Bioplastic using coffee grounds and manufacturing method therefor

Abstract

The present invention provides a method for manufacturing bioplastic using coffee grounds and bioplastic manufactured thereby, the method comprising the steps of: mixing coffee grounds with an inorganic additive and drying same to produce dried coffee ground powder; mixing the dried coffee ground powder with a resin composition to produce a plastic mixed composition; and extruding or injection molding the plastic mixed composition.

Description

Bioplastic using coffee grounds and its manufacturing method

[0001] The present invention relates to a bioplastic utilizing coffee grounds and a method for manufacturing the same.

[0002] With the rise of the biochemical industry utilizing plant resources, eco-friendly and biodegradable plastics are currently being actively researched. Biodegradable plastics can be broadly categorized into four types based on the raw materials used: natural polymers, chemically synthesized polymers, microbially produced polymers, and hybrids of natural and chemically synthesized polymers. Natural polymers are made from starch extracted from grains, cellulose derived from grain leaves or reeds, and proteins derived from the shells of crabs and shrimp. While relatively inexpensive, their inherent properties make them less processable than synthetic or microbial polymers. Chemically synthesized polymers are manufactured through a polymerization process using raw materials such as amino acids produced through fermentation. PLA, a prime example, is relatively expensive. Microbially produced polymers possess similar properties to conventional general-purpose resins such as PP and PE, but their high cost hinders their practical application in general plastic packaging or disposable plastic products. Lastly, the mixed type is produced by mixing natural materials such as starch and existing resins such as olefin, and is preferred because the process is relatively simple and the cost is competitive compared to existing products.

[0003] Coffee consumption continues to rise worldwide, and with it, coffee production, leading to a surge in the amount of coffee grounds generated after brewing. Coffee grounds refer to the coffee residue generated during the coffee bean processing process and the coffee extract residue left after coffee is extracted. While coffee grounds are utilized as feed, fertilizer, boiler feedstock, and adsorbents like activated carbon, their utilization remains limited. Coffee grounds, containing 10-15% coffee oil and a solids content of over 6,000 kcal per kg, represent a high-energy resource. However, only a small portion of the coffee grounds are used, with the majority being incinerated or landfilled like general waste. Because coffee grounds have a moisture content of 20-40%, incineration is difficult and the resulting smoke can pollute water and soil when landfilled. Therefore, there is a pressing need for ways to utilize these coffee grounds.

[0004] [Prior Art Literature]

[0005] [Patent Document]

[0006] Domestic Patent No. 10-1344471

[0007] The problem to be solved by the present invention is to provide a bioplastic using coffee grounds and a method for manufacturing the same, which has an elongation and tensile strength equivalent to those of plastics manufactured from existing chemical synthetic resins.

[0008] In order to solve the above problem, the present invention provides a method for manufacturing a bioplastic using coffee grounds, comprising the steps of mixing coffee grounds with an inorganic additive, drying the mixture, and then producing a dried coffee ground powder; mixing the dried coffee ground powder with a resin composition to produce a plastic mixture composition; and extruding or injecting the plastic mixture composition. The present invention also provides a bioplastic obtained by the above manufacturing method.

[0009] According to the method for manufacturing bioplastic using coffee grounds according to the present invention, mechanical properties such as tensile strength and impact resistance can be maintained at an equivalent level compared to existing petroleum-derived plastics.

[0010] Figure 1 is a schematic diagram of a method for manufacturing bioplastics according to one embodiment of the present invention.

[0011] Hereinafter, various embodiments of the present invention will be described with reference to the accompanying drawings. It should be understood that the present invention is not limited to specific embodiments, but rather encompasses various modifications, equivalents, and / or alternatives of the embodiments of the present invention. In the description of the drawings, similar reference numerals may be used for similar components.

[0012] In this document, the expressions "have", "may have", "include", or "may include" indicate the presence of a feature (e.g., a number, function, operation, or component such as a part), and do not exclude the presence of additional features.

[0013] In this document, the expressions "A or B," "at least one of A and / or B," or "one or more of A and / or B" can include all possible combinations of the listed items. For example, "A or B," "at least one of A and B," or "at least one of A or B" can all refer to cases where (1) at least one A is included, (2) at least one B is included, or (3) at least one A and at least one B are included.

