KR20230064640A - A method for manufacturing a 3-d printing filament - Google Patents

Abstract

One aspect of the present invention, (a) obtaining recycled resin particles by grinding the resin waste; And (b) preparing a 3D printing filament by melting and kneading a mixture containing the recycled resin particles and a thermoplastic resin to obtain a melt, and then extruding the melt to produce a 3D printing filament. .

Description

Manufacturing method of 3D printing filament {A METHOD FOR MANUFACTURING A 3-D PRINTING FILAMENT}

The present invention relates to a method for manufacturing a 3D printing filament, and more particularly, to a method for manufacturing a filament that can be applied to an FDM type 3D printer.

A 3D printer is a device that prints (molds) the three-dimensional shape of a real object based on a three-dimensional drawing (data). That is, after completing a 3D drawing using a CAD or 3D modeling program, the data is transmitted to the printer through a predetermined data interface, and the 3D printer performs the process of making the molded product based on the transmitted drawing data will do Specifically, after creating a virtual cross section based on the corresponding drawing data, a material such as metal or polymer is sprayed through a nozzle to create and fuse a continuous layer, thereby manufacturing a corresponding molded article.

3D printing is applied to various manufacturing fields such as architecture, structure (AEC), industrial design, automobile, aerospace industry, engineering, medical industry, biotechnology, fashion, and footwear.

3D printing technology includes the SLA (stereolithography) method of partially sintering a liquid-based material to produce a molded product, the SLS (selective laser sintering) method of producing a molded product by sintering a powder-based material, and the ejection of a solid-based material to produce a molded product. There are various methods such as fused deposition modeling (FDM).

In particular, there is an urgent need to improve the quality of FDM-type 3D printers, which are widely spread due to their low price and small size. FDM-type 3D printer refers to a 3D printer that creates a three-dimensional model by melting plastic filaments with the heat of a nozzle to turn them into a liquid and then stacking them layer by layer. Due to the nature of this technology, the layers are inevitably revealed on the surface of the completed three-dimensional model. The layered surface is exposed to the outside as it is, like a staircase. When stacking three-dimensional models, this problem can be solved by setting the thickness of one layer as thin as possible, but if the layers are stacked too thin, the strength of the finished model may be weakened. In addition, there is a limit to making the thickness of the layer thin because it is a method of extruding and stacking a liquid in which a plastic resin is dissolved. Most recently released FDM-type 3D printers can print with a thickness of about 0.1mm or support settings that are thinner than this, but if the thickness is set too thin, the printing speed becomes remarkably slow.

On the other hand, while environmental issues have recently emerged throughout society, polymer and rubber materials used for various household items, automobile parts, and electrical and electronic product parts do not rot and cause environmental pollution problems. is causing

In particular, among these industrial wastes, rubber wastes generated by rubber products, which are widely used in tires and the like, do not decompose naturally, so they are a major cause of environmental pollution such as water, soil and air pollution. If this is done, serious environmental destruction may be caused by rapidly increasing rubber waste.

Research on recycling methods for shoes, which generate as much rubber waste and foam waste as much as tires, is insufficient. This is considered to be due to the characteristics of shoes composed of various components in a complex manner, unlike tires entirely composed of a rubber matrix and various additives.

The present invention is to solve the problems of the prior art described above, and an object of the present invention is to balance eco-friendliness, economic feasibility, and processability by selectively applying resin waste that can be economically recycled/reused without undergoing an excessive pretreatment process. It is to provide a method for manufacturing a 3D printing filament that can be implemented in a conventional way.

One aspect of the present invention, (a) obtaining recycled resin particles by grinding the resin waste; And (b) preparing a 3D printing filament by melting and kneading a mixture containing the recycled resin particles and a thermoplastic resin to obtain a melt, and then extruding the melt to produce a 3D printing filament. .

In one embodiment, the average particle size of the recycled resin particles may be 0.05 ~ 5mm.

In one embodiment, the content of the recycled resin particles in the mixture may be 5 to 50% by weight.

In one embodiment, the resin waste may be one selected from the group consisting of defective products generated in the shoe sole manufacturing process, surplus after shoe sole cutting, equipment deposits, and a combination of two or more thereof.

In one embodiment, the resin waste may be a foam, non-foam, or a combination thereof.

In one embodiment, the recycled resin particles and the thermoplastic resin are soft or hard polyolefin elastomers, ethylenic copolymers, styrenic copolymers, polyethylene, polypropylene, polyurethane, polyester, nylon, polybutylene tere It may be one selected from the group consisting of phthalate, polycarbonate, polylactic acid, polyvinyl alcohol, polymethyl methacrylate, polyoxymethylene, and a combination of two or more of these.

