Experimental Study of Monitoring and Controlling of Composite Cure Process in Autoclave Featured with Fiber Optic Sensor

With the aid of the latest fiber optic sensing technology parameters in the cure process of ther- mosetting resin-matrix composite, such as temperature, viscosity,void and residual stress, can be monitored entirely and efficiently.In this paper, experiment results of viscosity measurement in composite cure process in autoclave using fiber optic sensors are presented. Based on the sensed information, a computer program is utilized to control the cure process. With this technology, the cure process becomes more apparent and controllable, which will greatly improve the cured products and reduce the cost.

Study on Effects of Curing Process on Characteristics of Marinated Beef Products

[Objectives]This study was conducted to compare the effects of different curing processes on the characteristics of marinated beef.[Methods]Marinated beef was obtained by two curing processes:static curing and injection and vacuum tumbling curing.The effects of the two curing processes on the production rate,curing absorption rate,water content,soluble protein content,amino acid nitrogen content,texture characteristics and microstructure of the product were compared.[Results]Compared with static curing,the production rate of marinated beef increased by 10%,the curing absorption rate increased by 28%,the texture and microstructure were improved,and the water content increased,while the soluble protein content decreased.As a result,the sensory score was higher.There was no significant difference in the content of amino acid nitrogen,but it decreased compared with raw meat.To sum up,injection and vacuum tumbling curing is more conducive to the processing of marinated beef.[Conclusions]This study provides a theoretical basis for the industrial production of marinated beef,and lays a foundation for in-depth exploration of injection and vacuum tumbling curing technique of marinated beef.

An Investigation of Stimulating the Autoclave Curing Process of Resin Matrix/Fiber Reinforced Composite Material, Ⅰ: Process model

A mathematical model is made which describes the curing process of composites constructed from continuous fiber-reinforced, thermosetting resin matrix prepreg materials, and the consolidation of the composite is developed. The model provides the variation of temperature distribution, the cure reaction process in the resin, the resin flow and fibers stress inside the composite, and the void variation and the residual stress distribution. It can be used to illustrate the mechanism of curing process and optimize the cure cycle of composite material in order to ensure the quality of a product.

Hot Mixing Behavior and Curing Process of Epoxy Asphalt

A new hot mixed epoxy asphalt system was developed. The reaction process of epoxy resin was characterized by Fourier transform infrared spectroscopy (FTIR). The viscosity was investigated by Brinell viscometer when epoxy resin was mixed with asphalt. The glass transition temperature (Tg), homogeneity, thermal stability and viscoelasticity of epoxy asphalt were analyzed by differential scanning calorimetry (DSC), metallographic microscope, thermogravimetric (TG) and dynamic mechanical analysis (DMA). The results showed that the viscosity of epoxy resin modified asphalt reached 1000 mPa·s for more than 180 minutes at 180 ℃, while the best construction process is mixing at 180 ℃ for 2 hours and curing at 60 ℃ for 4 days. The particle size of asphalt is less than 50 μm. In addition, the mechanical properties of the materials are uniform within the specified pavement thickness.

Rubber Curing Process Simulation Based on Parabola Model

The curing process of rubber fender was investigated. A parabola model was put forward for the first time, which described variation of rubber thermal properties such as heat conduction and specific heat. Based on Kamal and Sourour model, a modified Rafei kinetic model was used to predict the rubber curing kinetics. To compare with experimental data, the fender curing process was simulated by parabola model and linear model respectively. Additionally, the curing craft and structure of the fender were modified and evaluated based on finite element analysis （FEA）. As a result, the curing uniformity and efficiency of the fender was highly improved. It was investigated that, the parabola model correlated the rubber thermal behavior more precisely. The numerical prediction was in good agreement with the experimental evaluation.

