Metal composite PLA 3D printing wire rod with concentric structure and preparation method of metal composite PLA 3D printing wire rod

Abstract

The invention belongs to the technical field of materials, and particularly relates to a metal composite PLA 3D printing wire with a concentric structure and a preparation method thereof.The metal composite PLA 3D printing wire with the concentric structure is prepared from, by mass, 20-70 parts of a core layer and 30-80 parts of a metal composite outer skin layer; the core layer is PLA; the metal composite outer skin layer comprises the following components in parts by mass: 20-80 parts of a high polymer material, 0.5-3 parts of a coupling agent, 2-10 parts of an auxiliary agent and 10-70 parts of functional powder. The metal composite printing consumable has the advantages of being high in strength, low in cost, stable in production, high in yield, low in production cost, high in printability and the like, and a desktop-level printer can easily print metal composite printing consumables.

Description

Technical Field

[0001] The invention belongs to the field of material technology, and specifically relates to a metal composite PLA 3D printing wire with a concentric structure and a preparation method thereof. Background Art

[0002] Polylactic acid (PLA) is an environmentally friendly consumable. PLA comes from plant starch and non-fossil fuels. It can be self-biodegraded under certain composting conditions. Compared with other common 3D printing consumables, it has the advantages of no shrinkage, cracking and warping. Therefore, this type of material is more suitable for printing large models. At present, PLA consumable printing is a trend in the field of 3D printing. However, PLA3D printing materials generally have problems such as insufficient strength, mainly in the Z direction, which makes it difficult to popularize industrial applications. At the same time, PLA is a degradable material, which greatly limits its many applications in industry and outdoors. On the other hand, the metal composite 3D printing filaments on the market have low toughness due to the addition of metal components, making it difficult to stably produce on a large scale. There are also defects such as easy breakage and poor printing fluidity during the printing process, resulting in slow printing speeds, and it is difficult to achieve a very high level of metal content. Summary of the invention

[0003] In view of the deficiencies in the prior art, an object of the present invention is to provide a method for preparing a metal composite PLA 3D printing wire with a concentric structure.

[0004] In order to achieve the above object, the specific technical solution provided by the present invention is as follows:

[0005] A metal composite PLA 3D printing wire with a concentric structure, the metal composite PLA 3D printing wire with a concentric structure comprises the following components in mass percentage: 20-70 parts of a core layer and 30-80 parts of a metal composite outer skin layer;

[0006] The core layer is PLA;

[0007] The metal composite outer skin layer comprises the following components in percentage by mass: 20-80 parts of polymer material, 0.5-3 parts of coupling agent, 2-10 parts of auxiliary agent, and 10-70 parts of functional powder.

[0008] Furthermore, the polymer material is one or more of PE, PP, TPU, TPE, EVA, POE, PBAT, and silica gel.

[0009] Furthermore, the coupling agent is one or more of vinyl silane coupling agent, aluminate, titanate, and maleic anhydride grafted wax.

[0010] Furthermore, the auxiliary agent is one or more of maleic anhydride grafted PE, maleic anhydride grafted PP, maleic anhydride grafted TPU, maleic anhydride grafted EVA, maleic anhydride grafted POE, maleic anhydride grafted TPE, PE wax, stearic acid, ATBC tributyl citric acid, and pentaerythritol stearate.

[0011] Furthermore, the functional powder is one or more of aluminum powder, copper powder, iron powder, tungsten powder, silver powder, molybdenum powder, nickel powder, zinc powder, lead powder, graphite, aluminum oxide, zinc oxide, iron oxide, graphene, and carbon nanotubes.

[0012] The present invention also provides a method for preparing the above-mentioned metal composite PLA 3D printing wire with a concentric structure, comprising the following steps:

[0013] Adding the functional powder and the coupling agent into a high-speed mixer, and stirring to obtain the coupling agent-coated functional powder;

[0014] The coupling agent coated functional powder, polymer material and auxiliary agent are mixed and added into a twin-screw extruder for melt blending, extrusion granulation, and metal composite masterbatch;

[0015] The metal composite masterbatch and PLA are mixed and added into a single screw extruder for processing according to the formula. The extruded filament is cooled by water and pulled by a traction machine to control the wire diameter to obtain a metal composite PLA 3D printing filament with a concentric structure.

