阅读说明：本技术 一种3d打印用纤维增强热塑性复合材料长丝制备方法 (Preparation method of fiber-reinforced thermoplastic composite filament for 3D printing ) 是由 李宏福 韩进 牛康民 姜乃生 伍英 于 2021-09-08 设计创作，主要内容包括：本发明提供一种3D打印用纤维增强热塑性复合材料长丝制备方法,属于3D打印技术领域。该方法首先进行碳纤维丝束的展纱,然后进行纤维丝束预热和纤维与热塑性树脂浸渍,最后通过定径模具定型、冷却、收卷,得到连续纤维3D打印长丝。本发明是由热塑性树脂均匀纤维束得到的连续纤维复合材料3D打印长丝,该复合材料长丝具有高强度、高模量,并且制备的3D打印样件具有高的力学性能等优点。本发明方法能够高效连续制备3D打印长丝。(The invention provides a preparation method of a fiber reinforced thermoplastic composite filament for 3D printing, and belongs to the technical field of 3D printing. The method comprises the steps of firstly spreading carbon fiber tows, then preheating the carbon fiber tows, impregnating fibers and thermoplastic resin, and finally sizing, cooling and rolling through a sizing die to obtain the continuous fiber 3D printing filament. The continuous fiber composite 3D printing filament obtained by uniform fiber bundles of thermoplastic resin has the advantages of high strength and high modulus, and the prepared 3D printing sample piece has high mechanical property and the like. The method disclosed by the invention can be used for efficiently and continuously preparing the 3D printing filament.)

1. A preparation method of a fiber reinforced thermoplastic composite filament for 3D printing is characterized by comprising the following steps: the method comprises the following steps:

s1: fiber tow spreading: after the temperatures of the extruding device, the impregnating device and the sizing device are set, introducing thermoplastic resin from a feeding port of the extruding device, and introducing fibers from a yarn spreading rack;

s2: preheating fiber tows;

s3: fiber and thermoplastic resin impregnation: after the fiber tows reach the set temperature, opening the extrusion device, and extruding the thermoplastic resin into the impregnation device to be impregnated with the fibers;

s4: sizing through a sizing die: obtaining a 3D printing wire rod after passing through 1-5 sizing dies;

s5: cooling and rolling: and cooling and winding the obtained 3D printing wire rod to obtain the fiber reinforced thermoplastic composite filament for 3D printing.

2. The method of preparing a fiber reinforced thermoplastic composite filament for 3D printing according to claim 1, wherein: each fiber filament of the fiber reinforced thermoplastic composite filament for 3D printing is coated by resin, and the pore content of the filament is less than 5%.

3. The method of preparing a fiber reinforced thermoplastic composite filament for 3D printing according to claim 1, wherein: 20-80 parts of fibers in S1 and 80-20 parts of thermoplastic resin.

4. The method of preparing a fiber reinforced thermoplastic composite filament for 3D printing according to claim 1, wherein: the thermoplastic resin is one or more of polypropylene, polyethylene, polyamide, polyurethane, polylactic acid, polycarbonate, polyether ether ketone, polyphenylene sulfide and acrylonitrile-butadiene-styrene.

5. The method of preparing a fiber reinforced thermoplastic composite filament for 3D printing according to claim 1, wherein: the fiber is one or a mixture of carbon fiber, glass fiber, Kevlar fiber, basalt fiber, PBO fiber, aramid fiber, polyethylene fiber, polypropylene fiber, terylene and polyamide fiber.

6. The method of preparing a fiber reinforced thermoplastic composite filament for 3D printing according to claim 1, wherein: the preheating temperature of the fiber tows in the S2 is 0-400 ℃.

7. The method of preparing a fiber reinforced thermoplastic composite filament for 3D printing according to claim 1, wherein: the temperature of the impregnation device in the S1 is set to be 150-400 ℃, the temperature of the sizing device is set to be 150-400 ℃, and the temperature of the extrusion device is set to be 150-400 ℃.

8. The method of preparing a fiber reinforced thermoplastic composite filament for 3D printing according to claim 1, wherein: the diameter of the sizing hole of the sizing device is 0.1-10 mm.

9. The method of preparing a fiber reinforced thermoplastic composite filament for 3D printing according to claim 8, wherein: the diameter of the sizing hole of the sizing device is one of 0.1 mm, 0.2 mm, 0.3 mm, 0.4mm, 0.5 mm, 0.8 mm, 1.0 mm, 1.5 mm, 1.75 mm and 2.0 mm.

Technical Field

The invention relates to the technical field of 3D printing, in particular to a preparation method of a fiber reinforced thermoplastic composite filament for 3D printing.

Background

3D printing technology, also known as additive manufacturing, has recently spread worldwide due to its ability to be manufactured quickly. Among them, Fused Deposition Modeling (FDM) is the most widely used 3D printing technique because it uses inexpensive equipment and is easy to construct complex parts and thermoplastic filaments such as polylactic acid, nylon or ABS. However, one of the main drawbacks of the swatches printed with pure thermoplastic filaments is the poor mechanical properties, which limits the applications.

