Patent Application
20080057547
The present invention is conceived to solve the aforementioned problems in the prior art. An object of the present invention is to provide pulp and paper and a manufacturing method thereof, capable of preventing environmental contamination and protecting forests and not using a toxic chemical during beating or bleaching.
Another object of the present invention is to provide pulp and paper which is manufactured with waste from pulp material minimized and a manufacturing method thereof.
In order to accomplish the above objects, according to the present invention, a method of manufacturing pulp using Rhodophyta is provided, the method comprising: immersing Rhodophyta in an extraction solvent able to dissolve agar gel for a predetermined time period to dissolve the agar gel in the extraction solvent; converting the dissolved agar gel into a fiber by reacting the dissolved agar gel with a reaction solvent; curing the fiber using a curing agent; and pulping the cured fiber.
The conversion into the fiber may be performed by continuously extruding the agar gel solution into the reaction solvent using an extrusion nozzle, or by intermittently extruding the agar gel solution into the reaction solvent using a spray nozzle.
According to the present invention, a method of manufacturing pulp using Rhodophyta is provided, the method comprising: immersing Rhodophyta in an extraction solvent able to dissolve agar gel for a predetermined time period to dissolve the agar gel in the extraction solvent; and pulping after collecting a pulp material remaining after removal of the solution containing the dissolved agar gel.
According to the present invention, a method of manufacturing pulp using Rhodophyta is provided, the method comprising: immersing Rhodophyta in an extraction solvent able to dissolve agar gel for a predetermined time period to dissolve a portion of the agar gel in the extraction solvent; collecting a pulp material remaining after removal of the solution containing the dissolved portion of agar gel; curing the chipped pulp material using a curing agent; and pulping the cured fiber.
In this case, dissolving the portion of agar gel in the extraction solvent may be performed by immersing Rhodophyta in an alcohol-based solvent; followed by boiling.
The curing agent may comprise aldehyde. Also, the curing agent may comprise Glyoxal.
Further, the extraction solvent may be preferably used at a temperature of 80° C. or higher. The extraction solvent may comprise any one selected from water, alcohols, and ketones.
It is preferable that the reaction solvent be used at a temperature of 80° C. or higher. The reaction solvent may comprise alcohols or ketones, provided that the reaction solvent is a different material from the extraction solvent.
The dissolution may be performed by chipping Rhodophyta, followed by immersion in the extraction solvent.
Rhodophyta may be selected from Gelidium amansii, Gracilaria verrucosa, Cottonii, Spinosum, and combinations thereof.
The present invention provides pulp manufactured using Rhodophyta according to the above mentioned method.
The present invention provides a method of manufacturing paper, comprising preparing pulp manufactured using Rhodophyta according to the above mentioned method, and manufacturing paper using the pulp. The present invention provides paper manufactured according to this method.
The present invention provides a method of manufacturing paper, comprising preparing pulp manufactured using Rhodophyta according to the above mentioned methods, preparing wood pulp, mixing two or more of the above pulps, and manufacturing paper using the pulp mixture. The present invention provides paper manufactured according to this method.
Hereinafter, a detailed description will be given of the present invention.
Pulp and Paper Material: Rhodophyta
Unlike other seaweeds, the 4000 species of Rhodophyta live in relatively deep water and have small sizes. Rhodophyta have a wider habitat range than Chlorophyta and Phaeophyta, and grow naturally from shallow water to water as deep as light rays penetrate.
Agar is a product processed by extracting heteropolysaccharide as a cell wall component of Rhodophyta with hot water, followed by freezing, melting and drying. An agar material can be derived from Gelidium amansii, Pterocladia tenuis, Acanthopeltis japonica, Gracilaria verrucosa, Hypnea charoides, Ceramium kondoi, Ceramium boydenii, Gigartin tenella, Campylaephora hypnaeoides and Grateloupia filicina. Although the agar has various properties according to the species, habitat environments and manufacturing methods of agarphyte which is raw seaweed thereof, it consists mainly of agarose and agaropectin mixed at a ratio of 7:3. These components are an effective component of the agar. Neutral polysaccharide agarose having high gelling properties is used to provide high strength, while acidic polysaccharide agaropectin having low gelling properties serves to provide high viscoelasticity. The agar is composed of 13-24% water, 70-85% non-nitrogen material (carbohydrate), 1.5-3.0% crude protein, 0.2-0.3% ether extract, and 0.5-0.8% crude fiber and 1-3% ash component. The dried agar product absorbs 20 times its weight of water.