[0014] The expression "configured to" as used herein can be used interchangeably with, for example, "suitable for", "having the capacity to", "designed to", "adapted to", "made to", or "capable of". The term "configured to" does not necessarily mean "specifically designed to".

[0015] The terms used in this document are used only to describe specific embodiments and may not be intended to limit the scope of other embodiments. The singular expression may include the plural expression unless the context clearly indicates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by those of ordinary skill in the art described in this document. Terms defined in general dictionaries among the terms used in this document may be interpreted as having the same or similar meaning in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined in this document. In some cases, even if a term is defined in this document, it cannot be interpreted to exclude the embodiments of this document.

[0016] The embodiments disclosed in this document are presented for the purpose of explaining and understanding the disclosed technical content and are not intended to limit the scope of the present invention. Therefore, the scope of this document should be interpreted to include all modifications or various other embodiments based on the technical concept of the present invention.

[0017] Hereinafter, preferred embodiments of the present invention will be described in detail. Prior to this, it should be noted that the terms and words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings. Based on the principle that the inventor can appropriately define the concepts of terms to best explain his or her invention, they should be interpreted in a way that aligns with the technical spirit of the present invention.

[0018] Accordingly, the configurations of the embodiments described in this specification are only some of the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention, so it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0019] Throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise stated.

[0020] Hereinafter, the present invention will be described in detail.

[0021]

[0022] A method for manufacturing a bioplastic using coffee grounds according to one embodiment of the present invention comprises the steps of mixing coffee grounds with an inorganic additive, drying the mixture, and then producing a dried coffee ground powder, mixing the dried coffee ground powder with a resin composition to produce a plastic mixture composition, and extruding or injecting the plastic mixture composition. Each step is described in detail below.

[0023] The step of mixing the above coffee grounds with an inorganic additive and drying them to produce a dried coffee ground powder is a step to remove moisture and fatty acids from the coffee grounds and to make the coffee ground particles into a certain size.

[0024] The above coffee grounds may refer to both coffee grounds generated during the coffee bean processing process for coffee production and coffee extract grounds remaining after extracting coffee from coffee beans. The coffee grounds are composed of organic compounds such as cellulose, hemicellulose, and fatty acids. When the cellulose and hemicellulose in the coffee grounds are hydrolyzed, they can be decomposed into monosaccharides such as glucose, a hexose sugar, and xylose, a pentose sugar. When such coffee grounds are mixed with a biodegradable resin composition such as PLA to produce a plastic composite composition, they can be used as a raw material that is decomposed in both soil and the ocean.

[0025] The above inorganic additive is mixed to remove fatty acid components contained in coffee grounds and to increase formability by accelerating the crystallization rate during the forming process when forming the final product, bioplastic.

[0026] In the step of mixing the coffee grounds with an inorganic additive and drying them to produce a coffee grounds dry powder, the weight ratio of the coffee grounds to the inorganic additive may be 1:0.1 to 1. Preferably, the weight ratio of the coffee grounds to the inorganic additive may be 1:0.2 to 0.8. If the inorganic additive is included in an amount less than the above numerical range, moisture or fatty acid components of the coffee grounds may not be sufficiently removed, thereby lowering the hardness of the bioplastic, and if the inorganic additive is included in an amount exceeding the above numerical range, the productivity of the bioplastic may be reduced. In the step of mixing the coffee grounds with an inorganic additive and drying them to produce a coffee grounds dry powder, the inorganic additive may include at least one selected from the group consisting of calcium carbonate, silica, illite, zeolite, siliceous earth, calcium oxide, talc, mica, and clay, but is not limited thereto.

[0027] In the step of mixing the coffee grounds with an inorganic additive and drying them to produce a dried coffee ground powder, the drying may be performed at a temperature of 125°C to 180°C. Preferably, the drying may be performed at a temperature of 150°C to 180°C. The drying may be performed using a thermally stirring drum dryer. The mixing may be performed at a speed of 2,000 to 3,000 rpm in the thermally stirring drum dryer.

[0028] In the step of mixing the above coffee grounds with an inorganic additive and drying them to produce a dried coffee ground powder, the moisture content of the dried coffee ground powder may be 1 to 8%. If the moisture content of the dried coffee ground powder is below the above numerical range, uniform mixing with the inorganic additive may be difficult, and if it exceeds the above numerical range, the hardness of the bioplastic may be reduced.

