JPH0578304B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention relates to the structure of a drying sheet used in a house for drying brown leaf tobacco. In particular, by covering the entire inner frame of the tobacco leaf drying house with the drying sheet of the present invention, it is possible to prevent the production of rapidly drying leaves, stuffy/combed leaves, dull blue leaves, etc. in the dried leaf tobacco. (Prior art) Brown leaf tobacco is dried through three periods: a yellowing period, a browning period, and a bone drying period. Air drying takes 15 to 30 days, and 30 to 40 days for true leaves. It has long been pointed out that leaf tobacco dries quickly when air-dried in a leaf tobacco drying house made of synthetic resin film. We aim to use various types of films that reduce the transmittance of the film or blackout curtains that cover the outside of the film or the inner frame of the drying house, and we often promote ventilation by opening the hem and gable of the drying house during the day. The temperature and humidity inside the greenhouse is controlled to be below 35℃ and relative humidity above 70%. Rapidly dry leaves emerge within 2 to 3 hours under conditions of high temperature and low humidity (for example, 40° C., 50%), so the above measures are essential to prevent this. On the other hand, under long-term rain or cloudy conditions, the temperature becomes low and humid, so maintenance of the house must be done frequently, such as by removing the blackout curtains covering the inside and outside of the house, opening and closing the skirts and gables, or using wind-fired power equipment. The temperature and humidity inside the greenhouse is controlled to be above 20℃ and relative humidity below 85% to prevent stuffiness and curly leaves. Stuffy and combed leaves will appear in about two days under low temperature and high humidity conditions (for example, 20°C, 95%). Low temperature and high humidity conditions can also be prevented by using wind power equipment. However, if the drying greenhouses are scattered throughout the field, considerable labor is required. Additionally, if the temperature is raised too high to avoid low-temperature and high-humidity conditions, this will create the conditions for rapid drying of leaves. As mentioned above, rapid drying of leaves occurs in a short period of time, so great care is required. As described above, there is a range of suitable temperature and humidity conditions for drying brown leaf tobacco, and the current situation is that detailed drying management operations are performed within the drying house to ensure that the range is not exceeded. In particular, it is difficult to maintain humidity conditions due to temperature conditions, and operations such as stacking and tying the leaf tobacco in addition to the above are required. The present applicant previously disclosed in Japanese Patent Application No. 63-12675,
Although a coating material for drying brown leaf tobacco has been proposed, the present invention has the advantage of simplifying drying control operations, especially under low temperature and high humidity conditions, without causing rapid drying, stuffiness, etc.
The object of the present invention is to improve the invention of the prior application so that the production of comb leaves can be further suppressed. (Problems to be Solved by the Invention) The present invention enables drying without frequent drying management operations such as opening and closing the hem of the drying house and attaching and detaching the light-shielding curtain.
Prevents the formation of rapidly dry leaves under high temperature and low humidity conditions during sunny days, prevents the formation of stuffy and curly leaves under low temperature and high humidity conditions during long cloudy and rainy days, and also prevents blue dullness that occurs during low temperature and long rainy days. It is an object of the present invention to provide a sheet for drying brown leaf tobacco suitable for preventing leaves from drying. (Means for Solving the Problems) The present invention uses a moisture permeable film having a moisture permeability of 1000 g/m ² 24 hr or more as the outer film, and a moisture permeable film having a moisture permeability 100 g/m ² 24 hr or more greater than the outer film. A sheet for drying brown leaf tobacco, characterized by having an inner film, a water-absorbing resin held between the outer film and the inner film, and having an overall visible light transmittance of 5 to 50%. It is. In the moisture permeable film of the present invention, both the outer film and the inner film are made of materials such as nonwoven fabric, synthetic resin film, cloth, and paper. Particularly preferred is a nonwoven fabric that is highly flexible, has uniform strength in the longitudinal and lateral directions, is lightweight, and is relatively easy to design for moisture permeability.
The material of the nonwoven fabric is preferably a water-permeable fiber, and may be either a wet-laid nonwoven fabric or a dry-laid nonwoven fabric. The moisture permeability of the moisture permeable film must be 1000 g/m ² ·24 hr or more for the outer film, and the moisture permeability of nonwoven fabrics, cloth, and paper can be adjusted during the manufacturing process. If the moisture permeability adjusted during the manufacturing process is too high, coat with vinyl chloride/acrylic copolymer lacquer or polyvinyl alcohol (PVA).
