连续与短切CF增强PA6复合材料双喷头3D打印工艺参数优化

为提升连续碳纤维(CF)和短切CF增强尼龙6复合材料3D打印制件的力学性能、优化3D打印基础工艺参数，基于熔融沉积型3D打印工艺，通过自主搭建的双喷头3D打印实验平台制备打印制件，并以此为研究对象，设计4因素3水平正交试验，研究连续CF隔层数、连续CF打印间距、打印温度、打印速度四种工艺参数对打印制件拉伸强度和弯曲强度的影响。采用极差分析法得到最佳工艺参数组合，验证正交试验结果。使用扫描电子显微镜观察拉伸制件和弯曲制件的断裂面微观形貌，进一步探究了打印制件的层间断裂形貌特性和层内丝材分布规律。结果表明，当连续CF隔层数为1、连续CF打印间距为0.5 mm、打印温度为250℃、打印速度为900 mm/s时，打印制件的层内沉积线之间孔隙较少，层间结合效果较好，其拉伸强度和弯曲强度达到最高，分别为109.73 MPa和119.14 MPa，与短切CF增强尼龙6复合材料相比，拉伸强度提升了249%，弯曲强度提升了286%。     

3D打印工艺对木粉/聚乳酸材料性能的影响

采用熔融沉积法(FDM)3D打印工艺制作木粉(WF)与聚乳酸(PLA)质量比为3：100的WF/PLA复合材料,研究了打印工艺参数对WF/PLA复合材料力学性能的影响,确定了最佳打印工艺条件,然后,在最佳条件下,打印WF与PLA质量比为11：100的WF/PLA复合材料,并且,将该材料的性能与FDM 3D打印PLA试样进行了对比。结果表明,当打印层厚度为0.1 mm、打印温度为220℃、打印速度为50 mm/s、填充密度为100%、沉积角度为0时,WF/PLA复合材料的力学性能最佳。在该工艺条件下,WF与PLA质量比为11：100的WF/PLA复合材料的拉伸强度、拉伸模量、弯曲强度、弯曲模量和冲击强度分别为纯PLA的89.61%、97.56%、82.86%、92.40%和95.04%,与纯PLA相比,复合材料的表面润湿性能较好,吸水率显著增大。     

3D打印参数对聚乳酸力学性能的影响

通过3D打印制备了聚乳酸试样。研究了打印温度、速度、方向和热床温度等打印参数对PLA拉伸和弯曲性能的影响。结果表明,适当的打印温度能改善试样内部层与层之间的熔接痕缺陷。较高的打印速度增强了PLA分子链的取向;适当的热床温度有利于PLA晶体的形成和生长,从而提高其力学性能。纵向打印试样的力学性能普遍优于横向打印的。当打印温度、速度、方向和热床温度分别为(210~215℃)、80 mm/s、纵向和50℃时,PLA试样的综合力学性能最佳。     

连续玻璃纤维增强聚丙烯复合板材的性能研究

利用熔融浸渍工艺制备了单向连续玻璃纤维增强聚丙烯(PP)预浸带,将其制成编织物后,采用层压成型工艺成功制备了连续玻璃纤维增强PP复合板材.考察了预浸带的浸渍效果,分析了取样方向和编织物层数对复合板材力学性能的影响规律.结果显示,预浸带具有良好的浸渍效果,当预浸带编织物层数为5层时,复合板材综合性能最佳.     

3D打印参数对柔性聚乳酸服装面料力学性能的影响

针对熔融沉积成型(FDM)3D打印技术,以柔性聚乳酸(PLA)为打印材料,探讨了分层厚度、打印速度、打印温度、填充角度以及填充密度对3D打印服装面料力学性能的影响。打印模型的力学性能以拉伸强度和弹性模量为评价标准,采用单因素、正交试验分析法得到最优打印参数。结果表明:当填充密度为20%、分层厚度为0.3 mm、打印温度为210℃、填充角度为45°、打印速度为80 mm/s时,打印制品的力学性能最佳。     

