KR20220109682A - Fruit packaging material for quality preservation with ethylene gas adsorption performance and the manufacturing method thereof - Google Patents

Abstract

According to the present invention, a method for manufacturing an eco-friendly packaging material for fruits to preserve quality having ethylene gas adsorption performance comprises the steps of: S1) preparing torrefied wood powder by grinding torrefied wood obtained by heat treating wood; S2) modifying the surface of the torrefied wood powder by mixing the torrefied wood powder with an aqueous cationic polymer solution; S3) preparing a pulp slurry of corrugated cardboard by mixing pulverized corrugated cardboard with water; and S4) preparing a packaging material for fruits by drying the mixture after mixing the surface-modified torrefied wood powder obtained in step S2) with the pulp slurry of corrugated cardboard obtained in step S3).

Description

Fruit packaging material for quality preservation with ethylene gas adsorption performance and the manufacturing method thereof

The present invention relates to a fruit tree packaging material having ethylene gas adsorption performance and a method for manufacturing the same, and more particularly, to a method for manufacturing by adding torrefied wood flour and surface-modified torrefied wood flour in the fruit tree packaging material.

Currently, styrofoam trays or paper trays are commonly used as packaging materials for fruit trees in order to maintain the freshness of products by providing prevention, ventilation, and moisture removal performance due to long-distance distribution.

In addition, research on packaging materials that maintain the freshness of fruits and vegetables in the process of transporting and distributing fruits and vegetables is continuously being conducted.

On the other hand, ethylene gas is produced during ripening of fruits and vegetables.

Ethylene is a colorless hydrocarbon with the simplest structure among ethylene hydrocarbons that play an important role in affecting seed germination, flower flowering, plant growth and aging as a physiological process regulating hormone produced by plants. The amount of ethylene generated varies depending on the type of fruits and vegetables, and the effects on aging, ripening, and decay are different. Therefore, ethylene reduction technology has a great influence on the development of conventional packaging materials for quality preservation.

As a technology for preserving the commercial properties of fruits and vegetables by suppressing the production of ethylene gas, ethylene gas suppression technology, such as a technology to suppress the emission of ethylene gas and moisture by extracting fatty acid components extracted from agricultural products with poor commercial quality and coating them on the surface of fruits and vegetables This has been studied

However, the suppression of ethylene gas generation through the surface coating of fruits and vegetables is difficult to use in practice because it is very cumbersome to coat the surfaces of each fruits and vegetables.

Recently, with the development of the online fresh food market, the consumption of packaging paper for fruits and vegetables also increased due to the expansion of the online market for fruits and vegetables, which increased along with the development of the online fresh food market. The use of soft/hard plastic packaging boxes is mainly being made. However, since these soft/hard plastic packaging materials contain environmental pollution problems due to incombustible materials, interest in plastic container usage regulations and alternative packaging materials is increasing in recent years.

Therefore, the present invention provides an eco-friendly raw material that can be biodegradable in a natural environment for a soft/hard plastic packaging material containing environmental pollution problems in the food packaging market industry, which is growing together with the rapid growth of the online market and the development of the delivery industry. An object of the present invention is to provide an eco-friendly quality preservation fruit tree packaging material that can reduce environmental pollution problems by using fiber and torrefied wood flour, and has the ability to adsorb ethylene gas, which promotes aging and decay of fruits and vegetables, and a manufacturing method thereof. .

According to the present invention, a method for manufacturing an eco-friendly quality preservation fruit tree packaging material having ethylene gas adsorption performance comprises the steps of: S1) pulverizing torrefied wood obtained by heat treating wood to produce torrefied wood powder; S2) mixing the torrefied wood flour with a cationic polymer aqueous solution to modify the surface of the torrefied wood flour; S3) mixing the pulverized corrugated cardboard with water to prepare a corrugated cardboard pulp slurry; and S4) mixing the surface-modified torrefied wood powder obtained in step S2) with the corrugated cardboard pulp slurry obtained in step S3) and drying the mixture to prepare an orchard packaging material.

In addition, the cationic polymer aqueous solution in step S2) is characterized in that the aqueous solution prepared by mixing the cationic polymer solid powder and water.

In addition, in step S2), it is characterized in that 3% to 9% of torrefied wood flour is mixed with respect to the weight of the cationic polymer aqueous solution.

In addition, in the step S2), it characterized in that it further comprises the step of drying the mixture obtained by mixing the torrefied wood flour with a cationic polymer aqueous solution.

In addition, the mixture is characterized in that it is dried at 100 ~ 110 ℃.

In addition, it is characterized in that the heat treatment of the wood at a temperature of 300 ~ 350 ℃ in step S1).

In addition, in the step S4), it is characterized in that the surface-modified torrefied wood flour is mixed with the corrugated cardboard pulp slurry in an amount of 50% or less based on the weight of the fruit tree packaging material.

