纤维增强树脂复合材料3D打印流场分析与仿真

以纤维增强树脂基复合材料为研究对象,该材料由碳纤维和聚乳酸高分子材料复合而成。利用ANSYS CFX软件模块,对复合材料的流体状态和压力场进行了数值仿真,探究了以熔融沉积(FDM) 3D打印工艺制备纤维增强复合材料的流动特性和打印机理。首先,结合纤维增强复合材料的流动和受力规律,建立了打印流道及复合材料的三维模型;其次,描述了用于数值仿真复合材料的参数,得到了纤维增强树脂复合材料熔融成型时内部流场状态和界面压力分布,并进行了分析讨论;最后,通过实验验证了3D打印用于纤维增强树脂复合材料成型制造的可行性。研究结果为纤维增强树脂基复合材料的3D打印应用提供了必要的仿真与实验基础。     

3D打印用聚乳酸复合材料进展

聚乳酸(PLA)作为一种生物可降解聚合物已成为3D打印领域中的主要原料,但是,其脆性较大、耐热性能解差等缺陷限制了其应用。通过将聚乳酸与纤维、纳米填料等以一定方法制备聚乳酸复合材料,克服了聚乳酸的性能缺陷,具有了更为显著的性能优势,可以扩大PLA在3D打印的应用范围。通过查阅近5年3D打印用PLA复合材料方面的研究文献,对3D打印用PLA复合材料的类型进行了分类并对其研究进展进行了整理。综述了近年来研究较多的聚乳酸复合材料的制备方法、打印工艺及性能特点,主要包括聚乳酸/天然植物纤维、聚乳酸/碳纤维、聚乳酸纳米等复合材料,得到了3D打印用PLA复合材料存在的主要问题,并展望其未来的发展方向。     

用于3D打印的微晶纤维素/聚乳酸复合材料制备与性能研究

以微晶纤维素（MCC）为增强材料、聚乳酸（PLA）为基体,通过高温熔融共混、挤出、拉丝等流程,制备适用于熔融沉积成型（FDM）3D打印技术的MCC/PLA复合材料,并通过FDM型3D打印机打印出成品。讨论了MCC添加量对该复合材料的力学性能、热性能、微观结构以及3D打印性能的影响。研究结果表明,随着MCC添加量的增加,复合材料的力学性能呈现先增高后下降的变化趋势,当MCC添加量为3%时,其拉伸强度和弯曲强度达到最高,分别为54.55 MPa和64.25 MPa。红外分析证实了微晶纤维素与聚乳酸在熔融时发生了接枝共聚反应。热性能分析表明,添加少量MCC,可以提高复合材料的热稳定性和PLA的结晶度。MCC添加量为3%的MCC/PLA复合材料其力学性能、打印性能和外观达到最佳,可应用于FDM型3D打印技术。     

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。     

聚乳酸/玄武岩纤维复合材料的制备及性能研究

利用混杂原理,先将玄武岩纤维与聚乳酸纤维混合制成针刺毡,再与聚乳酸树脂复合,以提高树脂基体对增强体结构的渗透和结合性能。采用正交试验法,以混杂针刺毡中聚乳酸纤维含量、复合层压压力、复合层压温度为影响因素,讨论了混杂复合层压工艺对复合材料力学性能的影响。结果表明,采用混杂复合工艺有利于复合材料力学性能的改善,且混杂纤维含量在一定范围内时,复合材料的力学性能会随着混杂纤维含量的增加而线性增强,同时复合层压压力的增加也有利于复合材料力学性能的改善;采用混杂复合工艺时,复合层压温度对复合材料力学性能的影响规律不同于传统层压复合时复合层压温度对复合材料力学性能的影响,复合层压温度过高不利于复合材料力学性能的提高。     

3D打印纳米纤维素增强聚乳酸血管支架的体外力学性能研究

动脉粥样硬化疾病是当今人们生命健康的巨大威胁,而血管内介入治疗是最有效的治疗方法之一。金属血管支架是治疗动脉血管疾病的主要手段,但植入血管后会导致支架血栓和支架内再狭窄等问题。生物可吸收血管支架是有望解决支架血栓和支架内再狭窄的新一代血管支架。本文采用3D打印熔融沉积成型技术,分别成型具有不同壁厚、直径,以及采用不同打印填充路径的聚乳酸血管支架和纤维素纳米纤维/聚乳酸复合材料支架,采用平面压缩法和三点弯曲法对其进行体外力学性能测试,获得支架的径向支撑性能和纵向柔顺性能。研究结果表明:相比聚乳酸支架,复合材料支架的径向支撑性能最高提升了47.6%;在相同的支架壁厚和支架直径情况下,复合材料血管支架的纵向柔顺性高于聚乳酸血管支架,提升了20.2%。此外,极差分析结果表明,壁厚对支架体外力学性能影响最大,其次是支架直径,打印填充路径对支架体外力学性能影响较小。本研究的成果为新型生物可吸收降解支架的研制提供了新的思路。     

