KR102654692B1 - Recyling carboon complex and preparation method thereof - Google Patents

Abstract

The present invention is a pellet-type recycled carbon composite that has superior durability and strength than conventional recycled plastic and has a high utilization rate of waste plastic by dry mixing recycled plastic with milled carbon fiber, and a manufacturing method thereof. It's about.

Description

Recycled carbon composite and its manufacturing method {RECYLING CARBOON COMPLEX AND PREPARATION METHOD THEREOF}

The present invention relates to a recycled carbon composite obtained by recycling used plastic materials as a resin material and a method for manufacturing the same.

As plastic consumption increases every year, a huge amount of plastic waste is produced every day around our lives. According to Consumer Post (October 31, 2016), the amount of plastic produced worldwide between 1950 and 2015 amounted to approximately 8.6 billion tons, but the recycling rate of plastic was reported to be only about 9%.

Recently, as awareness of environmental protection has increased, movements for recycling and reuse have become stronger. In particular, recycling of waste plastic is actively taking place among product lines such as large home appliances and automobiles.

When recycling the above-mentioned waste plastic, the unit price of the product becomes cheaper and processing costs such as environmental charges can be reduced. However, there is a problem of poor quality such as durability and impact strength compared to plastic products produced from plastic raw materials, so research on this is urgently needed. This is the situation.

For example, in Japanese Patent Publication No. 2004-042461, waste plastic was reused, but the recycled plastic recycled in this way has problems with poor durability and impact strength, so improvements are needed.

Japanese Patent Publication No. 2004-042461 (2004.02.12.)

The present invention was developed to solve the above problems. By adding milled carbon fiber to waste plastic in the form of scrap, it has excellent durability and strength, and has a high utilization rate. We want to manufacture recycled carbon composites.

The recycled carbon composite of the present invention includes milled carbon fiber; and recycled plastic.

As a preferred embodiment of the present invention, the milled carbon fiber is carbon fiber waste, commercial polyacrylonitrile (PAN)-based carbon fiber, pitch-based carbon fiber, and rayon-based carbon fiber. It may be derived from one or more selected from carbon fiber.

As a preferred embodiment of the present invention, the recycled plastic is selected from polypropylene, polyethylene, high impact polystyrene, polyamide 6, and polyamide 66. It may be a recycled plastic containing one or more types of waste plastic.

As a preferred embodiment of the present invention, the recycled carbon composite may have a tensile strength of 45 to 60 MPa.

As a preferred embodiment of the present invention, the recycled carbon composite may have a flexural strength of 68 to 80 MPa.

As a preferred embodiment of the present invention, the recycled carbon composite may be of a pellet type.

As a preferred embodiment of the present invention, preparing recycled plastic; Producing a dry blend by dry blending the recycled plastic and milled carbon fiber; Manufacturing an injection molded product by melt-extruding the dry mixture; and cooling the injection molded product to produce a recycled carbon composite. may include.

As a preferred embodiment of the present invention, the recycled carbon composite may include the recycled plastic and the milled carbon fiber at a weight ratio of 1:0.10 to 1:0.70.

As a preferred embodiment of the present invention, the step of processing the recycled carbon composite to produce pellets may be further included.

The present invention can provide a recycled carbon composite that is superior in durability and strength to conventional recycled plastic made from recycled waste plastic and has a high utilization rate of waste plastic, and a method for manufacturing the same.

Figure 1 is an image of a recycled carbon composite pellet according to an embodiment of the present invention.
Figure 2 is an image of a recycled plastic product manufactured from recycled carbon composite according to an embodiment of the present invention.
Figure 3 is an image of the ABS resin prepared in Comparative Example 1 and the recycled carbon composite prepared in Example 1.
Figure 4 is a schematic diagram of a method for manufacturing recycled carbon composite according to an embodiment of the present invention.
Figure 5 is an image of the mixing process during the manufacturing process of recycled carbon composite according to an embodiment of the present invention.
Figure 6 is an image of a process for melt extrusion (injection) of a recycled carbon composite according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail through a manufacturing method of recycled carbon composite with reference to the attached drawings.

