熔融树脂胶膜碳纤维复合材料的研制

本文研制适合于制备热熔胶膜的改性环氧树脂基体,然后使用胶膜镶嵌热压合方法制备幅宽1200毫米的高品质连续碳纤维预浸料。预浸料和复合材料性能满足技术指标要求。     

复合材料用预浸料

(续 5)4　预浸料的类型和性能4 1　预浸料的类型随着复合材料研究和开发的不断进步 ,使用领域日渐扩大 ,复合材料构件不同制造工艺、不同工作条件对预浸料也提出了不同要求。为了适应来自多方面的需要 ,新的预浸料不断出现 ,预浸料的类型不断增加。按物理状态分类 ,预浸料分成单向预浸料、单向织物预浸料、织物预浸料 ;按树脂基体不同 ,预浸料分成热固性树脂预浸料和热塑性树脂预浸料 ;按增强材料不同 ,分成碳纤维 (织物 )预浸料、玻璃纤维 (织物 )预浸料、芳纶 (织物 )预浸料 ;根据纤维长度不同 ,分成短纤维 (4 76ｍｍ以下 )预浸料、长纤…     

复合材料用预浸料

１预浸料的基本概念预浸料是用树脂基体在严格控制的条件下浸渍连续纤维或织物,制成树脂基体与增强体的组合物,是制造复合材料的中间材料。它的一些性质直接带入复合材料中,是复合材料的基础。复合材料的性能在很大程度上取决于预浸料的性能。对于复合材料设计师来说,预浸料是具有一定力学性能的结构单元,可用以进行结构设计。对于复合材料工艺工程师而言,预浸料是制造结构的原料,可直接用以制造各种复合材料构件。预浸料的优劣关系到复合材料的质量。因此,预浸料对复合材料的应用和发展具有重要意义。预浸料从４０年代末期开始采用…     

热塑性复合材料研究及其在航空领域中的应用

本文介绍了热塑性复合材料的分类与组成,并简述了短纤维粒料(SFT)、长纤维粒料(LFT)、玻璃纤维毡增强热塑性片材(GMT)、织物预浸料和单向连续纤维增强热塑预浸料(CFRTP)的各自优点,连续纤维增强热塑性树脂的预浸料的主流制备工艺。结合高性能热塑性复合材料在国外航空领域中的应用,展望了其在我国的发展方向。     

国内外预浸料制备方法

预浸料是增强纤维浸渍树脂基体后制备复合材料的半成品,其性能取决于其原料性能及加工工艺。本文综述了预浸料的分类,介绍了国内外热固性预浸料和热塑性预浸料的工艺制备,包括增强纤维、树脂基体、固化体系等原料的选择及其制备方法,并比较了各种方法的适用性及优缺点。     

连续玻璃纤维增强PLA复合材料3D打印技术研究

以聚乳酸(PLA)为基体,连续玻璃纤维为增强体,采用熔融浸渍工艺制备连续玻璃纤维预浸丝,将制得的预浸丝作为3D打印耗材用于熔融沉积(FDM)的3D技术来制备连续玻璃纤维增强PLA复合材料试样,并研究了打印温度、层厚和打印速度对复合材料力学性能的影响。结果表明,当打印层厚为0. 5 mm,打印温度为230℃,打印速度为2 mm/s时,连续玻璃纤维增强PLA复合材料的弯曲性能最佳,弯曲强度和弯曲模量分别为327. 84 MPa和20. 293 GPa。综合考虑复合材料的力学性能、表面质量和尺寸稳定性,连续玻璃纤维增强PLA复合材料的最佳打印层厚为0. 5 mm,适宜的打印温度范围为200~220℃,打印速度范围为2~4 mm/s。     

环氧树脂/玻璃纤维复合材料性能研究与应用

研究了环氧树脂(EP)/玻璃纤维(GF)复合材料的力学性能。结果表明,EP/GF复合材料的常规性能和耐热性较好,夹层结构的滚筒剥离强度高,树脂具有韧性,扫描电镜分析发现复合材料界面粘接情况良好。该预浸料已用于直升机次承力结构。     

连续纤维增强热塑性预浸料制备工艺的研究进展

连续纤维增强热塑性复合材料综合性能优异,其应用与日俱增。作为热塑性复合材料制造用中间材料,连续纤维增强热塑性预浸料的制备和质量控制技术对于热塑性复合材料的发展来说至关重要。本文详细介绍了熔融浸渍法、溶剂浸渍法和粉末浸渍法三种工艺制备连续纤维增强热塑性预浸料的研究进展,总结了各种制备工艺的优缺点,并对高性能热塑性预浸料的发展趋势进行了展望。     