[0016] Furthermore, the rotation speed of the high speed mixer is 600-2000 rpm, and the stirring time is 5-30 min.

[0017] Furthermore, the ratio of the core layer of the wire to the wire radius is 0.2-0.8:1.

[0018] Furthermore, the parameters of the twin-screw extruder are: zone 1 100-110°C, zone 2 130-140°C, zone 3 140-150°C, zone 4 150-160°C, zone 5 170-180°C, zone 6 180-190°C, zone 7 190-200°C, zone 8 210-220°C, zone 9 220-230°C, die head 210-230°C, and rotation speed 50-250 rpm.

[0019] Furthermore, the parameters of the single screw extruder are: zone 1 180-190°C, zone 2 195-210°C, zone 3 210-220°C, zone 4 220-230°C, and a rotation speed of 10-100 rpm.

[0020] Beneficial Effects

[0021] The 3D printing wire obtained by the present invention has a concentric structure, a metal polymer as an outer layer, and a PLA as a core layer. The preparation method is simple and efficient. Through deposition melting (FDM), the metal powder component is evenly distributed on the outer surface of the printed device. At the same time, the layers are also mutually bonded with metal composite materials, which can realize the multifunctionalization of 3D printing devices, such as electroplating and microwave heating to increase the interlayer bonding strength, greatly improve the mechanical strength of the printed products and expand the practicality of the products. It solves many problems such as the existing materials can only reflect one material performance and printing model due to the single material, poor interlayer bonding, high cost of single metal composite materials, and difficulty in processing into wires.

[0022] The present invention can take into account the advantages of metal and PLA through metal composite PLA, and prepare a metal composite PLA 3D printing wire with a concentric structure, which has the advantages of high strength, low cost, production stability, high output, low production cost, high printability, etc., and can realize desktop printers to easily print metal composite printing consumables. The wire of the present invention concentrates the metal components in the outer skin layer, greatly saving the amount of metal components and additives, and the thickness ratio of the outer skin layer to the PLA core layer is adjustable, and concentric structure consumables with different costs and performances can be developed, and the core layer and the outer skin layer have a good combination.

[0023] The preparation method of the present invention has simple process conditions and can be achieved with a single screw; the layers are connected by metal composite layers of the outer skin layer, and the outer surface of the printed part is also a metal composite layer, which greatly improves the outdoor durability and strength of the printed part; the product can be further improved in strength, such as Z-axis strength and durability, by subsequent electroplating and microwave heating, and the appearance can be as beautiful as metal parts.

[0024] Expand the application areas of PLA3D printing consumables, such as automobiles, industrial machinery parts, aerospace, drones, robots, electronic devices and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a concentric structure metal composite 3D printing filament. The yellow part is the PLA core layer and the blue part is the metal composite outer layer.

[0026] Figure 2 For electroplating printed products.

[0027] Figure 3 Print parts with high strength for a metallic look.

[0028] Figure 4This is the metal composite PLA 3D printing wire with a concentric structure prepared in Example 1; (a) is a photo of the metal composite PLA 3D printing wire with a concentric structure prepared in Example 1 of the present invention; (b) is a concentric structure printing model and an enlarged view of the interlayer cross-section; (c) is a schematic diagram of the microwave heating print layer to fuse again to increase the interlayer adhesion. DETAILED DESCRIPTION

[0029] Example 1

[0030] A metal composite PLA 3D printing wire with a concentric structure includes the following components in percentage by mass: 80 parts of a metal composite outer skin layer and 20 parts of a core layer. The core layer is PLA.

[0031] The metal composite outer skin layer comprises: 80 parts of TPU, 0.5 parts of vinyl silane coupling agent, 6.5 parts of maleic anhydride grafted TPU, 3 parts of ATBC tributyl citric acid ester, 8 parts of aluminum powder, and 2 parts of carbon nanotubes;

[0032] The preparation method comprises the following steps:

[0033] (1) Aluminum powder, carbon nanotubes and vinyl silane coupling agent were added into a high-speed mixer in a mass ratio of 1, the speed was maintained at 600 rpm, and high-speed stirring was performed for 5 minutes to obtain coupling agent-coated functional powder;

[0034] (2) mixing the coupling agent coated functional powder, TPU, maleic anhydride grafted TPU, and ATBC, and adding them into a twin-screw extruder according to the formula for melt blending, extrusion granulation, and obtaining a metal composite masterbatch;

[0035] (3) The metal composite masterbatch and PLA obtained in (2) are mixed and added into a single screw extruder according to the formula for processing, the extruded wire is cooled by water, and the wire diameter is controlled by a traction machine to obtain a metal composite PLA 3D printing wire with a concentric structure, wherein the ratio of the core layer to the wire radius of the wire is 0.2:1.

