JP5381129B2 - Method for producing molded product containing coffee grounds and molded product - Google Patents

Description

  The present invention relates to a method for efficiently producing a molded product containing coffee grounds by various molding methods, and to a coffee ground-containing injection molded product produced by this method.

  Coffee grounds, which are industrial waste left after coffee is extracted from coffee beans, are being incinerated to use waste heat and are used as compost raw materials for various uses. As one of them, descriptions relating to the use of coffee grounds as one component of a resin composition are described in several documents.

  Patent Documents 1 to 3 include a printed circuit board base material, a body for an electrical appliance, and a communication device made of a material containing food waste, plant granules, a biodegradable resin, a thermosetting resin, or a thermoplastic resin. The body is described, and examples of plant powders include okara, bran, coffee bean residue, soybean meal, soy sauce residue, and beer residue. However, the descriptions in the embodiments of the inventions of Patent Documents 1 to 3 are only when okara is used, and no explanation is given when coffee grounds is used.

  The resin molded product described in Patent Document 4 is made of a plant fiber and a polyolefin resin, and is formed by injection molding or blow molding using pellets in which the polyolefin resin is 10% by weight or more and less than 50% by weight as a raw material. The plant fiber is at least one of bean curd, beer grounds and coffee grounds. Examples of Patent Document 4 include 50% by weight of tofu residue as plant fiber, 30% by weight of beer residue and 5% by weight of coffee residue, 40% by weight of tofu residue and 25% by weight of beer residue. Although the case where 4% by weight of the coffee grounds are mixed is described, an example using only the coffee grounds is not described.

  The method for producing a resin composition described in Patent Document 5 is a method for producing a resin composition including a kneading step in which a thermoplastic resin and an additive are heat-kneaded, and the claims include examples of additives. Coffee grounds are described as one of various substances. However, the description of the best mode for carrying out the invention only mentions ground coffee grounds as an example of the additive, and there is no description at all when the ground coffee is actually used.

  The invention described in Patent Document 6 is a method for producing a resin composition containing a natural filler, and includes a kneading step of kneading the resin and the natural filler, and the kneading step includes: In order to prevent blackening of the natural filler, the production method is carried out in the presence of a boron compound, and an example of the natural filler is ground coffee grounds. However, also in Patent Document 6, in the description of the best mode for carrying out the invention, as in Patent Document 5, only ground coffee grounds are cited as an example of a natural filler. There is no description of using coffee grounds.

  As described above, the description that coffee grounds can be used as one component of a molded product exists in several literatures. However, in order to obtain a molded product using a resin composition containing coffee grounds, There was no concrete description of what to do. In the inventions described in the patent documents listed above, a pre-kneading method is adopted in which both the filler and the resin are previously kneaded and pelletized, and the resulting pellet is melted again and molded. Therefore, it is not preferable from the viewpoint of energy saving and cost.

Japanese Patent Laid-Open No. 10-145021 Japanese Patent Laid-Open No. 10-145054 Japanese Patent Laid-Open No. 10-145055 JP 2002-52562 A Republished patent WO2004 / 033538 JP 2006-16461 A

  An object of the present invention is to provide a method for efficiently producing a resin molded product containing coffee grounds at low cost without preliminary kneading or pelletization, and a molded product obtained thereby.

  As means for solving the above-mentioned problems, the invention according to claim 1 is a method for producing a resin molded product containing coffee grounds, wherein the synthetic resin is 100 parts by weight and the water content is less than 3%. A resin molding containing coffee grounds, characterized in that the coffee grounds that pass through a 30-mesh sieve and that do not pass through a 50-mesh sieve are mixed after stirring and then molded. Product manufacturing method.

  In the invention according to claim 2, the synthetic resin is a thermoplastic resin having a melt flow rate (conforming to JIS K7210, hereinafter abbreviated as MFR) of 10 or more and less than 30, and the molding machine is an injection molding machine. It is a manufacturing method of the resin molded product containing the coffee grounds of Claim 1 characterized by the above-mentioned.

  The invention according to claim 3 is the method for producing a resin molded product containing coffee grounds according to claim 1 or 2, wherein the synthetic resin is a biodegradable resin.

Further, according to Claim 4 invention, the heat generated during formation form, according to claim 1, characterized in that carbonizing the coffee grounds any one of the resin molded article containing coffee grounds described in Section It is a manufacturing method.

