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Abstract

Currently, carbon fiber composite has been applied in the field of three-dimensional printing to produce the high-performance parts with complex geometric features. This technique comprise both the advantages of three-dimensional printing and the material, which are light weight, high strength, integrated molding, and without mold, and the limitation of model complexity. In order to improve the performance of three-dimensional printing process using carbon fiber composite, in this article, a novel molding process of three-dimensional printing for continuous carbon fiber composites is developed, including the construction of printing material, the design of printer nozzle, and the modification of printing process. A suitable structure of nozzle on the printer is adjusted for the continuous carbon fiber composites. For the sake of ensuring the continuity of composited material during the processing, a cutting algorithm for jumping point is proposed to improve the printing path during process. On this basis, the experiment of continuous carbon fiber composite is performed and the mechanical properties of the printed test samples are analyzed. The results show that the tensile strength and bending strength of the sample printed by polylactic acid–continuous carbon fiber composites increased by 204.7% and 116.3%, respectively compared with pure polylactic acid materials, and those of the sample printed by nylon–continuous carbon fiber composites increased by 301.1% and 17.4% compared with pure nylon materials, and those of test sample by nylon–continuous carbon fiber composites under the heated and pressurized treatment increased by 383.6% and 233.2% compared with pure nylon material.

Keywords

Performance three-dimensional printing continuous carbon fiber composites

Introduction

Nowadays, three-dimensional (3D) printing with carbon fiber (CF) attracts more and more attentions in both academic and industrial applications. It is undeniable that CF is suitable to the fields of aeronautics and astronautics, national defense, military, and new energy vehicles due to its excellent physical properties, such as high-temperature resistance, wear resistance, and fatigue resistance.^1–3 However, these applications are limited to some extent because of its complicated manufacturing process, high cost, and inability to produce structurally complex parts.^4,5 3D printing, as a kind of additive manufacturing technology, also has great application prospects in many field, which is the result of its characteristics that are one-piece forming, product diversity and no limitation of complexity of the model.^6,7 One of the most popular molding methods in the domain of 3D printing is fused deposition modeling (FDM), which is of short forming cycle, low cost, and easy operation. In principle, FDM is a layer-by-layer stacking process using molten thermoplastic material extruded from the nozzle to form 3D products.^8,9 However, the thermoplastic material cannot satisfy the performance demand of products in many application fields because of its poor strength.¹⁰ It is widely agreed that the combination of 3D printing and CF is able to produce complex structure and high-performance products with high efficiency.^11,12 Hence, the integration can be regarded as the powerful driving force for the development of 3D printing and CF applications.

At present, there are two ways to utilize CF in 3D printing, which are the printing with short carbon fiber composites (SCFCs)^13,14 and printing with continuous carbon fiber composites (CCFCs).¹⁵ For the SCFC, Tekinalp et al.¹⁶ found a reduction of inter-bead voids with the addition of fibers, which was attributed to a decrease in die swell and increase in thermal conductivity. However, smaller voids were found around the fiber contents. Matsuzaki et al. printed continuous fibers by feeding them through a nozzle simultaneously with polylactic acid (PLA). This technique also showed a non-uniform fiber distribution, as the fibers were not pre-impregnated in the matrix.¹⁷ Hao Xiu et al.¹⁸ obtained PLA-based composites with good stiffness–toughness balanced properties by adjusting CF network in PLA matrix by adding a small amount of soft poly(ether)urethane (PU). It is found that although the short carbon fiber (SCF) enhances the acrylonitrile butadiene styrene (ABS)/PLA material in a certain degree, the effect is not evident enough to reflect sufficiently the excellent performance of CF.^19,20 CCFC can make up this shortcoming, but many questions exist to be solved for 3D printing with CCFC, such as the continuity of feeding, the jumping of nozzle, the cutting of composites, and the control of multi-process parameters.

According to the current researches, two approaches are applied for the 3D printing of CCFC. One of them is to combine the continuous carbon fiber (CCF) with the thermoplastic material at the nozzle during the printing. The two materials are then extruded and pushed together to form a 3D model.^21,22 N Li et al.²³ used this method to test the performance of CCFC. It is found that CCF has significant effect on printing model performance. From the respects of technology and performance, Chuncheng Yang et al. introduced the process of ABS-CCFC in detail and tested the performance of printing model. This increased the in-plane mechanical properties by a factor of 2–5, but a limiting factor was the interlaminar shear properties of the printed part.²⁴ However, within this method, CCF and thermoplastic resin are mixed at the melt area of the nozzle, which easily aids the non-uniform distribution of CF in the resin and eliminates the need of mixing due to the small melting area. As a result, the enhancement effect of CCFC is reduced to some extent.