两种预浸工艺对玻璃布预浸料性能的影响

着重研究了用溶液法和热熔胶膜法工艺所制备的5231/823玻璃布预浸料的物理性能、工艺性能、力学性能和滚筒剥离性能,旨在探讨不同预浸工艺对预浸料及其复合材料性能的影响,试验结果表明:这2种工艺所制的5231/823预浸料的工艺性能和剥离性能相当,但在预浸料树脂含量控制精度方面,热熔法工艺高于溶液法工艺;在预浸料挥发分方面,热熔法工艺的较低,一般低于0.8%。在复合材料常规力学性能方面,一般前者高于后者。     

先进热塑性树脂预浸料用原材料

研究分析表明,现有碳纤维与热塑性树脂的相容性差,且其使用的环氧上浆剂不能承受250℃以上工艺温度,不宜用于热塑性树脂预浸料的制备;此外,目前热塑性树脂预浸料制备方法多种多样,不同的工艺方法要求热塑性树脂的形态也不尽相同。指出必须尽快开发出适合热塑性树脂预浸料的碳纤维,满足不同预浸工艺要求和形态各异的热塑性树脂基体。     

热固性树脂半固化片树脂流动度研究

采用聚丁二烯、丙酮、陶瓷粉填料和其他助剂,制得胶液,用偶联剂处理过的玻璃布在胶液中浸渍后,在70℃干燥脱溶剂,在140℃继续烘烤10 min,得到半固化状态的预浸片。将浸渍片按固定的尺寸裁切后即得到所需的热固性树脂半固化片。对半固化片关键指标之一的树脂流动度的影响因素及调控方法进行了较为详细的讨论。结果表明,在良好界面改性的同时,当陶瓷粉配比中球角比越小、烘道温度越高时,半固化片的树脂流动度越低,相反则流动度越大,流动度调整范围可从0.7%到20.5%。通过对相关影响因子的合理调控,就能得到满足不同使用要求的半固化片,满足不同情况下多层板的设计加工要求。     

Development and hot-melt impregnation of a model controlled flow prepreg system

A controlled-flow epoxy-based model prepreg resin system was developed. The formulation of the model controlled-flow resin was designed from performance information obtained from a commercially available controlled-flow resin, presently used in the aircraft industry. Thermoanalytical techniques including rheometry were used to provide the necessary information to develop the model system along with a formulation methodology developed by Seferis and co-workers. The model resin formulation, which was a combination of tetraglycidyl ether of methylenedianiline (TGMDA), diglycidyl ether of bisphenol-A (DGEBA), carboxyl-modified butadiene/acrylonitrile rubber (CMBN), carboxyl-terminated butadiene/acrylonitrile rubber (CTBN), bisphenol-A (BPA), diaminodiphenyl sulfone (DDS), and dicyandiamide (DICY), was hot-melt impregnated into unidirectional carbon fibers on a laboratory scale hot-melt prepreg machine. A two-parameter, three-level design of experiments was performed on the prepreg processing parameters in which impregnation temperature and pressure were varied. Thus, a total of nine different experimental prepregs were produced and characterized by resin content, extent of impregnation, and tack. The results from the characterization of the nine experimental prepregs are compared with the effects of the prepreg processing conditions. These results are also compared with the results generated for the commercial controlled-flow resin. Collectively, this work provides a fundamental basis by which the analysis and rational utilization of controlled-flow matrix prepregs can be effected.     

Properties of carbon fiber composite laminates fabricated by coresin film infusion process for different prepreg materials

A new cocured process called coresin film infusion (co‐RFI) process, which combines RFI process and prepreg/autoclave process, was introduced and four kinds of commercial carbon fiber prepreg material systems and a kind of resin film were applied to fabricate co‐RFI laminates. The compatibility between the resin film and the prepreg matrix and the application of co‐RFI process were investigated based on the resin flowability, glass transition temperature of cured resin, processing quality of laminate, and variation in resin modulus on cocured interphase region measured by nanoindentation. Furthermore, mode I (G_IC), mode II (G_IIC) delamination fracture toughness, and flexural strength and modulus were measured to evaluate the mechanical properties of cocured laminates with different prepreg materials. The experimental results show that thickness and fiber volume fraction of co‐RFI laminates with the four kinds of prepreg materials are similar to those of prepreg laminates and RFI laminate with acceptable differences. In addition, there are no obvious defects in co‐RFI laminates. Moreover, the reduced modulus of resin at cocured interface and glass transition temperature values of the mixed resin reflect good compatibility between prepreg matrix resin and RFI resin. The G_IC, G_IIC values, and flexural performances of cocured laminates lie between and even exceed those of prepreg laminates and RFI laminates, indicating no weakening effect in the cocured interface. Therefore, the co‐RFI process is believed to effectively fabricate composite with low cost and it can be applied using various prepreg systems. POLYM. COMPOS., 34:2008–2018, 2013. © 2013 Society of Plastics Engineers     

Thermal and air permeation properties of a carbon fiber/toughened epoxy based prepreg system

