碳纤维外壳的制造方法

正本发明公开了一种碳纤维外壳的制造方法,包括步骤:将单向碳纤维预浸料叠层排布形成内层和中间层,中间层上的单向碳纤维预浸料与内层上的单向碳纤维预浸料呈0°的夹角;将碳纤维平纹布预浸料铺设在中间层上形成外层;内层、中间层和外层形成预成型原料;将预成型原料放入模具中并按预设的成型条件固化成型,形     

一种非热压罐成型高性能玻璃布复合材料性能研究

对3233VB中温固化树脂进行流变性能和DSC分析分析,确定3233VB中温固化树脂的固化工艺;采用热熔法制备一种中温固化环氧玻璃布预浸料-3233VB/EW180B预浸料,通过真空袋法、模压法和热压罐法成型复合材料板,分别进行性能测试和对比。结果表明,3233VB/EW180B玻璃布预浸料适合真空袋法成型复合材料;3233VB树脂具有良好的韧性,夹层结构的抗滚筒剥离强度高,其预浸料可与蜂窝直接共固化;预浸料树脂质量分数相同时滚筒剥离强度随着预浸料层数的增加而提高。     

混杂纤维复合材料性能研究

对碳纤维织物、玻璃纤维织物和芳纶织物的性能进行测试,采用热熔法分别制备了一种增韧中温固化环氧碳纤维织物预浸料、玻璃纤维织物预浸料和芳纶织物预浸料。预浸料以单种预浸料铺层和不同纤维织物预浸料混合铺层方式铺贴组合,通过模压法成型复合材料层合板,进行性能测试并对比。结果表明,增韧中温固化环氧树脂的不同纤维织物预浸料混合铺层成型的层压板力学性能可以根据铺层设计优化,并不损失不同纤维铺层之间的界面性能。     

三菱化学开发新型碳纤维预浸料

<正>2019年4月11日,三菱化学宣布成功开发出一种外观美观且固化快速的碳纤维预浸料。这种新型预浸料可在1 min内实现固化,将主要用于预浸料压膜成型,广泛用于汽车外部零件、运动和休闲产品等。三菱化学公司快速固化预浸料开发历史较早,     

一种油罐用混杂型光固化预浸料性能研究

对影响混杂型UV预浸料的因素进行分析,试验证明预浸料一次性成型厚度与热引发剂浓度呈正相关,热引发剂(BPO)加入量为1.0%,最大可固化深度可达30.4 mm,为保证预浸料具有优异铺覆性,当增稠剂(MK 35)加入量为1.5%～2.0%时,工艺性能最佳。与传统UV预浸料进行性能对比,试验证明混杂型UV预浸料与传统UV预浸料力学性能相当,两种材料在相同条件下进行紫外光固化,前者一次性成型厚度较后者提高120.3%,解决了光固化成型厚度受限这一难题。     

基于变活化能模型的T800/环氧树脂预浸料固化反应动力学研究

为了深入了解某新型高温固化T800/环氧树脂预浸料的固化行为,借助差示扫描量热仪(DSC),采用非等温DSC法研究了T800/环氧树脂预浸料的固化反应过程。基于唯象模型,系统研究了该预浸料的固化反应特征温度及固化动力学参数,确定该预浸料中环氧树脂的固化反应动力学模型为自催化模型。采用等转化率法,分析了预浸料中环氧树脂的反应活化能随固化度的变化情况,结果表明在整个固化反应过程中,树脂固化反应活化能变化较大,传统模型法基于全固化过程活化能不变的假设无法准确描述该固化反应。采用变活化能自催化模型,利用粒子群全局优化算法,得到了T800/环氧树脂预浸料的固化动力学方程,结果表明该模型能较好地描述实验现象,可为进一步研究该预浸料的热力学性能及其成型过程中的质量控制提供理论基础。     

成型工艺对中温固化环氧树脂碳纤维复合材料性能影响

对3233中温固化环氧树脂黏度-温度曲线、凝胶时间-温度曲线和DSC进行了分析。采用热熔法制备了其碳布预浸料,通过热压罐法、模压法和真空袋法成型复合材料层合板,进行性能测试并对比。结果表明,3233中温固化树脂固化工艺为(125±5)℃固化90～120 min。采用热熔法制备的3233/CF3052中温固化环氧碳布预浸料具有良好工艺性能。模压成型和热压罐成型的层合板力学性能相当,略高于真空袋成型。3233树脂具有良好的韧性,夹层结构的抗滚筒剥离强度高,其预浸料可与蜂窝直接共固化。     