Representative properties of the agar include coagulability, viscoelasticity and water retentivity. Since the agar has the opposite properties, that is, coagulability and viscoelasticity, it is applicable as a stabilizer, a weighting agent, a forming agent, a thickening agent, a drying inhibitor and a property-maintaining agent by controlling the above two properties.
An aqueous agar solution exhibits gelling properties higher than those of other gel-forming agents. The aqueous agar solution forms gel at 32-43° C., such that the formed gel does not dissolve at a temperature of 80-85° C. or lower. Even though gelling and dissolution are repeatedly performed, original agar gel properties are not changed. Transparent agar gel is easily colored, and increases in refractive index and gloss when mixed with sugar, glucose and glycerin.
Carrageenan, which is a water-soluble polymer polysaccharide extracted from seaweeds such as the genus Chodrus and Euceuma belonging to Rhodophyta, is produced into three types, such as kappa-, lambda- and iota-, having different properties from one another, and the types thereof are selected or properly mixed according to required purposes. Carrageenan generally used as a thickener has the ability to form gel in water, in which the resulting gel is highly thermoreversible. Hence, the above material is used as a gelling agent for dessert jelly, jam, tea, aromatic agents or deodorizing agents.
A yield of agar per dried weight of agarphyte unit amounts to about 60-80%, which is similar to or higher than that of pulp extracted from wood.
Therefore, as the pulp and paper material of the present invention, various Rhodophyta, including Gelidium amansii, Gracilaria verrucosa, Cottonii, and Spinosum, are used. Alternatively, carrageenan or agar obtained from Rhodophyta maybe used.
The agar hydrothermally extracted from Gelidium amansii or Gracilaria verrucosa has higher strength than that of carrageenan hydrothermally extracted from Cottonii or Spinosum. In particular, the agar component hydrothermally extracted from Gracilaria verrucosa is higher in strength, compared to agar hydrothermally extracted from Gelidium amansii.
Carrageenan belonging to Rhodophyta such as Cottonii and Spinosum has the same properties as the gel component contained in Rhodophyta such as Gelidium amansii and Gracilaria verrucosa, in view of including a fibrous material usable for manufacturing pulp. Therefore, in the present invention, carrageenan belonging to Rhodophyta such as Cottonii and Spinosum, along with the agar component contained in Rhodophyta such as Gelidium amansii and Gracilaria verrucosa, goes by the name of ‘agar gel’.
Pulp Manufacturing
According to the present invention, pulp is manufactured using Rhodophyta as follows.
Rhodophyta such as Gracilaria verrucosa, Gelidium amansii, Cottonii or Spinosum are immersed in an alkali aqueous solution of potassium hydroxide (KOH) for a predetermined time period, and washed with water, followed by being partially dried. Here, through the immersion process of Rhodophyta in the alkali aqueous solution for a predetermined time period, Rhodophyta are slightly decolored while impurities are removed therefrom, and water content is constantly maintained. If Rhodophyta are not decolored, it is difficult to perform a subsequent bleaching process. Further, if Rhodophyta are completely dried, the fibrous material thereof is broken upon chipping through a beating process. Hence, upon processing Rhodophyta, the immersion of Rhodophyta in the alkali aqueous solution is commonly required. Techniques of immersing Rhodophyta in the alkali aqueous solution are well known in the art related to processing Rhodophyta, and hence, a description therefor is omitted.
The washed and semi-dried Rhodophyta are immersed in an extraction solvent. Thereby, the agar gel in Rhodophyta is extracted into the extraction solvent. The extraction solvent used for extracting the agar gel is exemplified by water, alcohols, such as ethyl alcohol or methyl alcohol, and ketones, such as acetone. As the extraction solvent any material may be used so long as it is able to dissolve the agar gel. Further, since the agar gel has a melting point of about 80° C., the extraction solvent should be a solvent capable of being heated to 80° C. or higher.
Here, as the area of Rhodophyta in contact with the extraction solvent increases, the agar gel is easily extracted. Thus, it is preferable that Rhodophyta be chipped before being immersed in the extraction solvent. The chipped fiber size of Rhodophyta may vary according to the selection of the user.
