共查询到19条相似文献,搜索用时 171 毫秒
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<正>通常,面粉作为填料添加到脲醛及其改性树脂中,以提高胶黏剂的初黏性及板材预压性能,并降低胶黏剂使用量及甲醛释放量。随着我国胶合板行业的迅速发展,每年相关产业消耗的工业面粉量已达30万t。无机填料作为脲醛及改性树脂的常用填料,不仅能增强树脂胶合性能,而且因其价格低廉、资源丰富,有望取代面粉的使用。 相似文献
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以酶解木质素和豆粕为原料制备了木质素基豆粕胶黏剂,优化了木质素基豆粕胶黏剂应用于杨木胶合板的热压工艺参数,探讨了不同工艺参数对胶合板胶合强度的影响。试验结果表明,木质素基豆粕胶黏剂制备胶合板的优化热压工艺参数为热压温度120℃、热压时间7.5 min(75 s/mm)、热压压力0.9 MPa、单面施胶量180 g/m2;影响胶合板胶合强度的工艺参数主次顺序是热压温度、热压压力、施胶量、热压时间;采用优化热压工艺条件制备3层胶合板,其Ⅱ类胶合强度大于1.0 MPa,符合GB/T 9846-2015《普通胶合板》中Ⅱ类胶合板要求。 相似文献
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为了推广花生蛋白基胶黏剂在胶合板中的应用以减少甲醛的释放,优化花生蛋白基胶黏剂应用于杨木胶合板热压条件,分析热压条件对胶合板湿态胶合强度的影响。结果表明:4个因素对湿态胶合强度的影响大小依次为:热压温度热压时间涂胶量热压压力;胶合板的最佳热压条件为热压温度120℃、热压时间8 min、热压压力1. 2 MPa、涂胶量220 g/m~2,在此条件下制备的胶合板湿态胶合强度为1. 09 MPa,符合GB/T 9846—2015中I类胶合板的要求(≥0. 70 MPa),且该热压工艺条件在工业化生产中能够实现。红外光谱分析表明固化后花生蛋白基胶黏剂亲水性基团减少,同时酰胺键增加,说明内部基团发生交联反应。 相似文献
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采用化学改性剂聚乙二醇(PEG)、聚乙烯亚胺(PEI)、马来酸酐(MAH)、环氧树脂(EP)和尿素对豆粕进行改性,制备豆粕基木材胶黏剂。研究单一改性剂和复合改性剂对胶黏剂胶合强度的影响,以胶黏剂黏度值、胶合强度和固形物含量为指标,通过单因素实验和正交实验优化得到最佳改性条件。同时,采用傅里叶红外光谱(FT-IR)、扫描电子显微镜(SEM)和X-射线衍射(XRD)分析了改性机理。结果表明:化学改性制备豆粕基木材胶黏剂的最佳工艺条件为PEG与PEI质量比7∶ 8、反应时间70 min、反应温度15 ℃、豆粕质量分数25%,此条件下制得的胶合板干、湿胶合强度分别为1.93 MPa和0.86 MPa,符合国标对Ⅱ类胶合板胶合强度(湿胶合强度≥0.70 MPa)的要求。化学改性剂可以破坏大豆蛋白分子结构,暴露出分子内部的极性与非极性基团,从而通过氢键、静电相互作用等与化学改性剂交联,增加了胶黏剂的黏结特性和耐水性。 相似文献
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为提高结构用胶合板的力学性能,本研究对使用不同胶黏剂、不同板坯结构以及不同工艺条件的玄武岩纤维增强树脂(BFRP)/结构用胶合板生产工艺进行了研究,并对复合材料的静曲强度、BFRP与结构用胶合板之间的胶合强度进行了检测与分析.结果表明:与未增强的结构用胶合板相比,BFRP增强结构用胶合板的静曲强度提高了1~2倍;羟甲基化间苯二酚(Hydroxymethylated Resorcinol,HMR)的使用大大改善了BFRP与木材界面的胶合性能.使用BFRP提高结构用胶合板的力学性能是切实可行的. 相似文献
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研究碳酸钙、高岭土和凹凸棒粉填料对密封纸板性能的影响。研究发现,随着填料用量的增加,密封纸板的抗张强度逐渐减小,压缩率逐渐增加,回弹率逐渐减小,紧度逐渐增加,蠕变松弛率逐渐减小。当填料用量相同时,以高岭土为填料的密封纸板抗张强度最大,碳酸钙次之,凹凸棒粉的最小;以碳酸钙为填料的密封纸板压缩率最大,凹凸棒粉的次之,高岭土的最小;回弹率则是以凹凸棒粉为填料的最高,碳酸钙的次之,高岭土的最小;对于紧度,以碳酸钙为填料的紧度最大,高岭土的次之,凹凸棒粉的最小;而对于蠕变松弛率则是凹凸棒粉的蠕变松弛率最大,高岭土次之,碳酸钙的最小。 相似文献
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Werner Hähnel Ibrahim Jussofie Felix Müller 《European Food Research and Technology》1995,200(4):244-246
High-resolution infrared (IR) spectra of emulsifiers for yeast-leavened bread were measured together with those of the individual components of wheat flour. Using the IR reflection technique, the entire dough was also investigated to give an insight into the development of structures in dough. The emulsifiers react with different components of wheat flour in a specific way. Using IR spectroscopy exact data for the strength of bonding and the kind of bonding between emulsifier and dough component can be obtained. 相似文献
