TECHNICAL FIELD

The present invention relates to pulp molded products including seaweed by-products and apple or green tea pomace and methods for producing the same.

BACKGROUND ART

Pulp molded products are eco-friendly packaging materials produced by dispersing wood pulp or recycled pulp such as newspaper or corrugated cardboard in water to create a uniform paper stock, shaping the paper stock such that the pulp fibers in the paper stock form a desired structure while the paper stock is absorbed in upper and lower molds, and drying the shaped paper stock. Since pulp molded products are cushioning materials made of biodegradable pulp resources, there is a continuously increasing demand for pulp molded products as eco-friendly packaging materials that can replace fossil fuel-based packaging materials such as Styrofoam. The expansion of online shopping, in practice, leads to an increase in the number of delivery packages. In addition, small households with one or two members become major economic players, resulting in an increased use of small parcels. Thus, the demand for eco-friendly and highly recyclable packaging materials is expected to further increase.

A three-dimensionally shaped molded product having an accommodation space is generally produced by molding paper pulp made from wood as a raw material. However, the use of wood as a raw material leads to logging, causing damage to nature. In an effort to solve this problem, Korean Patent No. 10-1847039 proposes a method for producing pulp from agar-agar. Although this patent publication specifically describes the production of pulp, it fails to suggest the production of a molded product. It has, however, been found that the high water absorption rate of the agar-agar pulp fibers makes it impossible to produce a molded product by a general method known in the art.

As the demand for functional materials such as antibacterial, antiviral, and antifungal materials increases, the utilization of eco-friendly functional materials is also attracting attention. Fruits such as tangerines, oranges, and apples can be typically utilized as eco-friendly functional materials. Korean Patent No. 10-1442502 specifically provides a method for making paper using fruit peels.

Organic wastes such as apple pomace and tangerine pomace are generated in large quantities after juice extraction and are usually disposed of by dumping at sea. However, since organic waste dumping at sea was banned, Considerable costs and difficulties have been entailed in securing approaches to disposal of organic wastes. Processes such as composting or landfilling are currently being applied to the disposal of organic wastes. However, such processes have limitations and impose a heavy economic burden in the disposal of wastes. Thus, an appropriate approach is urgently needed to dispose of wastes.

Since fruit pomace is produced after juice extraction from the fruit flesh, its water content is as high as about 80 to 85% when discharged. Fruit pomace contains functional components of fruits, such as antibacterials, antivirals, and antifungals, because it includes juice remaining unextracted and is composed of fibrous flesh and peel. The processing cost of fruit pomace is also increasing. Under such circumstances, various technologies for utilizing fruit pomace (including apple pomace) containing functional materials are being developed to maximize the resource value of the fruit pomace.

Since green tea pomace is produced after making tea, its water content is as high as about 80 to 85% when discharged. Green tea pomace includes juice remaining unbrewed and contains various fibrous functional components, including antibacterials such as catechins, antivirals, and antifungals. The processing cost of green tea pomace us also increasing. Under such circumstances, various technologies for utilizing green tea pomace containing functional materials are being developed to maximize the resource value of the green tea pomace.

There is a need for methods for producing molded products, taking into consideration the high water absorption rate of seaweed pulp and the antibacterial properties of fruit apple or green tea pomace.

DISCLOSURE
Technical Problem

The present invention has been made in an effort to meet the above need, and an object of the present invention is to provide pulp molded products including seaweed by-products and apple pomace and/or green tea pomace and methods for producing the pulp molded products.

Technical Solution

One aspect of the present invention provides a method for producing a pulp molded product, including: filtering out foreign materials from a seaweed sludge to prepare a stock of seaweed fibers (first step); separating fibers from apple pomace and adding the apple pomace fibers to the stock of seaweed fibers (second step); pulping the stock, to which the apple pomace fibers have been added, with agitation (third step); and producing a molded product using the pulp (fourth step).

A further aspect of the present invention provides a method for producing a pulp molded product, including: filtering out foreign materials from a seaweed sludge to prepare a stock of seaweed fibers (first step); separating fibers from green tea pomace and adding the green tea pomace fibers to the stock of seaweed fibers (second step); pulping the stock, to which the green tea pomace fibers have been added, with agitation (third step); and producing a molded product using the pulp (fourth step).

