Continuous fiber reinforced polymer flexible 3d printing filament, method of making and use thereof

Abstract

The present application relates to a kind of continuous fiber reinforced polymer flexible 3D printing filaments and its preparation method and application, product has core-spun yarn structure;Core yarn is inorganic fiber or thermosetting organic fiber;There is thermoplastic polymer powder between fiber and fiber in core yarn;Outer wrapping yarn is thermoplastic polymer filament;Thermoplastic polymer powder and thermoplastic polymer filament are the same material, or, material is different and the melting point of two is not more than 100 ℃ difference;Method: using thermoplastic polymer powder suspension to dip core yarn, then wrapping outer wrapping yarn on the surface of core yarn, i.e. continuous fiber reinforced polymer flexible 3D printing filament, can further be obtained by hot melting cavity continuous fiber reinforced polymer semi-rigid 3D printing filament;Application: for 3D printing, the effect of workpiece impregnation is good, or for weaving functional fabric, functional fabric can be used to make fireproof suit, heat shield etc..

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of 3D printing, and relates to a continuous fiber reinforced polymer flexible 3D printing filament and a preparation method and application thereof. BACKGROUND

[0002] 3D printing technology can quickly realize the integrated manufacturing of complex structures through layer-by-layer accumulation compared with traditional mechanical processing and casting manufacturing technology. Among many 3D printing technologies, the fused deposition modeling (FDM) 3D printing technology is the most widely used technology. With the in-depth application of FDM printing technology in various industries, the demand for 3D printing of large-size and high-strength components is becoming more and more vigorous. The manufacturing of large-size 3D printed components can be realized by increasing the movement stroke of the equipment and increasing the roller mode, for example, the FDM printing equipment of the blackbelt company can realize the printing of unlimited length in one direction, which can be used for the manufacturing of large structures of unmanned aerial vehicles; however, due to the increase of the structure length, the existing printing polymer materials cannot provide sufficient strength and modulus, and bending will occur under the action of gravity. The poor mechanical properties of 3D printed polymer components seriously restrict the development of polymer 3D printing. The key to realizing the 3D printing of large structures and high-strength components is to improve the mechanical properties of 3D printing materials.

[0003] The common way to improve the mechanical properties is to add nano fillers and short fibers to the polymer and make 3D printing filaments. However, the mechanical properties of the filament with short fibers are not much improved, which is difficult to meet the demand of high-performance 3D printed products. Taking Markforged, an international leading 3D printing company, as an example, the tensile modulus and bending strength of the Onyx filament containing fiber nylon matrix are only improved by 40% compared with the nylon filament, and the tensile strength is not improved. For 3D printing, if you want to achieve a quantitative improvement in the mechanical properties of the component, you can only introduce continuous fibers to achieve excellent mechanical properties of continuous fibers. Therefore, in recent years, the 3D printing of continuous fiber reinforced polymer materials has become an important direction of research in the field of 3D printing.

[0004] Continuous fiber FDM printing technology can be divided into real-time impregnation and pre-impregnation processes according to the impregnation method.

[0005] The real-time impregnation process is to make continuous fibers (carbon fibers, glass fibers, aramid fibers, etc.) and polymer filaments enter the print head through two feeding ports respectively, and the fibers and the melted polymer are combined in the melting zone of the print head to complete the impregnation process. This process does not need to modify the raw materials, and can directly use fiber yarns and polymer printing filaments. However, due to the short impregnation time, it is difficult for the resin to achieve good impregnation in the fibers, especially for high-performance special plastics with high viscosity; in addition, the continuous fibers are easily damaged during the printing process. Although researchers have developed spiral-shaped print heads and multi-stage filament feeding print heads to increase the impregnation time, it is still difficult to achieve good impregnation effect.