When explained with reference to FIG. 4, the manufacturing method of recycled carbon composite includes the first step of preparing recycled plastic; Step 2 of manufacturing a dry blend by dry blending the recycled plastic and milled carbon fiber; Step 3 of manufacturing an injection molded product by melting and extruding the dry mixture; And it may include a fourth step of cooling the injection molded product to produce a recycled carbon composite.

Specifically, stage 1 preparation may include recycled plastics selected from waste plastics according to recycling purposes.

Additionally, the waste plastic may be in the form of scrap.

In addition, the recycled plastic is a waste plastic containing one or more types selected from polypropylene, polyethylene, high impact polystyrene, polyamide 6, and polyamide 66. It may be recycled plastic, but is not particularly limited thereto.

Next, the second step mixing can be performed in a dry manner as shown in FIG. 5, and the weight ratio of the recycled plastic and the milled carbon fiber can be adjusted depending on the use of the recycled plastic, but preferably It may be included in a weight ratio of 1:0.10 to 1:0.70, more preferably in a weight ratio of 1:0.15 to 1:0.65, and even more preferably in a weight ratio of 1:0.20 to 1:0.60. . If the carbon fiber is included in a weight ratio of less than 0.10, there may be a problem of a decrease in tensile strength and flexural strength, and if it is included in a weight ratio exceeding 0.70, there may be a problem with a slight increase in tensile strength and flexural strength, and the waste plastic There may be a problem of reduced utilization, and as the heat distortion temperature becomes excessively high, a problem of poor processability may occur.

In addition, the milled carbon fiber includes polyacrylonitrile (PAN)-based carbon fiber waste, commercial polyacrylonitrile (PAN)-based carbon fiber, pitch-based carbon fiber, and rayon ( Rayon)-based carbon fibers, and preferably at least one selected from polyacrylonitrile (PAN)-based carbon fibers and commercial polyacrylonitrile (PAN)-based carbon fibers. may include.

In addition, the milled carbon fiber may have an average particle diameter of 5 to 10 μm, preferably 5 to 8 μm. If it is less than 5μm, there may be problems such as complicated milling processes or high costs, and if it exceeds 10μm, mixing with recycled plastic is not done uniformly, reducing the tensile and flexural strengths of the recycled carbon polymer. Problems with deterioration may occur.

Additionally, the milled carbon fiber may have an average length of 5 to 500 μm, preferably 20 to 500 μm. If the average length exceeds 500 μm, the mixing with recycled plastic may not be done uniformly, which may cause the tensile strength and flexural strength of the recycled carbon polymer to deteriorate.

Next, the three-stage melt extrusion can be performed according to the injection temperature of the recycled plastic and can be performed through the first row cylinder, second row cylinder, third row cylinder, and fourth row cylinder. As a preferred example of this, when the recycled plastic is ABS resin (acrylonitrile-butadiene-styrene resin), the first row cylinder is set to 220 to 250 ° C, preferably 225 to 245 ° C, and the second row cylinder is set to 220 to 250 ° C. The temperature of the third row cylinder is set to 215 to 245°C, preferably 220 to 240°C, and the temperature of the third row cylinder is set to 210 to 240°C, preferably 215 to 235°C. Injection can be performed after setting the temperature of the thermal cylinder to 210 to 230°C, and preferably the master batch to 215 to 225°C. The injection may be performed as shown in FIG. 6.

Additionally, the injection may be performed under a pressure of 80 to 200 MPa, and preferably may be performed under a pressure of 100 to 150 MPa.

Next, the fourth stage of cooling can be performed using cooling water at 40 to 80°C, preferably at 50 to 60°C.

Next, step 5 may further include processing the recycled carbon composite to produce pellets, and the recycled carbon composite pellet may have the form shown in FIG. 1.