The gel solution containing the dissolved agar gel is added to a reaction solvent, whereby the agar gel is converted into fibrous material usable as pulp. At this time, the gel solution may be added in various ways, as shown in the appended drawings.
As shown in
In this way, the use of a relatively simple device, such as the extrusion nozzle 210, results in the conversion of the agar gel into the fibrous material.
In cases of further increasing the reactivity of the gel solution and the reaction solvent, a gel solution 200 can be sprayed into a large amount of reaction solvent 100 using a spray nozzle 220, as shown in
When the gel solution 200 is sprayed through the spray nozzle, it is added to the reaction solvent 100 in a thinner form, compared to the extrusion manner using the extrusion nozzle 210. Thereby, thinner fibrous material results.
The reaction solvent includes alcohols or ketones. Any liquid, in addition to alcohols and ketones, may be used so long as the agar gel may be converted into the fibrous material usable as pulp. However, if the reaction solvent contains the same composition as the extraction solvent, the agar gel is dissolved in the reaction solvent, instead of being converted into fibrous material usable as pulp. Therefore, it is noted that the composition of the reaction solvent is different from the extraction solvent When the gel solution is reacted with the reaction solvent, the reaction solvent is preferably heated to 80° C. or higher so that the agar gel is not cured.
However, the fibrous material resulting from the above process is much lower in strength, heat resistance and chemical resistance which are properties required to manufacture paper. Accordingly, the fibrous material should be cured using an aldehyde-based curing agent, such as Glyoxal. The cured fibrous material is chipped into a size suitable for papermaking, followed by pulping. This pulping process is the same as the process after the fiber has been obtained in a conventional wood pulping process, and hence, a description therefor is omitted. Since the cured fibrous material does not change the composition thereof even though it is heated to a high temperature or comes into contact with other solvents during the papermaking, it can be used as pulp.
Moreover, selection of Rhodophyta is not limited to one specific type. That is, various types of Rhodophyta may be mixed together. For example, two or more selected from Gelidium amansii, Gracilaria verrucosa, Cottonii and Spinosum are mixed together. In particular, the addition of Gracilaria verrucosa, functioning to increase binding force, results in a final product having high strength. Accordingly, to obtain paper having high strength, Gracilaria verrucosa is used in a large amount.
The present applicant has manufactured paper using Rhodophyta by the following process. A detailed description will be given of the papermaking process, below.
5 g of agar derived from Gelidium amansii and 5 g of agar derived from Gracilaria verrucosa are introduced into 500 cc of water, and then stirred for 5 min while the temperature is maintained in the range from 90° C. to less than a boiling point. Then, a curing process is performed using a curing agent, such as Glyoxal. After completion of the curing process, the cured material is subjected to beating and is then mixed with 5 g (1 wt %) of a sizing agent which results from gumming an admixture of a pine resin (rosin), heated to 150° C. and dissolved, and 20% aqueous sodium hydroxide solution in equal amounts. Subsequently, the resultant reaction material is mixed with 2.5 g (0.5 wt %) of Alum and then stirred so that strong alkalinity of sodium hydroxide is neutralized for efficient reaction of the agar solution and the rosin gum. 8 g (1.6 wt %) of starch as a dry strength agent is added to the reaction mixture and then the mixture is stirred for uniform mixing. Thereafter, a sheet forming process leads to manufacturing transparent paper, provided that the temperature is continuously maintained in the range from 90° C. to less than a boiling point just until performing the sheet forming process. The above paper is mixed with 25 g (5 wt %) of calcium carbonate as a loading agent and stirred, followed by sheet forming, thus obtaining opaque white paper.
In addition, when extracting the agar gel from Rhodophyta and pulping it, the pulp material remaining after the agar gel has been extracted has similar properties to the mechanical pulp of wood, and thus, may be used as pulp without additional treatment. To exhibit higher strength, the pulping process may be performed after the curing treatment, according to the selection of the user. At this time, the pulping process may include a process of chipping the pulp into a size suitable for papermaking.