[0006] The pre-impregnation process avoids the above problems by preparing impregnated filaments in advance. Markforged company developed continuous carbon fiber reinforced nylon printing filaments, which achieved a bending modulus, bending strength and tensile strength of 51 GPa, 540 MPa and 800 MPa, respectively, which is more than 10 times higher than that of nylon filaments. Similarly, document 1 (Research on 3D printing preparation technology of continuous fiber reinforced PLA composite [J]. Fiber Composites, 2020, 37(3): 95-99) prepared continuous glass fiber reinforced polylactic acid (CGF / PLA) printing filaments using a polymer melt impregnation method to achieve a bending strength of 301 MPa, and document 2 (Preparation of continuous carbon fiber reinforced nylon composite pre-impregnated filaments and research on 3D printing performance [J]. Aviation Manufacturing Technology, 2021, 64(15): 24-33.) prepared continuous carbon fiber reinforced nylon printing (CCF / Nylon) filaments using a similar method, which achieved a tensile strength of 558 MPa. However, in the pre-impregnation method, the pre-impregnated filaments are rigid, which can cause damage to the fiber surface and damage to the mechanical properties. SUMMARY

[0007] The purpose of the present application is to solve the problems existing in the prior art, and to provide a continuous fiber reinforced polymer flexible 3D printing filament and a preparation method and application thereof.

[0008] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0009] A continuous fiber reinforced polymer flexible 3D printing filament has a core-spun yarn structure, which includes a core yarn and an outer covering yarn.

[0010] The core yarn is inorganic fiber or thermosetting organic fiber;

[0011] The fibers in the core yarn are distributed with thermoplastic polymer powder between the fibers;

[0012] The outer covering yarn is a thermoplastic polymer filament;

[0013] The thermoplastic polymer powder is of the same material as the thermoplastic polymer filament; or the thermoplastic polymer powder is of different material from the thermoplastic polymer filament, and the melting points of the two differ by no more than 100 DEG C;

[0014] The thermoplastic polymer powder in the core yarn can increase the distance between fibers in the core yarn, which is conducive to the infiltration of the thermoplastic polymer into the core yarn; the thermoplastic polymer filament on the outside of the core yarn can not only protect the core yarn, but also form a resin-rich area on the outside of the filament after melting, which is conducive to the bonding between 3D printing filaments.

[0015] The continuous fiber reinforced polymer flexible 3D printing filament can further obtain a continuous fiber reinforced polymer semi-rigid 3D printing filament through a hot melting cavity.

[0016] As a preferred technical solution:

[0017] The thermoplastic polymer powder has a particle size range of 800-1200 mesh.

[0018] The mass fraction of the thermoplastic polymer powder in the core yarn is 1-40%.

[0019] The linear density of the core yarn is 60-200 tex.

[0020] The core yarn is glass fiber, carbon fiber or aramid fiber.

[0021] The outer wrapping yarn is wrapped on the surface of the core yarn in double layers, and the wrapping directions of the double layers are opposite.

[0022] The twist of the wrapping is 600-1200 T / m.

[0023] The linear density of the outer wrapping yarn is 20-40 tex.

[0024] The material of the thermoplastic polymer powder or the thermoplastic polymer filament is selected from PLA, nylon, PPS, PEEK and PEKK.

[0025] The continuous fiber reinforced polymer flexible 3D printing filament further comprises a sizing agent, and the sizing agent is wrapped on the surface of the core yarn and the outer wrapping yarn.

[0026] The application also provides a method for preparing the continuous fiber reinforced polymer flexible 3D printing filament as described in any one of the above, after the core yarn is impregnated with the thermoplastic polymer powder suspension, the thermoplastic polymer filament is used as the outer wrapping yarn to wrap the surface of the core yarn, and the continuous fiber reinforced polymer flexible 3D printing filament is obtained.

[0027] As a preferred technical solution:

[0028] The method as described above, the thermoplastic polymer powder suspension is composed of thermoplastic polymer powder, surfactant (polyvinyl alcohol, polyethylene glycol, etc.) and water; the concentration of the thermoplastic polymer powder in the thermoplastic polymer powder suspension is 10-20wt%, and the concentration of the surfactant is 1-3wt%.