Continuous fibers play a crucial role in the field of composite materials due to their excellent mechanical properties and lightweight properties. The strength of the thermoplastic resin reinforced with continuous fibers is significantly improved compared to that of the thermoplastic resin reinforced with short fibers because the continuous fibers have lower porosity and higher strength. However, the continuous fiber 3D printing technology still has certain problems in terms of materials: low fiber content, layered printing sample pieces and the like, and can not meet the practical requirements of application.

The long basalt fiber thermoplastic consumable for 3D printing, the preparation method and the preparation device thereof in the prior art have the advantages of high strength, high modulus, impact resistance, high temperature resistance and the like, and the preparation method and the preparation device of the 3D printing thermoplastic composite consumable are also provided, so that the 3D printing consumable can be continuously produced, but the method does not well control the dipping condition of the printing wire.

According to the composite material for 3D printing and the preparation method thereof in the prior art, the obtained composite material substrate for 3D printing is of a skin-core structure, the core layer is made of a carbon fiber reinforced PA6T-6I or PA6T-66 (high melting point) composite material, the fiber content is 30-50%, and the overall mechanical property and the dimensional stability of the composite material substrate for 3D printing are ensured; the core layer is made of a carbon fiber reinforced PA6T-66 or PA6T-6 (slightly low melting point) composite material, the fiber content is 10% -20%, the dimensional accuracy of the composite material 3D printing base material is guaranteed, the technology is characterized in that the selection of the base material is strict, and the distribution of the fibers cannot be controlled, so that the performance of a final sample piece is low, and the actual requirement cannot be met.

Therefore, on the premise of ensuring uniform resin impregnation of fibers, the fiber content of the 3D printing filament and the section diameter of the 3D printing filament can be improved, the mechanical property of the 3D printing composite material can be further improved, and the 3D printing composite material can be pushed to a wider application field and is a problem in structural design and process departments and a problem which needs to be solved urgently.

Disclosure of Invention

The invention aims to solve the technical problems that the existing 3D printing fiber thermoplastic composite filament cannot be used for preparing a superfine 3D printing composite filament, the prepared filament is low in porosity of a sample piece after 3D printing, so that the mechanical property is improved, and the production efficiency is high.

The method comprises the following steps:

s1: fiber tow spreading: after the temperatures of the extruding device, the impregnating device and the sizing device are set, introducing thermoplastic resin from a feeding port of the extruding device, and introducing fibers from a yarn spreading rack;

s2: preheating fiber tows: preheating according to the set temperature;

s3: fiber and thermoplastic resin impregnation: after the fiber tows reach the set temperature, opening the extrusion device, and extruding the thermoplastic resin into the impregnation device to be impregnated with the fibers;

s4: sizing through a sizing die: obtaining a 3D printing wire rod after passing through 1-5 sizing dies;

s5: cooling and rolling: and cooling and winding the obtained 3D printing wire rod to obtain the fiber reinforced thermoplastic composite filament for 3D printing.

Wherein, each fiber filament of the fiber reinforced thermoplastic composite filament for 3D printing is coated by resin, and the pore content of the filament is less than 5%.

20-80 parts of fibers and 80-20 parts of thermoplastic resin in S1. Meanwhile, various auxiliary additives such as color master batch, antioxidant, flame retardant, compatilizer, nucleating agent, weather-resistant agent and the like can be additionally added according to the product requirements.

The thermoplastic resin is one or more of polypropylene, polyethylene, polyamide, polyurethane, polylactic acid, polycarbonate, polyether ether ketone, polyphenylene sulfide and acrylonitrile-butadiene-styrene.

The fiber is one or a mixture of carbon fiber, glass fiber, Kevlar fiber, basalt fiber, PBO fiber, aramid fiber, polyethylene fiber, polypropylene fiber, terylene and polyamide fiber.

The preheating temperature of the fiber tows in the S2 is 0-400 ℃.

In S1, the setting temperature of the dipping device is 150-400 ℃, the setting temperature of the sizing device is 150-400 ℃, and the setting temperature of the extrusion device is 150-400 ℃.

The diameter of the sizing hole of the sizing device is 0.1-10 mm.

Preferably, the sizing device has a sizing hole diameter of one of 0.1, 0.2, 0.3, 0.4, 0.5, 0.8, 1.0, 1.5, 1.75, 2.0 mm.

The technical scheme of the invention has the following beneficial effects:

according to the scheme, the continuous fiber reinforced thermoplastic composite material 3D printing filament obtained by uniformly impregnating and wrapping the thermoplastic resin with the continuous fiber bundles is high in fiber content, uniform in fiber distribution and controllable in cross-sectional diameter of the thermoplastic composite material filament, the mechanical property of the existing 3D printing composite material filament can be improved, the composite material filament can be continuously produced by the method, the production efficiency can be effectively improved, and the actual production requirement is met.

