Study on the Adhesive for the Production of High Strength Four Layer Composite Corrugated Board

In order to study of adhesive which is applicable to the production of high strength four layer composite corrugated board,the composite corrugated medium was respectively coated with cassava starch adhesive,environmental-friendly modified water glass binder,CP-88 starch adhesive,polyvinyl alcohol adhesive and polyvinyl acetate adhesive,then the edgewise crush resistance and flat crush resistance contrast experiment on produced corrugated board samples was tested.The experiment results demonstrated that the produced corrugated board with environmental-friendly modified water glass binder had high edgewise crush resistance,general flat crush resistance and more economic,so the environmental-friendly modified water glass binder can be used for the production of high strength four layer composite corrugated board.

Effect of Nanoparticles Reinforced Adhesive Layers on Microleakage of Tooth Restorations

Adhesive layer is an essential part of tooth colored restorations which play an important role in decreasing the microleakage between the tooth and restoration material after polymerization shrinkage. The purpose of this study was to evaluate the effect of deferent adhesive system of bonding agent on microleakage of nanocomposite resin in class II cavities. Two different types of adhesive systems: universal adhesive (ExciTE) and a newly developed adhesive (Nano-Bond) and one type of light-cured resin restorative material (nanocomposite resin) were used in this study. These adhesives were applied to prepared tooth cavities by either manufactures’ instructions or by an experimental method (single or double application). Nanocomposite resin was then placed and light-cured for 40 seconds. Teeth were subjected to 500 thermal cycles between 5&degC and 55&degC and were immersed in 3% methylene blue solution for 24 hours;microleakage was observed microscopically. The data were analyzed by a two-way ANOVA. For comparison between groups, Tukey’s post-hoc test was used. Nanoparticles reinforced adhesive system shows low microleakage in compare with universal adhesive system, and application of two adhesive layers also can decrease the microleakage. The ability of stress absorption by adhesive layer after polymerization shrinkage of restoration material will reduce the microleakage.

Influence of Phosphoric Acid Etching on the Bond Strength of a Universal Adhesive System to Caries-Affected Dentin

The purpose of this study was to evaluate the influence of acid etching on the bond strength of a universal adhesive system (Single Bond Universal, 3M) to caries-affected dentin. Forty permanent third molars were selected and carious lesions were induced by the microbiological method with?S. mutans?ATCC25175. Teeth were allocated randomly across four experimental designs (n?=?10): PA-I: phosphoric acid etching and application of the adhesive system, followed by immediate microtensile bond strength testing;PA-CC: phosphoric acid etching and application of the adhesive system, followed by microtensile bond strength testing after a 14-day cariogenic challenge;NPA-I: application of the adhesive system without acid etching, followed by immediate bond strength testing and NPA-CC: application of the adhesive system without acid etching followed by bond strength testing after 14-day cariogenic challenge. For microtensile bond strength testing,?a restoration with Charisma composite resin was made and each specimen was sectioned with a cross-sectional area of 1 mm2. Only adhesive and mixed fractures were considered for bond strength calculation. Results were evaluated by the Kruskal-Wallis and Friedman tests. The highest bond strengths were observed in the phosphoric acid etching groups (p??0.05). Cariogenic challenge did not affect bond strength (p?>?0.05). The predominant fracture type was adhesive. We conclude that phosphoric acid increased the bond strength of the Single Bond Universal system to caries-affected dentin, and that cariogenic challenge did not interfere with this bond strength.

The Adhesion and Formation Mechanism of Blast Furnace Gunning Layer

Basing on the study of the equilibrium relationship of interfacial tension among gunning particles, repaired surface and atmosphere, this test is in a position to draw a conclusion concerning the adhesion mechanism of the grinning refractory and the repaired surface, which illustrates the formation of the bottom gunning layer by moist fine gunning particles on the repaired surface. Also involved within the scope of discussion and probe are the patterns formed under this contacting effect and the formation mechanism of gunning layer. The analytic research regarding the behavior of gunning interface has ascribed the influence upon adhesion intensity to the quality of furnace gunning refractory, the state of the repaired surface and the gunning techniques.