[0029] The method as described above, the impregnation process is that the core yarn is unwound from the yarn drum and immersed in the thermoplastic polymer suspension, and then passes through the roller in the thermoplastic polymer suspension, and in this process, the roller can provide appropriate pressure and friction, and the impregnation in this way can solve the problem of low impregnation rate in the conventional way.

[0030] The method as described above, after impregnation and before wrapping, the core yarn is also dried, and the liquid carrying rate of the core yarn is controlled to be 50-80%, so that the wrapping property can be maintained, and the thermoplastic polymer powder can also be prevented from being carried out of the core yarn by the flow of the suspension.

[0031] The method as described above, the drying adopts a non-contact type hot oven, the temperature is 100-200℃, and the drawing speed is 1-1.5m / min, and the drying process can remove the surfactant on the surface of the core yarn.

[0032] The method as described above, when wrapping, the core yarn passes through the lower guide roller, the lower hollow spindle, the upper hollow spindle and the upper guide roller in turn from bottom to top, the core yarn converges with the outer wrapping yarn unwound from the bobbin when passing through the lower hollow spindle, and the core yarn converges with the outer wrapping yarn unwound from the bobbin again when passing through the upper hollow spindle, and they are jointly drawn to the take-up drum, wherein the rotation speeds of the lower hollow spindle and the upper hollow spindle are the same, and the rotation directions are opposite; this way can effectively protect the core yarn and prevent problems such as breakage and wear in the 3D printing process.

[0033] The method as described above, after wrapping, the desizing treatment and the sizing treatment are also carried out in turn; the application carries out impregnation, wrapping, desizing and sizing in turn, and in the surface treatment process (i.e. desizing and sizing) of the yarn, there is no fiber abrasion, and if the desizing, impregnation, wrapping and sizing are carried out in turn, there will be fiber abrasion in the surface treatment process (i.e. desizing and sizing) of the yarn.

[0034] The application further provides application of the continuous fiber reinforced polymer flexible 3D printing filament as described in any one of the above to 3D printing or weaving functional fabric, the printed product has good impregnation effect, and the functional fabric obtained by weaving can be used to make fireproof clothes, heat shields and the like.

[0035] Advantages

[0036] (1) The continuous fiber reinforced polymer flexible 3D printing filament has good flexibility and is not easy to break compared to rigid pre-impregnated printing filaments.

[0037] (2) The continuous fiber reinforced polymer flexible 3D printing filament has good wear resistance and can prevent the brittle core yarn from reducing the overall performance of the composite material due to wear during printing.

[0038] (3) In the continuous fiber reinforced polymer flexible 3D printing filament, the inside of the printing filament has pre-existing thermoplastic polymer powder, so that the printed product has good impregnation effect when applied to 3D printing, and the functional fabric obtained by weaving can be used to make fireproof clothes, heat shields and the like when applied to weaving functional fabric.

[0039] (4) In the continuous fiber reinforced polymer flexible 3D printing filament, the outer thermoplastic polymer filament can not only provide protection for the core yarn, but also form a resin-rich area outside the filament after melting, which can be beneficial to the bonding between 3D printing filaments and can improve the overall performance of fireproof clothes, heat shields and the like.

[0040] (5) The method is simple to prepare.

[0041] (6) The polymer of the application is suitable for both high and low viscosity, especially for high viscosity and high melting point polymers. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 SEM image of the cross section of the composite material filament printed by the continuous fiber reinforced polymer flexible 3D printing filament of Comparative Example 1;

[0043] Figure 2 SEM image of the cross section of the composite material filament printed by the continuous fiber reinforced polymer flexible 3D printing filament of Example 1. DETAILED DESCRIPTION

[0044] The application will be further described below in connection with specific embodiments. It should be understood that these embodiments are only used to illustrate the application and not to limit the scope of the application. Furthermore, it should be understood that those skilled in the art can make various modifications or changes to the application after reading the content taught by the application, and these equivalent forms also fall within the scope defined by the claims attached hereto.

