Polar-coordinate line-projection light-curing continuous 3D printing for tubular structures

3D printing techniques offer an effective method in fabricating complex radially multi-material structures.However,it is challenging for complex and delicate radially multi-material model geometries without supporting structures,such as tissue vessels and tubular graft,among others.In this work,we tackle these challenges by developing a polar digital light processing technique which uses a rod as the printing platform.The 3D model fabrication is accomplished through line projection.The rotation and translation of the rod are synchronized to project and illuminate the photosensitive material volume.By controlling the distance between the rod and the printing window,we achieved the printing of tubular structures with a minimum wall thickness as thin as 50 micrometers.By controlling the width of fine slits at the printing window,we achieved the printing of structures with a minimum feature size of 10 micrometers.Our process accomplished the fabrication of thin-walled tubular graft structure with a thickness of only 100 micrometers and lengths of several centimeters within a timeframe of just 100 s.Additionally,it enables the printing of axial multi-material structures,thereby achieving adjustable mechanical strength.This method is conducive to rapid customization of tubular grafts and the manufacturing of tubular components in fields such as dentistry,aerospace,and more.

A Rapid Generation Method of Character Doll with Rotatable Limbs Oriented to 3D Printer

Currently, 3D printing of the character dolls is a very practical application for the average person. But the model of doll which can be obtained is static so the posture of the doll is single. On the other hand, the modification of the model is very difficult to non-professions. This paper proposes an rapid generation method of character doll with rotatable limbs, which is through adding the sphere joint to the doll＇s model automatically. After the model is segmented by drawing a line interactively, the sphere joint is created based on the segmentation boundary through entity modeling method. Lastly the two models of the doll and the joint are composited and printed. Some doll＇s model are tested on the FDM（Fused Deposition Modeling） 3D printer using this process. The results are more interesting and the efficiency has been greatly improved compared with modifying the model manually.

Structure Design of Underwater Micro Robot

A submergible robot model has been presented, and for 3D printing measures, their parts have been modified enough. It has been shown in our design that using printable connectors—a few engines and weight arrangements can be carried out, permitting distinctive moving prospects. After presenting our configuration and delineating a bunch of potential structures, a helpful model dependent on open-source equipment and programming arrangements has been presented conditionally. The model can be effectively tried in a few makes-a plunge streams and lakes throughout the planet. The unwavering quality of the printed models can be strained distinctly in generally shallow waters. Nonetheless, we accept that their accessibility will inspire the overall population to construct and test submerged robots, subsequently accelerating the improvement of imaginative arrangements and applications.

The Effect of Consumption on the Appearance of Closers Implemented by 3D Printer Technology (FDM)

The shift towards sustainability in the fashion industry has become an urgent necessity and a national duty, where the life cycle of garments poses a negative impact on the environment, which increases strongly with the huge increase in the daily consumption of garments and fast fashion. One of the most prominent solutions that have been proposed is to change the manufacturing system in a way that would help reduce costs, reduce supply and provide products that are more closely related to the individual customer need. Accessories such as (closers) are an important part of the fashion industry, and therefore, this study aimed to produce closers using (FDM) technology, which is one of the least expensive and most widespread 3D printing technologies. These closers are then tested in the laboratory according to AATCC standard specifications for garments and closers to ensure the applicability of this technology in the implementation of closers for designers and manufacturers in medium and small facilities. This study relied on the experimental exploratory approach, and the results proved the success of the proposed closers, as the implemented models passed the standard tests with distinction.