Moisture permeability can be reduced by subjecting the entire surface or a portion thereof to a surface treatment such as lamination with a film or the like. In synthetic resin films,
After the film is manufactured, the moisture permeability can be adjusted by punching pinholes in the film. The moisture permeability of the outer film was determined by taking into account the maximum amount of water removed during drying of brown leaf tobacco. The moisture permeability of the inner film must be set to be at least 100 g/m ² ·24 hr greater than that of the outer film. The moisture permeability of the inner film can also be adjusted in the same way as the adjustment of the outer film. The drying sheet of the present invention is normally used to cover the inner frame of a drying house; in this state, the inner film faces the leaf tobacco suspended within the inner frame, and the outer film covers the ceiling of the drying house. face Therefore, when the drying sheet of the present invention is used in a drying house during the day, the outer film is exposed to higher temperature and lower humidity conditions than the inner film.
When releasing moisture from the water-absorbing resin held in the drying sheet of the present invention to leaf tobacco during the day, it is effective that the inner film has a higher moisture permeability than the outer film. The outer film and/or the inner film may be kneaded or coated with acid black, nigrosine, or
Carbon black, aluminum foil powder and other coloring agents can be used. The drying sheet of the present invention is characterized in that a water-absorbing resin is held between the above-mentioned outer film and inner film. Water-absorbing resin has a large amount of hydrophilic groups in its molecules, and has the property of absorbing 30 to 1000 times its own weight of water, retaining it, and releasing the water depending on conditions. A polymer substance. Water-absorbing resins include starch, acrylic,
There are DVA types, CMC types, etc., but starch types, which have a slow absorption rate, are particularly suitable. Preferably, hydrophilic fibers such as cellulose pulp or a fungicide are mixed and retained together with the water-absorbing resin. In addition, in order to supplement the moisture absorption effect of the water absorbent resin, a moisture absorbent such as calcium chloride may be added. The fungicide plays a role in preventing mold from forming on the outer film and the inner film as a result of increased moisture content due to moisture absorption by the water-absorbing resin. The outer film and inner film are usually bonded together using an adhesive. As the adhesive, polymers such as acrylic resin, vinyl chloride, polycarbonate, and polyester, copolymers thereof, or mixtures thereof are used. It is also a heat-adhesive fiber.
By mixing SWP, EA, Melty, etc. with water-absorbing resin, hydrophilic fiber, anti-fog agent, etc., sandwiching it between the outer film and the inner film, heating it in an oven, and pressing it, the films on both sides are separated. It can also be glued. Furthermore, in order to almost completely block the passage of ultraviolet rays between the two sheets, ultraviolet absorbers such as salicylic acid esters, benzophenones, benzotriazoles, nickel salts, and cyanoacrylates, or UV absorbers in the ultraviolet region are added. It is preferable to use one or more types of pigments, dyes, etc. Thereby, the drying sheet of the present invention can also be given the ability to prevent "white blurred leaves". By setting the visible light transmittance of the entire drying sheet of the present invention to 5 to 50%, preferably 5 to 25%, direct sunlight can be applied even when the light shielding curtain installed on the ceiling of the drying house is removed. Even when drying is carried out, it is possible to prevent a sudden rise in temperature in the area surrounded by the drying sheet of the present invention in the drying house. (Function) To explain how to use the drying sheet of the present invention, the drying sheet of the present invention is generally hung on the inner frame of a drying house so as to surround the leaf tobacco suspended within the inner frame. coated with A portion of the moisture that evaporates from the hung tobacco leaves is absorbed and retained by the water-absorbing resin of the drying sheet of the present invention, but on sunny days, the indoor temperature rises during the day, causing the leaves to dry out rapidly. High temperature above 40℃, relative humidity
When trying to achieve a low humidity condition of 70% or less, the visible light transmittance is 5 to 50%, preferably 5 to 25%, so temperature rise is suppressed and the moisture retained in the water absorbent resin is released. It plays the role of preventing the relative humidity within the inner frame from dropping below 70%. On the other hand, if rain and cloudy weather continue, stuffy leaves and
Insufficient dehydration due to low temperatures below 20°C and high humidity conditions above 85% relative humidity, which causes the formation of curly leaves, can be prevented by the hygroscopic action of the water-absorbing resin of the drying sheet of the present invention. When low temperatures and long rains continue due to abnormal weather, etc., the yellowing of leaf tobacco that is being dried does not progress due to the low temperature.