In addition, in the step S1), the wood is heat treated in the superheated steam treatment device 100, and the superheated steam treatment device 100 is provided with a water pipe through which water supplied from the water supply tank 111 flows and burns the raw material therein. A combustion furnace 110 for generating steam, a moisture separator 112 for separating and removing moisture from the steam generated by the combustion furnace 110, and a combustion gas outlet at the end of the combustion furnace 110 and It is composed of an exhaust gas flow pipe connected to the exhaust gas flow pipe and a vapor flow pipe formed in the exhaust gas flow pipe, so that the steam flowing in from the moisture separator 112 moves through the steam flow pipe and overheats the steam by the exhaust gas flowing through the exhaust gas flow pipe A plurality of superheaters 113 , a rotating housing 121 , and a plurality of wings 122 coupled to the inner circumferential surface of the housing 121 , and coupled to the inner circumferential surface by rotation of the housing 121 . The blade 122 rotates together and superheated steam generated from the superheater flows into the housing 121, and the superheated steam dryer 120 for superheating steam drying the wood chips supplied into the housing. do.

In addition, the superheated steam processing apparatus 100 has an interior partitioned into upper and lower chambers 131a and 131b by a horizontal wall 132 , and the lower chamber 131a has a superheated steam dryer under the horizontal wall 132 . An inlet through which the superheated steam is introduced is formed, an outlet through which the superheated steam flows out is formed on one side of the upper chamber 131b above the horizontal wall 132, and the inlet is formed in a tangential direction to the inner circumferential surface of the lower chamber 131a. A centrifuge tube 131 connected to It is made in the shape of a cone whose inside becomes narrower toward the direction, and the impurity-removed water supply container 135 is connected to one side of the lower part of the cone-shaped centrifugal separator 131 in the tangential direction of the inner circumferential surface to supply the impurity-removed water. Impurity removal water is supplied from the removal water supply container 135 in the tangential direction of the inner circumferential surface and rotates, and while rotating in the opposite direction to the rotation direction of the superheated steam, the impurities are collected from the superheated steam and collected at the bottom. It is characterized in that it further comprises.

In addition, the wood is characterized in that the pine wood nematode disease or oak wilt disease pest damage.

According to the present invention, it is possible to reduce the concentration of ethylene gas and volatile organic compounds in the same packaging container by providing adsorption performance of ethylene gas and volatile organic compounds, and improve the quality preservation performance of fruits and vegetables through reduction of ethylene gas concentration. A packaging material for fruits and vegetables for preserving quality and a method for manufacturing the same are provided.

1 is a block diagram of an apparatus for treating superheated steam in the present invention;
2 is a view showing a cross-section of the superheated steam dryer in the superheated steam processing apparatus of FIG. 1;
3 is a longitudinal sectional view showing the discharge part of the superheated steam dryer of FIG. 1;
4 is a view showing an impurity remover in the superheated steam processing apparatus of FIG. 1;
5 is a schematic diagram of the manufacturing process of the fruit tree packaging material of the present invention,
6 is a view showing an apparatus for manufacturing a fruit tree packaging material of the present invention,
7 is a view showing the change of zeta-potential according to the heat treatment temperature and time of wood in the present invention,
8 is a view showing the change in surface charge according to the addition of a cationic polymer aqueous solution,
9 is a graph of the results of the ethylene adsorption test,
10 is a graph showing the results of the carbon dioxide adsorption test,
11 is a view showing the gas adsorption test process of the fruit tree packaging material of the present invention;
12 is a graph showing the results of the ethylene gas adsorption test of the fruit tree packaging material of the present invention;
13 is a view showing the fruit preservation test process of the fruit tree packaging material of the present invention,
14 is a graph showing the results of the volatile organic compound adsorption test of the fruit tree packaging material of the present invention according to FIG. 13;
15 is a graph showing the results of the ethylene oxide adsorption test of the fruit tree packaging material of the present invention according to FIG. 13 .

Unless defined otherwise, all technical terms used herein have the same meaning as commonly used by those skilled in the art to which the present invention belongs, and the nomenclature used in this specification and the experimental method described below is using a method commonly used in this technical field.

In one aspect, the present invention provides (a) torrefied wood flour manufacturing step, (b) cationic polymer (C-PAM) hydration step, and (c) surface modification step through mixing of torrefied wood powder and cationic polymer material And, (d) the preparation step of the corrugated cardboard fiber, (e) comprising the step of mixing the surface-modified torrefied wood flour of (c) with the corrugated cardboard fiber of (d).

The present invention provides fruit trees with adsorption performance of ethylene gas and volatile organic compounds, including torrefied wood flour in wood-based fiber packaging materials, and surface-modified torrefied wood flour for quality preservation performance of fruit trees (including fruits and vegetables) A method for manufacturing a packaging material for quality preservation is provided.

Hereinafter, the manufacturing method of the fruit tree packaging material for quality preservation according to the present invention will be described in more detail.