[0045] Example 1

[0046] A preparation method of a continuous fiber reinforced polymer flexible 3D printing filament, the specific steps are as follows:

[0047] (1) Preparation of raw materials:

[0048] Core yarn: carbon fiber, linear density 60 tex;

[0049] Outer wrapping yarn: thermoplastic polymer filament, material PEEK, linear density 20 tex;

[0050] Thermoplastic polymer powder: material PEEK, average particle size 800 mesh;

[0051] Water;

[0052] Surfactant: polyvinyl alcohol;

[0053] Sizing agent;

[0054] (2) The core yarn is unwound from the yarn drum and immersed in the thermoplastic polymer suspension, and then wound around the roller in the thermoplastic polymer suspension and pulled out from the thermoplastic polymer suspension; wherein the thermoplastic polymer powder suspension is composed of thermoplastic polymer powder, surfactant and water; the concentration of thermoplastic polymer powder in the thermoplastic polymer powder suspension is 10wt%, and the concentration of surfactant is 1wt%;

[0055] (3) The core yarn after step (2) is dried, and the drying adopts a non-contact type heat drying channel, the temperature is 100℃, the pulling speed is 1m / min, and the liquid rate of the core yarn is controlled to be 80%;

[0056] (4) The outer wrapping yarn is wrapped on the surface of the dried core yarn; when wrapping, the core yarn passes through the lower guide roller, the lower hollow spindle, the upper hollow spindle and the upper guide roller in turn from bottom to top, the core yarn is combined with the outer wrapping yarn unwound from the bobbin when passing through the lower hollow spindle, and the core yarn is combined with the outer wrapping yarn unwound from the bobbin again when passing through the upper hollow spindle, and then they are jointly pulled to the winding drum, wherein the rotation speeds of the lower hollow spindle and the upper hollow spindle are the same, and the rotation directions are opposite;

[0057] (5) The product of step (4) is subjected to desizing treatment and sizing treatment in turn, and a continuous fiber reinforced polymer flexible 3D printing filament is obtained.

[0058] The finally prepared continuous fiber reinforced polymer flexible 3D printing filament has a core-spun yarn structure, including a core yarn and an outer wrapping yarn; the thermoplastic polymer powder is distributed between the fibers in the core yarn; the mass fraction of the thermoplastic polymer powder in the core yarn is 28%; the outer wrapping yarn is wrapped in two layers on the surface of the core yarn, the wrapping directions of the two layers are opposite, and the twist of the wrapping is 600T / m; the sizing agent is wrapped on the surface of the core yarn and the outer wrapping yarn.

[0059] The finally prepared continuous fiber reinforced polymer flexible 3D printing filament is used for 3D printing, and the printed product has good impregnation effect, and the SEM image of the cross section is as shown in Figure 2 The finally prepared continuous fiber reinforced polymer flexible 3D printing filament is used for 3D printing, and the printed product has good impregnation effect, and the SEM image of the cross section is as shown in

[0060] Comparative Example 1

[0061] A preparation method of a continuous fiber reinforced polymer flexible 3D printing filament, which is basically the same as that of Example 1, except that: in step (1), no thermoplastic polymer powder is prepared, and the thermoplastic polymer suspension in step (2) is replaced by a solution composed of a surfactant (the mass is the same as that of Example 1) and water (the mass is the same as that of Example 1).

[0062] The finally prepared continuous fiber reinforced polymer flexible 3D printing filament is used for 3D printing (the process is the same as that of Example 1), and the printed product has poor impregnation effect, and the SEM image of the cross section is as shown in Figure 1 .