Integrated Design of D.D.I., Filament Winding and Curing Processes for Manufacturing the High Pressure Vessel(Type Ⅱ)

As energy crisis and environment pollution all around the world threaten the widespread use of fossil fuels,compressed natural gas(CNG)vehicles are explored as an alternative to the conventional gasoline powered vehicles.Because of the limited space available for the car,the composite pressure vessel(TypeⅡ)has been applied to the CNG vehicles to reach large capacity and weight lightening vehicles.High pressure vessel(TypeⅡ)is composed of a composite layer and a metal liner.The metal liner is formed by the deep drawing and ironing(D.D.I.)process,which is a complex process of deep drawing and ironing.The cylinder part is reinforced by composite layer wrapped through the filament winding process and is bonded to the liner by the curing process.In this study,an integrated design method was presented by establishing the techniques for FE analysis of entire processes(D.D.I.,filament winding and curing processes)to manufacture the CNG composite pressure vessel(TypeⅡ).Dimensions of the dies and the punches of the 1 st(cup drawing),2 nd(redrawing-ironing 1-ironing 2)and 3 rd(redrawing-ironing)stages were calculated theoretically,and shape of tractrix die to be satisfied with the minimum forming load was suggested for life improvement and manufacturing costs in the D.D.I.process.Thickness of the composite material was determined in the filament winding process,finally,conditions of the curing process(number of heating stage,curing temperature,heating rate and time)were proposed to reinforce adhesive strength between the composite layers.

Study on preparation of fast curing novolaks for the shell process

To save energy and raise molding and coremaking productivity, the synthetic procedure of novolaks for the shell process was investigated. The study indicated that it was difficult to obtain fast curing novolaks under strongly acidic conditions alone. A novel synthetic procedure was proposed for preparing novolaks in a two-step manner, a divalent metal salt catalyzed novolak preparation followed by a strong acid catalyzed novolak preparation. The optimum conditions for the two-step procedure were determined by orthogonal experiment design. The results showed that it was easy to prepare fast curing novolaks with cure time in the range of 20 s to 30 s and softening point in the range of 80℃ to 90℃ under complex catalysis conditions.

CURING PROCESS OF PHOTOPOLYMER RESIN BOND DIAMOND TOOLS

Analytical simulation and corresponding proof-test are adopted to study the principle of the curing process of photopolymer resin diamond tools. The influence of the diamond as abrasives in photopolymer resin owing to the absorptivity of the diamond for the UV light on the photopolymer resin curing process is discussed. Based on the above, a kind of diamond tool—dicing blade is selected to analyze the curing process of photopolymer bond diamond tools. An analytical model of curing process is developed and a correlation curve between the depth of polymerization of the photopolymer resin diamond tools and the exposure time to represent the curing process of photopolymer bond dicing blade. A test is done to proof-test the validity of the analytical model and the correlation curve. The simulated data fit the experimental results, which demonstrates the analytical models and numerical algorithm are of high reliability. The analytical simulation method could possibly be used to optimize the curing cycle and improve the quality of the photopolymers resin bond diamond tools.

MICRO-PHASE SAEPARATION IN EPOXY RESIN WATERBORNE PARTICLES DURING CURING PROCESS

Sub-micron sized phenolic epoxy resin waterborne particles were prepared by phase inversion emulsification. Micro-phase separation occurred during the curing process at high temperature. The as-prepared samples possessed one glass transition temperature （Tg） and two exothermal processes during DSC heating scannings. After being thermally treated above the exothermal peak temperature, they possessed two glass transition temperatures with the disappearance of exothermal peaks, whilst a core/shell structure was formed. This was likely related with the outward diffusion of reactive oligomers to the outer layer of particles.

The Curing Process and Elastic Modulus of HTPB-Containing Polyurethanes

By means of the functionality distribution deduced and weight averaged functionality a and molecular size vb2, the sol-gel distribution equations of HTPB(Hydroxyl terminated polybutadiene) + TDI (Toluene-2, 4-diisocyanate) expressed by the model of Aai-B2 type polycondensation were solved and the elastic modulus were calculated. The experimental results of HTPB+TDI curing process indicate that a, vb2 and functionality distribution function are available basically.