[0036] The parameters of the twin-screw extruder are: zone 1 100°C, zone 2 130°C, zone 3 140°C, zone 4 150°C, zone 5 170°C, zone 6 180°C, zone 7 190°C, zone 8 210°C, zone 9 220°C, die head 220°C, and rotation speed 50 rpm.

[0037] The parameters of the single screw extruder are: 190°C in zone 1, 210°C in zone 2, 220°C in zone 3, 230°C in zone 4, and a rotation speed of 100 rpm.

[0038] Example 2

[0039] A metal composite PLA 3D printing wire with a concentric structure includes the following components in percentage by mass: 30 parts of a metal composite outer layer and 70 parts of a core layer. The core layer is PLA.

[0040] The metal composite outer skin layer comprises: 10 parts of POE, 10 parts of EVA, 0.5 parts of vinyl silane coupling agent, 2.5 parts of maleic anhydride grafted wax, 3 parts of maleic anhydride grafted POE, 4 parts of pentaerythritol stearate, and 70 parts of copper powder;

[0041] The preparation method comprises the following steps:

[0042] (1) Add copper powder, vinyl silane coupling agent and maleic anhydride grafted wax into a high-speed mixer at a mass ratio of 1, maintain the speed at 1000 rpm, and stir at high speed for 30 minutes to obtain coupling agent-coated functional powder;

[0043] (2) mixing the coupling agent coated functional powder, POE, EVA, maleic anhydride grafted wax, maleic anhydride grafted POE, and pentaerythritol stearate, adding the mixture into a twin-screw extruder for melt blending according to the formula, and extruding and granulating to obtain a metal composite masterbatch;

[0044] (3) The metal composite masterbatch and PLA obtained in (2) are mixed and added into a single screw extruder according to the formula for processing, the extruded wire is cooled by water, and the wire diameter is controlled by a traction machine to obtain a metal composite PLA 3D printing wire with a concentric structure, wherein the ratio of the core layer to the wire radius of the wire is 0.7:1.

[0045] The twin-screw extruder parameters are: zone 1 110°C, zone 2 130°C, zone 3 150°C, zone 4 160°C, zone 5 180°C, zone 6 190°C, zone 7 200°C, zone 8 220°C, zone 9 230°C, die head 230°C, and rotation speed 250 rpm.

[0046] The parameters of the single screw extruder are: zone 1 180-190°C, zone 2 195-210°C, zone 3 210-220°C, zone 4 220-230°C, and a rotation speed of 10 rpm.

[0047] Example 3

[0048] A metal composite PLA 3D printing wire with a concentric structure includes the following components in percentage by mass: 50 parts of a metal composite outer layer and 50 parts of a core layer. The core layer is PLA.

[0049] The metal composite outer skin layer comprises: 20 parts of PE, 20 parts of PBAT, 0.5 parts of aluminate, 0.5 parts of titanate, 5 parts of maleic anhydride grafted PE, 5 parts of ATBC tributyl citric acid ester, 40 parts of silver powder, 4 parts of lead powder, and 5 parts of graphene;

[0050] The preparation method comprises the following steps:

[0051] (1) Add silver powder, lead powder, graphene, aluminate, and titanate coupling agent into a high-speed mixer at a mass ratio of 1, maintain the speed at 1000 rpm, and stir at high speed for 20 minutes to obtain coupling agent-coated functional powder;

[0052] (2) mixing the coupling agent coated functional powder, PE, PBAT, maleic anhydride grafted PE, and ATBC, and adding them into a twin-screw extruder according to the formula for melt blending, extrusion granulation, and obtaining a metal composite masterbatch;

[0053] (3) The metal composite masterbatch and PLA obtained in (2) are mixed and added into a single screw extruder according to the formula for processing, the extruded wire is cooled by water, and the wire diameter is controlled by a traction machine to obtain a metal composite PLA 3D printing wire with a concentric structure, wherein the ratio of the core layer to the wire radius of the wire is 0.5:1.