The recycled carbon composite manufactured by the above method may include milled carbon fiber and recycled plastic.

Additionally, the recycled carbon composite may have a tensile strength of 45 to 60 MPa, preferably 50 to 60 MPa.

Additionally, the recycled carbon composite may have a flexural strength of 68 to 80 MPa, preferably 72 to 80 MPa.

In addition, the recycled carbon composite may have a utilization rate of 88 to 100%, preferably 94 to 98%, as measured by Equation 1 below. If the utilization rate is less than 88%, the recycling rate may be poor due to the low content of recycled plastic among the injection products manufactured using the recycled carbon composite.

[Relationship 1]

Additionally, the recycled carbon composite may have a heat distortion temperature of 85.0 to 101.0°C, preferably 91.0 to 100.0°C. If the heat distortion temperature is less than 91.0°C, there may be a problem of weakening strength when used at high temperatures, and if it exceeds 101.0°C, the processability of the carbon composite may be significantly reduced.

On the other hand, the recycled carbon composite of the present invention can be used to manufacture recycled plastic products as shown in Figure 2, and can be used to manufacture automobile interior and exterior materials, home appliances, housings, IT devices, toys, and office equipment. It can be used in console boxes, top panel interior materials, bumpers, undercovers, refrigerators, vacuum cleaners, washing machines, fans, TVs, monitors, kitchen products, etc.

Hereinafter, the present invention will be described in more detail through examples. However, the following examples do not limit the scope of the present invention, and should be interpreted to aid understanding of the present invention.

[Example]

Example 1: Preparation of recycled carbon composite

A mixture was prepared by dry mixing recycled plastic (waste plastic), mainly ABS plastic, and milled carbon fiber at a weight ratio of 1:0.43. At this time, the milled carbon fibers had an average particle diameter of 8 μm and an average length of 200 μm.

Then, the above mixture was melt-extruded under a pressure of 100 MPa to prepare an injection product.

At this time, in the melt extrusion, the temperature of the first row cylinder is set to 235°C, the temperature of the second row cylinder is set to 230°C, the temperature of the third row cylinder is set to 225°C, and the temperature of the fourth row cylinder is set to 220°C. It was performed by injection at ℃.

Then, the injection molded product was cooled using cooling water at 60°C to produce a recycled carbon composite.

Examples 2 to 4: Manufacturing of recycled carbon composites

A recycled carbon composite was manufactured in the same manner as in Example 1, but Examples 2 to 4 were performed with the weight ratio of recycled plastic and milled carbon fiber as shown in Table 1 below.

Comparative Example 1: ABS resin production

An injection molded product was manufactured by melting and extruding ABS plastic under a pressure of 70 MPa. At this time, in the melt extrusion, the temperature of the first row cylinder is set to 235°C, the temperature of the second row cylinder is set to 230°C, the temperature of the third row cylinder is set to 225°C, and the temperature of the fourth row cylinder is set to 220°C. It was performed by injection at ℃.

Then, the injection molded product was cooled using cooling water at 25°C to produce ABS resin.

Meanwhile, the ABS resin can be manufactured in a form like the left image in FIG. 3.

Comparative Example 2 ~ Comparative Example 4: Manufacturing of recycled carbon composite

A recycled carbon composite was manufactured in the same manner as in Example 1, but Comparative Examples 2 to 4 were performed using the weight ratio of recycled plastic and milled carbon fiber as shown in Table 2 below.

Experimental Example 1: Physical property evaluation

The physical properties of the recycled carbon composites manufactured in Examples 1 to 4 and Comparative Examples 2 to 4 and the ABS resin injection molded products manufactured in Comparative Example 1 were evaluated in the following manner, and the results are shown in Tables 1 to 4 below. Shown in 2.

(1)Tensile strength measurement

It was measured according to the ASTM D638 method.

(2)Measurement of bending strength

It was measured according to the ASTM D790 method using a 3-point banding method.