[0029] In the step of mixing the above coffee grounds with an inorganic additive and drying them to produce a dried coffee grounds powder, the dried coffee grounds powder may have a mesh size of 800 to 1,300. If the dried coffee grounds powder has a size less than the above numerical range, when the dried coffee grounds powder and the resin composition are mixed, the content of the dried coffee grounds powder may be large, which may impair the properties of the plastic mixture composition. If the content exceeds the above numerical range, the bioplastic may actually be harmful to the environment.

[0030] The step of mixing the above-mentioned dried coffee grounds powder and the resin composition to produce a plastic mixed composition is to increase the formulation stability of the plastic mixed composition by uniformly distributing the dried coffee grounds powder in the resin composition.

[0031] The above resin composition may include at least one selected from the group consisting of polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), high-density polyethylene (HDPE), polylactic acid (PLA), polyhydroxyalkanoate (PHA), polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), and thermoplastic starch (TPS).

[0032] In the step of mixing the above-mentioned dried coffee grounds powder and the resin composition to produce a plastic mixed composition, the weight ratio of the above-mentioned dried coffee grounds powder and the resin composition may be 1:1 to 20. Preferably, the weight ratio of the above-mentioned dried coffee grounds powder and the resin composition may be 1:4 to 10. If the weight of the resin composition is less than the above-mentioned numerical range, the physical properties of the plastic mixed composition, such as heat resistance and tensile strength, may be reduced, and if it exceeds the above-mentioned numerical range, it may cause environmental problems.

[0033] In the step of mixing the above-mentioned dried coffee grounds powder and the resin composition to produce a plastic mixed composition, the resin composition may include polyethylene (PE) and polypropylene (PP), and the weight ratio of the above-mentioned dried coffee grounds powder, polyethylene (PE), and polypropylene (PP) may be 1:1 to 10:1 to 10. If the content of the polyethylene is less than the above-mentioned numerical range, the strength of the final product, the bioplastic, may be reduced, and if it exceeds the above-mentioned numerical range, the elasticity and resilience may be reduced. If the content of the polypropylene is less than the above-mentioned numerical range, the final product, the bioplastic, may be easily torn, and if it exceeds the above-mentioned numerical range, it may be difficult to control the thickness to be suitable for the intended use of the bioplastic.

[0034] In the step of mixing the above-mentioned dried coffee grounds powder and the resin composition to produce a plastic mixed composition, the resin composition may include polylactic acid (PLA) and polybutylene adipate terephthalate (PBAT), and the weight ratio of the above-mentioned dried coffee grounds powder to polylactic acid (PLA) and polybutylene adipate terephthalate (PBAT) may be 1:1 to 10:1 to 10. When the content of the polylactic acid (PLA) is below the above-mentioned numerical range, durability for a certain period of time may be reduced, and when the content exceeds the above-mentioned numerical range, environmental pollution may occur. When the content of the polybutylene adipate terephthalate (PBAT) is below the above-mentioned numerical range, processability may be reduced, and when the content exceeds the above-mentioned numerical range, toxic waste may be generated, which may rather cause environmental pollution.

[0035] The step of extruding or injecting the above plastic mixture composition is for pelletizing the plastic mixture composition or producing a plastic product. The temperature at which the plastic mixture composition is extruded or injected may be 120°C to 200°C, for example 120°C to 190°C, for example 130°C to 180°C, for example 140°C to 170°C.

[0036] After the step of extruding or injecting the plastic mixture composition, a step of molding the plastic mixture composition that has undergone the step of extruding or injecting the plastic mixture composition, heat-treating it, and then drying it may be further included.

[0037] The above molding can be performed using any method known in the art, such as extrusion molding, injection molding, compression molding, pressure molding, blowing or blow molding, calendaring, rotational molding, casting or thermoforming.

[0038] The weight parts for the components in each step above are as follows. The weight parts are based on 100 parts by weight of the coffee grounds.