The other strategy is to mix the CCF with the thermoplastic material before printing and then printing parts with the CCF composite on an FDM printer. Q Hu et al.²⁵ studied this kind of method and analyzed the effect on the performance of the model caused by printing time, printing speed, and layer thickness. Melenka et al.²⁶ evaluated and predicted the elasticity of the fiber-reinforced 3D-printed structures by using MarkOne, which is a 3D printer developed by MarkForged, Inc, for CCFC. Dickson et al.²⁷ assessed the performance of continuous carbon, Kevlar, and glass fiber–reinforced composites that are used to print parts by MarkOne. However, for the 3D printing with CFCC, the jumping point during process has not been considered yet. Since existing the jumping of nozzle in the printing process, the above two kinds of strategies have great limitations, which is that only simple model is able to be done (Table 1). When there is a jumping point in the process of complex model path, the above scheme is unworkable.

Table 1.

Overview of studies on printing of reinforced filaments.

Study	Reinforcement	Matrix	Approach for composites	Tensile strength
A Ashori et al.¹³	SCF	PP	Manufacture the SCFC by melt blending and hot-press processing	Strength from 38.2 to 43.4 MPa
NG Karsli and A Aytac¹⁴	SCF	PA6	Prepare the SCFC by using melt mixing method	Strength from 38 to 86 MPa
HL Tekinalp et al.¹⁶	SCF	ABS	Prepare the SCFC before printing	Strength from 35 to 65 MPa
P Bettini et al.¹⁵	CCF	PLA	Produce the CCFC by fused deposition modeling	Strength from 34 to 203 MPa
R Matsuzaki et al.¹⁷	CCF	PLA	Produce the CCFC by fused deposition modeling	Strength from 40 to 185 MPa
H Xiu et al.¹⁸	SCF	PLA and PU	Prepare the CCFC by melt blending	Strength from 68.3 to 100 MPa
Z Quan et al.¹⁹	SCF	ABS	Produce the SCFC by designing a 3D orthogonal preform	Strength from 3.14 to 4.9 MPa
ZH Li et al.²⁰	SCF	PTFE	Prepare the SCFC by melt blending and hot-pressing techniques	Strength from 33.8 to 85 MPa
X Tian et al.²¹	CCF	PLA	Mix the CCF and PLA in nozzle during printing	Strength from 110 to 335 MPa
N Li et al.²³	CCF	PLA	Mix the CCF and PLA in nozzle during printing	Strength from 28 to 91 MPa
C Yang et al.²⁴	CCF	ABS	Mix the CCF and ABS in nozzle during printing	Strength from 30 to 200 MPa
Q Hu et al.²⁵	CCF	PLA	Prepare The CCFC before printing	Strength from 74.2 to 541.7 MPa
GW Melenka et al.²⁶	Continous Kevlar fiber	Nylon	Prepare The CCFC before printing	Strength from 5 to 92 MPa
AN Dickson et al.²⁷	CGF, CCF, CKF	Nylon	Prepare The CCFC before printing	Strength from 38.2 to 43.4 MPa

SCF: short carbon fiber; SCFC: short carbon fiber composite; CCFC: continuous carbon fiber composite; PLA: polylactic acid; ABS: acrylonitrile butadiene styrene; PU: poly(ether)urethane; PTFE: polytetrafluoroethylene; CCF: continuous carbon fiber.

To solve the above problems, a novel CCF 3D printing process is put forward in this article, including the construction of printing material, the design of printer nozzle and the modification on path jumping during printing process. First, two kinds of CCF composite are constructed by mixing CCF with PLA and Nylon separately. Then, the 3D printing process and the key relationships of multi-process parameters are introduced. According to the continuity characters of CF composites, the path-jumping identification and processing method of complex model is proposed. Finally, the testing of continuous CF composites is performed, and the mechanical properties of the sample are analyzed. The results show that CCF has an obvious enhancement effect on PLA/Nylon. This article contributes a new reference and data support to the applications of molding process of continuous CF 3D printing.