Another aspect of the present invention provides a method for producing a pulp molded product, including: filtering out foreign materials from a seaweed sludge to prepare a stock of seaweed fibers (first step); separating fibers from apple pomace and green tea pomace and adding the apple pomace and green tea pomace fibers to the stock of seaweed fibers (second step); pulping the stock, to which the apple and green tea pomace fibers have been added, with agitation (third step); and producing a molded product using the pulp (fourth step).

Yet another aspect of the present invention provides a pulp molded product including seaweed and produced by any of the methods described herein.

Effects of the Invention

According to the methods of the present invention, pulp molded products including seaweed by-products are produced using apple pomace and/or green tea pomace. The presence of seaweed as a biodegradable and eco-friendly material and the addition of apple pomace and/or green tea pomace allow the pulp molded products to have natural antibacterial and anti-insect functions.

MODE FOR CARRYING OUT THE INVENTION

The present invention will now be described in more detail.

According to one aspect of the present invention, there is provided a method for producing a pulp molded product including seaweed, the method including: filtering out foreign materials from a seaweed sludge to prepare a stock of seaweed fibers (first step); separating fibers from apple pomace and adding the apple pomace fibers to the stock of seaweed fibers (second step); pulping the stock, to which the apple pomace fibers have been added, with agitation (third step); and producing a molded product using the pulp (fourth step).

According to a further aspect of the present invention, there is provided a method for producing a pulp molded product including seaweed, the method including: filtering out foreign materials from a seaweed sludge to prepare a stock of seaweed fibers (first step); separating fibers from green tea pomace and adding the green tea pomace fibers to the stock of seaweed fibers (second step); pulping the stock, to which the green tea pomace fibers have been added, with agitation (third step); and producing a molded product using the pulp (fourth step).

According to another aspect of the present invention, there is provided a method for producing a pulp molded product including seaweed, the method including: filtering out foreign materials from a seaweed sludge to prepare a stock of seaweed fibers (first step); separating fibers from apple pomace and green tea pomace and adding the apple pomace and green tea pomace fibers to the stock of seaweed fibers (second step); pulping the stock, to which the apple pomace and green tea pomace fibers have been added, with agitation (third step); and producing a molded product using the pulp (fourth step).

In each of the methods, the pulp may be prepared by a series of processes including sludge filtration, pulping, and pulp filtration.

The seaweed sludge may include one or more of agar-agar (Ceylon moss), sea string, sea mustard, and kelp. The seaweed sludge may be raw seaweed that has undergone softening. The seaweed sludge may be obtained by removing extracts available as foods from softened raw seaweed. The seaweed sludge in an unpurified state may contain foreign materials.

The sludge filtration can be performed by filtering out foreign materials from the seaweed sludge in a filter to extract a pulp stock. The pulp stock, from which foreign materials having a large particle size have been filtered out, may include small raw seaweed species (e.g., agar-agar, sea string, sea mustard, and kelp). The raw seaweed species may remain unpeeled. The pulp stock extracted by the sludge filtration may be accommodated in a pulping machine for subsequent pulping.

The apple pomace or green tea pomace may be added after coarse materials are sorted out and fibers are separated. When apple pomace or green tea pomace is used without further processing to produce a pulp molded product, it is not evenly distributed and may become lumpy. It is preferable that the apple or green tea pomace is subjected to mechanical defibration after sorting based on mesh, including sorting fruit peels and flesh fibers having large particle sizes and fine particles on the basis of size. The defibration can be performed using a suitable device such as a kneader, a PFI mill, a colloid mill, a roll mill, a disintegrator, a refiner, a jet mill or a homogenizer. A predetermined weight of the apple pomace fibers obtained after defibration pretreatment and sorting is added to produce a pulp molded product. The weight of the apple pomace fibers is preferably determined such that the occurrence of possible problems during processing can be prevented.

The use of the apple pomace ensures antibacterial, antiviral, and antifungal properties of a final molded product due to the presence of components such as flavonoids.

The use of the green tea pomace ensures antibacterial, antiviral, and antifungal properties of a final molded product. Green tea (Camellia sinensis) is an evergreen shrub belonging to the family Camellia. Since green tea contains catechin, flavonoid, theanine, caffeine tannin, and various vitamins, it can impart antibacterial properties, deodorizing performance, anti-rancidity, and an inhibitory function on microbial growth to a final molded product.