  Moreover, invention of Claim 5 is a resin molded product containing the coffee grounds manufactured by the method of any one of Claims 1-4.

  The method for producing a resin molded product containing coffee grounds according to the present invention comprises 100 parts by weight of a synthetic resin, a water content of less than 3%, passes through a 30 mesh sieve, and does not pass through a 50 mesh sieve. It is characterized by molding after mixing 50 parts by weight or more and less than 200 parts by weight of the ground, so it does not require pre-kneading or pelletization, and forms the coffee grounds and synthetic resin pellets as raw materials It is possible to efficiently obtain a molded article by a simple method in which the mixture is directly stirred and mixed in the hopper of the machine. By adding coffee grounds, which is an industrial waste, resin can be saved, and a low-cost molded product can be obtained. The method of the present invention is also an excellent method from the viewpoint of energy saving.

  In addition, since the molded product according to the present invention contains coffee grounds and has a coffee scent, it can be suitably used for applications where the coffee scent is preferred. Moreover, since the molded article has the deodorizing effect inherent in the coffee grounds, it can be suitably used for applications that similarly require the deodorizing effect. Moreover, since it absorbs the odor of the resin, it is also suitable for applications where the odor of the resin is disliked.

  In addition, when the synthetic resin is a thermoplastic resin having an MFR of 10 or more and less than 30, it is easy to remove the thermoplastic resin and the coffee grounds in the hopper of the molding machine even if the injection molding method is used. A molded product can be obtained by a simple method of mixing.

  In addition, when the synthetic resin is a biodegradable resin, since the obtained molded product is a biodegradable material, the molded product itself is also biodegradable. It can be suitably used for applications that require high performance.

Further, by heat during forming shape, when so as to carbonize the coffee grounds, because the carbon resulting from carbonization to act as a black pigment, obtained molded article black even without particularly adding a pigment There is an effect that it is. In addition, the deodorizing effect is further enhanced by the action of carbon.

It is sectional explanatory drawing which showed typically the manufacturing method of the resin molded product containing the coffee grounds which concerns on this invention. It is a perspective view of the coaster which is an example of the resin molded product containing the coffee grounds which concern on this invention.

The manufacturing method of the resin molded product containing the coffee grounds which concerns on this invention is demonstrated in detail according to drawing. FIG. 1 is an explanatory cross-sectional view schematically showing a method for producing a resin molded product containing coffee grounds according to the present invention. In this figure, a method for manufacturing in the injection molding process, for forming the shape method, but is not limited to injection molding. The coffee grounds 2 and the resin pellets 3 charged into the hopper 4 of the injection molding machine 1 are stirred and mixed by the stirring device 5 in the hopper and guided into the cylinder 6 of the injection molding machine. The mixed composition of the coffee grounds and the resin pellets contained in the cylinder is extruded by the screw 7, heated and melted by the heater 8, and further uniformly kneaded and mixed by the screw 7. The melted resin composition is injected into the mold 9 and becomes a molded product.

  The coffee grounds 2 and the resin pellets 3 that are put into the hopper 4 may be fed in a fixed amount so as to have a predetermined mixing ratio, or may be charged after roughly mixing at a predetermined mixing ratio. As the stirring device 5, a stirring device having a relatively simple structure using a propeller, a screw or the like rotating at a low speed is sufficient, and the shearing force is strong as in a kneading device such as a Banbury mixer or a Henschel mixer, and the resin generates heat and melts. Such an apparatus is not preferred. If pre-mixing is sufficient, the stirrer in the hopper can be omitted, but it is more likely to clog in the hopper compared to the case of using only normal resin pellets. However, it would be more stable if there was a way to force it to some extent. The method according to the present invention is characterized in that prior to injection molding, there is no need for a step of kneading and extruding the resin and coffee grounds by a pelletizer and then pelletizing them.