3D printing process of CCFCs

Principle of CCFCs preparation

Printing material preparation is the foundation of 3D printing, which directly affects the production quality of products to some extent. In order to achieve better material, CCFC is constructed before printing process. The schematic of CCFC preparation is shown on Figure 1. The thermoplastic resin is heated by the heat tube that is used to transfer the heat from the heating block to the resin. With the rise of temperature, the resin is fused enough to mix with CCF completely. Then, the mixture is pulled out from the shaped nozzle by the drag of guide wheel to obtain the CCFC with specified diameter. The nozzle can be replaced for achieving the CCFC with different diameters. Once pulled out, the mixture is cooled by the water cooling machine immediately to form CCFC and rolled up by coiling machine next. Finally, the generated CCFC volume can be used to print object on 3D printer.

Figure 1.

The principle of the preparation of CCFC.

3D printing process of CCFCs

In this section, the 3D printing process with CCFC volume is introduced. The principle is shown in Figure 2. The CCFC enters the printer’s nozzle under the action of the feed mechanism. The nozzle can realize horizontal movement of two directions in the X and Y axis. The work platform can realize the vertical movement of the Z axis. Through the coordinated movement of these three directions, a 3D model can be accumulated on the work platform.

Figure 2.

The printing process of CCFC.

During the printing process, the cutting process is the key factor for the sake of the continuity of CCFC. For the model with complex structure, it is inevitable to generate path breakpoint for nozzle jumping during printing. During the jumping distance, the nozzle is supposed to have no material in it. Hence, an early cutting strategy is adopted to cut CCFC in advance when a nozzle jumping is going to happen. This cutting strategy requires to set the cutter at a distance from the nozzle. It would not influence the printing process and is easy to realize. But after the cutting, the following feeding of CCFC is important, which would decide whether the printing process can be implemented as normal. The molding process of 3D printing with CCFC is based on the FDM in this article, but the nozzle of the 3D printer belonging to FDM cannot achieve the function of printing CCFC. Hence, the design of nozzle is optimized from the following three aspects:

The melting zone of nozzle is shortened, which is used to melt the printing material. The excessive melting zone would over soften the CCFC in general so that the nozzle is easy to be blocked by the material.

Double-heating rod is equiped to ensure the temperature. The melting state of the composites would be affected by narrowing the melting zone. The double-heating method aims to make the material heated to the targeted state.

Under the premise of not damaging nozzle structure, the cutting mechanism is set at the shortest distance from the nozzle. Since the CCFC with diameter of 1 mm is used, long distance would cause the material to bend. As a result, the material would not be fed into the nozzle smoothly.

Printing path handling with jumping point

Generally, it is expected to reduce the amount of jumping point as much as possible during 3D printing procedure to keep the continuity of the CCFC. However, jumping point is still unavoidable during 3D printing process, especially for printing the object with complex structure. When jumping point is coming during printing, cutting action would be implemented in advance to stop feeding the material into the nozzle. In this way, the nozzle would be empty when it jumps a distance to targeted position so as to avoid the falling of molten material from nozzle during jumping.

A printing path of a complex model is shown in Figure 3. It can be seen that there are seven jumping points on the printing path. In order to realize the above operation, it is essential to deal with the path of jumping of the printing for CCFC.

Figure 3.

A path of complex model.

For complex 3D model path processing, there must be jump point (G0). Because of the continuity of CCFC and the distance $(l)$ between cutting point and nozzle, G-code needs to be modified to set the cutting in advance for jumping point, as shown in Figure 4(a).

Figure 4.

The processing method of path jumping point.

As shown in Figure 4(b), G1 indicates the accumulation of material on the Z direction of coordinate during printing. G0 refers to the fast moving of nozzle in printing, which is an idle movement, and this is where the jump point is. $(X_{n}, Y_{n})$ is the position of nozzle before jumping, and $(X_{n + 1}, Y_{n + 1})$ is the targeted position of nozzle after jumping. $E_{n}$ is the amount of material that has been extruded by the printer in $(X_{n}, Y_{n})$ . Due to the existence of the distance $(l)$ , the cutting point cannot be inserted directly at the jumping point, thus the cutting point is set at the position of distance $(l)$ before the jumping point, which is between $(X_{m}, Y_{m})$ and $(X_{m + 1}, Y_{m + 1})$ . The corresponding G-code is “M 4569.” The way to identifying the position of cutting point is as follows:

First, the jump point $(X_{n + 1}, Y_{n + 1})$ is found according to the G0, and then the last step $(X_{n}, Y_{n})$ is taken as the starting point. Step up to find the point $(X_{m}, Y_{m})$ , between which the interval is the distance $(l)$ from $(X_{n}, Y_{n})$ . The computing equation is $E_{n} - E_{m} = l$ . Therefore, after the G-code $(G 1 X_{m} Y_{m} E_{m})$ , the G-code “M 4569” for clipping instruction is inserted, which is the cutting process for the jumping point $(X_{n + 1}, Y_{n + 1})$ . By analogy, the cutting processes for other six jumping points of the whole 3D model can be embedded into the G-code to complete the printing process.