熔融微分3D打印制造MWCNTs/PLA可导电功能性制品

3D打印技术发展已日趋成熟,其特殊的增材制造原理使得材料利用率极高,方便快捷的成型方法推动了3D技术的发展。但3D打印产品使用耗材单一、制品强度较弱、应用范围不广泛等缺点抑制了3D打印技术在传统塑料加工行业的应用。一种新型聚合物熔体微分3D打印设备,可使用碳纳米管(MWCNTs)/聚乳酸(PLA)复合材料制造可导电3D打印产品。结果表明:该复合材料(10%MWCNTs)导电制品导电率可达到1.6 S/m,且该复合材料具有优异的可打印性能;使用聚合物熔体微分3D打印机以纸片为基材打印制造简易电路图,该电路图在纸基板上附着力强;使用熔体微分3D打印机制作防静电托盘制品,SEM图像表明,该托盘制品层与层之间结合紧密,成型精度以及刚度均可符合使用要求。通过实验对比,验证了该新型聚合物熔体微分3D打印机对MWCNTs/PLA复合材料制备可导电制品具有可行性,且可为3D打印电路板及防静电制品提供理论基础和技术指导。     

打印温度对3D打印用黄芪药渣/聚乳酸材料性能的影响

为了探究黄芪药渣/聚乳酸(APS/PLA)材料3D打印过程中打印温度参数对产品性能的影响,以熔融挤出法制备了黄芪药渣/聚乳酸复合材料(APS/PLA-CM)线材,采用熔融沉积成型(FDM)-3D打印工艺打印试样,研究了打印温度对复合材料力学性能及热性能的影响.通过力学测试及扫描电子显微镜(S EM)观察层间结合情况发现...     

纤维增强复合材料3D打印研究进展

3D打印技术的快速发展使对3D打印制品强度的需求日趋增高,但传统3D打印耗材无法同时满足良好的打印效果和较高的强度,纤维增强成为解决上述问题的1种有效途径。介绍了国内外3D打印纤维增强复合材料的成形工艺研究,按增强纤维的长度将增强方式分为长纤维增强和短纤维增强,其中,将长纤维增强按照纤维嵌入基体的顺序分类为长纤维直接增强和和长纤维间接增强,将短纤维增强按照增强工艺分类为共混-挤出制丝-打印增强、共混-光固化打印增强、共混-直接挤出打印增强。运用熔体微分3D打印机引出了熔体微分3D打印纤维增强复合材料的概念。     

芳纶增强复合材料波纹夹层3D打印与力学性能研究

为解决波纹夹层结构传统制备方法存在的问题,采用熔融沉积(FDM)3D打印技术制备芳纶增强聚乳酸复合材料波纹夹层结构,并研究切片层高与打印温度对波纹夹层结构力学性能的影响。结果表明:当试样的切片层高为0.1 mm,打印温度为210℃时,复合材料波纹夹层结构的力学性能最好;试样的弯曲强度和冲击强度与切片层高呈负相关;随着打印温度的升高,试样的弯曲强度和冲击强度呈现先增大后减小的趋势。通过分析复合材料电镜图发现,切片层高的降低,有利于芳纶与聚乳酸基体的结合。     

聚乳酸/碳纤维复合材料的3D打印线丝制备及其性能研究

本研究用高混机充分混合碳纤维(CF)和聚乳酸(PLA),再通过单螺杆挤出机制备出聚乳酸/碳纤维(PLA/CF)复合材料线丝,并成功地制备3D打印试样。通过测试PLA/CF复合材料线丝的力学性能,热性能,断面形态,发现PLA/CF复合材料线丝的耐热性高于纯PLA线丝,并且CF含量为1%的复合材料线丝的断裂强度可达70 MPa,高于纯PLA线丝的断裂强度,证明CF对PLA本体有增强效果。但随CF含量增加,断裂强度却有一定程度的下降,这可能是高含量CF的分散和复合材料的界面等因素影响的结果。     

