一种新型无机耐热涂料

日本关西涂料有限公司,发明一种新型无机聚合物耐热涂料,已于1985年初出售商品。本涂料的耐热温度与过去耐热涂料相比 (有机涂料约200℃,无机涂料约450℃)有大幅度提高,大约为600℃(被涂物若为无机物时达900℃)另外,尚具有在加热时涂膜减量少的特点。耐热涂料有以下优点: 1.常温下可制成牢固的涂膜。 2.树脂结构稳定、耐候性好。 3.树脂为网状结构,化学稳定性好。     

SiO2改性低表面能纳米结构无毒海洋防污涂料

以合成的有机硅改性丙烯酸树脂为主要成膜物质,在颜填料不变的基础上添加纳米SiO2,制成了低表面能纳米结构无毒海洋防污涂料,讨论了树脂用量和纳米SiO2对涂膜附着力及其与液体接触角的影响,分析了低表面能防污涂料的表面结构.结果表明,树脂用量为25%～30%时,涂膜的附着力为1级,涂膜与水的接触角为150°,涂膜表面为纳米-微米阶层状结构.     

F_(2314)基常温固化涂料的改性研究

用改性树脂对F2314树脂涂料进行改性,研究不同的改性树脂用量和固化剂的种类以及其用量对F2314树脂涂料涂膜的影响,并对共混膜进行了表征。结果表明,F2314树脂与改性树脂的共混比为8∶2而且固化剂的用量为改性树脂的15%时,涂膜的附着力、硬度达到了最大值,而且外观也很平整;红外光谱测试表明,F2314树脂与改性树脂之间发生了相互作用;共混膜的SEM照片可见涂膜表面是网状结构,类似半互穿网络聚合物(IPN)结构。     

高温有机硅涂料

有机硅具有优良的热稳定性和耐氧化性能,透紫外线,耐紫外线降解。有机硅树脂的耐高温和耐天候性能使其成为高温涂料的理想材料。未改性的有机硅树脂可与有机树脂混合,以降低成本或改善粘附力、耐腐蚀和固化性能。     

从专利看氟树脂涂料的发展动向

日本氟树脂涂料的产量以20～30%的年增长率持续增长,预计1991年产量在5000吨以上。氟树脂涂料抗粘连性、耐热性、耐化学品性、电气特性等性能极佳,虽然有施工性不良、涂膜有孔隙形成的缺点,但聚四氟乙烯等均聚物型热塑性氟树脂涂料已使用于食品等的广泛领域。此外,还有施工性较好的四氟乙烯—六氟丙烯共聚合树脂等共聚物型热塑性氟树脂涂料和改性型热塑性氟树脂涂料,后者有可在低温下烘烤成膜等的特点,但耐热性、耐化学品性、抗粘连性等不可避免要降低。氟树脂涂料可分为在水中或有机溶剂中分散型,溶剂蒸发后形成膜的溶液型,在常温或通常烘烤条件下交联硬化形成耐久性良好的涂膜、可望使用于各种建材、大型建筑等的热固性氟树脂涂料四类。     

漆酚醛缩聚物/丙烯酸树脂/TiO2复合涂料的制备及性能

采用Sol-Gel法制备了漆酚缩甲醛聚合物/多羟基丙烯酸树脂/TiO2纳米复合涂料(UFP/MPA/TiO2),并用透射电镜、动态机械热分析、红外光谱和其它手段对复合涂膜进行测试。结果表明,TiO2以40 nm~80 nm的粒子均匀地分布于m(UFP)∶m(MPA)=5∶2的UFP/MPA聚合物基体中,且纳米TiO2粒子和聚合物间存在着较强的氢键。纳米TiO2粒子的引入,使得该复合涂膜具有比UFP或UFP/MPA涂膜更好的抗紫外线性能、常规物理力学性能和动态力学性能。     

碳纤维体系导电涂料的制备工艺

研制了一种以丙烯酸酯类树脂为基料的改性碳纤维体系导电涂料.用单因素方法确定改性碳纤维/树脂质量比,偶联剂的种类、用量以及添加方式、涂料的固化工艺等方面对涂料电性能的影响关系,然后用正交实验进一步优化各因素对涂膜导电性能的影响,确定了制备碳纤维体系导电涂料的最佳工艺条件为:改性碳纤维/树脂质量比为0,7,钛酸酯偶联剂TMC-102采用预处理用量为1%(wt,下同)和直接加入用量为1.5%相结合,制得的导电涂料综合性能较好;固化温度为50℃下固化20min,涂膜厚度为150μm时,其表面电阻率达到1.02Ω/sq.     

碳纳米管导静电涂料导静电性能的影响因素

目前,导静电涂料的导电介质多以碳系和金属氧化物为主,不能兼顾涂料的防腐蚀与导电性能,对以碳纳米管(CNTs)作为导电介质和以环氧改性有机硅树脂作为导静电涂料基体树脂的研究均较少.利用环氧树脂改性有机硅低聚物合成了改性树脂,采用红外光谱对产物进行了表征,研究了碳纳米管含量、酸化处理、固化剂、分散剂含量对由CNTs制备的导静电涂料涂膜的导静电性能的影响.结果表明:CNTs含量对提高涂膜导静电性能有影响,CNTs含量为2.0％时导静电性能很好;CNTs酸化处理后涂膜的导静电性能得到明显提高;固化剂聚酰胺650含量为30.0％时,涂膜固化性能和导静电性能最优;分散剂能很好地提高CNTs分散性能,十二烷基苯磺酸钠/改性树脂(质量比)和十八醇/改性树脂(质量比)均在2.0％时达到其最佳效果.     

粉末涂料防腐蚀性能的评价

近年来迅速发展的粉末涂料,可一次获得很厚的涂膜,生产效率高,不用溶剂,操作安全,因而广泛应用。现将涂料的试验及评价结果概述如下。一、涂膜的物理性能图1列举了环氧树脂、丙烯酸树脂、聚酯树脂三种粉末涂料的涂膜温度和抗拉强度、纵弹性模量、延伸率的关系。表1为抗拉强度的试验条件。上述三种树脂的粉末涂料之涂膜,在20～80℃温度范围内,其物理性能变化不大,以环氧树脂的物理性能更为优异,尤其是它的低温延伸性能良好。所以在钢制件上     

纳米ATO/TiO_2填料聚氨酯透明隔热涂料的制备与性能

为了制备隔热性能和透光性均较好的建筑物玻璃隔热涂料,以水性聚氨酯为成膜物质,纳米氧化锡锑(ATO)和纳米二氧化钛(TiO2)为填料,制备了水性纳米透明隔热玻璃涂料。采用扫描电镜、隔热膜温度测试仪及紫外分光光度计对纳米ATO与TiO2粒子在涂料涂膜中的分散稳定性、涂料涂膜的隔热性能及光学性能进行了分析,研究了纳米TiO2与ATO浆料配比及涂膜厚度对涂料涂膜性能的影响。结果表明:纳米ATO与TiO2浆料通过硅烷偶联剂KH-570改性,再辅以分散剂分散,经过高速分散和超声波分散后,与聚氨酯复合制得了分散稳定的复合透明涂料;该涂料不仅具有良好的成膜性能,且涂膜经红外灯照射60 s后,与空白玻璃对比,隔热温差最高达6.23℃,在保证良好的可见光透过率及隔热性能的前提下,最佳纳米TiO2与ATO浆料体积比为2∶20,最佳涂膜厚度为75μm,此时涂料涂膜隔热温差达3.60℃。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...