Printing process parameters

In the printing process of CCFC, in order to avoid the blocking and breakage of CCFC, it is necessary to ensure that the speed of the feeding equals the speed of the nozzle movement. In our experiment, the related parameters are set by using CURA, which is an engine for handling printing path according to the 3D model file. The relationships of the internal speeds can be expressed as the following formulas

$V_{1} = h • d_{1} • v_{1} • t$ (1)

$V_{2} = \frac{π}{4} d_{2}^{2} • v_{2} • t • η$ (2)

In formula (1), $V_{1}$ is the extrusion amount of the nozzle, $d_{1}$ is the nozzle diameter, $v_{1}$ is the speed of nozzle moving, and $h$ is the layer height. In formula (2), $V_{2}$ is the input quantity of material, $d_{2}$ is the material diameter, $v_{2}$ is the feed speed, and $η$ is the percentage of feed. In both formulas, $t$ denotes the printing time.

According to the principle of printing $V_{1} = V_{2}$ , which is that the extrusion amount from the nozzle should equal the input amount to nozzle, and the printing requirements for CCFC, $v_{1} = v_{2}$ , which expresses that the speed of feeding should equal that of nozzle movement, the following equation is obtained from the above formulas (1) and (2)

$\frac{π • d_{2}^{2}}{4 • h • d_{1}} η = 1$ (3)

Therefore, the printing parameters should be set according to formula (3). For the CCFC with 1 mm diameter, the multi-process parameters of printing are specified in Table 2.

Table 2.

The printing parameters of CCFC.

Parameters	Amount
Nozzle diameter	1.0 mm
Material diameter	1.0 mm
Feed speed	20 mm/min
Printing speed	20 mm/min
Floor height	1.0 mm
Feed ratio	100%

The configuration of printing parameters is very significant for CCFC. Different from that of pure thermoplastic materials, the printing process with CCFC needs to ensure continuity of CCFC as possible.

Experimental equipment and results

Material preparation

Material preparation equipment

In order to compare the performance, two kinds of CCFC composite are made. The manufacturing device for CCFC mainly consists of heating block, heat transfer tube, shaping nozzle, guide wheel, and coiling machine, as shown in Figure 5(a). Two types of thermoplastic resins are applied to combine CCF to generate CCFC, which are PLA and Nylon. Using the device, CCF is mixed with PLA and Nylon separately to generate PLA-CCFC and Nylon-CCFC. Their samples are shown in Figure 5(b). Their melting temperatures for PLA and Nylon are 200°C and 245°C, respectively, the diameter of CCFC is 1.0 mm and the mixing ratio of CCF in CCFC is 9.5%.

Figure 5.

(a) The device of CCFC preparation and (b) the sample of PLA-CCFC and Nylon-CCFC.

Post-deposition compaction

In the process printing, the bonding between layers and the interface of fiber and nylon composite are low, so it is necessary to heat and pressurize the sample of Nylon-CCFC after printing. Hence, the printed sample is placed in a 245°C environment to complete the post-processing, as shown in Figure 6.

Figure 6.

The schematic of test for post-treatment.

Experimental equipment

As shown in Figure 7(a), it is an improved 3D printer suitable for CCFC on the basis of FDM technology. The 3D motion of the nozzle can be realized by the X, Y and Z axis motion structures. Then, the CCFC is stacked on the working platform with the cooperation of the extrusion and cutting of the nozzle. The structure of the nozzle is shown in Figure 7(b). The feeding mechanism supplies power to feed the CCFC into the heated nozzle. The cutting mechanism cuts CCFC in advance to ensure the smooth progress of printing. The nozzle is heated by double-heating rods, which can reach high temperature of 260°C immediately. The rapid heating can save the waiting time for printing. In this experiment, the printing temperature of PLA-CCFC is 200°C and that of nylon-CCFC is 245°C.

Figure 7.

(a) The 3D printer for CCFC and (b) the structure of the nozzle.