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。     

石墨烯增强尼龙复合材料3D打印工艺研究

研究的是石墨烯增强尼龙复合材料(Graphene-PA6)如何合理应用于熔融沉积制造(FDM)3D打印技术。通过熔融共混法制备了该复合材料,并设计了正交实验,对该材料的FDM工艺进行了详细研究,得出以下结论:基于Graphene-PA6材料,当设置FDM工艺参数喷嘴温度245℃,底板温度60~70℃,打印速度27 mm/s,喷嘴直径0.4 mm,层厚0.20 mm时,该复合材料的FDM工艺效果最好。对于制品力学性能结果值的影响程度由大到小分别是石墨烯含量、喷嘴温度、打印速度和底板温度。当石墨烯质量分数为0.05%时,用上述FDM工艺参数所打印出的成型件力学性能最佳。     

连续碳纤维增强聚乳酸复合材料的研究

采用自行设计组装的熔融浸渍流水线,以聚乳酸(PLA)为基体,连续碳纤维(CF)为增强体,制备连续碳纤维增强聚乳酸(CCF/PLA)预浸带。研究了加工温度、张紧力、牵引速度以及纤维含量对预浸带拉伸强度的影响。结果表明:在实验范围内,加工温度为220℃、张紧力为11 N、牵引速度为4 r/min时,预浸带拉伸强度最高,且拉伸强度随加工温度及纤维含量升高而增大。     

FDM工艺参数对聚乳酸/石墨烯复合材料制件弯曲性能的影响

为了提高聚乳酸(PLA)复合材料3D打印制件的性能,采用三因素三水平正交试验设计,研究了用熔融沉积成型(FDM)工艺3D打印PLA/石墨烯复合材料制件过程中,打印层高、填充密度以及构建取向对制件弯曲性能的影响。结果表明,石墨烯对PLA/石墨烯复合材料制件有较好增强效果,各试验参数对3D打印PLA/石墨烯复合材料制件弯曲强度的影响大小顺序为：构建取向>填充密度>层高,且当构建取向为侧立方式,填充密度为80%,层高为0.2 mm时,制件具有最佳的弯曲强度;对复合材料制件弯曲弹性模量的影响大小依次为：填充密度>层高>构建取向,且当构建取向为侧立,填充密度为80%,层高为0.1 mm时,制件具有最佳的弯曲弹性模量。     

打印方式对熔融沉积成型制品性能的影响

通过挤出成型制备了可用于熔融沉积成型(FDM)的聚乳酸(PLA)/麦秸粉复合线材,然后打印成标准测试样条。研究了填充密度、层厚、打印速度、温度对3D打印制品的密度、打印时间、弯曲强度、弯曲模量、冲击强度以及动态力学性能的影响。结果表明:当打印制品的填充密度从20%提高到100%时,可以获得更高的力学性能和模量,弯曲强度、弯曲模量、冲击强度、储能模量分别提高了88.46%、44.20%、75.93%、43.39%,打印时间则延长了50.82%;当层厚从0.2 mm增加到0.7 mm时,制品的弯曲强度、弯曲模量、冲击强度分别下降了42.01%、39.94%、44.27%,但打印时间缩短了70.65%;当打印速度从20 mm/s提高到60 mm/s时,制品的弯曲强度、弯曲模量、冲击强度分别下降了33.52%、39.71%、37.14%,但打印时间缩短了43.75%;此外,温度的升高有利于制品层间的结合,当温度从190℃升至240℃时,制品的弯曲强度、弯曲模量、冲击强度分别提高了55.82%、33.33%、25.08%,但对打印时间没有影响。     

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.     

Study on mechanical properties of powder impregnated glass fiber reinforced poly(phenylene sulphide) by injection molding at various temperatures

The prepreg of continuous glass fiber reinforced poly(phenylene sulphide) (PPS) was prepared using the powder impregnation technique and cut into the pellets, in which the length of glass fibers was the same as the pellets. After injection molding, the mechanical properties were tested and the effects of the pellet length, fiber content, and thermal treatment on the mechanical properties at different temperatures were studied. It is found that the tensile strength and flexural strength of 6‐mm pellet sample are slightly higher than that of 3‐ and 12‐mm pellet samples. The tensile strength, flexural strength, and modulus decrease significantly with increasing the temperature. The notched Izod impact strength at 85ºC is higher than both at 25ºC and 205ºC. At 205ºC, the glass fiber reinforced PPS composites can still keep better mechanical properties. When the fiber content ranges from 0 to 50%, the mechanical properties increase with increasing the fiber contents at different temperatures, except the notched Izod impact strength do not further increase at 145 and 205ºC with raising the fiber content from 40 to 50%. Thermal treatment could improve the mechanical properties of the composites at higher serving temperature. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

