶量和防水剂等工艺因素对稻草中密度纤维板性能的影响。结果表明 :在实验室条件下 ,当板材名义密度为 0 .8g/ cm3和施胶量为 17%时 ,脲醛树脂胶稻草中纤板性能达到现行国家标准一等品的要求 ;施加 1.2 %的石蜡乳液 ,板材的耐水性亦能满足国标要求     

稻草原料酸碱性及稻草中密度纤维板的性能

测试分析了稻草原料的ｐＨ值和缓冲容量，分别使用脲醛树脂胶和异氰酸酯胶在特定工艺条件下压制了稻草中密度纤维板，并测试了板材性能。结果表明：１）稻草秸秆原料呈弱碱性，缓冲容量远高于普通木材；经热磨处理获得的稻草纤维呈弱酸性，其缓冲容量虽较稻草秸秆有一定幅度的下降，但仍高于普通木材；２）脲醛树脂或异氰酸酯稻草中密度纤维板的性能都明显优于相应的碎料板；在密度０．８０ｇ／ｃｍ３和施胶量１７％的条件下，脲醛树脂稻草中密度纤维板性能达到国标ＧＢ／Ｔ１７６５７－１９９９一等品的要求，在密度０．８０ｇ／ｃｍ３和施胶量６％的条件下，异氰酸酯稻草中密度纤维板性能达到国标ＧＭ／Ｔ１７６５７－１９９９优等品要求。     

Effects of silane coupling agent level and extraction treatment on the properties of UF-bonded reed and wheat straw particleboards

Urea formaldehyde resin bonded reed and wheat particleboards with a density of 0.7g/cm³ were manufactured from two types of particle: fine and coarse particles. The effects of the silane coupling agent (SCA) level and ethanol-benzene (EB) treatment on the board properties were examined. For SCA, epoxide silane (SiEP) and amino silane (SiNH) were used for reed and wheat particles, respectively. The results are summarized as follows. (1) For both reed and wheat boards, the internal bond (IB) strength and thickness swelling (TS) were significantly improved at up to 5% SCA content, but the effectiveness of treatment kept constant at above 5%. (2) The level of SCA had little effect on the bending strength, especially for the boards composed of coarse particles. (3) EB treatment upgraded both the IB and TS of wheat board significantly. (4) SiEP incorporation improved the IB and TS of reed board significantly, whereas EB treatment was more effective for wheat board. (5) The dimensional stability of both reed and wheat boards under varying humidity could be improved by increasing the level of SCA and by EB treatment. EB treatment was more effective than SCA addition.     

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.     

低摩尔比脲胶在竹材碎料板中的应用

降低尿素与甲醛的摩尔比可降低脲醛树脂中游离甲醛含量，但对脲醛树酯的缩聚和粘结强度会产生一些不利的影响．用新研制的脲醛树脂胶粘剂在竹材碎料板中进行了应用．结果表明：中密度板的各项性能指标均远低于高密度板，密度在0．9g／cm3以上可获得较好的产品质量;随着施胶量的增加，静曲强度和平面抗拉强度增加，厚度膨胀率下降，施胶量以8％～12％为宜；产品质量达到刨花板质量的国家标准．     

Straw-wood composites bonded with various adhesive systems

In order to study the feasibility of utilizing wheat straw as an alternative raw material for panels, experimental one-layer particleboards were produced by mixing straw with industrial wood particles in various proportions (100:0, 75:25, 50:50, 25:75, 0:100). Three different adhesive systems were used for blending the raw materials: a UF resin (E₂ grade), a PMDI resin and various UF:PMDI combinations (10:0, 8:2, 7:3, 6:4, 5:5). The evaluation of the mechanical and hygroscopic properties of panels showed the following results: Partial replacement of wood particles from straw in panels bonded with pure UF resin resulted in deterioration of all properties except linear swelling. Partial or whole substitution of wood by straw in PMDI bonded panels, improved the bending strength and all hygroscopic properties of the panels but reduced the internal bond (dry and wet) and screw holding strength, although to a much smaller degree compared to UF bonded panels. The properties of panels bonded with various UF:PMDI combinations and comprising 50% wood and 50% straw were considerably improved by increasing the PMDI content. In terms of the properties, pure straw panels or panels made of certain wood/straw mixtures, if bonded with PMDI resin or the appropriate UF:PMDI combination, can be used for specific applications where high quality panels are required according to the specifications of the related standards. Received 11 February 1998     

Study on Surface Wettability of Wheat Straw

INTRODUCTIONSome scientists and specialists think that agriculturalresidues are the second forest resource in China.Straw boards use the agricultural residues, such aswheat straw, rice straw and so on, as main rawmaterial, which are one-year-growth plants and veryrich in China. Producing straw boards can increasewood resource and decrease consumption of wood(Zhou Dingguo, et al, 2000).Wetting is a term to describe what happens when aliquid meets with a solid surface. The surface contact…     

Properties of wheat straw particleboards bonded with different types of resin

Wheat straw particleboard bonded with a urea–formaldehyde (UF) resin, usually employed in the manufacture of wood-based particleboards, or with a resin based on epoxidised oil was manufactured using a compression molding machine. The effects of resin type on internal bond strength, flexural modulus, and thickness swelling were examined. The properties of boards using UF resins were poor. Internal bond strength and thickness swelling, linked to adhesion quality, were especially low. The high compatibility between straw particles and oil-based resin was explained in terms of straw surface free energy. In straw, this parameter exhibits a much lower polar component than wood species and leads to higher compatibility with resins based on oil than with water-soluble systems like UF.     

麦秸刨花板的耐水性能研究

本文研究了用MDI与UF两种胶粘剂以不同比率混合后制造的麦秸刨花板的耐水性能。结果表明：随着胶粘剂中MDI比率的增加，麦秸刨花板的耐水性能提高，但改善的程度逐渐趋缓；在一定范围内，提高麦秸刨花板的密度，可以降低其吸水厚度膨胀率。