Drawings

Fig. 1 is a schematic preparation flow diagram of a preparation method of a fiber reinforced thermoplastic composite filament for 3D printing according to the present invention;

FIG. 2 is a schematic view of a sizing die used in the method for making a fiber reinforced thermoplastic composite filament for 3D printing according to the present invention;

FIG. 3 is a diagram of a product obtained in an example of the present invention;

fig. 4 is a schematic actual cross-sectional view of a fiber reinforced thermoplastic composite filament for 3D printing prepared according to the present invention.

Wherein: 1-fiber bundle; 2, unfolding a creel; 3-a heating device; 4-an extrusion device; 5-a dipping device; 6-sizing device; 7-a traction device; 8, a winding device; 9-carbon fibers; 10-resin matrix.

Detailed Description

In order to make the technical problems, technical solutions and advantages of the present invention more apparent, the following detailed description is given with reference to the accompanying drawings and specific embodiments.

The invention provides a preparation method of a fiber reinforced thermoplastic composite filament for 3D printing.

The method comprises the following steps:

s1: fiber tow spreading: after the temperatures of the extruding device, the impregnating device and the sizing device are set, introducing thermoplastic resin from a feeding port of the extruding device, and introducing fibers from a yarn spreading rack;

s2: preheating fiber tows;

s3: fiber and thermoplastic resin impregnation: after the fiber tows reach the set temperature, opening the extrusion device, and extruding the thermoplastic resin into the impregnation device to be impregnated with the fibers;

s4: sizing through a sizing die: obtaining a 3D printing wire rod after passing through 1-5 sizing dies;

s5: cooling and rolling: and cooling and winding the obtained 3D printing wire rod to obtain the fiber reinforced thermoplastic composite filament for 3D printing.

Wherein, each fiber filament of the fiber reinforced thermoplastic composite filament for 3D printing is coated by resin, and the pore content of the filament is less than 5%.

20-80 parts of fibers and 80-20 parts of thermoplastic resin in S1.

The thermoplastic resin is one or more of polypropylene, polyethylene, polyamide, polyurethane, polylactic acid, polycarbonate, polyether ether ketone, polyphenylene sulfide and acrylonitrile-butadiene-styrene.

The fiber is one or a mixture of carbon fiber, glass fiber, Kevlar fiber, basalt fiber, PBO fiber, aramid fiber, polyethylene fiber, polypropylene fiber, terylene and polyamide fiber.

In S1, the setting temperature of the dipping device is 150-400 ℃, the setting temperature of the sizing device is 150-400 ℃, and the setting temperature of the extrusion device is 150-400 ℃. The preheating temperature of the fiber tows in the S2 is 0-400 ℃.

The diameter of the sizing hole of the sizing device is 0.1-10 mm. The sizing device is shown in detail in fig. 2.

The following description is given with reference to specific examples.

As shown in fig. 1, a yarn spreading frame 2, an extruding device 4, a soaking device 5, a sizing device 6, a traction device 7 and a winding device 8 are connected in sequence according to the process sequence, the yarn spreading frame 2 is provided with a heating device 3, and a fiber bundle 1 is led in from the yarn spreading frame 2.

In the specific implementation, the glass fiber is used as a reinforcing material, PLA (polylactic acid) is used as a base material, and the superfine high-fiber-content high-performance 3D printing wire with the diameter of 0.3-0.4mm is prepared, and the specific preparation steps are as follows:

step 1: setting the temperature of an extrusion device, a dipping device and a sizing device;

step 2: pouring the dried PLA into the extruder from a main feeding port, and introducing the glass fiber from a yarn spreading device;

and step 3: and (3) opening the extrusion device when the temperature of each device rises to the required temperature, extruding resin into the impregnation device to impregnate the carbon fibers, obtaining a 3D printing wire rod with the diameter of 0.3-0.4mm after passing through 1-5 sizing dies, and then printing by using a 3D printer according to the requirements of stretching and bending the standard part to obtain a sample, wherein each carbon fiber 9 is coated by a resin matrix 10 as shown in figures 3 and 4.

Comparative example 1

Pure PLA was 3D printed using the same printing parameters as in example 1 and tested for tensile and flexural properties.

Comparative example 2

And carrying out a tensile test on the single 3D printing wire.

The 3D printing wire prepared by the method has the advantages of high carbon fiber content, small diameter of the printing wire, good dimensional stability and high mechanical property, and the specific test data are shown in Table 1.

Table 1 performance parameters of 3D printed wires and samples obtained from examples and comparative examples

The experimental results in the table 1 show that the 3D printing fiber reinforced thermoplastic composite material 3D printing wire prepared by the preparation method has better mechanical property than the prior art, the impregnation effect is good, the fiber distribution is uniform, and the mechanical property of the obtained continuous wire is excellent.

In conclusion, the continuous fiber reinforced thermoplastic 3D printing wire material for 3D printing provided by the invention has the advantages that various performances are obviously improved, the continuous fiber reinforced thermoplastic 3D printing wire material can be suitable for printing sectional materials with various structures, the application range of the continuous fiber reinforced thermoplastic 3D printing wire material can be expanded, and 3D printing is developed in other fields, such as: automotive applications, etc.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.