[0054] The twin-screw extruder parameters are: zone 1 110°C, zone 2 140°C, zone 3 150°C, zone 4 160°C, zone 5 180°C, zone 6 190°C, zone 7 200°C, zone 8 220°C, zone 9 230°C, die head 230°C, and rotation speed 200 rpm.

[0055] The parameters of the single screw extruder are: 190° C. in zone 1, 210° C. in zone 2, 220° C. in zone 3, 230° C. in zone 4, and a rotation speed of 90 rpm.

[0056] Example 4

[0057] A concentric metal composite PLA 3D printing wire comprises the following components in percentage by mass: 40 parts of a metal composite outer layer and 60 parts of a core layer. The core layer is PLA.

[0058] The metal composite outer skin layer comprises: 30 parts of TPU, 7.5 parts of PBAT, 0.5 parts of vinyl silane coupling agent, 1 part of aluminate, 1 part of titanate, 6.5 parts of maleic anhydride grafted TPU, 3 parts of pentaerythritol stearate, 0.5 parts of ATBC, 20 parts of alumina, 20 parts of aluminum powder, and 10 parts of carbon nanotubes;

[0059] The preparation method comprises the following steps:

[0060] (1) Alumina, aluminum powder, carbon nanotubes, vinyl silane coupling agent, aluminate, and titanate are added into a high-speed mixer in a mass ratio of 1, maintained at a speed of 1200 rpm, and stirred at high speed for 15 minutes to obtain coupling agent-coated functional powder;

[0061] (2) mixing the coupling agent coated functional powder, TPU, PBAT, maleic anhydride grafted TPU, pentaerythritol stearate, and ATBC, and adding them into a twin-screw extruder for melt blending according to the formula, extruding and granulating to obtain a metal composite masterbatch;

[0062] (3) The metal composite masterbatch and PLA obtained in (2) are mixed and added into a single screw extruder according to the formula for processing, the extruded wire is cooled by water, and the wire diameter is controlled by a traction machine to obtain a metal composite PLA 3D printing wire with a concentric structure, wherein the ratio of the core layer to the wire radius of the wire is 0.6:1.

[0063] The parameters of the twin-screw extruder are: zone 1 110°C, zone 2 140°C, zone 3 150°C, zone 4 160°C, zone 5 180°C, zone 6 190°C, zone 7 200°C, zone 8 220°C, zone 9 230°C, die head 230°C, and rotation speed 100 rpm.

[0064] The parameters of the single screw extruder are: 190° C. in zone 1, 210° C. in zone 2, 220° C. in zone 3, 230° C. in zone 4, and a rotation speed of 80 rpm.

[0065] Example 5

[0066] A metal composite PLA 3D printing wire with a concentric structure includes the following components in percentage by mass: 30 parts of a metal composite outer layer and 70 parts of a core layer. The core layer is PLA.

[0067] The metal composite outer skin layer comprises: 20 parts of PP, 50 parts of TPE, 10 parts of silica gel, 1 part of vinyl silane coupling agent, 1.5 parts of maleic anhydride grafted PP, 0.5 parts of maleic anhydride grafted TPE, 2 parts of stearic acid, 5 parts of iron powder, 5 parts of graphite, and 5 parts of iron oxide;

[0068] The preparation method comprises the following steps:

[0069] (1) Add iron powder, graphite, iron oxide and vinyl silane coupling agent in a mass ratio of 1 into a high-speed mixer, maintain the speed at 100 rpm, and stir at high speed for 20 minutes to obtain coupling agent-coated functional powder;

[0070] (2) mixing the coupling agent coated functional powder, PP, TPE, silica gel, maleic anhydride grafted PP, maleic anhydride grafted TPE, and stearic acid, adding the mixture into a twin-screw extruder for melt blending according to the formula, and extruding and granulating to obtain a metal composite masterbatch;

[0071] (3) The metal composite masterbatch and PLA obtained in (2) are mixed and added into a single screw extruder according to the formula for processing, the extruded wire is cooled by water, and the wire diameter is controlled by a traction machine to obtain a metal composite PLA 3D printing wire with a concentric structure, wherein the ratio of the core layer to the wire radius of the wire is 0.7:1.