1 is a block diagram of a superheated steam processing apparatus in the present invention, FIG. 2 is a cross-sectional view of the superheated steam dryer in the superheated steam processing apparatus of FIG. It is a longitudinal cross-sectional view, and FIG. 4 is a view showing an impurity remover in the superheated steam processing apparatus of FIG. 1, and FIG. 5 is a schematic diagram of the manufacturing process of the fruit tree packaging material of the present invention.

1. Lumber harvesting and chipping stage

First, in the present invention, wood as a raw material is felled, cut to about 1 m, and then chipped and crushed to a size of about 10 cm using an industrial chipper or the like while containing the bark. The wood used as the main material at this time is general bamboo, pine, Rigida pine, larch, cypress, radiata pine, eucalyptus, melanti, cypress, birch, chestnut, cypress, cedar, oak, red oak, oak, white Various mixed tree species with a clear history of occurrence including oak, oyster oak, oak, wild cherry, someiyoshino cherry, acacia, weight tree, poplar, and acacia from Vietnam can be used. Low-value-added raw materials such as tree by-products of gardening, trees damaged by pests such as pine wilt disease and oak wilt, and bamboo can also be used. In addition, agricultural by-products such as rice husks, straw, and sugar cane dregs can also be used.

In the embodiment of the present invention, oak wilt disease-damaged wood, which is an unused forest biomass resource in Korea, was used. Oak wilt disease-damaged trees have been spreading since 2011 and have been occurring sporadically every year, with about 10,249 occurrences reported every year. In an embodiment of the present invention, oak wilt disease-damaged wood was used as a high-value-added resource of unused forest biomass resources through the development of packaging materials for fruit trees and imparting gas adsorption performance.

2. Superheated steam treatment step

The wood chips that have been cut and chipped as described above are subjected to superheated steam treatment using a superheated steam treatment device.

The superheated steam processing apparatus 100 used in the present invention will be described as follows. 1 is a block diagram of an apparatus for treating superheated steam according to the present invention, FIG. 2 is a view showing a cross-section of a superheated steam dryer in the apparatus for treating superheated steam according to the present invention, and FIG. It is a longitudinal sectional view showing a part, and FIG. 4 is a view showing an impurity remover in the superheated steam processing apparatus of the present invention.

The superheated steam processing apparatus 100 of the present invention generates superheated steam by a combustion furnace 110 for generating steam by burning raw materials such as pellets and wood, and high-temperature exhaust gas discharged from the combustion furnace 110 . The superheater 113 for heating, the superheated steam dryer 120 for superheated steam drying the wood chips using the superheated steam supplied from the superheater 113, and the superheated steam discharged from the superheated steam dryer is supplied to remove impurities. and an impurity remover 130 for removing it.

The combustion furnace 110 is for generating high-temperature steam by burning raw materials such as wood pellets and wood, and a water pipe through which water supplied from the water supply tank 111 flows is installed in the combustion furnace 110 .

In this way, by the combustion of the raw material in the combustion furnace 110, the water pipe installed in the combustion furnace 110 is heated to generate steam, and the high-temperature combustion gas generated by the combustion of the raw material is the combustion formed at the end of the combustion furnace. It is discharged through the gas outlet.

The steam generated by the combustion furnace 110 is temporarily stored in the moisture separator 112 and then sent to the superheater 113 . The steam generated by the combustion furnace 110 is wet steam, and the moisture separator 112 separates and removes moisture from the wet steam. The moisture separator 112 removes moisture from the wet steam using a cyclone or the like. The steam from which moisture has been removed from the moisture separator 112 is sent to the superheater 113 .

The superheater 113 is for generating superheated steam by superheating the steam generated by the combustion furnace 110 using the high-temperature combustion gas discharged from the combustion furnace 110, and the combustion at the end of the combustion furnace 110 is It consists of an exhaust gas flow pipe connected to the gas outlet, and a vapor flow pipe formed in the exhaust gas flow pipe. Accordingly, in the superheater 113 , the steam generated in the combustion furnace 110 moves through the steam flow pipe and at the same time, the steam is overheated by the exhaust gas flowing through the exhaust gas flow pipe. The superheated steam in the superheater 113 is supplied to the superheated steam dryer 120 .

The superheated steam dryer 120 dries wood chips with superheated steam, and includes a rotating housing 121 and a plurality of blades 122 coupled to an inner circumferential surface of the housing 121 .

2 is a cross-sectional view of the superheated steam dryer 120 according to the present invention, and by the rotation of the housing 121, a plurality of blades 122 coupled to the inner circumferential surface are rotated together, and thereby the input hopper 120a The wood chips supplied into the housing 121 from is treated dry.

In addition, discharge guide portions each formed in a spiral shape are formed on the inner circumferential surface of the right end of the superheated steam dryer 120 to discharge the wood chips through the rotation of the housing 121 .

3 is a view showing the discharge unit 123 of the superheated steam dryer 120 according to the present invention, and the discharge unit 123 is supplied with superheated steam treated wood chips and superheated steam, and the superheated steam is discharged to the top , the dried wood chips are configured to discharge the loaded superheated steam-treated wood chips by rotating a rotary shaft 125 on which a plurality of rotary plates 124 are radially installed.