The blue color remains as it was when it was harvested, and combined with lack of dehydration, the leaves become dull blue. In particular, when the drying sheet of the present invention is used, the nighttime temperature during low temperatures and long rainy days is at least 1% lower than when it is not used.
The temperature rises by ~2°C, and along with the moisture absorption ability of the water-absorbing resin, it is possible to prevent the appearance of dull blue leaves. The heat retention at night is thought to be due to the heat accumulated in the drying sheet of the present invention during the day being released at night. By using the drying sheet of the present invention in combination with the light-shielding curtain normally used in drying greenhouses, it can cope with a wider range of weather conditions and prevent the formation of rapidly dry leaves, stuffy leaves, curly leaves, and dull blue leaves. You will be able to do this. (Example) To further explain the drawings showing one embodiment of the drying sheet of the present invention, FIG. 4 is a partial sectional view of the drying sheet of the present invention, and 1 in the figure is a Drying sheet, 2 is an outer film, 3 is an inner film, 4 is a water-absorbing resin, 5 is a fungicide,
6 is cellulose pulp, 7 is outer film 2
It is a thermal adhesive fiber for bonding the inner film 3 and the inner film 3. The specifications of each member of the drying sheet 1 of the present invention having the above structure are as follows for each example. Example 1 Outer film Material Non-woven fabric Dovesheet T {manufactured by Honshu Paper Co., Ltd.} Moisture permeability 7000g/m ²・24hr Air permeability 21000ml/min.・cm ²・100mmH ₂ O Dyeing Blackened by spraying 3% acid black solution with a spray gun staining. Inner film Material Non-woven fabric Palcross PFT-68 {manufactured by Honshu Paper Co., Ltd.} Moisture permeability 9500g/m ²・24hr Air permeability 35000ml/min.・cm ²・100mmH ₂ O Water-absorbing resin and retention method Sumikagel S-50 {Sumitomo Chemical manufactured by Kogyo Co., Ltd. 50g per ^1m2 . Adhesive Celogen BSH-10 {manufactured by Daiichi Kogyo Seiyaku Co., Ltd.} 1
% aqueous solution evenly applied to the inner film. Adhesives are used as a fungicide.
1% of TBZ-FL25 {manufactured by San-Ai Oil Co., Ltd.} was mixed. Holding the sheets on both sides They were adhered at 1m intervals using double-sided tape. Visible light transmittance 10% Area 55m ² Moisture absorption characteristics As shown in Figure 2 at a temperature of 25°C and a relative humidity of 95%. Moisture release characteristics As shown in Figure 3 at a temperature of 35°C and a relative humidity of 50%. Example 2 Outer film Material Non-woven fabric Subanbond Moisture permeability 6500g/m ²・24hr Dyeing Dyeed black with a 2% nigrosine aqueous solution. Inner film Material Non-woven fabric Subanbond Moisture permeability 11000g/m ²・24hr Water-absorbing resin and retention method Sumikagel N-100
{Manufactured by Sumitomo Chemical Co., Ltd.} 50g per ^1m2 .
On the inner film, a dry defibrated cellulose bulb, a heat-adhesive fiber SWP {manufactured by Mitsui Petrochemicals Co., Ltd.}, a water-absorbing resin and a fungicide Cyaisol 400 {manufactured by San-Ai Oil Co., Ltd.} are mixed. Then, an outer film was laminated on top of the outer film, and after air was suctioned from the bottom, the film was heated in an oven and pressed to bond the films on both sides. Visible light transmittance: 15% Next, an explanation will be given with reference to FIG. 1 showing one mode of use of the drying sheet 1 of the present invention. 10 is a synthetic resin vinyl film that covers the outside of the house pipe 9; 11 is a removable light-shielding curtain that covers the ceiling of the synthetic resin vinyl film 10; 12 is a drying house 8; The drying sheet 1 of the present invention is attached to the inner frame 12 for hanging the leaf tobacco 13 provided therein.
is hung so as to surround the hung leaf tobacco 13. 14 is a hanging tool for hanging the leaf tobacco 13. Experimental Example A drying house 8 with an area of 22.5 m ² was covered with a synthetic resin vinyl (matte) film 10, and the outside thereof was covered with a light-shielding curtain (90% light-shielding rate) 11. The drying sheet 1 of the present invention of Example 1 was hung on the inner frame 12.