[0039] In the step of mixing the coffee grounds with an inorganic additive and drying them to produce a dried coffee ground powder, 100 parts by weight of the coffee grounds and 10 to 30 parts by weight of the inorganic additive may be included. If the inorganic additive is included in an amount less than the above numerical range, moisture or fatty acid components of the coffee grounds may not be sufficiently removed, which may lower the hardness of the bioplastic. If the inorganic additive is included in an amount exceeding the above numerical range, the productivity of the bioplastic may be reduced.

[0040] In the step of mixing the above-mentioned dried coffee grounds powder and the resin composition to produce a plastic mixed composition, 500 parts by weight of the above-mentioned dried coffee grounds powder and 2,000 to 8,000 parts by weight of the resin composition may be included. If the weight of the resin composition is less than the above-mentioned numerical range, the physical properties of the plastic mixed composition, such as heat resistance and tensile strength, may be reduced, and if it exceeds the above-mentioned numerical range, it may cause environmental problems.

[0041] According to another embodiment of the present invention, a bioplastic using coffee grounds manufactured by any one of the above manufacturing methods is provided.

[0042] The above bioplastics may include any plastic made from renewable raw materials. These bioplastics may include eco-friendly plastics that reduce carbon dioxide emissions during the production process, as well as biodegradable plastics that completely decompose into water and carbon dioxide under certain conditions due to the action of microorganisms.

[0043] According to another embodiment of the present invention, a bioplastic using coffee grounds manufactured by any one of the above manufacturing methods may be an eco-friendly plastic. The eco-friendly plastic may include dried coffee grounds powder and at least one resin composition selected from the group consisting of polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), and high-density polyethylene (HDPE). Preferably, the eco-friendly plastic may include dried coffee grounds powder and at least one resin composition selected from the group consisting of polyethylene (PE), polypropylene (PP), low-density polyethylene (LDPE), and high-density polyethylene (HDPE).

[0044] According to another embodiment of the present invention, a bioplastic using coffee grounds manufactured by any one of the above manufacturing methods may be a biodegradable plastic. The biodegradable plastic may include dried coffee grounds powder and at least one resin composition selected from the group consisting of polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), and polybutylene succinate (PBS).

[0045]

[0046] Hereinafter, the present invention will be described in more detail through examples. These examples are intended solely to illustrate the present invention more specifically, and it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples, in accordance with the gist of the present invention.

[0047]

[0048] Examples and Comparative Examples

[0049] Example 1

[0050] 100 g of coffee grounds was mixed with 30 g of calcium carbonate and dried at 150°C for 1 hour to produce a dried coffee grounds powder (S1).

[0051] A plastic mixture composition was created by mixing 150 g of the above-mentioned dried coffee grounds powder and 850 g of polyethylene (PE) (S2).

[0052] The above plastic mixture composition was injected to produce a bioplastic (S3).

[0053] Example 2

[0054] The same procedure as Example 1 was followed, except that 7 g of calcium carbonate was mixed in step S1 of Example 1.

[0055] Example 3

[0056] The same procedure as Example 1 was followed, except that 10 g of calcium carbonate was mixed in step S1 of Example 1.

[0057] Example 4

[0058] The same procedure as Example 1 was followed, except that 100 g of calcium carbonate was mixed in step S1 of Example 1.

[0059] Example 5

[0060] The same procedure as Example 1 was followed, except that 120 g of calcium carbonate was mixed in step S1 of Example 1.

[0061] Example 6

[0062] The same procedure as Example 1 was followed, except that 150 g of polyethylene (PE) was mixed in step S2 of Example 1.

[0063] Example 7

[0064] The same procedure as Example 1 was followed, except that 600 g of polyethylene (PE) was mixed in step S2 of Example 1.

[0065] Example 8

[0066] The same procedure as Example 1 was followed, except that 1,500 g of polyethylene (PE) was mixed in step S2 of Example 1.

[0067] Example 9

[0068] The same procedure as Example 1 was followed, except that 3,000 g of polyethylene (PE) was mixed in step S2 of Example 1.

[0069] Examples 10 to 18

[0070] The same procedure as in Examples 1 to 9 was followed, except that polylactic acid (PLA) was mixed in place of polyethylene (PE) in step S2 of Examples 1 to 9.

[0071] Comparative Example 1

[0072] The same procedure as Example 1 was followed, except that calcium carbonate was not mixed in step S1 of Example 1.

[0073] Comparative Example 2

[0074] The same procedure as Example 10 was followed, except that calcium carbonate was not mixed in step S1 of Example 10.