[0063] Example 2

[0064] A preparation method of a continuous fiber reinforced polymer flexible 3D printing filament, and the specific steps are as follows:

[0065] (1) Preparation of raw materials:

[0066] Core yarn: carbon fiber, linear density is 150 tex;

[0067] Outer wrapping yarn: thermoplastic polymer filament, material is PEEK, linear density is 25 tex;

[0068] Thermoplastic polymer powder: material is PEEK, average particle size is 850 mesh;

[0069] Water;

[0070] Surfactant: polyvinyl alcohol;

[0071] Sizing agent;

[0072] (2) the core yarn is unwound from the yarn bobbin and immersed in a thermoplastic polymer suspension, and passes through the thermoplastic polymer suspension after passing around a roller in the thermoplastic polymer suspension; wherein the thermoplastic polymer powder suspension is composed of thermoplastic polymer powder, surfactant and water; the concentration of the thermoplastic polymer powder in the thermoplastic polymer powder suspension is 15wt%, and the concentration of the surfactant is 2wt%;

[0073] (3) drying the core yarn after the immersion in step (2), the drying uses a non-contact type heat drying channel, the temperature is 150℃, the pulling speed is 1.2m / min, and the liquid retention rate of the core yarn is controlled to be 75%;

[0074] (4) wrapping the outer cover yarn on the surface of the dried core yarn; when the core yarn passes through the lower guide roller, the lower hollow spindle, the upper hollow spindle and the upper guide roller in turn from bottom to top, the core yarn is combined with the outer cover yarn unwound from the bobbin when passing through the lower hollow spindle, and the core yarn is combined with the outer cover yarn unwound from the bobbin again when passing through the upper hollow spindle, and then the combined yarns are pulled to the winding drum, wherein the rotation speeds of the lower hollow spindle and the upper hollow spindle are the same, and the rotation directions are opposite;

[0075] (5) sequentially performing desizing treatment and sizing treatment on the product of step (4), to obtain the continuous fiber reinforced polymer flexible 3D printing yarn.

[0076] The finally prepared continuous fiber reinforced polymer flexible 3D printing yarn has a core-spun yarn structure, including a core yarn and an outer cover yarn; the thermoplastic polymer powder is distributed between the fibers in the core yarn; the mass fraction of the thermoplastic polymer powder in the core yarn is 30%; the outer cover yarn is wrapped on the surface of the core yarn in double layers, the wrapping directions of the double layers are opposite, and the twist of the wrapping is 800T / m; the sizing agent is wrapped on the surface of the core yarn and the outer cover yarn.

[0077] The finally prepared continuous fiber reinforced polymer flexible 3D printing yarn is used for 3D printing, and the printed product has good impregnation effect, and can also be used for weaving functional fabric, and the functional fabric obtained by weaving can be used for making fireproof clothes, heat shield, etc.

[0078] Example 3

[0079] A preparation method of a continuous fiber reinforced polymer flexible 3D printing yarn, the specific steps are as follows:

[0080] (1) preparation of raw materials:

[0081] Core yarn: glass fiber, linear density is 200tex;

[0082] Outer cover yarn: thermoplastic polymer yarn, material is PEKK, linear density is 35tex;

[0083] Thermoplastic polymer powder: PEKK, average particle size 1200 mesh;

[0084] Water;

[0085] Surfactant: polyvinyl alcohol;

[0086] Sizing agent;

[0087] (2) The core yarn is unwound from the yarn drum and immersed in the thermoplastic polymer suspension, and then passes through the roller in the thermoplastic polymer suspension; wherein the thermoplastic polymer powder suspension is composed of thermoplastic polymer powder, surfactant and water; the concentration of thermoplastic polymer powder in the thermoplastic polymer powder suspension is 20wt%, and the concentration of surfactant is 3wt%;

[0088] (3) The core yarn after step (2) is dried, and the drying adopts a non-contact type heat drying channel, the temperature is 200℃, the pulling speed is 1.3m / min, and the liquid rate of the core yarn is controlled to be 69%;

[0089] (4) The outer wrapping yarn is wrapped on the surface of the dried core yarn; when the core yarn passes through the lower guide roller, the lower hollow spindle, the upper hollow spindle and the upper guide roller in turn from bottom to top, the core yarn is combined with the outer wrapping yarn unwound from the bobbin when passing through the lower hollow spindle, and the core yarn is combined with the outer wrapping yarn unwound from the bobbin again when passing through the upper hollow spindle, and then the two are jointly pulled to the winding drum, wherein the rotation speeds of the lower hollow spindle and the upper hollow spindle are the same, and the rotation directions are opposite;

[0090] (5) The product of step (4) is subjected to desizing treatment and sizing treatment in turn, and a continuous fiber reinforced polymer flexible 3D printing filament is obtained.