Investigate the Effect of the Magnetic Field on the Mechanical Properties of Silicone Rubber-Based Anisotropic Magnetorheological Elastomer during Curing Process

In this investigation,a new silicone rubber-based MRE material was prepared to be used as a forming medium in manufacturing thin-walled complexshaped Ni-based tubes through the bulging process.Thus,it is significant to investigate the effect of magnetic field intensity,magnetic field loading time,and angle on the mechanical properties of the prepared MRE material during the curing process.The obtained results showed that increasing the magnetic field intensity during the curing process can improve the orientation of the chain structure in the elastomer matrix effectively.However,its mechanical properties are the best under the corresponding magnetic field intensity of 321 mT.Besides,by extending the magnetic field loading time in the curing process,the orientation of the chain structure was optimized,at the same time,the mechanical properties were also improved,and the best loading time is about 20–25 min.By changing the loading angle of the magnetic field during the curing process,the mechanical properties of the MRE were improved.When the loading angle of the magnetic field is 90°,the elastomer showed the best compression mechanical properties and excellent compression reversibility.Besides,for the anisotropic MRE material,the performance with magnetic compression is always better than that without magnetic compression.

Kinetics of Autoclave Curing Process on Autoclaved Aerated Concrete with Magnetite Tailings

Lightweight and energy saving autoclaved aerated concrete(AAC) acting as a newbuilding material were prepared by using magnetite tailings from iron ore as main rawmaterials,and the purpose of comprehensive utilization of tailings resources was to improve their utilization efficiency.The effects of curing system on AAC product performance were discussed.The autoclave curing reaction kinetics was studied as well as the generated amount of hydration product trends over autoclave curing temperature and time were analyzed.The results indicated that the properties of AAC was in accordance with Chinese national standard the A3.5 B06 class of GB/T11968-2006 by prepared from magnetite tailing as the main rawmaterials.Meanwhile,autoclave curing process was controlled by the diffusion velocity through the products ' layers of reactants,and the apparent activation energy of autoclave curing process was 19.269 k J/mol.Compressive strength of aerated concrete is improved by mutual cementation between the appropriate amount of calcium silicate hydrate and tobermorite crystal.

典型复合材料结构固化变形仿真预测与控制验证

针对典型复合材料结构固化成型过程中变形难以控制的问题,本文对典型复合材料结构的固化变形进行仿真预测,从固化工艺和模具补偿两方面对固化变形加以控制和验证。固化工艺方面以各设计点变形数据为基础确定了最优固化工艺曲线,模具补偿方面提出了一种构件有限元模型自适应调整的方法,综合考虑固化工艺参数与模具型面补偿采用了一种基于全局补偿量的协同控制方法。结果表明,通过仿真模拟L形构件的固化变形误差为12.4%,借助响应面优化算法得到的L形构件最优固化工艺曲线其固化变形预测值与各试验设计点最大变形的最小值偏差不超过3.3%;T形加筋壁板有限元模型经自适应调整后,对于下表面与目标型面之间的偏差距离,数值模拟值与试验测量值的最大相对误差为17.20%。通过全局补偿量的协同控制方法对半筒形壁板的模具进行补偿,其固化变形最大值相比于传统单一模具型面补偿控制方法降低了接近90%。

整体化“E”形复合材料框成型工艺设计

随着航空先进复合材料应用愈发广泛,复合材料零件的形式逐渐增多,应用也愈发广泛,框是飞机的重要组成部分,常用作机身隔框或其他骨架零件,其直接影响着飞机的外形准确度和结构承载能力,“E”形复合材料框的巧妙设计和尝试提高了复合材料框的整体化水平,避免了金属框类零件难加工、疲劳性差等缺点,分析此“E”形复合材料框零件的结构特点,基于真空袋-热压罐成型方法,阐述了该类零件成型的工艺难点和关键控制点,巧妙设计成型工装方案,严格控制工艺操作流程,制造出内部质量好、外形尺寸精准、外观良好的复合材料“E”形框零件。

基于压电喷墨技术3D打印纳米银墨水的固化工艺研究

为了改善喷墨3D打印纳米银墨水的导电性,研究热台固化、近红外固化和光热耦合固化对纳米银墨水固化后微观形貌和电导率的影响。通过压电喷墨打印纳米银墨水,并用热台和近红外灯对纳米银薄膜进行固化。结果表明:热台固化时,纳米银薄膜的电阻率随固化时间和固化温度的升高而降低,在固化时间25 min,固化温度140℃时下降至99μΩ·cm;近红外固化时,固化功率1000 W,固化时间4 min的条件下,电阻率为33.2μΩ·cm;光热耦合固化时,纳米银薄膜的电阻率随扫描功率和固化时间的增加而降低,基板加热温度160℃、扫描功率为1000 W、固化时间60 s的条件下,电阻率为3.75μΩ·cm。光热耦合固化烧结颈的生长速度明显优于热固化及光固化。