基于DSC的预浸料固化工艺评价和优化

采用差示扫描量热法(DSC)测量了预浸料固化反应热过程。并对预浸料固化的影响因素、固化参数的确定,以及通过DSC确定预浸料的固化参数对预浸料固化工艺进行评价和通过预浸料固化动力学对预浸料的固化工艺进行优化。     

阻燃环氧树脂及其复合材料性能研究

本文主要介绍了一种高温固化阻燃环氧树脂体系的工艺性能和其玻璃布复合材料性能。该树脂具有良好的耐热性、韧性和阻燃性。采用热熔胶膜法制备玻璃布预浸料,通过对预浸料经热压罐成型的复合材料进行相关性能测试,结果表明,树脂体系固化工艺适应性强,可以在150～180℃完全固化,可以在135℃预固化;其预浸料可与蜂窝直接共固化,夹层结构抗滚筒剥离强度高。复合材料的玻璃化转变温度大于200℃;玻璃布复合材料的燃烧性能较好,可以用于具有阻燃要求的复合材料结构件。     

脱离热压罐的预浸料：革命性的预浸料技术

在航空航天用复合材料结构件,特翮是主结构件制造领域,采用热炉固化、真空袋压预浸料即脱离热压罐的预浸料工艺,以其相对于传统的热压罐预浸料工艺更加灵活、成型更快以及更加经济等优势显示出了极好的应用前景。     

COMPARISON OF METHODS OF ANALYSIS OF GYPSUM1

The different analytical methods proposed for the evaluation of gypsum have been subjected to an experimental test. A combination method, consisting of a fusion with KHCO₃ and determination of CaO by KMnO₄ titration, the SO₃ by Andrews method of titration of BaCrO₄ has been found to give very reliable results with the least consumption of time.     

氢气纯度分析方法准确性的探讨

ONACCURACYOFANALYSISOFOFHYDROGEN1前言我公司目前应用的氢气纯度分析方法有两种,一种是爆炸反应法,另一种是焦性没食子酸吸收法。几年来,人们对两种分析方法的准确性曾有过褒贬不一的评论。这里我们也谈谈自己粗浅的观点。2爆炸法测定氢气纯度一定量的氢气样品与适量的空气之均匀混合物因反应后生成液体水而引起气体体积减少,减少的体积等于参加反应气体体积之和。其中l／3为氧气,2／3为氢气。根据氢气取样量和反应前后混气体体积之差,以及氢气在反应中的体积比例关系,可计算出样品的氢气纯度。计算公式式中：A一混…     

HEASUREHENT OF INSTANTANEOUS RATES OF LOSS OF VOIATILE COMPOUNDS DURING DRYING OF DROPS

A novel technique serves to monitor instantaneous rates of loss of a volatile solute from a suspended drop during drying. A highly sensitive electron capture detector is used to monitor concentrations of SF6 released into a flowing gas stream from a suspended, drying drop. Simultaneously, the appearance and morphological development of the drop are monitored with a video camera. This provides the wherewithal of relating instantaneous rates of loss of the volatile solute to particular events during the development of particle morphology.

Initial experiments have been carried out with drops of aqueous solutions of glucose, sucrose, maltodextrin and coffee extract. The results clearly display the onset of the volatiles-retentive selective diffusion phenomenon. There is also substantial loss of the volatile component later in the drying process, when the drops undergo repeated ex ansion, bursting and cratering due to the formation of internaf bubbles. These experiments appear to be the first quantitative demonstration of major losses accompanying changes in drop morphology.     

SEDIMENTATION OF BINARY MIXTURES OF PARTICLES OF UNEQUAL DENSITIES AND OF DIFFERENT SIZES

A model is developed for the sedimentation from a suspension of two particle species of unequal densities and of different sizes. The composition and the thickness of various layers in the sediments are predicted using graphical and analytical methods. The model predictions were in excellent agreement with experimental results, when the particle size ratio was ≥ 108. When size ratio of the particles was 2.60 and 4.31 the agreement occurred in about 50 percent of the cases.     