The superheated steam discharged from the discharge part 123 of the superheated steam dryer 120 is introduced into the impurity remover 130 . 4 shows the impurity remover 130 . The impurity remover 130 is for removing impurities contained in the superheated steam in the superheated steam treatment process by the superheated steam dryer from the introduced superheated steam. , acetic acid, methanol, and the like are removed to remove particulate impurities together with these substances.

The inside of the impurity remover 130 is divided into upper and lower chambers 131a and 131b by a horizontal wall 132 . In the lower chamber 131a, an inlet through which superheated steam is introduced is formed just below the horizontal wall 132, and a centrifugal separator 131 connected to the inlet in a tangential direction to the inner circumferential surface is installed, and the horizontal wall 132 has a centrifugal separator. A guide pipe 133 is formed long inside the separation tube 131 , and an outlet through which superheated steam flows is formed in one side of the upper chamber 131b on the upper side of the horizontal wall 132 . The lower portion of the impurity remover 130 is formed in a cone shape that becomes narrower toward the lower end, and a discharge valve (not shown) for discharging impurities discharged from the centrifugal separator 131 is provided at the lower end.

In addition, an impurity-removed water supply container 135 is connected to one side of the lower portion of the cone-shaped centrifuge tube 131 in the tangential direction of the inner circumferential surface to supply the impurity-removed water. Accordingly, the impurity-removed water is supplied from the impurity-removed water supply container 135 in the tangential direction of the inner peripheral surface and rotates. At this time, the impurity as described above is collected from the superheated steam while turning in the opposite direction to the rotational direction of the superheated steam. collected at the bottom.

The impurity remover 130 has the above configuration, so that the introduced superheated steam flows in through the inlet and rotates to descend while the impurity moves through the inner wall of the centrifugal separator 131 by centrifugal force. The collected impurities are collected at the bottom of the impurity remover 130 . As such, the superheated steam from which impurities are removed is supplied to the combustion furnace 110 again, reheated and circulated.

The wood chips are dried by the superheated steam treatment apparatus 100 having the configuration as described above, whereby the wood chips are dried to remove moisture and other volatile substances including carbon monoxide, carbon dioxide, acetic acid, and methanol in addition to moisture. will remove Through this process, the specific surface area and porosity are improved compared to the existing wood, and the drying treatment can be performed quickly by performing the drying treatment by superheated steam from which moisture has been removed compared to general steam. quality is improved.

Also, at the same time, the carbon content per unit weight of the wood chips is increased by the superheated steam. In the present invention, the carbon content is increased to less than 50 wt% to 80 wt%. Through such a treatment process, the weight of the wood chips decreases and the carbon content per unit weight increases.

In an embodiment of the present invention, after raising the temperature to a temperature of 300 ° C. to 350 ° C. using the above-described superheated steam processing apparatus 100, and then inserting the oak wilt disease damage produced in the form of a chip, the step of varying the reaction time carry out At this time, in the present invention, since the sample is put in a state that has reached a high temperature, a superheated steam treatment facility in which steam is injected is used to prevent overcharging and fire due to ignition of the raw material. In the case of producing torrefied wood flour using an existing carbonization furnace, processing time is long and continuous production is impossible. .

3. Crushing process

The torrefied wood chips recovered through the above heat processing step are pulverized through a wood chip-only grinder (or chipper). In this pulverization process, the wood chips can be pulverized with a wood chip-only pulverizer or, after pulverization with a pulverizer, the wood chips can be further processed into fibers with a defibrator or grinder.

The wood flour that has undergone the pulverization process in this way is collected after pulverization for mixing with an aqueous polymer electrolyte solution, which will be described later, and the wood flour in the range of 75 μm to 106 μm is stored in a hot air dryer under a temperature condition of 105° C. or less.

4. Cationic Polymer Hydration Step

Next, an aqueous solution of the cationic polymer material is prepared.

The aqueous solution of the cationic polymer material is for cationic surface modification of the torrefied wood powder obtained as described above, and the zeta potential of general wood (Zeta Potential, surface charge of particles in aqueous solution) is approximately -18 mv. Meanwhile, in the present invention, the zeta potential of torrefied wood powder heat-treated as described above shows a strong negative charge of about -17 mv to -57 mv. The torrefied wood flour, which has a high level of negative charge, is easily surface-modified by the cationic polymer aqueous solution, and ethylene gas and volatile organic compounds are adsorbed to the pores and surface of the torrefied wood flour substituted with a positive charge. The cationic polymer electrolyte aqueous solution is prepared by mixing the cationic polymer powder and distilled water in the present invention, followed by stirring at a stirring speed of 400 rpm or more for 5 hours or more, and the concentration of the polymer material can be adjusted according to the use. In the present invention, an aqueous solution of 0.1% wt to 1% wt based on parts by weight of the aqueous solution was prepared and used. The cationic polymer material used in the present invention uses a tertiary amine-based polyacrylamide (Catiomic Polyacrylamide), has low toxicity as a C, H, O, N compound, has a wide reaction range, and has no problems due to secondary elution. It is a polymer material with a very high positive charge. Polyacrylamide is a white or pale yellow colored polymeric material formed from polyacrylamide: 2-propenamide (CH2: CHCONH2), which is used for various purposes such as binders, dispersion aids, lubricants, crystal shape control agents, etc. It is not soluble in alcohol, glycol, ester, etc., and the nitrogen content decreases at a temperature of 150°C or higher, thereby weakening the reactivity. Currently, it is mainly used as a binding agent and stabilizer for paper or fibers.