[0072] The parameters of the twin-screw extruder are: zone 1 110°C, zone 2 140°C, zone 3 150°C, zone 4 160°C, zone 5 180°C, zone 6 190°C, zone 7 200°C, zone 8 220°C, zone 9 230°C, die head 230°C, and rotation speed 100 rpm.

[0073] The parameters of the single screw extruder are: 190°C in zone 1, 210°C in zone 2, 220°C in zone 3, 230°C in zone 4, and a rotation speed of 100 rpm.

[0074] Comparative Example 1

[0075] A metal composite PLA 3D printing filament with a concentric structure comprises the following components in percentage by mass: 30 parts of a metal composite outer skin layer and 70 parts of a core layer, wherein the core layer is PLA.

[0076] The metal composite outer skin layer includes: 20 parts of PP, 50 parts of TPE, 10 parts of silica gel, 2 parts of stearic acid, 5 parts of iron powder, 5 parts of graphite, and 5 parts of iron oxide;

[0077] The preparation method comprises the following steps:

[0078] (1) Mixing iron powder, graphite, iron oxide with PP, TPE, silica gel and stearic acid, and adding them into a twin-screw extruder according to the formula for melt blending, extrusion granulation, and obtaining a metal composite masterbatch;

[0079] (2) The metal composite masterbatch and PLA obtained in (1) are mixed and added into a single screw extruder according to the formula for processing, the extruded wire is cooled by water, and the wire diameter is controlled by a traction machine to obtain a metal composite PLA 3D printing wire with a concentric structure, wherein the ratio of the core layer to the wire radius of the wire is 0.7:1.

[0080] The parameters of the twin-screw extruder are: zone 1 110°C, zone 2 140°C, zone 3 150°C, zone 4 160°C, zone 5 180°C, zone 6 190°C, zone 7 200°C, zone 8 220°C, zone 9 230°C, die head 230°C, and rotation speed 100 rpm.

[0081] The parameters of the single screw extruder are: 190°C in zone 1, 210°C in zone 2, 220°C in zone 3, 230°C in zone 4, and a rotation speed of 100 rpm.

[0082] Comparative Example 2

[0083] A metal composite PLA 3D printing wire with a concentric structure includes the following components in percentage by mass: 90 parts of a metal composite outer skin layer and 10 parts of a core layer. The core layer is PLA.

[0084] The metal composite outer skin layer comprises: 20 parts of PP, 50 parts of TPE, 10 parts of silica gel, 1 part of vinyl silane coupling agent, 1.5 parts of maleic anhydride grafted PP, 0.5 parts of maleic anhydride grafted TPE, 2 parts of stearic acid, 5 parts of iron powder, 5 parts of graphite, and 5 parts of iron oxide;

[0085] The preparation method comprises the following steps:

[0086] (1) Add iron powder, graphite, iron oxide and vinyl silane coupling agent in a mass ratio of 1 into a high-speed mixer, maintain the speed at 100 rpm, and stir at high speed for 20 minutes to obtain coupling agent-coated functional powder;

[0087] (2) mixing the coupling agent coated functional powder, PP, TPE, silica gel, maleic anhydride grafted PP, maleic anhydride grafted TPE, and stearic acid, adding the mixture into a twin-screw extruder for melt blending according to the formula, and extruding and granulating to obtain a metal composite masterbatch;

[0088] (3) The metal composite masterbatch and PLA obtained in (2) are mixed and added into a single screw extruder according to the formula for processing, the extruded wire is cooled by water, and the wire diameter is controlled by a traction machine to obtain a metal composite PLA 3D printing wire with a concentric structure, wherein the ratio of the core layer to the wire radius of the wire is 0.1:1.

[0089] The parameters of the twin-screw extruder are: zone 1 110°C, zone 2 140°C, zone 3 150°C, zone 4 160°C, zone 5 180°C, zone 6 190°C, zone 7 200°C, zone 8 220°C, zone 9 230°C, die head 230°C, and rotation speed 100 rpm.

[0090] The parameters of the single screw extruder are: 190°C in zone 1, 210°C in zone 2, 220°C in zone 3, 230°C in zone 4, and a rotation speed of 100 rpm.