In one embodiment, the melt viscosity of the melt may be 5,000 ~ 50,000cPs.

Another aspect of the present invention provides a 3D printing filament prepared by the above method.

A method for manufacturing a 3D printing filament according to an aspect of the present invention includes the steps of pulverizing resin waste to obtain recycled resin particles; And after melting and kneading the mixture containing the recycled resin particles and thermoplastic resin to obtain a melt, and then extruding the melt to produce a 3D printing filament, the resin waste can be economically recycled / reused without going through an excessive pretreatment process. Eco-friendliness, economy, and processability can be realized and improved in a balanced way.

The effects of the present invention are not limited to the above effects, and should be understood to include all effects that can be inferred from the detailed description of the present invention or the configuration of the invention described in the claims.

1 shows a method for manufacturing a 3D printing filament according to an embodiment of the present invention.
2 shows a resin waste according to an embodiment of the present invention.
3 to 5 show experimental results for Examples and Comparative Examples of the present invention.

Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and, therefore, is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part is said to be "connected" to another part, this includes not only the case where it is "directly connected" but also the case where it is "indirectly connected" with another member interposed therebetween. . In addition, when a part "includes" a certain component, it means that it may further include other components without excluding other components unless otherwise stated.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 shows a method for manufacturing a 3D printing filament according to an embodiment of the present invention.

Referring to FIG. 1, a method for manufacturing a 3D printing filament according to an aspect of the present invention includes: (a) crushing resin waste to obtain recycled resin particles; and (b) preparing a 3D printing filament by melting and kneading a mixture containing the recycled resin particles and a thermoplastic resin to obtain a melt, and then extruding the melt.

In the step (a), the resin waste may be pulverized to obtain recycled resin particles. The resinous waste is discarded in a processed state of a raw material composition containing a plurality of components, and may contain additives such as fillers (fillers), lubricants, processing aids, and compatibilizers included in conventional resin products as they are. Therefore, when it is treated and reused, the amount of the aforementioned additives may be significantly reduced or, in some cases, additional additives may not be added. However, when the resin-made waste is left unattended for a long period of time, when the initially given physical properties are significantly changed or contaminated, there is a limit to securing sufficient economic feasibility because a pretreatment process is required to restore the physical properties or remove contaminants.

In contrast, FIG. 2 shows a resin waste according to an embodiment of the present invention.

Referring to FIG. 2, the resin waste is a defective product generated in the shoe sole manufacturing process (FIG. 2 (c)), surplus after shoe sole cutting (FIG. 2 (a)), equipment deposits (FIG. 2 (b)), and two of these It may be one selected from the group consisting of the above combinations. Since these wastes are generated during and/or immediately after the shoe sole manufacturing process, if they are collected and collected in a timely manner, the physical properties initially given to the shoe sole can be maintained substantially the same, and exposure to the external environment such as actual use can be reduced. Since it is fundamentally blocked, it is possible to effectively solve problems caused by contamination of conventional waste.

The resinous waste is simply pulverized to have a predetermined average particle size without undergoing an excessive pretreatment process including washing, and then kneaded with other resins to be processed and molded into filaments that can be applied to FDM-type 3D printers. .

The grinding is performed in one device selected from the group consisting of an attrition mill, a ball mill, a jet mill, a resonance acoustic mixer, and a combination of two or more thereof. It may be performed by, but is not limited thereto.

The average particle size of the recycled resin particles may be 0.05 to 5 mm, preferably 0.05 to 3 mm. If the average particle size of the regenerated resin particles is less than 0.05 mm, the regenerated resin particles and the thermoplastic resin cannot be uniformly kneaded in the subsequent step (b), so defects such as random projections and irregularities on the surfaces of the manufactured filaments and molded products. this can happen If the average particle size of the regenerated resin particles exceeds 5 mm, the melt viscosity of the melt may excessively increase and processability may deteriorate, and some of the regenerated resin particles may be exposed as they are on the surface of the manufactured filament, and the filament may be When a molded article is manufactured using the recycled resin particles, the nozzles of the FDM-type 3D printer may be closed, and thus the maintainability of the 3D printer may deteriorate.

In step (b), after melting and kneading the mixture containing the recycled resin particles and the thermoplastic resin to obtain a melt, the melt may be extruded to produce a 3D printing filament.