5. Surface modification step by mixing torrefied wood flour and cationic polymer material

In this process, after adding the torrefied wood flour prepared above to the aqueous solution of the cationic polymer material as described above, the mixture is stirred for 1 hour to 5 hours at a stirring speed of 400 rpm or more, followed by hot air drying at a temperature of 105±5° C. for 24 hours.

6. Preparation of Corrugated Fibers

Corrugated cardboard fiber used as a raw material of the packaging material for quality preservation of the present invention was corrugated cardboard fiber (old corrugated container). This is a regenerated fiber that has completed washing and deinking of the recovered boxes and packaging paper after use, and has received corrugated cardboard for paper manufacture in the form of a roll provided for research, sealed and refrigerated to prevent external contamination and fiber corruption. It was stored and used.

In the step of the present invention, corrugated paperboard paper prepared in the form of a roll is ground to about 1 cm ² , mixed with distilled water, diluted to a concentration of 1% wt, and then a high-speed dissociator is used to prepare a corrugated paper paper pulp slurry having a concentration of 1% wt. Corrugated paperboard pulp slurry production can be made through a fiberization process using a grinder or refinery.

7. Mixing step of corrugated cardboard fiber with torrefied wood flour and surface-modified torrefied wood flour

In this step, the prepared raw material for packaging material for orchard packaging is prepared by mixing the prepared paperboard paper pulp slurry of 1% wt or less with torrefied wood flour and surface-modified torrefied wood flour in different amounts. Although the corrugated cardboard pulp slurry of 1% wt or less has a very low concentration, a stirring speed of 400 rpm or more is required when mixing with the additive material due to the hydrophilic group and flexibility of the fibers, and a sufficient stirring process of 10 minutes or more is included.

8. Manufacturing stage of fruit tree packaging material

In this process, a wood-based fruit tree packaging material for preserving quality is manufactured using the raw material for the fruit tree packaging material prepared above. The corrugated cardboard pulp slurry and raw materials with different additives and addition amounts are prepared in the form of a board using the fruit tree packaging material manufacturing apparatus according to the present invention.

Figure 5 is a view showing the entire manufacturing process of the present invention, Figure 6 is a schematic diagram of the fruit tree packaging material manufacturing apparatus of the present invention.

The fruit tree packaging material manufacturing apparatus according to the present invention is composed of a reduced pressure dehydration molding machine 200 including a molding cylinder 210 .

Raw materials including corrugated cardboard pulp slurry and surface-modified torrefied wood flour are put in a molding cylinder 210 and then dehydrated under reduced pressure through a reduced pressure dehydration molding machine 200 to produce a round board shape.

Air is discharged from the reduced pressure dewatering machine 200 by the vacuum device 220 connected to the reduced pressure dewatering machine 200 to be decompressed and vacuumed, and a mesh is disposed under the forming cylinder 210 .

At this time, characteristics such as molding shape, basis weight, and bulk can be manufactured differently depending on the intended use and the user, and in the present invention, it was manufactured in a circular form with a basis weight of 100 g/m ² . The finished wet fruit packaging material was finally manufactured through a drying process for 6 to 24 hours under hot air drying conditions of 100±5°C.

[Example]

Surface charge comparison experiment, gas adsorption force experiment, and component change comparison experiment of the additive material used for manufacturing the fruit tree packaging material for quality preservation according to the present invention were conducted. A removal efficiency test and a storage performance test in an airtight container were performed.

1) For the heat-treated wood used in the present invention, oak wilt diseased wood, which has a small utility value among unused forest biomass resources in Korea, was used.

Using the superheated steam processing apparatus 100 of the present invention, torrefied oak chips were manufactured through heat treatment at a temperature of 300°C, 330°C, and 350°C for 10 minutes, 15 minutes, and 20 minutes, respectively, and then 75㎛ - 106㎛ Grind to the size of , and store in a hot air dryer under a temperature condition of 105℃ or less.

2) The cationic polymer material was hydrated at a concentration of less than 0.2% compared to the aqueous solution, and in this example, a cationic polymer aqueous solution having a concentration of 0.2% per 1 L of the total weight was prepared.

After adding 1%, 3%, 5%, 7%, and 9% of the aqueous cationic polymer solution hydrated to a concentration of 0.2%, respectively, based on the weight of torrefied powder, 1,000 ml of distilled water was added each, followed by stirring.