The cutting mechanism of the 3D printer compose a cutting motor, a synchronous wheel, a synchronous belt, and a cutting knife, as shown in Figure 8(a). Under the action of synchronous wheel and synchronous belt, the cutting motor drives the cutting knife to rotate. When the cutting motor receives the cutting signal from the controller of printer, the cutting knife would rotate in circle to cut the CCFC. The state of cutting mechanism before cutting is displayed in Figure 8(a), and the state after cutting is displayed in Figure 8(b).

Figure 8.

The cutting mechanism (a) before cutting and (b) after cutting.

Performance test

The enhancement effect of CCF can be evaluated quantitatively through the mechanical performance of the printing model. In this article, the tests of tensile and three-point bending are implemented to measure the performance of printed sample. Two kinds of samples are prepared, which are the printed models by PLA-CCFC and Nylon-CCFC. In view of the phenomenon that the Nylon-CCFC is not completely stuck, it is needful to do the post-processing by adding temperature and pressure.

Tensile test

The tensile test model is designed and printed according to the standard GB/T1040.1-2006. The size diagram of the sample for the tensile test is shown in Figure 9(a). The length of the sample is 150 mm, the width is 15 mm, the thickness is 3 mm, and the tensile speed is 5 mm/min. The CCFC are closely aligned in the direction of length. The printed sample of tensile test is shown in Figure 9(b).

Figure 9.

(a) The model of tensile test and (b) the printed sample of tensile test.

Three-point bending test

The bending test was carried out in the form of three-point bending, which is according to the standard GB/T449:2005. The size of the sample for the three-point bending test is shown in Figure 10(a). The length is 80 mm, the width is 15 mm, the thickness is 5 mm, the bending speed is 5 mm/min, and the three-point bending length is 50 mm. CFs are closely aligned along the length of the sample and are perpendicular to the direction of the bending. The printed sample is shown in Figure 10(b).

Figure 10.

(a) The mode of three-point bending test and (b) the printed sample of three-point bending test.

Result analysis

Printing test of path cutting

The proposed cutting method for jumping point is verified through the experiment in this section. In this experiment, the length accuracy is tested at first. A simple sample is supposed to be printed with the length of 50 mm using the above printer which is equipped with the cutting mechanism and CCFC. As shown in Figure 11, the lengths of three obtained samples are 50.5, 50.8, and 50.7 mm, respectively. All their errors are less than 2%, which proves that the accuracy of cutting mechanism is able to satisfy the demand of product to some extent.

Figure 11.

The printing of CCFC with a length of 50 mm.

Next, a flange model is used to verify the proposed method. As shown in Figure 12(a), the flange is a hexagon with four holes. It is necessary to have a jumping point during the printing. And the distance between the cutting points with the nozzle of the experimental device is 15 mm. Hence, the printing path is processed according to the proposed method. As shown in Figure 3, ①–⑦ is the jumping point between the model contour, 1–7 is the cutting point corresponding to the jump point. The processed path is tested by the 3D printer, and the final printing sample is shown in Figure 12(b). It can be seen that the position of cutting point is consistent with the result of the path processing, and the correctness of the cutting algorithm is verified.

Figure 12.

(a) The flange model and (b) the printing sample.

Printing test of PLA-CCFC

The measure values of tensile and bending strength of the sample printed by PLA-CCF composite is shown in Figure 13. The composite contains 9.5% of CCF. It can be seen that the values of the tensile strength and bending strength of the pure PLA printing sample are 48.8 and 76.06 MPa. Compared with the composite that mixes PLA with SCF, the values of the samples combined increased to 60.4 and 86 MPa, respectively. While, compared to the PLA-CCF composite, the tensile strength and bending strength increased to 148.7 and 164.5 MPa, respectively. The enhancement effect of PLA-CCF composite is increased by 200.5% and 116.3%, respectively, which is much superior to PLA-SCF and pure PLA. This is because that SCF is distributed within PLA in a confused way, while CCF is mixed with PLA in a close-packed way. Therefore, the CCF composite can improve the physical properties of the composites under the function of the excellent properties of CF.

Figure 13.

The tensile strength and bending strength of PLA model.

Printing test of Nylon-CCFC

The experiment for Nylon-CCF composite is carried out, and the result values are shown in Figure 14. The composite consists of Nylon and 9.5% of CCF. It can be seen that the tensile and bending strength of pure Nylon-printed samples are 27.4 and 35.5 MPa, and that of the experimental sample with Nylon-CCF composite are increased to 109.9 and 41.66 MPa, respectively, which are increased by 301.1% and 17.4%. It is obvious that the tensile strength of the Nylon-CCF increases dramatically, while the bending strength does not increase remarkably. However, after treatment, the tensile and bending strength of the sample of Nylon-CCF composite increase to 132.5 and 118.3MPa, respectively, which are improved by 383.6% and 233.2%. It shows that the properties of samples printed by Nylon-CCFC are greatly improved by the heating and pressurization.