The pulp stock may further include one or more vegetable by-products in addition to the seaweed and the apple pomace. Specific examples of the vegetable by-products include coconut shells, grain husks, and coffee powders. The grains may be, for example, rice, barley, bean, red bean, millet, sesame, wheat, and corn.

The pulping can be performed by agitating the pulp stock accommodated in the pulping machine. For the pulping, the apple pomace or green tea pomace fibers are added to the raw seaweed fibers as pulp components obtained after seaweed extraction and are evenly spread at a uniform concentration in a liquid (e.g., water).

The pulping may further include cutting the seaweed in the pulp stock. The seaweed cutting can accelerate pulping of the pulp stock. Specifically, the seaweed sludge may be cut to a length of 5 to 20 mm. Red algal pulps developed hitherto are not suitable for use in papermaking because of their short fiber length. Thus, the method of the present invention further includes adjusting the length of the seaweed pulp fibers, which is described below. If the length is less than 5 mm, the fibers become obstacles to the production of a molded product during molding. Meanwhile, if the length is greater than mm, the pulping rate of the stock may be reduced.

A propeller may be arranged in the pulping machine to agitate the pulp stock for pulping. The pulp stock may receive kinetic energy to create a turbulent flow. The slower the rotational speed of the propeller for agitating the pulp stock, the lower the pulping rate of the pulp stock. The rotational speed of the propeller may be set to 20 rpm to 50 rpm. Heat and pressure may be applied to the inside of the pulping machine to accelerate the pulping. The lower the thermal energy applied, the lower the pulping rate of the pulp stock. Meanwhile, the greater the thermal energy, the more often the seaweed in the pulp stock is cut, resulting in a shorter length of the seaweed. The lower the pressure applied, the lower the pulping rate of the pulp stock into the seaweed pulp. Meanwhile, the higher the pressure applied, the thinner the seaweed in the pulp stock becomes, with the result that the seaweed is more often cut, resulting in its shorter length. In view of this, it is preferable to determine the temperature and pressure ranges.

For the purpose of accelerating the pulping, one or more chemical catalysts may be added to the stock. The chemical catalysts may be hydrogen peroxide and sodium hydroxide. Bleaching may be further performed to whiten the seaweed pulp. The pulping and bleaching may be repeated many times to make the pulp white and pure. In this case, however, the seaweed pulp fibers may be reduced in length.

The method may further include measuring and adjusting the water content of the highly moist seaweed to process the seaweed. It is desirable to determine whether the concentration of the pulp stock is suitable for molding the pulp stock into a molded product having a uniform thickness or a delicate shape. The optimum water content of the pulp stock is preferably 30 to 50%. In order to adjust the water content of the seaweed, heat may be applied to the machine to evaporate or dehydrate the pulp stock or a fresh pulp stock or water may be further added.

Thereafter, the pulp can be further processed to produce a molded product. A pulp molded product can be produced by filling and pressurizing the pulp stock in a molding machine. The molding machine may include lower and upper molds. The molding can be performed by wet molding, dry molding or a combination thereof. Wet molding and dry molding differ from each other by how to fill the lower mold with the pulp stock. According to wet molding, the lower mold is submerged in a bath filled with the pulp stock and is allowed to ascend vertically to fill the lower mold with the pulp stock. According to dry molding, the pulp stock is poured directly into the lower mold.

According to yet another aspect of the present invention, there is provided a pulp molded product including seaweed and produced by any of the methods described herein. The use of the eco-friendly materials, including seaweed, allows the pulp molded product to be biodegradable. The sorting of the seaweed sludge on the basis of length and sorting out of coarse materials from the apple or green tea pomace before pulping ensure a desired surface of the pulp molded product. In addition, the pulp including seaweed with a high water content is prevented from gelling, enabling the production of the pulp molded product in an intact form. Furthermore, the presence of the apple or green tea pomace ensures antibacterial and antiviral functions of the pulp molded product.

The foregoing has described rather broadly the features and technical advantages of the present invention in order to better understand the scope of the present invention as set forth in the appended claims. It will be understood by those skilled in the art that the invention can be implemented in other specific forms without changing the technical spirit or essential features of the present invention. Therefore, it should be noted that the forgoing embodiments are merely illustrative in all aspects and are not to be construed as limiting the invention. The scope of the invention is indicated by the appended claims rather than the foregoing detailed description. All changes or modifications derived from the appended claims and their equivalents should be construed as falling within the scope of the invention.