彰显龙岩CB-1烟叶清甜蜜甜香型风格密集烘烤工艺研究

研究龙岩地区‘翠碧一号’的密集烘烤工艺,为彰显其清甜蜜甜香型风格提供参考。为彰显‘翠碧一号’烟叶清甜蜜甜香型风格,以福建龙岩烟区栽种‘翠碧一号’下、中、上部的适熟烟叶为实验材料,设置3种烘烤工艺,采用“背靠背”编烟方式编竿装烟,对烤后烟叶分别按下、中、上部进行分级,然后进行鉴定,统计外观、化学成分及感官质量等信息。结果显示,‘翠碧一号’(CB-1)品种烟叶下部烟宜采用T3(高温/高低高湿)烘烤工艺,关键烘烤阶段干/湿球温度为:变黄期38~40/37~38℃、凋萎期42/36℃、变筋期46/36℃、干片期50~54/38~39℃、干筋期60~65/40~42℃,中、上部烟叶宜采用T1(高温/高湿)烘烤工艺,关键烘烤阶段干/湿球温度为:变黄期38~40/37~38℃、凋萎期42/38℃、变筋期46/38℃、干片期50~54/39~40℃、干筋期60~65/40~42℃。该研究为彰显‘翠碧一号’香型的密集烘烤工艺提供技术参考。

2022年中国粉末涂料行业年度报告

以中国化工学会涂料涂装专业委员会和全国涂料工业信息中心的行业统计数据、国家统计局发布的数据及行业调研为基础,阐述了2022年我国粉末涂料行业运行概况,并提出了未来行业发展建议。

基于熔模铸造的DLP光固化增材制造装备的研制

文章将DLP光固化成型技术与熔模铸造工艺相结合,研制了适用于陶瓷浆料打印的光固化增材制造装备。以实现DLP光固化成型工艺参数:曝光时间、曝光层厚及曝光强度等为设计出发点,合理设计光固化打印机的选型及零部件布置,验证最佳工艺参数,确定了设备最佳曝光时间为30~35 s;最佳打印曝光层厚为0.1 mm。

模具材料线胀系数对复合材料固化变形的影响研究

为了研究模具材料线胀系数对复合材料固化变形的影响,面向复合材料零件热压罐固化成形工艺过程,针对复合材料成形模具材料与复合材料零件线胀系数不一致导致复合材料零件热固化变形的问题,研究了模具与复合材料零件相互作用关系,推导了模具对复合材料固化变形的理论模型,利用ABAQUS等仿真软件建立了模具温度场的数值模拟模型,并将模具热变形的模拟数据与复合材料零件变形的试验数据进行了对比分析。结果表明,不同材料模具型面各位置变形值与型面结构特征无关,与型面大小有关;模具材料与复合材料的线胀系数差异越大,复合材料零件变形量越大。

实用化高比能准固态锂离子电池体系的研究

针对锂离子电池中电解液易泄漏、易燃烧,甚至引发爆炸等潜在安全问题,本文将单一的醚类小分子物质作为单体,与LiPF_(6)基电解液混合制备预聚前驱体,在60℃下原位衍生为非流动态的黏弹性凝聚体。通过调控单体比例、优化原位固化工艺,制备出高镍/高硅准固态锂离子电池。经测试,2.1 Ah电池体系在0.3 C电流下循环寿命达600圈,保持率比同期液态高1.8%。由更高硅含量的负极构成的36 Ah电池体系的比能量高达351 Wh/kg,500圈循环容量保持率达88.36%,准固态锂离子电池具有优异的低温性能,-20℃下容量保持率达85.6%,结果表明固化电解质在电池层内部及层间起到了良好的结构稳定性作用。该高比能准固态锂离子电池体系的开发为后续固态电池的进一步实用化提供了切实可行的途径。