[0091] The finally prepared continuous fiber reinforced polymer flexible 3D printing filament has a core-spun yarn structure, including a core yarn and an outer wrapping yarn; the thermoplastic polymer powder is distributed between the fibers in the core yarn; the mass fraction of the thermoplastic polymer powder in the core yarn is 32%; the outer wrapping yarn is wrapped on the surface of the core yarn in double layers, the wrapping directions of the double layers are opposite, and the twist of the wrapping is 900T / m; the sizing agent is wrapped on the surface of the core yarn and the outer wrapping yarn.

[0092] The finally prepared continuous fiber reinforced polymer flexible 3D printing filament is used for 3D printing, and the printed product has good impregnation effect; it can also be used for weaving functional fabric, and the functional fabric obtained by weaving can be used for making fireproof clothing, heat shield, etc.

[0093] Example 4

[0094] A preparation method of a continuous fiber reinforced polymer flexible 3D printing filament, the specific steps are as follows:

[0095] (1) Preparation of raw materials:

[0096] Core yarn: glass fiber, linear density of 180 tex;

[0097] Outer wrapping yarn: thermoplastic polymer filament, material of PLA, linear density of 30 tex;

[0098] Thermoplastic polymer powder: material of PLA, average particle size of 1100 mesh;

[0099] Water;

[0100] Surfactant: polyethylene glycol;

[0101] Sizing agent;

[0102] (2) The core yarn is unwound from the yarn drum and immersed in the thermoplastic polymer suspension, and then passes through the roller in the thermoplastic polymer suspension; wherein the thermoplastic polymer powder suspension is composed of thermoplastic polymer powder, surfactant and water; the concentration of thermoplastic polymer powder in the thermoplastic polymer powder suspension is 18wt%, and the concentration of surfactant is 1wt%;

[0103] (3) The core yarn after step (2) is dried, and the drying adopts a non-contact type hot oven, the temperature is 150℃, the pulling speed is 1.4m / min, and the liquid rate of the core yarn is controlled to be 60%;

[0104] (4) The outer wrapping yarn is wrapped on the surface of the dried core yarn; when wrapping, the core yarn passes through the lower guide roller, the lower hollow spindle, the upper hollow spindle and the upper guide roller in turn from bottom to top, the core yarn is combined with the outer wrapping yarn unwound from the bobbin when passing through the lower hollow spindle, and the core yarn is combined with the outer wrapping yarn unwound from the bobbin again when passing through the upper hollow spindle, and then they are jointly pulled to the winding drum, wherein the rotation speeds of the lower hollow spindle and the upper hollow spindle are the same, and the rotation directions are opposite;

[0105] (5) The product of step (4) is subjected to desizing treatment and sizing treatment in turn, and a continuous fiber reinforced polymer flexible 3D printing filament is obtained.

[0106] The finally prepared continuous fiber reinforced polymer flexible 3D printing filament has a core-spun yarn structure, including a core yarn and an outer wrapping yarn; thermoplastic polymer powder is distributed between the fibers in the core yarn; the mass fraction of the thermoplastic polymer powder in the core yarn is 33%; the outer wrapping yarn is wrapped on the surface of the core yarn in double layers, the wrapping directions of the double layers are opposite, and the twist of the wrapping is 1000T / m; the sizing agent is wrapped on the surface of the core yarn and the outer wrapping yarn.

[0107] The finally prepared continuous fiber reinforced polymer flexible 3D printing yarn is used for 3D printing, and the printed product has good impregnation effect, and can also be used for weaving functional fabric, and the woven functional fabric can be used for manufacturing fireproof clothes, heat shield, etc.