The coffee grounds used in the method of the present invention will be described. The water content of the coffee grounds needs to be less than 3%. Coffee grounds usually contain 5 to 20% moisture, but when the moisture content is 3% or more, water vapor is generated in the cylinder of the molding machine, causing the screw to idle, and the mixture of resin and coffee grounds is removed. Molding may become difficult as a result of the inability to melt.
Even if it is forcibly molded, the molded product becomes brittle due to foaming with water vapor, and bubbles are also generated on the surface of the molded product. Setting the water content of the coffee grounds to less than 3% is also effective in preventing the resin mixture from adhering to the mold. Therefore, prior to molding, a step of drying the coffee grounds while stirring is required. In addition, when trying to make use of the fragrance of coffee in a molded article, it is desirable to dry the generated coffee grounds while being as fresh as possible, and to leave 1 to 3% of the moisture in the coffee grounds.

  In general, coffee beans are pulverized to about 30 to 50 mesh and used for extraction, so the coffee grounds produced after extraction can be used with almost the same particle size, but mixing of coarse particles and fine powder is preferable. Therefore, it is preferable to have a particle size that passes through a 30-mesh sieve and does not pass through a 50-mesh sieve. If coarse particles that do not pass through a 30-mesh sieve are mixed, fluidity may be insufficient when mixed with a resin. If fine powder that passes through a 50-mesh sieve is mixed, the coffee grounds tend to aggregate and form a lump, and uniform dispersion may be difficult. Since the opening diameter of the sieve also varies depending on the wire diameter of the sieve, the particle size of the coffee grounds cannot be accurately defined by the mesh value alone. The particle size of the coffee grounds which is about 0.5 mm or less and does not pass through the 50 mesh sieve is about 0.3 mm or more. Therefore, the preferred particle size of the coffee grounds can be expressed as 300 μm or more and 500 μm or less.

  A wide variety of thermoplastic resins and thermosetting resins can be used as the synthetic resin used in the method of the present invention. As thermoplastic resins, polypropylene resin, low density polyethylene resin, linear low density polyethylene resin, polystyrene resin, acrylonitrile styrene copolymer resin, acrylonitrile butadiene styrene copolymer resin, polyvinyl alcohol resin, ethylene vinyl acetate copolymer resin Thermoplastic resins such as ethylene propylene rubber (EPR) and polylactic acid resin can be preferably used. Among these resins, a grade that has a low melting point and can be molded at a temperature of 210 ° C. or lower is more preferable.

  If the mixed resin composition of the thermoplastic resin and the coffee grounds stays in the heating cylinder of the molding machine for a long time, the carbonization of the coffee grounds proceeds, so that the residence time can be kept within 2 minutes at a temperature of 210 ° C. or lower. preferable.

However, to carbonize the coffee grounds using heat during forming shapes, carbon black produced by this process by using in place of the black pigment, in order to obtain a black moldings, it can be molded at higher temperatures Resin can also be used. Coffee grounds that have been carbonized further enhance the deodorizing effect.

  In particular, when a molded product is produced by an injection molding method, the thermoplastic resin is preferably a thermoplastic resin having an MFR (based on JIS K7210) of 10 or more and less than 30. If the MFR is less than 10, the resin tends to fill the mold later than the coffee grounds. If the MFR is 30 or more, the coffee grounds tend to be filled later than the resin, and in any case, there is a risk that the resin and the coffee grounds are not well dispersed and a uniform molded product cannot be obtained. is there.

When ordinary thermoplastic resin is used, the coffee grounds lose water and is surrounded by the resin, making it difficult to rot, so it can be used for flower pots and other applications. When a resin is used, a molded product having biodegradability is obtained. Polylactic acid resin has a high affinity with coffee grounds and fuses well with coffee grounds. In addition, since molded products are easily decomposed in the soil, they can be used as plant pots or planting pots that are buried directly in the soil instead of ordinary flower pots. It functions as a fertilizer. Of course, it can also be used as a solid fertilizer from the beginning.

  Moreover, as a thermosetting resin, a phenol resin, a urea resin, a melamine resin, etc. can be used most preferably. When a thermosetting resin is used, it can be suitably used for applications requiring heat resistance such as an ashtray.

  About the compounding ratio of a synthetic resin and coffee grounds, coffee grounds shall be 50 to less than 200 weight part with respect to 100 weight part of resin. When the blending amount of the coffee grounds is less than 50 parts by weight, the effect of adding the coffee grounds is weakened. When the amount is 200 parts by weight or more, the molded product becomes brittle, and the coffee grounds fall off from the surface of the molded product, or the entire molded body tends to collapse, which is not preferable. When the weight of the coffee grounds in the weight of the molded product exceeds 50%, the molded product falls under industrial waste. When it is 50% or less, it is handled as a plastic molded product. Which one to select is mainly determined by its application.