After completion of the stirring process, hot air drying was performed at a temperature of 105° C. or lower for 24 hours, and then surface-modified torrefied wood powder was finally prepared.

3) Next, corrugated cardboard fiber (old corrugated container) was used for the manufacture of the fruit packaging material. In the step of the present invention, corrugated paperboard paper prepared in a roll form is pulverized to about 1 cm ² , mixed with distilled water, diluted to a concentration of 1% wt, and then a high-speed dissociator is used to prepare a 1% wt concentration of corrugated paper paper pulp slurry.

4) Mix the dissociated cardboard paper pulp slurry with wood flour, torrefied wood flour, and activated carbon so as to be 50% or less, specifically 10%, 30%, or 50% of the weight of the fruit tree packaging material to be prepared based on a basis weight of 100 g/m ² . After the mixing is completed and after a sufficient stirring process, it is manufactured in the form of a round board using the fruit tree packaging material manufacturing apparatus of the present invention, and then dried at a temperature of 105° C. or less.

5) Measurement of specific surface area

In this experiment, the specific surface area and porosity of torrefied wood powder manufactured using the superheated steam treatment device 100 were measured using a specific surface area measurement facility. As shown in Table 1 (increase in specific surface area by heat treatment of wood) It can be seen that the specific surface area of the torrefied powder that has undergone the heat treatment process at a temperature of 200° C. is increased by 10 times or more compared to the specific surface area of the wood flour that has not been subjected to the heat treatment of the present invention. It can be seen that the difference between the 250°C temperature condition and the 350°C temperature condition is not large. In the case of porosity, there is no significant increase in porosity due to heat treatment, and the average size of the pores does not show a significant difference.

Non
-Treatment
200℃-20min
250℃-20min
350℃-20min Specific surface area
(m ² /g)
1.154
14.5
34.12
34.25 porosity(cm) ³ /g) 0.022 0.0259 0.029 0.0288 pore size 4.5 7.5 6.8 8.11

6) Zeta Potential Measurement

In this experiment, an experiment to measure the zeta potential of wood flour, torrefied wood flour, and activated carbon was performed. For the measurement of the surface charge of each sample, each sample diluted to a concentration of 2% was measured for the surface charge of the sample using the AFG ANALYTIC GMBH instrument. The measurement result of the surface charge of each sample is shown in FIG.

7 shows the change in the zeta potential, and it can be seen that the oak has a surface charge of -19.5 mv, and the zeta potential displacement occurs greatly as the carbonization temperature increases and the carbonization time increases. In the case of zeta-potential displacement change, it can be seen that the difference between the 20-minute treatment condition and the 25-minute treatment condition is large at 300°C, and the 330°C treatment condition also has a large displacement difference between the 20-minute treatment condition and the 25 minute treatment condition. . However, in the 350℃ temperature condition, the potential change is reduced as the treatment time increases, and it is judged that the effect of the surface modification treatment by the cationic polymer will decrease. is judged to be Therefore, as a material for packaging material to be manufactured in the present invention, it is judged that torrefied wood flour produced by superheating steam treatment at a temperature of 350° C. for 20 minutes is the most effective.

Next, by measuring the surface charge of the torrefied wood flour treated with the surface modification, the possibility of gas adsorption due to the potential difference was determined. The Zeta Potential value of the surface-modified torrefied wood flour is shown in FIG. 8 . It represents the Zeta Potential value of torrefied wood flour manufactured through a superheated steam treatment process for 20 minutes at a temperature of 350° C. A high positive charge is exhibited as the amount of the polymer material is increased, and in the present invention, a maximum positive charge of 34.1 mv is exhibited.

7) Ethylene gas and carbon dioxide adsorption experiment

In this experiment, the gas adsorption performance of wood flour, torrefied wood flour, and activated carbon used as additive materials for quality preservation packaging was evaluated. The controllability of ethylene gas and carbon dioxide was checked to determine the freshness maintenance of fruit trees. In this experiment, activated carbon, torrefied wood flour, and surface-modified samples were put into a sealed container, sealed, and then ethylene gas was injected. In order to evaluate the adsorption rate of ethylene gas and carbon dioxide after reaction for a certain period of time (1 hour, 24 hours), the concentrations of ethylene gas and carbon dioxide remaining in the container were measured using an AGC Series 600 Gas Chromatograph. In FIG. 9, the ethylene gas adsorption performance of activated carbon, torrefied wood flour (TWF), and surface-modified torrefied wood flour (TWF + C-PAM) was shown, and when 3% C-PAM was added, about 40% ethylene within 1 hour It shows the gas adsorption performance, and it can be seen that the adsorption performance of about 70% appears after 24 hours.

However, it can be seen that the difference in the maximum adsorption performance of ethylene gas is not large according to the increase in the amount of C-PAM added.

It can be seen that the initial ethylene gas removal performance increases with the increase in the amount of C-PAM added to about 80% and 55%, respectively, in the initial ethylene gas residual concentration within 1 hour under the C-PAM addition condition of 7% or more and the 9% addition condition. However, it can be seen that the difference in ethylene gas adsorption performance is not significant when the residual concentration of ethylene gas within 24 hours is 55% and 53%, respectively, and the addition amount of C-PAM aqueous solution is 7% or more.