The content of the recycled resin particles in the mixture may be 5 to 50% by weight. If the content of the recycled resin particles in the mixture is less than 5% by weight, the melt viscosity is excessively low, and processability may be deteriorated. Even in this case, some of the recycled resin particles may be exposed as they are on the surface of the filament. In addition, if the content of the recycled resin particles in the mixture exceeds 50% by weight, the recycled resin particles and the thermoplastic resin cannot be uniformly kneaded in the subsequent step (b), so that there are no protrusions on the surfaces of the filaments and molded products. , defects such as irregularities may occur.

The resinous waste may be a foamed material, a non-foamed material, or a combination thereof. When the resinous waste is a foam, the filament may have a predetermined foamability independently of the properties of the thermoplastic resin to be kneaded with the recycled resin particles.

When the resinous waste is a non-foam material, the properties of the filament may depend on the properties of the thermoplastic resin mixed with the recycled resin particles. Specifically, when the thermoplastic resin is a foamable resin, the filament may be foamable, and when the thermoplastic resin is a non-foamable resin, the filament may be non-foamable.

The recycled resin particles and the thermoplastic resin are soft or hard polyolefin elastomers, ethylenic copolymers, styrenic copolymers, polyethylene, polypropylene, polyurethane, polyester, nylon, polybutylene terephthalate, polycarbonate, poly It may be one selected from the group consisting of lactic acid, polyvinyl alcohol, polymethyl methacrylate, polyoxymethylene, and a combination of two or more of these.

In particular, each of the recycled resin particles and the thermoplastic resin may be a thermoplastic elastomer, preferably polyurethane and/or an ethylene-based copolymer. For example, the ethylene-based copolymer may be one selected from the group consisting of ethylene vinyl acetate, ethylene butyl acrylate, ethylene ethyl acrylate, and a combination of two or more thereof, preferably, may be ethylene vinyl acetate, More preferably, the content of vinyl acetate may be 10 to 20% by weight of ethylene vinyl acetate, but is not limited thereto. In addition, when the recycled resin particles and the thermoplastic resin are of the same type, kneading, blending, compatibility, and processability and surface properties of filaments and molded products can be further improved.

Melt viscosity of the melt may be 5,000 ~ 50,000cPs. The melt viscosity of the melt may be determined by the average particle size of the recycled resin particles, the content of the recycled resin particles in the mixture, and the like. If the melt viscosity of the melt is less than 5,000 cPs, the recycled resin particles and the thermoplastic resin cannot be uniformly kneaded, and in some cases, phase separation or layer separation occurs between the recycled resin particles and the thermoplastic resin, resulting in reduced processability. In addition, some of the recycled resin particles may be exposed as they are on the surface of the manufactured filament. In addition, even when the melt viscosity of the melt exceeds 50,000 cPs, the recycled resin particles and the thermoplastic resin cannot be uniformly kneaded, and the load applied to the equipment increases, resulting in reduced processability and the surface of the filament produced. Some of the regenerated resin particles may be exposed as they are, and surface properties may deteriorate.

Hereinafter, embodiments of the present invention will be described in detail.

Preparation Example 1

Foam particles with an average particle size of 5 mm were prepared using a milling grinder after washing foam waste (scrap, defective products, surplus foam after cutting, etc.) generated in the shoe sole manufacturing process.

Preparation Example 2

Foam particles having an average particle size of 0.05 mm (50 μm) were prepared using a milling grinder after washing foam waste (scrap, defective products, surplus foam after cutting, etc.) generated in the shoe sole manufacturing process.

Preparation Example 3

Foam particles having an average particle size of 3 mm were prepared using a milling grinder after washing foam waste (scrap, defective products, surplus foam after cutting, etc.) generated in the shoe sole manufacturing process.

Production Example 4

Foam particles having an average particle size of 0.01 mm (10 μm) were prepared using a milling grinder after washing foam waste (scrap, defective products, surplus foam after cutting, etc.) generated in the shoe sole manufacturing process.

Preparation Example 5

Foam particles having an average particle size of 6 mm were prepared using a milling grinder after washing foam waste (scrap, defective products, surplus foam after cutting, etc.) generated in the shoe sole manufacturing process.

Examples and Comparative Examples

Thermoplastic polyurethane (TPU), foam particles, compatibilizers, processing aids, and stabilizers according to one of Preparation Examples 1 to 5 were put into a kneader in the ratios shown in Tables 1 and 2 below, and melted at 150 ° C. for 10 minutes, After kneading, it was extruded to prepare pellets.