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涂布颜料对涂布纸性质和涂层覆盖的影响 总被引:3,自引:1,他引:3
研究了不同颜料组成对涂布纸性质和涂层覆盖的影响.研究发现:与常规水洗高岭土相比,含剥片土涂层的印刷表面粗糙度值比较高;常规水洗高岭土中加入煅烧高岭土比例较小时,其印刷表面粗糙度值基本没有变化,但增加到一定比例时,印刷表面粗糙度值有显著的增加.另外,涂料中加入剥片土以及在常规水洗高岭土中加入适当比例的煅烧土,均有利于改善涂层覆盖. 相似文献
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Ismail Aydin Cenk Demirkir Semra Colak Gursel Colakoglu 《Holz als Roh- und Werkstoff》2017,75(1):63-69
Increasing demand for wood based panel products and shortage of wood as raw material have triggered many efforts to utilize residues generated annually by the forest industries including a large portion of bark in panel production. In this study, the effects of using bark flours as additives obtained from different wood species (walnut, chestnut, fir and spruce), having much polyphenol content, on some physical and mechanical properties and formaldehyde emission of plywood panels were examined. Wheat flour, which has been used widely as additive in plywood manufacturing, served as control. Plane tree (Platanus orientalis) logs were obtained for veneer manufacturing. Urea formaldehyde (UF) resin with 55 % solids content was used as adhesive. The bonding shear strength, bending strength, modulus of elasticity (MOE), density, equilibrium moisture content and formaldehyde emission of plywood panels were determined according to related standards. It was found that the use of flours obtained from the barks of chestnut and fir trees in the glue mixture decreased the formaldehyde emission of panels. The bonding strength values of the test panels made using the glue mixture including the flour of walnut and spruce barks as additive were lower than those of the panels with adhesive containing the flour of fir and chestnut barks. The panels manufactured with adhesives including the flour of fir bark gave the highest bending strength and modulus of elasticity values. 相似文献
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N. W. Tschoegl J. A. Rinde T. L. Smith 《Journal of the science of food and agriculture》1970,21(2):65-70
A method and an apparatus are described for determining the large deformation and rupture properties of wheat flour doughs in simple tension. Dough rings are submerged in a liquid of matching density to prevent the dough from deforming under its own weight and are stretched at constant rates of extension until rupture occurs. Stress-strain curves obtained at different temperatures and extension rates on doughs prepared from a medium strength flour and a weak flour are presented, and the effects of rest period, mixing time, and mixing atmosphere on dough properties are discussed. 相似文献