  In addition to synthetic resin and coffee grounds, adding a small amount of lubricant such as liquid paraffin or epoxidized soybean oil or adding a foaming agent such as azodicarbonamide for the purpose of improving moldability and mold releasability You can also. When a foaming agent is added, the molded product is reduced in weight, and a space is formed inside the molded product. As a result, the deodorizing effect of the molded product is enhanced.

  About the metal mold | die used for shaping | molding, it is necessary to give surface treatment, such as chrome plating, nickel plating, or titanium nitride coating, to the surface which contact | connects the resin mixture of a metal mold | die. The surface of the steel or aluminum substrate is not preferable because vaporized components generated from the coffee grounds adhere to the surface or the coffee grounds are easily burnt. Further, it is desirable to periodically apply a release agent to the surface of the mold. The mold temperature is preferably 60 ° C. or higher in the case of injection molding.

The forming shape method, other injection molding method described above, extrusion molding, compression molding, forming the shape method, such as a vacuum pressure forming method can be selected. Which molding method is selected is appropriately selected according to the shape of the molded product to be manufactured and the purpose of use.

  Examples of the use of the resin molded product containing coffee grounds according to the present invention include various articles such as coasters and trays used in a coffee shop, and cat repellents etc. Examples of applications that make use of the deodorizing effect include ashtrays, storage containers for deodorizing agents, and pet supplies. In addition, it can be used for gardening supplies such as flower pots and seedling pots, building materials such as floor deck materials and window frame materials. When a biodegradable resin is used as a synthetic resin, it should be used for fishing equipment, fishery materials, forestry materials, etc. in addition to agricultural materials such as flower pots, seedling pots and solid fertilizers buried in the soil. Can do. Hereinafter, based on an Example, the manufacturing method and molded product of the molded product containing the coffee grounds which concern on this invention are demonstrated more concretely.

The coffee grounds were dried, coarse particles were removed with a 30-mesh sieve, and fine powder was removed with a 50-mesh sieve to prepare coffee grounds having a particle size range of 300 μm to 500 μm. The water content of the coffee grounds was adjusted to a range of 1-2%.
1 part by weight of liquid paraffin was added to and mixed with 100 parts by weight of low density polyethylene resin (Nippon Polyethylene, Novatec LD LJ18041, MFR 23 g / 10 min), and the surface of the resin pellet was wetted with liquid paraffin. Of coffee grounds was added and stirred to mix evenly. The mixing was performed by a screw type stirring device attached to a hopper of an injection molding machine. The injection mold was a direct sprue type, and the surface in contact with the resin of the mold was treated with titanium nitride. The mold temperature was set to 60 ° C. A coaster having the shape shown in FIG. 2 was created. The weight of the coaster was about 70 g, which was about 70% of the molding capacity of 100 g of the injection molding machine. The obtained molded product had a good surface condition and had a coffee scent, which was suitable as a coaster for a coffee shop.

DESCRIPTION OF SYMBOLS 1 ... Injection molding machine 2 ... Coffee grounds 3 ... Resin pellet 4 ... Hopper 5 ... Stirrer 6 ... Cylinder 7 ... Screw 8 ... Heater 9 ... Molding Mold 10 ... Molded product (coaster)

Claims (5)

A method for producing a resin molded product containing coffee grounds, comprising 100 parts by weight of a synthetic resin, a water content of less than 3%, passing through a 30 mesh screen and not passing through a 50 mesh screen 50 A method for producing a resin-molded product containing coffee grounds, which comprises stirring and mixing at least part by weight and less than 200 parts by weight, followed by molding. 2. The coffee grounds according to claim 1, wherein the synthetic resin is a thermoplastic resin having a melt flow rate (based on JIS K7210) of 10 or more and less than 30, and the molding machine is an injection molding machine. A method for manufacturing a resin molded product. The method for producing a resin molded product containing coffee grounds according to claim 1 or 2, wherein the synthetic resin is a biodegradable resin. By heat at the time of forming the form, method for producing a resin molded article containing coffee grounds according to any one of claims 1 to 3, characterized in that carbonizing the coffee grounds. The resin molded product containing the coffee grounds manufactured by the method of any one of Claims 1-4.