10 shows the adsorption performance of carbon dioxide and shows results generally similar to the adsorption performance of ethylene gas. Carbon dioxide adsorption performance also shows that activated carbon (AC) shows the best performance, 80% removal within 1 hour, and 100% adsorption after 24 hours. Torrefied wood flour shows a very low level of carbon dioxide adsorption performance of 5% for the first hour, and about 20% of carbon dioxide adsorption performance after 24 hours.

And, when 3% of C-PAM was added, carbon dioxide adsorption performance of about 40% was exhibited after 1 hour.

8) Gas adsorption performance of fruit tree packaging material

Next, in order to evaluate the gas adsorption performance of the fruit tree packaging material manufactured in step 4), an orchard packaging material containing 50% of activated carbon (AC), torrefied wood flour, and surface-modified torrefied wood flour was prepared as shown in FIG. The mixing board was put into the lower end of the desiccator, and then the desiccator was sealed using vacuum grease. After introducing about 18ppm of ethylene standard gas through the top valve of the sealed desiccator, react for 12 hours, 24 hours, and 48 hours, respectively, at a temperature of 25 ± 1℃. collected. The ethylene gas collected in the Tedlar bag was measured using gas chromatography, and the adsorption performance was evaluated by comparing the residual concentration to the initial concentration. As shown in FIG. 12, it was confirmed that the gas adsorption performance of the fruit tree packaging material exhibited a maximum of 65% ethylene gas adsorption performance when 7% of a cationic polymer aqueous solution was added. (C-PAM 5%-50% in FIG. 12 50% means that 50% of surface-modified torrefied wood flour is contained relative to the total weight of the fruit tree packaging material)

9) Evaluation of Fruit Preservation Performance of Fruit Tree Packaging Materials

In order to evaluate the fruit preservation performance of each prepared fruit tree packaging material according to the mixture quality and mixing ratio conditions, each fruit was enclosed as shown in FIG. 13 and then a desiccator was sealed. The desiccator containing the sealed fruits, corrugated paper stock, and mixing board mixed with additives was stored in a constant temperature and humidity chamber under harsh conditions of 30°C and 16300 lux of visible light. In general, in order to suppress the generation of ethylene in fruits, they are stored at a low temperature and in the absence of visible light, and it is known that at a temperature of 35° C. or higher, the aging by ethylene is reduced due to the deterioration of the enzyme that causes the ripening. Therefore, in this study, in order to test the adsorption performance of the mixing board for fruit tree packaging, ethylene was generated by maintaining a temperature of 30℃ for the growth of fruits. .

Next, FIG. 14 is a result showing the concentration of volatile organic compounds inside the desiccator containing the fruit tree packaging material and fruits. The surface modification prepared by mixing 7% and 9% of cationic polymer material compared to torrefied wood flour content In the case of the mixed board for fruit tree packaging with treated torrefied wood flour added, the initial concentration of volatile organic compounds is somewhat higher than that of activated carbon (AC) and torrefied wood flour, but it can be seen that after 3 days, it appears lower than that of other materials. From 5%-50% indicated in FIG. 14, 5% represents 5% C-PAM and 50% represents that 50% of surface-modified torrefied wood powder is contained relative to the total weight of the fruit tree packaging material)

15 is a result showing the ethylene oxide reduction performance of the mixing board for fruit tree packaging in which each additive material is mixed. After the initial day, the concentration of ethylene oxide was 133 ppm without addition, 75 ppm for activated carbon (AC), 76 ppm for torrefied wood flour added, and 72 ppm for torrefied wood flour added with C-PAM. It shows ethylene gas adsorption performance.

In the case of the mixed board for fruit tree packaging to which activated carbon (AC) is added, the ethylene oxide removal performance tends to decrease after 4 days, and the removal performance is at a level of 31%, which is somewhat lower than the initial 44% removal efficiency.

The mixed board for fruit tree packaging with torrefied wood flour also shows a similar tendency to activated carbon (AC) and has a longer duration than activated carbon (AC).

In the case of a mixed board manufactured using C-PAM-7% torrefied wood flour, the removal performance is somewhat lower than that of activated carbon (AC) and torrefied wood flour, and in the case of 5%, it is the lowest level among the materials used. It was shown that the ethylene oxide gas removal performance of

In the case of the mixed board manufactured using C-PAM-9% torrefied wood flour, it was found that not only the initial removal rate of ethylene oxide gas but also the durability were excellent.

Therefore, in the present invention, adsorption performance of ethylene gas and volatile organic compounds is provided by manufacturing a wood-based fiber packaging material containing torrefied wood flour with increased voids and specific surface area, which is manufactured through torrefied wood flour manufacturing technology, and It is possible to manufacture packaging materials (fruit trays and packaging materials) with increased cushioning performance by increasing the bulk properties of the material.