茶多酚提取方法进展

本文综述了国内外现有茶多酚提取方法的现状以及近期的研究进展，并对其优缺点进行了评价。这将有助于中低档茶的综合利用和茶多酚的进一步开发应用。     

ANALYSIS OF RECENT MEASUREMENTS OF THE VISCOSITY OF GLASSES

Viscosity of Simple Soda-Silicate 500° to 1400°C Comparison of the results given by English with those of Washburn, Shelton and Libman, indicates a discrepancy in the absolute values of log₁₀ viscosity amounting to 0.6, those of Washburn et al., being relatively too high. If correction for this is made, the isothermal curves of log₁₀ viscosity as a function of soda content are smooth up to 50% Na₂O, showing no inflection. The observations as a function of temperature T are all represented within accidental error by an equation of the type where all three constants vary regularly with the composition. Change of Viscosity of Glass (6SiO₂, 2Na₂O) due to Molecular Substitution of CaO, MgO and Al₂O₃ for Na₂O The effect is clearly brought out by plotting (from the results of English) the change of log₁₀η due to the substitution as a function of temperature. The curves each show a sharp bend at a temperature between 840° and 1050°C, which is designated the aggregation temperature T_a. If we divide these curves by the corresponding percentage substituted, we get curves for each oxide which are straight and parallel below the aggregation temperatures, the slopes (increase of change of log₁₀η per 100°C) being −0.056 (CaO), −0.055 (MgO), −0.018 (A1₂O₃) per per cent oxide substituted. For substitution of 1/2 molecule the slopes are −0.325 (CaO), −0.23 (MgO) and −0.18 (Al₂O₃) per 100°. At the aggregation temperature the change of log₁₀η per per cent is a minimum, 0.03 to 0.06 for CaO, 0.12 for MgO, 0.07 for Al₂O₃. Evidence of Aggregation in Glasses, from viscosity Measurements The sharp bends in the plots of change of log₁₀η due to substitution of an oxide for Na₂O, suggest the beginning of molecular aggregation at these temperatures. These aggregation temperatures are close to the devitrification temperatures, but the effect on the viscosity curves cannot be due to actual devitrification since it does not change with time. Taking the aggregation temperatures as equal to devitrification temperatures, additional isotherms are roughly sketched into the equilibrium triangle of the system Na₂O-CaO-SiO₂. Change of Viscosity of Glass (4SiO₂, 2Na₂O) due to of Substitution of B₂O₃ for SiO₂ The change of log₁₀η (from the results of English) is plotted as a function of temperature, and also the change of log₁₀η per per cent B₂O₃. The curves are more complex than for the substitution for Na₂O.     

环氧树脂羟基值测定方法的研究

利用乙酸酐、吡啶和浓硫酸混合的乙酰化试剂测定环氧树脂中羟基值含量的方法具有操作简便、滴定终点明显和分析结果误差小等优点。     

骑式摩托车油箱喷涂工艺的改进

面对日益激烈的市场竞争,摩托车油箱外观质量越来越成为影响销售的因素之一。文章介绍了改进工艺后的油箱涂装,该涂装体系提高了油箱外观的丰满度,降低了油箱涂装的生产成本。     

用两个形状指数表征粉煤灰颗粒形貌的研究

引用两个形状指数表征颗粒形状的概念,即先将颗粒形状近似为椭圆,再将椭圆图像分离:以圆为基准的颗粒宏观形状指数δ;以光滑椭圆为基准的颗粒轮廓凹凸度,即微观形状指数ζ。分析和发展了近似椭圆模型。并运用图像分析仪对粉煤灰、水泥样品进行实验。结果表明,粉煤灰颗粒的两个形状指数δ和ζ都大于水泥颗粒。证明粉煤灰颗粒的球形度、表面光滑度优于水泥,而且,随着粒径增大,δ和ζ呈下降趋势,表明磨制颗粒越粗。(?)粒形状越不规则。文中还运用近似椭圆模型再现了颗粒的模拟图像。     

典型煤碳燃烧特性研究和数值模拟

本文以三种典型煤的碳燃烧为研究对象，分别采用简单一维沉降燃烧方式和等温加热燃烧方式，实验研究了煤在快速加热条件下，其碳的初期和中，后期燃烧过程。以实验为基础，建立了煤的碳燃烧模型，变工况数值模拟了煤的碳燃烧过程，揭示了煤不同条件下的单颗粒碳燃烧特性。