Effect of Different Pretreatments to Post-space on Bonding Strength of Fiber Posts Luted with a Self-adhesive Resin Cement

The effects of different post-space pretreatments on the retentive force of fiber posts cemented with a self-adhesive resin cement were investigated. Twenty-eight single-canal premolars were obturated by Resilon using warm vertical compaction and treated with distilled water, 2.5% NaOCl, 17% EDTA and 2.5% NaOCI; or 17% EDTA, 2.5% NaOCI, and ultrasonic agitation （U/E/N treatment）. Subsequently, radicular dentin surfaces were observed under scanning electron microscopy （SEM）. RelyX Fiber Posts were cemented in the treated canals by using RelyX U100, and thin-slice push-out test and SEM observation of coronal and apical regions of the specimens were performed. Data were analyzed using two-way ANOVA and Tukey＇s HSD post- hoc tests, and the percentage of failure type was calculated. Ultrasonic/EDTA/NaOC1 irrigation showed the maximum effectiveness in removing the smear layer and debris on the dentin surface. The apical bond strength of the experimental groups was significantly higher than that of the control group （P〈 0.05）. Adhesive failure between cement and dentin was the most common mode of failure. No obvious RDIZ or resin tag was detected. Chemical irrigants facilitated the bonding of these fiber posts, and ultrasonic activation improved retention. Future studies should evaluate the effectiveness of irrigation on fiber post push-out strength in fatigue cycling condition.

Research on the Shrinking of 2-components Adhesive with Automatically Calculating Hologram

In this paper, used BSO(Bi12SiO（20）) crystal as a hologram recording material,TV-camera as a detector, and a holographic setup controlled by a computer, automatically calculating hologram of 3-interferograms method is theoretically and experimentally studied. This new holographic recording material and automatically calculating hologram make it possible to use real-time holography in an industry. As a practical example, the shrinking of 2-components adhesive in 4 h is measured.

蓄盐沥青混合料与冰层粘结程度评价方法探究

为了能更精确地评价蓄盐沥青混合料与冰层的粘结程度,通过对拉拔头、冰层冻结方式、拉拔方式等方面进行改进,采用粘结强度和残冰率作为蓄盐沥青混合料与冰层粘结程度的评价指标,开发出一种基于马歇尔试件全断面的试验方法。试验结果表明,试件与冰层之间的粘结强度及残冰率随温度降低而增加,蓄盐沥青混合料在-10℃以内能降低试件与冰层的粘结强度30%以上,-7℃的粘结强度相比于普通沥青混合料减小约50%,-9℃以内残冰率减小比例均大于50%。冰层与试件粘结强度的测量准确度随残冰率的增大而降低,建议在-10℃内采用本试验方法。开发的评价试件与冰层粘结程度的试验方法区分度较高,试验的变异系数在10%以内,稳定性较好。

雅赛尔11.8 tex弹力包芯纱生产实践

为了提高雅赛尔纤维弹力纱纺纱质量,以纺雅赛尔11.8 tex弹力包芯纱为例,介绍雅赛尔、氨纶弹力丝的性能指标及工艺流程;详细分析纺纱各生产工序采取的技术措施、工艺配置及注意事项;通过对细纱、筒纱质量指标的测试,说明雅赛尔11.8 tex弹力包芯纱成纱指标良好、质量稳定。指出:提高雅赛尔纤维品种强力、减少其成纱毛羽、控制氨纶丝包覆质量是保证成纱质量的关键;生产过程中,要优选各工序工艺,明确控制要点及参数,合理配置相关器材和车间温湿度,加强各工序过程控制和设备维护保养。

公路沥青路面施工中的铣刨摊铺施工技术探讨

铣刨摊铺施工是公路工程沥青路面施工中的关键技术,具有操作便捷、占道时间少以及质量较高等优势,在提高公路工程路面施工质量方面起到了积极的促进作用,不仅可以对道路表层进行及时修补,还可以提高路面施工的平整度,对现有的路面结构可以进行翻修,科学处理路面施工中出现的不同病害问题,提高了路面行车的安全性能,保证了路面美观性和良好的路况,为路面行车安全提供了充分保障。对此,本文将主要介绍公路沥青路面铣刨摊铺技术的应用流程和具体方式,并提出技术质量控制要点。

基于有限元分析的简支梁桥桥面防水粘结层力学响应研究

防水粘结层被破坏是导致简支梁桥桥面铺装出现病害的主要原因。通过数值模拟对不同简支梁桥桥型进行防水粘结层力学响应分析,明确防水粘结层在不同桥型结构中的受力状态,总结沥青铺装层模量和厚度对防水粘结层力学响应指标的影响。研究结果表明,简支梁桥桥型对防水粘结层力学响应的影响不大;增加沥青铺装层模量对控制防水粘结层最大拉应力和沥青铺装层变形能起到较好的作用;增加沥青铺装层厚度能有效控制防水粘结层法向拉应力和分散车轮荷载。研究结果能够为桥面铺装的结构设计提供理论基础,提高简支梁桥的服役寿命。