[0108] Example 5

[0109] A preparation method of a continuous fiber reinforced polymer flexible 3D printing yarn, and the specific steps are as follows:

[0110] (1) Preparation of raw materials:

[0111] Core yarn: aramid, linear density is 90 tex;

[0112] Outer wrapping yarn: thermoplastic polymer yarn, material is nylon, linear density is 40 tex;

[0113] Thermoplastic polymer powder: material is nylon, average particle size is 1000 mesh;

[0114] Water;

[0115] Surfactant: polyethylene glycol;

[0116] Sizing agent;

[0117] (2) The core yarn is unwound from the yarn drum and immersed in the thermoplastic polymer suspension, and then passes through the roller in the thermoplastic polymer suspension; wherein the thermoplastic polymer powder suspension is composed of thermoplastic polymer powder, surfactant and water; the concentration of thermoplastic polymer powder in the thermoplastic polymer powder suspension is 13wt%, and the concentration of surfactant is 2wt%;

[0118] (3) The core yarn after step (2) is dried, and the drying adopts a non-contact type heat drying channel, the temperature is 120℃, the pulling speed is 1m / min, and the liquid rate of the core yarn is controlled to be 78%;

[0119] (4) The outer wrapping yarn is wrapped on the surface of the dried core yarn; when wrapping, the core yarn passes through the lower guide roller, the lower hollow spindle, the upper hollow spindle and the upper guide roller in turn from bottom to top, the core yarn is combined with the outer wrapping yarn unwound from the bobbin when passing through the lower hollow spindle, and the core yarn is combined with the outer wrapping yarn unwound from the bobbin again when passing through the upper hollow spindle, and then the core yarn and the outer wrapping yarn are jointly pulled to the winding drum, wherein the rotation speeds of the lower hollow spindle and the upper hollow spindle are the same, and the rotation directions are opposite.

[0120] (5) The product of step (4) is subjected to desizing treatment and sizing treatment in turn, and a continuous fiber reinforced polymer flexible 3D printing yarn is obtained.

[0121] The finally prepared continuous fiber reinforced polymer flexible 3D printing yarn has a core-spun yarn structure, including a core yarn and an outer wrapping yarn; the fibers in the core yarn are distributed with thermoplastic polymer powder; the mass fraction of the thermoplastic polymer powder in the core yarn is 35%; the outer wrapping yarn is wrapped with double layers on the surface of the core yarn, the wrapping directions of the double layers are opposite, and the twist of the wrapping is 1200T / m; the sizing agent is wrapped on the surface of the core yarn and the outer wrapping yarn.

[0122] The finally prepared continuous fiber reinforced polymer flexible 3D printing yarn is used for 3D printing, and the printed workpiece has good impregnation effect, and can also be used for weaving functional fabric, and the woven functional fabric can be used for making fireproof clothes, heat shields and the like.

[0123] Embodiment 6

[0124] A preparation method of a continuous fiber reinforced polymer flexible 3D printing yarn, the specific steps are as follows:

[0125] (1) Preparation of raw materials:

[0126] Core yarn: aramid, linear density is 100 tex;

[0127] Outer wrapping yarn: thermoplastic polymer yarn, material is PPS, linear density is 30 tex;

[0128] Thermoplastic polymer powder: material is PPS, average particle size is 900 mesh;

[0129] Water;

[0130] Surfactant: polyethylene glycol;

[0131] Sizing agent;

[0132] (2) The core yarn is unwound from the yarn drum and immersed in the thermoplastic polymer suspension, and then passes through the thermoplastic polymer suspension after winding around the roller in the thermoplastic polymer suspension; wherein the thermoplastic polymer powder suspension is composed of thermoplastic polymer powder, surfactant and water; the concentration of the thermoplastic polymer powder in the thermoplastic polymer powder suspension is 12wt%, and the concentration of the surfactant is 3wt%;

[0133] (3) The core yarn after step (2) is dried, the drying adopts a non-contact type heat drying channel, the temperature is 110℃, the pulling speed is 1.5m / min, and the liquid rate of the core yarn is controlled to be 50%;