[0091] Table 1. Summary of concentric structure consumables performance

[0092]

[0093] The above data show that the concentric structure metal composite FDM printing wire obtained by the raw materials and preparation method of the present invention has a higher production speed and printing speed than the control example, and has better toughness and strength. The relevant coupling agent and auxiliary agent components can greatly increase the mechanical properties, and the auxiliary agent can significantly improve the processing fluidity and the maximum printing speed. When the ratio of the concentric structure ratio to the core layer and the consumable radius is less than 0.2, the mechanical properties, processing properties, and printing speed all show a significant downward trend.

[0094] The above-mentioned specific implementation methods are further detailed descriptions of the present invention application, but the scope of protection of the claims of the present invention is not limited to the scope described in the implementation methods. All technical solutions using equivalent deformations, etc. fall within the scope of protection of the claims of the present invention.

Claims

1. A metal composite PLA 3D printing wire with a concentric structure, characterized in that: The concentric metal composite PLA 3D printing wire comprises the following components in percentage by mass: 20-70 parts of a core layer and 30-80 parts of a metal composite outer skin layer; The core layer is PLA; The metal composite outer skin layer comprises the following components in percentage by mass: 20-80 parts of polymer material, 0.5-3 parts of coupling agent, 2-10 parts of auxiliary agent, and 10-70 parts of functional powder.

2. The metal composite PLA 3D printing wire with a concentric structure according to claim 1, characterized in that: The polymer material is one or more of PE, PP, TPU, TPE, EVA, POE, PBAT, and silica gel.

3. The metal composite PLA 3D printing wire with a concentric structure according to claim 1, characterized in that: The coupling agent is one or more of vinyl silane coupling agent, aluminate, titanate, and maleic anhydride grafted wax.

4. The metal composite PLA 3D printing wire with a concentric structure according to claim 1, characterized in that: The auxiliary agent is one or more of maleic anhydride grafted PE, maleic anhydride grafted PP, maleic anhydride grafted TPU, maleic anhydride grafted EVA, maleic anhydride grafted POE, maleic anhydride grafted TPE, PE wax, stearic acid, ATBC tributyl citric acid, and pentaerythritol stearate.

5. The metal composite PLA 3D printing wire with a concentric structure according to claim 1, characterized in that: The functional powder is one or more of aluminum powder, copper powder, iron powder, tungsten powder, silver powder, molybdenum powder, nickel powder, zinc powder, lead powder, graphite, aluminum oxide, zinc oxide, iron oxide, graphene, and carbon nanotubes.

6. The method for preparing the metal composite PLA 3D printing wire with a concentric structure according to claim 1, characterized in that: The following steps are involved: Adding the functional powder and the coupling agent into a high-speed mixer, and stirring to obtain the coupling agent-coated functional powder; The coupling agent coated functional powder, polymer material and auxiliary agent are mixed and added into a twin-screw extruder for melt blending, extrusion granulation, and metal composite masterbatch; The metal composite masterbatch and PLA are mixed and added into a single screw extruder for processing according to the formula. The extruded filament is cooled by water and pulled by a traction machine to control the wire diameter to obtain a metal composite PLA 3D printing filament with a concentric structure.

7. The method for preparing the metal composite PLA 3D printing wire with a concentric structure according to claim 6, characterized in that: The rotation speed of the high speed mixer is 600-2000 rpm, and the stirring time is 5-30 min.

8. The method for preparing the metal composite PLA 3D printing wire with a concentric structure according to claim 6, characterized in that: The ratio of the core layer of the wire to the wire radius is 0.2-0.8:

1.

9. The method for preparing the metal composite PLA 3D printing wire with a concentric structure according to claim 6, characterized in that: The parameters of the twin-screw extruder are: zone 1 100-110°C, zone 2 130-140°C, zone 3 140-150°C, zone 4 150-160°C, zone 5 170-180°C, zone 6 180-190°C, zone 7 190-200°C, zone 8 210-220°C, zone 9 220-230°C, die head 210-230°C, and rotation speed 50-250 rpm.

10. The method for preparing the metal composite PLA 3D printing wire with a concentric structure according to claim 6, characterized in that: The parameters of the single screw extruder are: zone 1 180-190°C, zone 2 195-210°C, zone 3 210-220°C, zone 4 220-230°C, and a rotation speed of 10-100 rpm.

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