The prepared pellets were put into an extruder, extruded at 200 ° C, and then cooled with 20 ° C cooling water to prepare a filament for a 3D printer having a diameter of 1.75 mm.

division Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 foam particles
(type) Preparation Example 1 Preparation Example 1 Preparation Example 1 Preparation Example 2 Preparation Example 2 Preparation Example 2 Preparation Example 3 TPU 95 70 50 95 70 50 50 foam particles 5 30 50 5 30 50 50 compatibilizer 5 5 5 5 5 5 5 processing aid 5 5 5 5 5 5 5 stabilizator 2 2 2 2 2 2 2

(unit: parts by weight)

division Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 foam particles
(type) Preparation Example 1 Preparation Example 1 Production Example 4 Preparation Example 5 TPU 40 99 50 50 foam particles 60 One 50 50 compatibilizer 5 5 5 5 processing aid 5 5 5 5 stabilizator 2 2 2 2

(unit: parts by weight)

Experimental example

Melt viscosity (cPs) of the melts melted and kneaded by a kneader in Examples and Comparative Examples was measured using a Brookfield Viscometer. In addition, the extrusion processability of the pellets according to Examples and Comparative Examples, the surface state of the filament, and the surface state of the molded product manufactured by applying the filament to an FDM-type 3D printer were visually observed, and the results are shown in Tables 3 to 3. It is shown in Table 4 and FIGS. 2 to 4 (◎: excellent, ○: good, X: poor).

division Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 melt viscosity 5,000 5,800 6,000 12,000 42,000 50,000 10,000 pellet
extrusion processability ○ ◎ ◎ ◎ ○ ○ ◎ filament
surface state ◎ ○ ◎ ◎ ◎ ◎ ◎ molding
surface state ◎ ◎ ◎ ◎ ◎ ◎ ◎

division Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 melt viscosity 75,000 2,300 55,000 60,000 pellet
extrusion processability X X X X filament
surface state X X X X molding
surface state X X X X

Referring to Table 3 and Table 4, in the case of the examples, mixing and kneading between the raw materials in the kneader machine and extruder were uniform, resulting in excellent processability in the process of manufacturing pellets and filaments, and the surface of the filaments and molded products manufactured accordingly. No defects or damage such as any protrusions or irregularities were observed.

On the other hand, in the case of Comparative Example 1 in which the content of the foam particles is 60 parts by weight and Comparative Example 3 in which the average particle size of the foam particles is 0.01 mm, the mixing between the raw materials is not uniform in the process of manufacturing the pellets and filaments, and the filaments prepared accordingly A large number of projections and irregularities were observed on the surface of the molded article. In the case of Comparative Example 2 in which the content of the foam particles was 1 part by weight, the melt viscosity was excessively low, and the processability was deteriorated, and accordingly, some of the foam particles were observed as they were on the surface of the filament. Even in the case of Comparative Example 4 in which the average particle size of the foam particles was 6 mm, the melt viscosity was excessively high, resulting in poor processability. As a result, some of the foam particles were observed as they were on the surface of the filament. The maintainability of the 3D printer was significantly reduced by closing the nozzle of the 3D printer.

The above description of the present invention is for illustrative purposes, and those skilled in the art can understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts should be interpreted as being included in the scope of the present invention.

Claims (8)

(a) pulverizing the resin waste to obtain recycled resin particles; and
(b) preparing a 3D printing filament by melting and kneading a mixture containing the recycled resin particles and a thermoplastic resin to obtain a melt, and then extruding the melt to produce a 3D printing filament. According to claim 1,
The average particle size of the regenerated resin particles is 0.05 ~ 5mm, a method for producing a 3D printing filament. According to claim 1,
The content of the recycled resin particles in the mixture is 5 to 50% by weight, a method for producing a 3D printing filament. According to claim 1,
The resin waste is one selected from the group consisting of defective products generated in the shoe sole manufacturing process, surplus after shoe sole cutting, equipment deposits, and a combination of two or more of them. According to claim 4,
The resinous waste is a foam, non-foam, or a combination thereof, a method for producing a 3D printing filament. According to claim 1,
The recycled resin particles and the thermoplastic resin are soft or hard polyolefin elastomers, ethylenic copolymers, styrenic copolymers, polyethylene, polypropylene, polyurethane, polyester, nylon, polybutylene terephthalate, polycarbonate, poly A method for producing a 3D printing filament, which is one selected from the group consisting of lactic acid, polyvinyl alcohol, polymethyl methacrylate, polyoxymethylene, and a combination of two or more of them. According to claim 1,
The melt viscosity of the melt is 5,000 ~ 50,000cPs, a method for producing a 3D printing filament. A 3D printing filament manufactured by the method according to any one of claims 1 to 7.

Images