热处理工艺对3D打印PLA试件力学性能的影响

在熔融堆积成形制造技术中,成形制品的热处理工艺对于其力学性能和外观有较大影响。以熔体微分粒料3D打印机为实验平台,以PLA为实验材料,在相同工艺参数下,打印15个拉伸试件,并将其分成5组,其中,第一组不做处理,第二至第四组分别在不同的温度下进行热处理。将5组试件进行拉伸测试,得到每组平均最大拉伸强度,并取样进行X-射线衍射分析,通过Jade软件对图谱进行结晶度计算,得到了在不同温度下试件的结晶度,分析了热处理温度、最大拉伸强度、结晶度之间的相互关系。实验结果表明:随着热处理温度的提高,试件的最大拉伸强度和结晶度都呈先增大后减小的趋势,且试件的拉伸强度和结晶度成正相关关系。热处理温度在100~120℃之间时,试件的拉伸强度最大;在100℃时,结晶度达到最高。仅从试件的拉伸强度考虑,最佳热处理温度为100℃。

3D打印在教育中的创新应用

随着3D打印的兴起,不断有学者将其应用于教育中。通过文献并结合国内外3D打印在教育中的案例,详细分析、总结了其在教育中的具体应用及效果,同时对其发展进行了预测。

FDM彩色3D打印机控制系统的研究

目前FDM 3D打印机存在成型件颜色单一的缺陷,为了解决这一问题,通过对现有挤出系统及传统配色标准的研究,提出了CMYKW的配色方案,并对标准G-Code指令进行研究。开发了控制电路板,通过打印实验,验证了CMYKW的配色方案及控制系统有效性。实现了彩色3D打印,为进一步研究彩色3D打印技术提供了一种解决方案。

粒料3D打印机机头传热结构优化设计

在熔融沉积成型制造技术中,热流道及喷头的温度场对聚合物的流动及沉积有很大影响。针对现有的聚合物熔体微分粒料3D打印机,建立机头的三维模型,运用有限元分析的方法得到其温度场分布。模拟结果表明,热源与喷头之间存在较大温差,且热流道温度分布不均匀。针对以上结构的缺点,提出机头结构的优化方案,并对其所用材料进行改进。对优化后的机头再次进行有限元热分析,分析结果表明,优化后的机头热源与喷头之间的温差显著减小,且热流道的温度分布趋于均匀。因此,3D打印机机头结构优化方案对于聚合物熔体的稳定输送及沉积成型有重要意义。

FDM彩色3D打印机挤出装置结构设计

色彩信息是一个物体不可或缺的元素,当前基于FDM的3D打印机无法完成彩色3D打印,从而阻碍了3D打印件视觉表现力。为了解决这一问题,在深入研究FDM 3D打印机工作原理的基础上,对传统3D打印机挤出装置进行了改进,设计了一套基于CMYK-W的彩色3D打印机挤出装置。通过打印试验,将打印件的色彩信息与标准比色卡比对,验证了所设计的彩色3D打印机挤出装置达到设计要求,为彩色3D打印技术的进一步研究提供了一种有效的解决方案。

基于三维扫描和3D打印的鼻套模具制作关键技术

为解决喷火表演鼻子容易烧伤的问题,运用三维扫描技术进行反求设计,并用3D打印方法制造。首先,使用三维扫描仪获得鼻子部位扫描曲面,运用Meshmixer软件对曲面处理得到鼻子三维数字模型;其次,绘制鼻套设计所需三维模型并与鼻子三维模型进行布尔运算,得到鼻套模具三维模型,将模型数据导出为切片软件可识别的STL文件;然后,设置熔融沉积成型3D打印机参数、添加外部冷却设备,以聚乙烯醇(PVA)为打印耗材,对鼻套模具进行打印;最后,使用硅胶浇注、热水溶模的方法得到一体成型的鼻套模型。结果表明:该方法能够有效应用于鼻套模型的制作,实现三维扫描曲面壳体到模具实体的转化,为类似产品的制造提供了一种方法。

Optimizing mechanical properties of HIPS fabricated with low-cost desktop 3D printers:investigating the impact of process parameters