热塑性树脂熔融浸渍连续纤维装置

研制开发了一套热塑性树脂熔融浸渍连续纤维的小型装置,该装置主要包括分丝系统、浸渍系统和上光系统等部分,其特点是利用柱状辊系分散和浸渍纤维束,利用该装置可制备纤维质量比在30％－60％的连续纤维（碳纤维,玻璃纤维）增强热塑性树脂（聚丙烯、尼龙等）基预浸带。本文对浸渍装置的设计和工作原理进行了分析说明。     

FDM 3D打印工艺参数对PLA制件力学性能的影响

采用五因素四水平正交试验设计,对16组不同工艺参数(打印层厚、填充密度、打印温度、填充速度、外壳厚度)的FDM 3D打印聚乳酸(PLA)制件力学性能进行了测试和结果分析,确定了影响PLA制件力学性能的主要因素,其中,外壳厚度对制件力学性能影响最为明显,打印温度影响最小,同时分析得到了在打印层厚0.15 mm,填充密度40%,打印温度210℃,填充速度60 mm/s,外壳厚度1.6 mm条件下可获得力学性能最佳的制件。最后对试验数据进行回归分析,拟合得到了FDM打印工艺参数与PLA制件力学性能指标的数学模型;通过对不同打印工艺参数的试样进行试验验证,表明该模型拟合误差小(5%以内),可靠性高,可用来对FDM 3D打印制件的加工提供参考。     

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.     

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。     

连续玻纤增强聚丙烯预浸带熔融浸渍过程纤维断裂研究

为提高连续玻纤增强聚丙烯预浸带（PP/GF）性能,采用熔融浸渍法制备连续玻璃纤维增强聚丙烯预浸带,研究了PP熔体浸渍连续GF束过程。基于Weibull分布函数建立了纤维断裂数学模型,预测预浸带生产过程中纤维断裂率并描述实验结果。结果表明,模型与实验数据吻合较好,能够为工业化生产提供指导;纤维束在浸渍模具中受到树脂熔体的作用,及纤维与设备之间的摩擦是影响纤维断裂的主要因素,适当提高浸渍模具温度,降低纤维束牵引速度,增大浸渍模具间隙能有效降低纤维断裂率,提高工艺稳定性。     

3D打印PLA/CF便携式塑料挂钩

提出了一种区别于传统塑料挂钩的新型便携式挂钩研发思路,采用纤维增强聚乳酸复合材料并基于3D打印技术辅助完成了便携式挂钩的原理验证和零件设计。首先采用纤维增强聚乳酸复合材料3D打印弯曲试样进行了力学性能测试,结果表明纤维增强聚乳酸复合材料其力学性能满足用来辅助研发新型便携式挂钩的要求。其次利用3D打印技术对新型便携式挂钩进行了原理及原型的验证。     

Performance of long glass fiber‐reinforced polypropylene composites at different injection temperature

Long glass fiber‐reinforced polypropylene composites were prepared using self‐designed impregnation device. Effects of the different injection temperature on mechanical properties, crystallization, thermal, and dynamic mechanical properties of long glass fiber‐reinforced polypropylene composites were discussed. The differential scanning calorimetry (DSC) results indicate that the melting peak temperature of PP/LGF composites gradually reduced, however, the crystallinity of PP/LGF composites gradually increased with increasing injection temperature. Thermo‐gravimetric analyzer (TGA) results demonstrate that with increasing injection temperature, the temperature of the PP/LGF composites melt increased, the viscosity of the PP/LGF composites melt lowered, the mold filling of the PP/LGF composites melt was easy, the shear force of glass fiber was relatively low, which made the residual length of glass fiber in products increase. Dynamic thermal mechanical analyzer (DMA) results show that the storage modulus of PP/LGF composites is the highest while the injection temperature is at 290°C, and the peak value of tan σ of PP /LGF composites at 290°C is minimal, which indicates that the mechanical properties of PP /LGF composites at 290°C is the best. What' more, the injection temperature at 290°C significantly ameliorated “glass fiber rich skin” of products of glass fiber‐reinforced composites. J. VINYL ADDIT. TECHNOL., 24:233–238, 2018. © 2016 Society of Plastics Engineers