Figure 14.

The tensile strength and bending strength of Nylon model.

Moreover, the bending stress–time curve of a sample printed by Nylon-CCFC is shown in Figure 15. It is displayed that the curve has three jump points before reaching the damage load. The sample of Nylon-CCFC after a bending test is shown in Figure 16(a). It can be found that the sample does not break completely. But the bending strength reduces due to the disconnect between the three layers, which is consistent with stress–time curve in Figure 15. It indicates that the bonding between the layers of the Nylon-CCFC is not sufficient in the printing process. In addition, the result of tensile test is shown in Figure 16(b). The fracture surface of the sample is a bevel, which indicates that there is a gap in the printed sample model. This is because that Nylon-CCFC has the high melting point, which is 245°C, and the fluidity is not good so that the last printed layer has been solidified and cannot be adhered to the next printed layer during the printing process. In addition, the temperature of the material squeezed out from the nozzle is not enough to melt the printed layer so that the Nylon-CCFC between the two layers cannot be completely stuck. The existence of gap between the two layers decreases the physical performance of the printed sample. In order to give full play to the enhancement effect of CCF to Nylon material, the printing sample should be heated and pressurized after printing.

Figure 15.

The bending stress–time curve of a Nylon-CCFC.

Figure 16.

(a) The sample of a Nylon-CCFC after a bending test and (b) the sample of a Nylon-CCFC after a tensile test.

Conclusion

In order to give a full play to the CCFC in 3D printing, a new molding process suitable for the composite is proposed in this article, including preparation of CCFC, the improvement of printing process and the related experiments. The main contents include the following aspects:

The construction method for CCFC is studied at first. PLA, nylon, and CCF are used as raw materials to produce two kinds of CCFC (PLA-CCFC/Nylon-CCFC) suitable for FDM technology.

An improved molding process for the CCFC is researched from the structure of device and the printing path. A new structure of nozzle suitable for CCFC is developed, which can realize the cutting operation. Then, the printing process parameters suitable for the printing process are configured in the light of the principle of 3D printing and the characteristics of CCFC.

A cutting algorithm for the jumping points is proposed to identify the cutting point according to the jumping points in the G-code. And the correctness of the algorithm had been verified through the related experiments. It is shown that the accuracy of the cutting mechanism can satisfy the performance demand of printed objects.

Finally, the performance of the molding process of continuous CF 3D printing is verified through experiments. The performances of the prepared PLA-CCFC and Nylon-CCFC are tested. The results show that the tensile strength and bending strength of 3D-printed test sample by PLA-CCFC increased by 204.7% and 116.3%, respectively, compared with pure PLA materials and that of the sample printed by Nylon-CCFC increased by 301.1% and 17.4%, respectively, compared with pure nylon materials, and that of the sample printed by Nylon-CCFC under the heated and pressurized treatment increased by 383.6% and 233.2%, respectively, compared with pure Nylon material. The above data show that CCF has a strong enhancement in performance of thermoplastic resin. It shows that this molding process of continuous CF 3D printing contributes to taking full advantage of CCF to enhance the performance of 3D-printed object.

Footnotes

Handling Editor: AHI Mourad

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research,authorship,and/or publication of this article.

Funding

The author(s) disclosed receipt of the following financial support for the research,authorship,and/or publication of this article: This work was supported by the “Fundamental Research Funds for the Central Universities,” (grant no. 175104003),the “Fundamental Research Funds for the Central Universities,” (grant no.2018III065GX) and the “Institute of Advanced Materials and Manufacturing Technology,Wuhan University of Technology.”

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Molding process and properties of continuous carbon fiber three-dimensional printing

Abstract

Keywords

Introduction

3D printing process of CCFCs

Principle of CCFCs preparation

3D printing process of CCFCs

Printing path handling with jumping point

Printing process parameters

Experimental equipment and results

Material preparation

Material preparation equipment

Post-deposition compaction

Experimental equipment

Performance test

Tensile test

Three-point bending test

Result analysis

Printing test of path cutting

Printing test of PLA-CCFC

Printing test of Nylon-CCFC

Conclusion

Footnotes

Declaration of conflicting interests

Funding

References