Recently,low-cost desktop three-dimensional(3D)printers,employing the fused deposition modeling(FDM)technique,have gained widespread popularity.However,most users cannot test the strength of printed parts,and little information is available about the mechanical properties of printed high-impact polystyrene(HIPS)parts using desktop 3D printers.In this study,the user-adjustable parameters of desktop 3D printers,such as crisscross raster orientation,layer thickness,and infill density,were tested.The experimental plans were designed using the Box-Behnken method,and tensile,3-point bending,and compression tests were carried out to determine the mechanical responses of the printed HIPS.The prediction models of the process parameters were regressed to produce the optimal combination of process parameters.The experimental results showcase that the crisscross raster orientation has significant effects on the flexural and compression strengths,but not on the tensile strength.With an increase in the layer thickness,the tensile,flexural,and compression strengths first decreased and then increased,reaching their minimum values at approximately 0.16 mm layer thickness.In addition,they all increased with an increase of infill density.It was demonstrated that when the raster orientation,layer thickness,and infill density were 13.08°/–76.92°,0.09 mm,and 80%,respectively,the comprehensive mechanical properties of the printed HIPS were optimal.Our results can help end-users of desktop 3D printers understand the effects of process parameters on the mechanical properties,and offer practical suggestions for setting proper printing parameters for fabricating HIPS parts.

3D打印机断料检测提醒及视频实时监控装置的设计

为改善现有3D打印机断料检测系统自动化程度不高、功能不全的问题,设计实现了一个3D打印机断料检测提醒及视频实时监控装置.装置主要由断料检测、提醒模块和视频监控与控制模块组成.断料检测与提醒模块采用光电传感器完成发出信号和主动控制打印机暂停的功能,使用蜂鸣器和LED灯作为近距离提醒,使用单片机和GSM模块负责远程提醒.视频监控模块采用Raspberry Pi开发板、Web摄像头、声音传感器和Android客户端,实现对实时视频的获取、传输以及客户端通过发出报警信号远程人工控制打印机的暂停.实现了断料检测、报警、主动控制和人工监控的功能,既整合了现有断料检测装备的功能,又在已有功能基础上进行扩展,提升了自动化程度和人工远距离的可操控性.

基于ARM的桌面型3D打印机控制系统的设计与优化

在分析传统3D打印机结构组成和工作原理的基础上,选用ARM Cortex-M3内核LPC1768为微控制器。采用熔融沉积造型技术(FDM),针对传统采用单路固定数据传输导致打印速度过慢的问题,采用打印效率和打印速度对偶分析方法,融入频分多路复用方法实现桌面型3D打印机的多目标集优化控制,并对速度量化指标进行评估,根据不同频率传送各路打印请求信息,实现打印速度提升。通过仿真并搭建测试平台,最后对设计的3D打印机进行性能测试,验证该桌面型3D打印机控制系统设计的可行性与有效性。

Analysis on nasal airway by using scale-adaptive simulation combined with standard κ-ω model and 3D printing modeling physical experiment

The physiological structure of the upper respiratory tract is complex and varies with each individual,and the circulating air has turbulent performance.In this paper,based on computed tomography(CT)medical images published online and the three-dimensional(3D)printing technology,a 3D model of the human upper respiratory tract was reconstructed and an experimental device of the upper respiratory tract was made.We implemented the respiratory experiment and measured the flow rate,and a scale-adaptive κ-ω model is applied for numerical simulation,the results are in good agreement.The flow field during respiratory was analyzed by coronal velocity cross section,vortex line and particle tracks.We found that the relatively strong shear effect happens at the areas of nasal valve and nasopharynx.In the middle and upper nasal tract,vortex line separation occurs and there is significant passage effect.The results indicate that SAS method is effective in studying upper respiratory airflow.

Effects of Selected Printing Parameters on the Fire Properties of 3D-Printed Neat Polylactic Acid(PLA)and Wood/PLA Composites

The effects of selected printing parameters on the fire properties of additively produced composites from neat polylactic acid(PLA)and wood/PLA filaments were investigated.The reaction to fire of the 3D-printed specimens was tested according to the ISO 5660-1 cone calorimeter test method.The results showed that the properties of the specimens when exposed to fire were significantly affected by the incorporation of wood flour into the PLA filament.It was also interesting that PLA specimens had much better reactions to fire than the wood/PLA specimens.Time to ignition was found to be much longer in the 3D-printed PLA specimens.Although the maximal heat release rate was a little higher in the PLA than the wood/PLA specimens,the duration of HRR was longer for the wood/PLA specimens.The initial mass of the specimens was smaller in the wood/PLA composites,but during the radiant heat exposure the mass typically decreased slower than in the PLA specimens.