In addition, in cases where chipped Rhodophyta are boiled at about 78° C. for 4 hours under atmospheric pressure using ethyl alcohol as the extraction solvent suitable for extracting the agar gel from Rhodophyta, only a portion of agar gel is extracted from Rhodophyta. Here, slight decoloration occurs while the portion of agar gel is extracted. Since the pulp material remaining after the portion of agar gel has been extracted contains the other portion of agar gel, the strength of the remaining pulp material is high. The remaining pulp material containing some agar gel is cured for pulping. To further increase the strength of the remaining pulp material, the pulp material remaining after the agar gel has been extracted is cured in the same manner as in the curing process of the fibrous material produced from the agar gel. The resulting pulp is further suitable for use in paper pulp. As mentioned above, the pulping process may include the process of chipping the pulp into the size suitable for papermaking.
The obtained pulp may be manufactured into the paper according to a general papermaking process.
As for the papermaking, the paper made using the pulp resulting from the agar gel has properties like paper made from chemical wood pulp, whereas the paper made using pulp obtained from the remaining pulp material has properties like paper made from mechanical wood pulp. Further, the paper manufactured using the pulp obtained from the remaining material has higher strength than that of the paper manufactured using the pulp resulting from the agar gel. Therefore, the pulp obtained from the agar gel, the pulp obtained from the remaining pulp material, and the pulp obtained from the remaining pulp material containing some agar gel, are mixed at various ratios, according to the selection of the user.
Moreover, a predetermined amount of wood pulp (mechanical pulp and/or chemical pulp) may be additionally included upon papermaking using Rhodophyta. In this way, addition of the wood pulp results in drastically increased paper strength and a smooth paper surface.
Papermaking Process
In general, ‘paper’ means a sheet formed of cellulose fibers of network structure suitable for use in printing, writing and packaging, and ‘papermaking’ means the process of manufacturing the paper adequate for desired use purposes through various treatments. Although the process of manufacturing the paper, that is, the papermaking process, slightly varies according to the use purposes of the end product paper, it is commonly performed as follows.
(1) Beating
When pulp manufactured in pulp factories is used for papermaking without any process, the resultant paper has drawbacks, such as low strength, a rough surface and very high air-permeability, and thus is difficult to be generally used. This is because natural pulp fibers are hard and have a low surface area, and therefore do not bind together.
Accordingly, the fiber is mechanically treated in water to be suitable for sheet forming. This process is referred to as beating, which is classified into free beating which cuts the fiber and wet beating causing fibrillation. The beating process results in removal of an outer layer of the fiber, internal fibrillation, longitudinal cutting of the fiber, the formation of fine fiber, and partial dissolution of a chemical composition. The beating process functions to soften the fiber so as to increase the binding of fibers. Thus, the higher the degree of beating, the denser the paper.
(2) Sizing
This process acts to provide resistance to the permeation of ink or water into the paper. Here, the usable reagent is referred to as a sizing agent. The sizing process is classified into surface sizing and internal sizing.
(3) Loading
This process serves to mix the pulp and a mineral material, such as clay or calcium carbonate, upon sheet forming, thereby increasing the opacity, printability and basis weight of paper.
(4) Sorting and Cleaning
These processes function to remove impurities from the paper material so that the resulting paper has uniform properties, before the paper material is fed into a paper machine.
(5) Sheet Forming
This process functions to form a web on a wire using the paper material composed of a mixture of the pulp, the sizing agent, the loading agent, and various additives, followed by compression, dehydration and drying, to obtain the paper. According to the formation manners of the web on the wire, the paper machine is classified into a fourdrinier machine, a cylinder machine, and a twin wire machine.
(6) Processing
This process is used to subject the manufactured paper to various processing treatments, such as coating, denaturation, absorption and layering
In the papermaking method according to the present invention, Rhodophyta rather than wood pulp is used as a pulp and paper material. Thus, although the beating process is not indispensably performed, it may be preferably performed upon using agarphyte. If an agar product having high purity is used, the beating process is not required. Further, the steps (2) to (6) may be selectively carried out.
Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
As described above, the present invention provides pulp and paper made from Rhodophyta and a method of manufacturing the same. When the manufacturing method of the pulp of the present invention is applied, the following advantages can be expected:
Moreover, the manufacturing method of the pulp according to the present invention is advantageous because the paper can be manufactured even without the use of wood, whereby various environmental problems, such as global warming, can be solved through forest conservation.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2003 0080330 | Nov 2003 | KR | national |
| 10 2004 0092297 | Nov 2004 | KR | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/KR04/02939 | 11/12/2004 | WO | 00 | 2/2/2007 |