[0075] Experimental Example 1

[0076] The tensile strength of the bioplastics produced in Examples 1 to 9 and Comparative Example 1 was measured. The bioplastics were cut into 100 mm lengths and 15 mm widths, and then, using an INSTRON universal testing machine (4206-001, manufacturer: UTM) according to ASTM D 882, the chuck spacing was set to 50 mm, and the test was performed at a room temperature of 25°C at a tensile speed of 200 mm / min, and the tensile strength was measured using a program built into the equipment ([Table 1]).

[0077] Tensile strength (Mpa) Example 1 13.8 Example 28.5 Example 3 10.5 Example 4 11.7 Example 5 11.6 Example 6 11.4 Example 7 12.3 Example 8 13.4 Example 9 12.5 Comparative Example 18.5

[0078] Experimental Example 2

[0079] The elongation of the bioplastics produced in Examples 1 to 9 and Comparative Example 1 was measured. The bioplastics were cut into 4 cm wide and 1 cm long pieces, and the maximum deformation just before fracture was measured at a speed of 50 mm / min using a universal testing machine (4206-001, manufacturer: UTM) from INSTRON. The ratio of the maximum deformation to the initial length was calculated as the elongation ([Table 2]).

[0080] Elongation (%) Example 178.6 Example 268.5 Example 372.5 Example 455.7 Example 561.6 Example 662.4 Example 765.3 Example 873.4 Example 970.5 Comparative Example 158.5

[0081] Experimental Example 3

[0082] The tensile strength of the bioplastics produced in Examples 10 to 18 and Comparative Example 2 was measured. The bioplastics were cut into 100 mm lengths and 15 mm widths, and then, using an INSTRON universal testing machine (4206-001, manufacturer: UTM) according to ASTM D 882, the chuck spacing was set to 50 mm, and the test was performed at a room temperature of 25°C at a tensile speed of 200 mm / min, and the tensile strength was measured using a program built into the equipment ([Table 3]).

[0083] Tensile strength (Mpa) Example 10 15.8 Example 117.8 Example 12 12.3 Example 13 13.9 Example 14 12.0 Example 15 12.4 Example 16 13.3 Example 17 13.4 Example 18 12.1 Comparative example 28.5

[0084] Experimental Example 4

[0085] The elongation of the bioplastics produced in Examples 10 to 18 and Comparative Example 2 was measured. The bioplastics were cut into 4 cm wide and 1 cm long pieces, and the maximum deformation just before fracture was measured at a speed of 50 mm / min using a universal testing machine (4206-001, manufacturer: UTM) from INSTRON. The ratio of the maximum deformation to the initial length was calculated as the elongation ([Table 4]).

[0086] Elongation (%) Example 1088.6 Example 1173.4 Example 1279.1 Example 1367.7 Example 1468.6 Example 1572.7 Example 1679.3 Example 1771.4 Example 1870.0 Comparative Example 263.5

Claims

1. A step of mixing coffee grounds with inorganic additives and drying them to produce coffee grounds dry powder; A step of mixing the above-mentioned dried coffee grounds powder and a resin composition to produce a plastic mixed composition; and A step of extruding or injecting the above plastic mixture composition A method for manufacturing bioplastics using coffee grounds containing .

2. In claim 1, A method for manufacturing bioplastic using coffee grounds, wherein in the step of mixing the coffee grounds with an inorganic additive and drying them to produce a dried coffee ground powder, the weight ratio of the coffee grounds to the inorganic additive is 1:0.1 to 1.

3. In claim 1, A method for producing a bioplastic using coffee grounds, wherein in the step of mixing the dried coffee grounds powder and the resin composition to produce a plastic mixed composition, the weight ratio of the dried coffee grounds powder and the resin composition is 1:4 to 10.

4. In claim 1, A method for manufacturing bioplastic using coffee grounds, wherein in the step of mixing the coffee grounds with an inorganic additive and drying them to produce a dried coffee ground powder, the inorganic additive includes at least one selected from the group consisting of calcium carbonate, silica, illite, zeolite, siliceous earth, calcium oxide, talc, mica, and clay.

5. A bioplastic using coffee grounds manufactured by any one of the manufacturing methods of claims 1 to 4.

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