基于STM32矿用3D打印机

3D打印潮流正迅速影响各行各业,在此涉及到一款以STM32为控制核心,矿用的3D打印机,能够在短时间内快速成型,并且使用模糊PID控制对打印机内部的各个方向的运动曲线进行处理,用于煤矿的日常工作当中。

Parametric Design Used in the Creation of 3D Models with Weaving Characteristics

The art of weaving is an ancient and beautiful technique that never fades. Various weaving techniques and various totem patterns contain rich cultural connotations. The development of cultural and creative industries often uses existing environmental materials to deconstruct and use them in innovative ways to reinspire and present another style. With the rapid progress of computer-aided design technology, digital applications in the design practice has become an important element, and parametric design is the best popular design method in recent years. This paper is mainly in view of the weaving crafts in the traditional culture of the world occupies an important role, and the precious traditional weaving crafts gradually lost. Therefore, it is planned to construct a 3D model with knitting characteristics through a parametric design method, and print out the prototype through the 3D printing mechanism, that is, the traditional craftsmanship is integrated into the modern manufacturing process with innovative techniques, to show the new style of this weaving craft culture that is different from the past, so that it not only retain its inherent spirit, but also can promote this ideal of cultural creativity.

3D printed millireactors for process intensification

The scope of the present research aims at demonstrating the 3D printing use in the manufacturing of microchannels for chemical process applications. A comparison among digital model processing applications for 3D print(slicers) and a print layer thickness analysis were performed. The 3D print fidelity was verified in several devices, including the microchannels’ printing with and without micromixer zones. In order to highlight the 3D print potential in Chemical Engineering, the biodiesel synthesis was also carried out in a millireactor manufactured by 3D printing. The millireactor operated under laminar flow regime with a total flow rate of 75.25 ml·min^-1(increment of about 130 times over traditional microdevices used for biodiesel production).The printed millireactor provided a maximum yield of Ethyl Esters of 73.51% at 40 ℃, ethanol:oil molar ratio of7 and catalyst concentration of 1.25 wt% and residence time about 10 s. As a result of flow rate increment attained in the millireactor, the number of required units for scaling-up the chemical processes is reduced. Using the approach described in the present research, anyone could produce their own millireactor for chemical process in a simple way with the aid of a 3D printer.

未来的3D打印房屋

A US company,Mighty Buildings,can 3D⁃print a house and stick it in your back⁃yard for just￡75,000.Mighty Buildings uses a 20ft⁃high printer stored in a California warehouse to make you a small cottage(小屋)and ships it to your property on a truck.

Development of Broadband LHCP Pyramidal Horn Antenna with Septum Gaussian Profile Polarizer for CP-SAR Sensor Onboard Microsatellite

Horn Antenna has many applications such as communication, radar, and standard reference antenna for measurement. In this research, we designed a pyramidal horn for a Circularly Polarized Synthetic Aperture Radar (CP-SAR) sensor onboard a microsatellite. We utilized a 3D printer with Fused Deposition Modelling (FDM) technology for fast, low-cost, and low-weight production. Polylactide (PLA) material was used to construct 3D structures, and a copper conductive coating was painted on its surface. Gaussian distribution function was employed to create a septum polarizer profile. NPC-220 A with 1.6 thickness and 2.17 dielectric constant was used to make a microstrip monopole antenna and stripline feeding to feed the pyramidal horn to generate TE01 mode at one side of the waveguide. The design, parametric studies, and measurements are discussed in this paper. The designed antenna can achieve wide bandwidth 28% of 3 dB axial ratio, and more than 22% of s11 ≤ −10 dB in working frequency that is acceptable for CP-SAR requirement on the microsatellite.