(3)Measurement of heat distortion temperature

According to ASTM D648, the temperature at which thermal deformation was initiated was measured under 0.45 MPa atmospheric pressure conditions and 1.85 MPa atmospheric pressure conditions, respectively.

Example 1 Example 2 Example 3 Example 4 Weight ratio (recycled plastic:carbon fiber) 1:0.43 1 : 0.11 1:0.25 1:0.67 Tensile strength (MPa) 51.22 46.53 48.69 55.34 Flexural strength (MPa) 75.31 72.95 74.21 77.59 Heat distortion temperature (℃) 97.7 92.4 94.6 99.9

Comparative Example 1 Comparative example 2 Comparative Example 3 Comparative Example 4 Weight ratio (recycled plastic: carbon fiber) 1:0 1:0.8 1:1.0 1:1.5 Tensile strength (MPa) 37.91 56.35 56.56 56.88 Flexural strength (MPa) 67.9 77.98 78.06 78.28 Heat distortion temperature (℃) 82 102.5 105.3 107.9

Looking at Tables 1 to 2 above, the recycled carbon polymers prepared in Examples 1 to 4 were found to have excellent physical properties.

On the other hand, the ABS resin of Comparative Example 1 manufactured without milled carbon fiber had significantly lower tensile and flexural strengths compared to the recycled carbon composite of Example 1 manufactured by adding carbon fiber. It was found to be low.

In addition, Comparative Examples 2 to 4, which were manufactured using milled carbon fibers exceeding a weight ratio of 0.70, had higher tensile strength and flexural strength when compared with Example 4, which was manufactured using carbon fibers at a weight ratio of 0.67. It was found that the degree of increase was slight, and as the heat distortion temperature was excessively high, processability was found to be poor.

Simple modifications or changes of the present invention can be easily implemented by those skilled in the art, and all such modifications or changes can be considered to be included in the scope of the present invention.

Claims (9)

It is a melt extrusion injection product containing recycled plastic and milled carbon fiber with an average length of 20 to 500㎛ at a weight ratio of 1:0.10 to 1:0.70.
The recycled plastic is a waste plastic containing at least one selected from polypropylene, polyethylene, high impact polystyrene, polyamide 6, and polyamide 66. It is a recycled plastic,
The milled carbon fiber includes polyacrylonitrile (PAN)-based carbon fiber waste, commercial polyacrylonitrile (PAN)-based carbon fiber, pitch-based carbon fiber, and rayon (Rayon). ) is derived from one or more selected from carbon fibers,
A recycled carbon composite that satisfies a tensile strength of 45 to 60Mpa and a heat distortion temperature of 85.0 to 101.0°C.
delete delete delete According to paragraph 1,
The recycled carbon composite is characterized in that the flexural strength is 68 to 80 MPa.
According to paragraph 1,
The recycled carbon composite is a recycled carbon composite, characterized in that the recycled carbon composite is of pellet type.
Preparing recycled plastic;
Preparing a dry blend by dry blending the recycled plastic and milled carbon fibers with an average length of 20 to 500 ㎛ at a weight ratio of 1:0.10 to 1:0.70;
Manufacturing an injection molded product by melt-extruding the dry mixture; and
Performing a process including manufacturing a recycled carbon composite by cooling the injection molded product,
The recycled plastic is a waste plastic containing at least one selected from polypropylene, polyethylene, high impact polystyrene, polyamide 6, and polyamide 66. It is a recycled plastic,
The milled carbon fiber includes polyacrylonitrile (PAN)-based carbon fiber waste, commercial polyacrylonitrile (PAN)-based carbon fiber, pitch-based carbon fiber, and rayon (Rayon). ) is derived from one or more selected from carbon fibers,
A method of manufacturing a recycled carbon composite, characterized in that the recycled carbon composite satisfies a tensile strength of 45 to 60Mpa and a heat distortion temperature of 85.0 to 101.0°C.
delete In clause 7,
A method for producing a recycled carbon composite, further comprising processing the recycled carbon composite to produce pellets.