基于防水粘结层附着力的桥面铺装层间粘结强度和抗剪强度预测

针对目前水泥混凝土复合式桥面铺装层间结合效果有损评价方法存在的弊端,通过室内试验建立特定桥面铺装结构和材料条件下组合结构的层间粘结强度和层间剪切强度与附着力之间的函数关系,同时求得温度修正系数;根据测得的工程现场防水粘结层的附着力计算得到组合结构的层间粘结强度和抗剪强度,进而换算成20℃条件下的强度标准值;并参照相关规范对实际工程层间结合效果进行质量评定。结果表明,防水粘结层对水泥混凝土的附着力与组合结构的层间粘结强度及抗剪强度存在较强的线性正相关,且强度预测值与实测值的误差基本都在10%以内;强度预测值换算成标准值后可直接借助规范进行层间结合效果评价。

强流脉冲电子束改性粘结层温度场研究

为探究不同能量密度、不同脉宽时间对粘结层沿深度温度的影响以及对表层温度的影响,通过运用有限元分析软件ABAQUS,模拟运算了强流脉冲电子束轰击粘结层表面过程中粘结层内部温度场的分布情况并对不同条件下的温度场分布进行了分析。结果显示,能量密度为4 J/cm^(2)、脉冲时间为6.0μs,或能量密度达到6 J/cm^(2)时、脉宽在1.5μs以上时可使粘结层发生部分熔化从而达到改性的效果。

环氧沥青钢桥面铺装施工技术分析

该文以清云高速公路肇云大桥的钢桥面铺装工程为例,探究环氧沥青混凝土的铺装工艺及技术要点。正式铺装前需要做好钢桥面的喷砂除锈和清洁处理,营造良好的铺装环境。然后,洒布黏结层和喷涂环氧富锌防锈漆。拌和环氧沥青混凝土,由运输车将混合料从拌和站运送到施工现场完成摊铺后,分别进行初压、复压、终压,保证摊铺料的密实度达标。最后,根据天气情况确定养护时间,养护完毕后开放通车。

冰层对光伏支架桩基础稳定性的影响分析

为研究冰层对光伏支架桩基础稳定性的影响,通过建立水塘内水体和塘下土体的垂向温度分布数学模型,获得各典型年的冰层厚度变化过程,进行数值求解,确定冰层温度应力计算的几何模型;建立冰层热应力计算的数学模型,采用ANSYS程序对冰层应力场进行有限元求解及模型验证分析单桩在土体和冰层共同作用下的受力,进行稳定性评估;针对桩布设条件,计算桩与冰层应力分布规律,并进行对比分析。结果显示:同等环境条件下,桩体总长度大于9 m、桩体入土埋深大于4.4 m时,在计算所考虑的典型年气温变化条件下,桩体是安全可靠的,不会产生上拔现象。

J-56室温快速固化胶粘剂施工工艺方法研究

J-56室温快速固化胶粘剂属于丙烯酸酯接触反应固化型胶粘剂,主要用于铝制标牌的粘接,其为多组分胶粘剂,配制、施工工艺较为复杂。在实际施工过程中,操作不当会导致胶粘剂不能固化、标牌脱落的现象。为了更好地应用J-56室温快速固化胶粘剂,保证标牌粘接质量,特做试验验证。试验结果表明:使用J-56室温快速固化胶粘剂进行粘接时,胶层不宜过厚,在保证不漏涂的情况下,胶层应薄而均匀;涂覆完成后应立即合拢被粘物,使胶粘剂充分接触反应,从而达到完全固化。

粘接结构波动特性的矩阵表示法及参数影响

为丰富多层复合材料界面形态检测方式,笔者构建了一种声波传播界面矩阵模型。分别用空气和水模拟粘接结构的界面为脱粘和进水状态,导出了横波入射下的多层结构中的声反射和透射系数表达式;研究了超声波与不同形态界面的相互作用,分析了入射角度对声波传播特性的影响。结果表明:当横波入射角度介于30°~40°或30°~60°之间,分别采用横波的反射系数法或透射系数法可较容易区分出完好连接、脱粘以及进水界面;除了0°、临界角和90°外,采用纵波透射系数法也较容易鉴别界面形态;无论横波入射角度为多大,采用纵波反射系数法均不能很好地区分脱粘和进水界面。该方法为实验时采用超声波检测粘接结构提供了依据。