This study addresses thermal and air permeation properties of a new toughened prepreg system. Voids in the uncured prepreg structure can affect the void content in the final composite structure. A new, toughened prepreg system, commercially available for aircraft structural application, was utilized in this study. The prepreg was subjected to thermal and rheological characterization to understand the basic prepreg properties. These experiments were followed by a prepreg air permeation study to investigate prepreg processing and its influence on the prepreg structure. Crosslinking of the resin matrix was monitored with prepreg specimens without extracting resin from the prepreg. Along with thermal property measurements, the air flow rate significantly decreased in initial static experiments, followed by equilibrium permeability values. An air permeation model divided the air permeability into intralaminar and interlaminar permeabilities. Interlaminar air permeation was found to be more pronounced than intralaminar air permeation in this particular prepreg system. These permeation measurement results were explained using optical microscopy, proving that the application of vacuum could eliminate significant porosity in the laminate. Collectively, understanding prepreg thermal and air permeation properties was considered to be important; the voids in uncured prepreg may cause the voids in the final composite structure. Voids in the prepreg can be attributed to the heterogeneity and anisotropy of the toughened prepreg structure, resulting from particular prepreg processing techniques. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 5–16, 1997     

Near Infrared Spectroscopy for On-line Monitoring of Alkali- Free Cloth/Phenolic Resin Prepreg During Manufacture

A NIR method was developed for the on-line monitoring of alkali-free cloth/phenolic resin prepreg during its manufacturing process. First, the sizing content of the alkali-free cloth was analyzed, and then the resin, soluble resin and volatiles content of the prepreg was analyzed simultaneously using the FT-NIR spectrometer. Partial least square (PLS) regression was used to develop the calibration models, which for the sizing content was preprocessed by 1stDER +MSC, for the volatile content by 1stDER +VN, for the soluble resin content by 1stDER +MSC and for the resin content by the VN spectral data preprocessing method. RMSEP of the prediction model for the sizing content was 0.732 %, for the resin content it was 0.605, for the soluble resin content it was 0.101 and for volatiles content it was 0.127. The results of the paired t-test revealed that there was no significant difference between the NIR method and the standard method. The NIR spectroscopy method could be used to predict the resin, soluble resin and the volatiles content of the prepreg simultaneously, as well as sizing content of alkali-free cloth. The processing parameters of the prepreg during manufacture could be adjusted quickly with the help of the NIR analysis results. The results indicated that the NIR spectroscopy method was sufficiently accurate and effective for the on-line monitoring of alkali-free cloth/phenolic resin prepreg.     

直升机尾梁用碳／环氧复合材料的性能

介绍了一种适用于制造直升机主承力构件－尾梁的改性环氧树脂／T300碳纤维预浸料及其复合材料的工艺性能和主要力学性能。     

Void formation model and measuring method of void formation condition during hot pressing process

For resin matrix composites, voids are common defects that can seriously deteriorate the properties of the composite parts. Thus, the elimination of voids is a crucial element in controlling the manufacturing process of composite parts. This article focuses on void formation originating from hygroscopic water for resin matrix composite laminates prepared with hot pressing process. The Kardos void formation model was developed to analyze the critical resin pressure for the initiation of voids, and the influencing factors were investigated experimentally to validate the modified model. It is found that resin pressure and gel temperature are the two key parameters to control void defects and that entrapped air in prepreg stacks must be considered in the void formation model. Furthermore, a simple method was established to measure the relationship between porosity and the processing parameters, and the void formation conditions of the resin and the prepreg stack were also studied. The theoretically predicted void formation conditions and the experimental results were compatible for the studied cases. These results are valuable for eliminating void defects, optimizing processing parameters, and enhancing the performance of composite parts. POLYM. COMPOS., 31:1562–1571, 2010. © 2009 Society of Plastics Engineers     

树脂基复合材料湿法缠绕成型研究进展

缠绕成型可获得性能优异的复合材料及其制品.相对于干法缠绕成型而言,湿法缠绕成型可有效降低复合材料的制造成本.本文简要介绍了湿法缠绕用增强材料的状况,综述了湿法缠绕用树脂基体和湿法缠绕工艺的研究进展     

The development of an epoxy resin system for the injection molding of long-fiber epoxy composties

The Combination of reaction injection molding and pultrusion has resulted in a new processing technique, RIM-Pultrusion, Which has been used to produce a thermoplastic epoxy prepreg. This prepreg has been used to produce a long-fiber injection molded phenoxy/carbon fiber composite with near-Zero void content. A heat-activated curing system has been developed, which allows injecton molding of the prepreg to form a thermostet long-finer epoxy/carbon finber composite. The RIM- pultrusion conditions for producing an injection moldable prepreg are described. Capillary rheomety is used to study the epoxy resin to determine the proper molar ratio for RIM-Pultrusion. The long-fiber epoxy compostie is analyzed with dynamic mechanical analysis (DMA) and Fourier transform infrared spectroscopy (FTIR). Also., the impact strength and solvent resistance of the long-fiber composite are examined. The properties of the thermoset long-fiber epoxy xomposite are compared to those of a thermoplastic injection molded long-fiber phenoxy composite.