Poly(lactic acid)–thermoplastic poly(ether)urethane composites synergistically reinforced and toughened with short carbon fibers for three‐dimensional printing

In this study, we prepared short‐carbon‐fiber (CF)‐reinforced poly(lactic acid) (PLA)–thermoplastic polyurethane (TPU) blends by melt blending. The effects of the initial fiber length and content on the morphologies and thermal, rheological, and mechanical properties of the composites were systematically investigated. We found that the mechanical properties of the composites were almost unaffected by the fiber initial length. However, with increasing fiber content, the stiffness and toughness values of the blends were both enhanced because of the formation of a TPU‐mediated CF network. With the incorporation of 20 wt % CFs into the PLA–TPU blends, the tensile strength was increased by 70.7%, the flexural modulus was increased by 184%, and the impact strength was increased by 50.4%. Compared with that of the neat PLA, the impact strength of the CF‐reinforced composites increased up to 1.92 times. For the performance in three‐dimensional printing, excellent mechanical properties and a good‐quality appearance were simultaneously obtained when we printed the composites with a thin layer thickness. Our results provide insight into the relationship among the CFs, phase structure, and performance, as we achieved a good stiffness–toughness balance in the PLA–TPU–CF ternary composites. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46483.     

Preparation,properties, and laser processing of poly(ɛ-caprolactone)/poly(lactic acid) blends with addition of natural fibers as a potential for printing plates application

In this research, biodegradable blend of poly(ɛ-caprolactone) (PCL) and poly(lactic acid) (PLA) is proposed as a new material for the production of a printing plate for embossing process. Printing plates for embossing consist of raised printing elements and recessed nonimage elements. In production of printing plates, laser technology was used in order to form a relief printing plate. The embossing process is based on the principle of the pressure of the relief printing plate into the printing substrate, which causes the controlled deformation of the substrate and three-dimensional (3D) effect. Coir fibers (CFs) were added as a natural filler to PCL/PLA blends to improve and adjust the properties of produced blends. Scanning electron microscopy micrographs, dynamic mechanical analysis analysis, roughness, and hardness were measured on prepared materials, and 2D and 3D microscopy was conducted on laser engraved printing plates. Results have shown that the addition of CFs improved the mechanical properties of produced materials. DMA results indicate the semicrystalline structure of all prepared blends, and that the addition of CFs raises the elasticity of the composites. Laser engraving showed that it is possible to engrave the produced biodegradable materials and to use it as a material for production of printing plates.     

3D printing of copper particles and poly(methyl methacrylate) beads containing poly(lactic acid) composites for enhancing thermomechanical properties

Poly(lactic acid) (PLA) composite filaments with different copper (Cu) contents as high as 40 and 20 wt% of poly(methyl methacrylate) (PMMA) beads have been fabricated by twin-screw extruder for 3D printing. A fused-deposition modeling (FDM) 3D printing technology has been used to print the PLA composites containing hybrid fillers of Cu particles and PMMA beads. The morphology, mechanical, and thermal properties of the printed PLA composites were investigated. The tensile strength was slightly decreased, but storage modulus and thermal conductivity of PLA composites were significantly improved by adding Cu particles in the presence of PMMA beads. The PLA composites with hybrid fillers of 40 wt% of Cu particles and 20 wt% of PMMA beads resulted in thermal conductivity of 0.49 W m⁻¹ K⁻¹ which was three times higher than that of the bare PLA resin. The facilitation of the segregated network of high-thermally conductive Cu particles with the PMMA beads in PLA matrix provided thermally conductive pathways and resulted in a remarkable enhancement in thermal conductivity.     

Anisotropy of poly(lactic acid)/carbon fiber composites prepared by fused deposition modeling

It is well known that 3D printed parts prepared by fused deposition modeling (FDM) exhibit large anisotropy of mechanical properties. In this article, poly(lactic acid; PLA)/carbon fiber (CF) composites with different built orientations (X, Y, Z) were prepared by FDM. The effects of printing temperature, speed, orientations, and layer thickness on the mechanical properties of the composites were systematically investigated. The mechanical properties of PLA/CF composites show more significant anisotropy. The orientation of the fibers along the printing direction is displayed by scanning electron microscopy. Printing parameters bring almost no effect on mechanical properties of the X-construct oriented specimen, and bring obvious effect on those of the Y-construct oriented specimen and Z-construct oriented specimen. According to the analysis, carbon fiber can amplify this anisotropy from layer fashion, and the key factors from printing parameters are porosity and bond strength between fuses. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48786.     