铆钉高度对胶铆复合连接接头性能的影响

以1mm厚的DC04钢板与2mm厚的5052铝合金板为铆接对象,在两板之间添加厚度为0.1mm、0.2mm、0.3mm的结构胶,并分别用4mm、5mm和6mm高的铆钉制备自冲铆接接头。通过拉伸剪切试验分析失效形式、观察不同接头的截面成形,并通过电化学腐蚀试验研究添加结构胶对接头的耐蚀性影响。结果表明:铆钉高度一定时,胶厚为0.1mm的接头拉剪强度最大,胶厚的增加会减小接头的内锁值。不同高度的铆钉会造成接头不同的失效形式,4mm高的铆钉接头的主要失效形式为胶层失效后上下板分离;5mm高的铆钉接头失效形式是铆钉脱离下板失效;6mm高的铆钉失效形式为上板撕裂,铆钉脱离上板失效。添加结构胶可以提高接头的耐蚀性,且随着胶厚的增加,耐蚀性也随之增加。

聚氨酯类钢桥面铺装中防水粘结层抗剪性能研究

聚氨酯钢桥面铺装材料具有优异的综合路用性能,使用该材料有望解决传统沥青类钢桥面铺装材料在钢桥严苛的使用环境下耐久性差、使用寿命短等问题,但目前针对其适宜的防水粘结层材料的研究很少。因此,针对聚氨酯铺装层下的2种防水粘结层材料(聚氨酯胶粘剂、环氧树脂粘结剂)进行剪切强度试验,分析了结构的层间剪切性能在防水粘结剂涂覆量、防水粘结层材料、碎石撒布量和养生时间影响下的变化规律。研究结果表明,聚氨酯防水粘结层的抗剪切性能均显著优于环氧树脂防水粘结层,增加防水粘结剂的涂覆量可以增加界面的粘结面积,但防水粘结层过厚会导致抗剪强度在达到峰值后下降;防水粘结层在表干时成型的试件抗剪强度最好,未表干时最差;碎石撒布量也会影响防水粘结层的抗剪强度,故在满足施工条件的前提下,应尽量减小碎石撒布量。

PVB夹层玻璃分层脱胶的失效分析研究

通过分析各类PVB夹层玻璃脱胶的案例,对其脱胶的原因进行了分类总结。总结了PVB夹层玻璃加工商和建筑安装中的一些注意事项,能有效避免夹层玻璃的分层脱胶问题。探究了杂质因素中玻璃碎渣对分层脱胶的影响、外力因素中钢化玻璃内应力以及使用夹紧装置对分层脱胶的影响、外部化学物质侵蚀因素中密封胶和封边剂对分层脱胶的影响、玻璃种类因素中彩釉玻璃和镀膜玻璃以及普通浮法玻璃两面的性质对分层脱胶的影响、PVB中间膜因素中膜片配方、树脂粉羟基含量、含水率以及黏结力调整剂对分层脱胶的影响、气候因素中热量、水分、盐分等不同气候对分层脱胶的影响。

聚氨酯钢桥面铺装防水粘结层剪切疲劳性能研究

聚氨酯混合料桥面铺装材料具有优异的综合路用性能,有望解决传统沥青类钢桥面铺装材料在钢桥严苛使用环境下耐久性差、使用寿命短等问题,但目前对与之相匹配的防水粘结层材料的研究还很少。因此,针对2种防水粘结层材料(聚氨酯、环氧树脂)进行剪切疲劳试验,以分析温度和应力对防水粘结层剪切疲劳寿命的影响。研究结果表明:在-10~70℃的温度区间内,2种防水粘结层的剪切疲劳寿命均呈现缓慢—快速—缓慢下降的趋势。在相同应力比和温度下,聚氨酯防水粘结层的剪切疲劳寿命是环氧树脂防水粘结层的1.02~1.40倍,表明聚氨酯防水粘结层抗剪切破坏能力更强,更适宜作为聚氨酯钢桥面铺装结构的防水粘结层。在不同温度下,2种防水粘结层的剪切疲劳寿命均随着应力比的增加而下降,且中温区(10~25℃)和高温区(50~70℃)剪切疲劳寿命对应力作用的敏感性要显著高于低温区(-10~0℃)。