In addition, the surface modification treatment reaction of torrefied wood flour using the cationic polymer material of the present invention replaces the surface of torrefied wood flour, which exhibits a negative charge, with a positive charge to produce a packaging material with increased electrostatic adsorption performance of gas molecules. It is expected to be able to replace the Styrofoam tray, etc., which has an environmental pollution problem due to the existing non-degradable material.

200: molding machine 210: molding cylinder
220: vacuum device

Claims (12)

S1) preparing torrefied wood powder by pulverizing torrefied wood obtained by heat-treating wood;
S2) mixing the torrefied wood flour with a cationic polymer aqueous solution to modify the surface of the torrefied wood flour;
S3) mixing the pulverized corrugated cardboard with water to prepare a corrugated cardboard pulp slurry; and
S4) mixing the surface-modified torrefied wood flour obtained in step S2) with the corrugated cardboard pulp slurry obtained in step S3) and drying to prepare an orchard packaging material;
A method of manufacturing a fruit tree packaging material for quality preservation, comprising a. According to claim 1,
In the step S2), the cationic polymer aqueous solution is an aqueous solution prepared by mixing a cationic polymer solid powder and water. According to claim 1,
In step S2), the cationic polymer aqueous solution is mixed with 3% to 9% based on the weight of torrefied wood flour. According to claim 1,
In step S2), the method of manufacturing a fruit tree packaging material for preserving quality, characterized in that it further comprises the step of drying the mixture obtained by mixing the torrefied wood flour with a cationic polymer aqueous solution. 5. The method of claim 4,
A method of manufacturing a fruit tree packaging material for quality preservation, characterized in that the mixed solution is dried at 100 to 110°C. According to claim 1,
A method of manufacturing a fruit tree packaging material for quality preservation, characterized in that the wood is heat-treated at a temperature of 300 to 350° C. in step S1). According to claim 1,
A method of manufacturing a fruit tree packaging material for quality preservation, characterized in that in the step S4), surface-modified torrefied wood flour is mixed with the corrugated cardboard pulp slurry in an amount of 50% or less based on the weight of the fruit tree packaging material. According to claim 1,
A method of manufacturing a fruit tree packaging material for quality preservation, characterized in that in the step S4), the material including the surface-modified torrefied wood flour and the corrugated cardboard pulp slurry is manufactured in the form of a board using a reduced pressure dehydration molding machine including a molding cylinder. According to claim 1,
In the step S1), the wood is heat-treated in the superheated steam processing apparatus 100, and the superheated steam processing apparatus 100 is
A water pipe through which water supplied from the water supply tank 111 flows is installed and a combustion furnace 110 for burning raw materials to generate steam therein;
a moisture separator 112 for separating and removing moisture from the vapor generated by the combustion furnace 110;
It is composed of an exhaust gas flow pipe connected to the combustion gas outlet at the end of the combustion furnace 110 and a steam flow pipe formed in the exhaust gas flow pipe, so that the steam flowing in from the moisture separator 112 moves through the steam flow pipe and the discharge A superheater 113 for superheating the steam by the exhaust gas flowing through the gas flow pipe;
A rotating housing 121 and a plurality of wings 122 coupled to the inner circumferential surface of the housing 121, and a plurality of wings 122 coupled to the inner circumferential surface by the rotation of the housing 121 together Fruit tree packaging material for quality preservation, characterized in that it rotates and includes a superheated steam dryer 120 for superheated steam drying the wood chips supplied into the housing by introducing superheated steam generated from the superheater into the housing 121 manufacturing method. 10. The method of claim 9, wherein the superheated steam processing device (100)
The interior is divided into upper and lower chambers 131a and 131b by a horizontal wall 132, and an inlet through which superheated steam is introduced from the superheated steam dryer is formed below the horizontal wall 132 in the lower chamber 131a, An outlet through which superheated steam flows is formed at one side of the upper chamber 131b above the horizontal wall 132,
A centrifuge tube 131 to which the inlet is connected in a tangential direction to the inner circumferential surface is installed in the lower chamber 131a, and a guide tube 133 is elongated below the inside of the centrifuge tube 131 on the horizontal wall 132. is formed, and the lower portion of the centrifugal separator 131 is formed in a cone shape that becomes narrower toward the bottom,
At one side of the lower portion of the cone-shaped centrifugal separator 131 , an impurity-removed water supply container 135 is connected in a tangential direction of the inner circumferential surface to supply the impurity-removed water, and the impurity-removed water from the impurity-removed water supply container 135 is connected to the inner circumferential surface. Fruit tree for quality preservation, characterized in that it further comprises an impurity remover 130 that is supplied in the tangential direction of the A method of manufacturing a packaging material. According to claim 1,
The wood is a method of manufacturing a packaging material for fruit trees for quality preservation, characterized in that the wood is a tree damaged by pests of pine wilt disease or oak wilt disease. A packaging material for quality preservation produced by the manufacturing method according to any one of claims 1 to 11.

Images