CF表面改性对3D打印PLA/CF试件力学性能的影响

以短切碳纤维(CF)和聚乳酸(PLA)为实验原料,用硝酸在恒温水浴加热条件下对短切CF进行表面处理,并做表征,结果表明,硝酸处理后短切CF的表面粗糙度显著增大,并且出现了较多的沟槽;硝酸处理后CF(002)和(100)石墨晶面的衍射强度有明显提升,并且CF表面C元素含量相对未处理的有所降低,而O元素和N元素的含量有所提高。在双螺杆挤出造粒机上分别配比CF质量分数为5%的未经硝酸处理和硝酸处理后的PLA/CF粒料颗粒,并在粒料3D打印机上制得两种纤维增强的拉伸、弯曲、冲击试件,研究了短切CF的表面处理对3D打印PLA/CF试件综合力学强度的影响。结果表明,硝酸处理后PLA/CF试件的综合力学性能有明显提升。     

Enhancing the mechanical properties of 3D printed polylactic acid using nanocellulose

We report here a systematic investigation of the mechanical properties of polylactic acid (PLA) processed by fused filament fabrication (FFF) 3D printing vs PLA processed by compression molding. Our results show that the tensile strength and modulus of FFF-PLA is 49% and 41% lower, respectively, than compression molded samples of PLA. We also demonstrate here an approach to augment the mechanical properties of 3D printed PLA using nanocellulose. Incorporation of a small quantity (1 wt%) of cellulose nanofibers (CNF) was found to enhance the tensile strength and modulus of 3D printed PLA by 84% and 63%, respectively. X-ray microtomography was used to probe the morphology of 3D printed PLA and PLA/CNF composites. 3D printed PLA/CNF composites had significantly lesser voids as compared to neat 3D printed PLA. Differential scanning calorimetry study revealed that CNF can accelerate the nucleation and crystallization of 3D printed PLA leading to enhanced crystallinity. The thermal stability of 3D printed PLA/CNF composites was not compromised by the addition of CNF. The enhanced mechanical properties of 3D printed PLA/CNF composites can be ascribed to higher crystallinity and lesser defects.     

Development of fish scale particle reinforced PLA filaments for 3D printing applications

This study investigated incorporating fish scale powder (FSP) as a bio-filler into polylactic acid (PLA) raw material for polymeric 3D printing. The PLA/FSP filaments were evaluated for various properties (tensile strength, tensile modulus, elongation, diameter deviation, thermogravimetric analysis, surface roughness, and SEM analysis) at different compositions (PLA, PLA/FSP10, PLA/FSP20, and PLA/FSP30 wt%). The results revealed that PLA filaments reinforced with 20 wt% FSP achieved the highest tensile strength, and modulus is 44.49 MPa and 2.83 GPa. The filaments reinforced with neat PLA and PLA with 10 wt% fish scale powder exhibited minor diameter deviations of +0.002 and −0.002. The surface roughness of the neat PLA filament is notably higher, registering a value of 1.459 μm. This finding highlights the importance of considering surface characteristics in filament selection for 3D printing applications. The microscopic analysis confirmed a uniform distribution of FSP particles in the 20 wt% composition PLA/FSP filaments. These results suggest that PLA/FSP (20 wt%) is an optimal feedstock for 3D printing, especially in developing biomaterials like bio-scaffolds.     

连续碳纤维增强热固性酚醛树脂复合材料的3D打印工艺及性能研究

针对连续碳纤维增强热固性酚醛树脂复合材料3D打印成型工艺的技术难题,本文提出了浸渍-原位预固化-后固化的3D打印成型方案,实现了连续碳纤维增强热固性酚醛树脂复合材料的3D打印成型,并研究浸渍温度对酚醛树脂接触角与表面张力,以及打印工艺对样件形貌和力学性能的影响规律。结果表明:当浸渍温度为40 ℃,预固化温度为180 ℃时,纤维-树脂界面结合效果最佳,原料具备成型条件;当打印间距为0.5 mm时,样件的弯曲强度及模量达到最大值,分别为660.00 MPa和57.99 GPa,层间剪切强度达到20.14 MPa。此连续碳纤维增强热固性酚醛树脂复合材料一体化制备工艺解决了3D打印热固性树脂原位成型难的问题,为制备具有复杂结构的连续纤维增强热固性树脂复合材料提供了参考。