In addition, a conventional light-shielding curtain having the same transmittance as the drying sheet 1 of the present invention was hung over the inner frame, and the other conditions were the same as those of the present invention plot to provide a control plot. In both the invention plot and the control plot, 560 Burley tobacco plants (with 11 leaves) harvested by cutting the stems were hung as they were on August 5th without being subjected to "rough draining" treatment in advance. Drying management consisted of the minimum level of management of opening and closing the hem and gable once in the morning and evening for the inventive plot and the control plot, and the ceiling light-shielding curtain 1 on the second day if the rainy weather continued for two days.
Drying was allowed to proceed until the end of drying without performing any steps other than removing step 1. On a sunny day on the 8th day after the start of drying (progress of leaf tobacco drying is 30% browning) and on a cloudy rainy day on the 10th day after the start of drying (progress of leaf tobacco drying is 50% browning), inside the drying house during the day. Figures 5 and 6 show the results of investigating changes in relative humidity. As is clear from Figure 5, the control area has relative humidity
About 3 hours passed from before 2:00 pm to after 4:00 pm under low humidity conditions of 70% or less, whereas in the invention area, the relative humidity during the day was higher than the control area, and the humidity conditions did not reach 70% or less. Ta. This shows that the drying sheet of the present invention is useful for preventing the formation of rapidly drying leaves.
Furthermore, as is clear from Figure 6, even though it was a cloudy and rainy day and it rained from 10:00 to 11:00, the present invention area was much more stable than the control area throughout the day due to moisture absorption of the water-absorbing resin after 1:00 p.m. The humidity was low. This shows that the drying sheet of the present invention is useful for preventing the formation of stuffy leaves and comb leaves. In addition, Figures 7 and 8 show the results of investigating changes in nighttime temperature and relative humidity on the 16th day after the start of drying (the progress of leaf tobacco drying is 90% browning). As is clear from FIG. 7, the inventive plot accumulates heat during the day and releases the heat at night, so the night temperature is 1 to 2° C. higher than in the control plot. Furthermore, as is clear from FIG. 8, the relative humidity can be lowered at night than in the control area due to moisture absorption by the water-absorbing resin. Due to its heat retention and moisture absorption effects at night,
Under long-term low temperature and high humidity conditions, it is possible to prevent dull blue leaves that occur due to low night temperatures and delayed dehydration. Leaf tobacco drying was completed on August 30th for the invention plot and September 2nd for the control plot, and the drying was completed at 36 kg and 35.2 kg, respectively.
Got Kg. The results of the quality investigation of the dry leaves are shown in Table 1.

[Table] As is clear from Table 1, no production of leaves with reduced quality was observed in the plots of the present invention. (Effects) As described above, by using the drying sheet of the present invention for drying brown leaf tobacco, it is possible to prevent the production of leaves with poor quality such as rapidly dry leaves, stuffy leaves, combed leaves, and dull blue leaves. . Drying management operations such as opening and closing the hem and end portions and attaching and detaching the light-shielding curtain during the drying period, which were conventionally frequent, can be kept to a minimum, making it extremely labor-saving.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing one mode of use of the drying sheet of the present invention, and FIG. 2 is a graph showing the moisture absorption characteristics of an example of the drying sheet of the present invention at a temperature of 25° C. and a relative humidity of 95%. Figure 3 also shows the temperature at 35℃,
A graph showing the moisture release characteristics at a relative humidity of 50%, FIG. 4 is a partial cross-sectional view showing the cross-sectional structure of an example of the drying sheet of the present invention, and FIG. Figure 6 is a graph showing the change in the relative humidity inside the drying house during the day on a sunny day when drying. Figure 6 is a graph showing the change in relative humidity inside the drying house during the day on a cloudy and rainy day. Figure 7 is the same. FIG. 8 is a graph showing changes in the temperature inside the drying house at night, and FIG. 8 is a graph showing changes in relative humidity inside the drying house at night. 1...Drying sheet, 2...Outer film, 3
...Inner film, 4...Water absorbent resin.

Claims (1)

[Claims] 1. A moisture permeable film with a moisture permeability of 1000 g/m ^2.24 hr or more is the outer film, a moisture permeable film with a moisture permeability of 100 g/m ^2.24 hr or more than the outer film is the inner film, and the space between the outer film and the inner film is A sheet for drying brown leaf tobacco, which retains a water-absorbing resin and has an overall visible light transmittance of 5 to 50%.