[0134] (4) wrapping the outer covering yarn on the surface of the dried core yarn; when wrapping, the core yarn passes through the lower guide roller, the lower hollow spindle, the upper hollow spindle and the upper guide roller in turn from bottom to top, the core yarn converges with the outer covering yarn unwound from the bobbin when passing through the lower hollow spindle, and the core yarn converges with the outer covering yarn unwound from the bobbin again when passing through the upper hollow spindle, and they are jointly pulled to the winding drum, wherein the rotation speeds of the lower hollow spindle and the upper hollow spindle are the same, and the rotation directions are opposite;

[0135] (5) sequentially performing desizing treatment and sizing treatment on the product of step (4) to obtain the continuous fiber reinforced polymer flexible 3D printing yarn.

[0136] The finally prepared continuous fiber reinforced polymer flexible 3D printing yarn has a core-spun yarn structure, including a core yarn and an outer covering yarn; the fibers in the core yarn are distributed with thermoplastic polymer powder between the fibers; the mass fraction of the thermoplastic polymer powder in the core yarn is 29%; the outer covering yarn is wrapped on the surface of the core yarn in double layers, the wrapping directions of the double layers are opposite, and the twist of the wrapping is 700T / m; the sizing agent is wrapped on the surface of the core yarn and the outer covering yarn.

[0137] The finally prepared continuous fiber reinforced polymer flexible 3D printing yarn is used for 3D printing, and the printed product has good impregnation effect, and can also be used for weaving functional fabric, and the woven functional fabric can be used for making fireproof clothing, heat shield and the like.

Claims

1. A continuous fiber-reinforced polymer flexible 3D printing filament, characterized in that, The core yarn has a core yarn structure comprising a core yarn and an outer wrapping yarn; The core yarn is inorganic fiber or thermosetting organic fiber; Thermoplastic polymer powder is distributed between fibers in the core yarn; The outer wrapping yarn is thermoplastic polymer filament; the outer wrapping yarn is wrapped in double layers on the surface of the core yarn, and the wrapping directions of the double layers are opposite; the twist of the wrapping is 600-1200T / m; The thermoplastic polymer powder and the thermoplastic polymer filament are of the same material; or the thermoplastic polymer powder and the thermoplastic polymer filament are of different materials, and the melting points of the two are not more than 100℃.

2. The continuous fiber-reinforced polymeric flexible 3D printing filament according to claim 1, characterized in that, The particle size of the thermoplastic polymer powder is 800-1200 mesh.

3. The continuous fiber-reinforced polymeric flexible 3D printing filament of claim 1, wherein, The mass fraction of the thermoplastic polymer powder in the core yarn is 1-40%.

4. A method of producing a continuous fiber-reinforced polymeric flexible 3D printing filament according to any one of claims 1 to 3, characterized in that, After the core yarn is impregnated with the thermoplastic polymer powder suspension, the core yarn is wrapped with the thermoplastic polymer filament as the outer wrapping yarn on the surface of the core yarn, and a continuous fiber-reinforced polymer flexible 3D printing filament is obtained.

5. The method of claim 4, wherein, After impregnation, the core yarn is dried before wrapping, and the liquid carrying rate of the core yarn is controlled to be 50-80%.

6. The method of claim 4, wherein, During wrapping, the core yarn passes through a lower guide roller, a lower hollow spindle, an upper hollow spindle and an upper guide roller in sequence from bottom to top, the core yarn converges with the outer wrapping yarn unwound from the spool when passing through the lower hollow spindle, and the core yarn converges with the outer wrapping yarn unwound from the spool again when passing through the upper hollow spindle, and is jointly pulled to a winding drum, wherein the rotation speeds of the lower hollow spindle and the upper hollow spindle are the same, and the rotation directions are opposite.

7. The method of claim 4, wherein, After wrapping, the core yarn is subjected to desizing treatment and sizing treatment in sequence.

8. Use of a continuous fiber-reinforced polymer flexible 3D printing filament according to any one of claims 1 to 3, characterized in that, For 3D printing.

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