JP2000000032A - Biodegradable nursery container and molding of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nursery container set at least a part of the container body to rapidly biodegrade after transplantation to soil allowing not disturbing the growth of a nursery root. SOLUTION: The container molded from a material comprising paper fiber incorporated with starch and polyvinyl alcohol, has thin parts of 0.05 to 0.50 mm thickness made on the side wall 2 and the bottom 3 of the container body 1 at the ratio of 5 to 30% of the surface area to the surface of the container body 1 setting the container to easily collapse by biodegradation in the soil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method of growing seedlings of trees, horticultural plants, vegetables, and the like, which have been sown and germinated, and displaying them as commodities. TECHNICAL FIELD The present invention relates to a biodegradable seedling raising container that does not hinder root growth and a technique for forming the same.

[0002]

2. Description of the Related Art A conventional seedling raising container has a wall thickness of 0.2.
~ 0.4mm vinyl sheet thermoformed into a bowl shape,
A so-called polypot was used. Although this seedling raising container has advantages such as easy production, easy handling, and low cost, it is not biodegradable when transplanted to soil as it is, so it remains in the soil. And hinder the growth of seedlings.

Therefore, when transplanting the grown seedlings to the soil, it is necessary to remove the seedling container from the seedlings and transplant only the seedlings. In the case of a large amount, the removal work requires a great deal of labor. In addition, there is a problem that the root of the seedling is easily damaged during the removing operation. In addition, there was a problem in terms of disposal of the removed nursery containers related to the generation of dioxin.

In order to solve such a problem, a material easily decomposed by soil microorganisms, that is, an aliphatic polyester or lactic acid-based plastic having biodegradability is used, and this material is injection-molded to form a seedling raising container. So that the growth of the seedlings is not hindered,
A seedling container having a plurality of rectangular holes has been proposed (for example, see Japanese Patent Application Laid-Open No. 8-98628).

[0005] Also, a so-called coconut powder 4 which is a fiber dry powder material produced from mesocarp of coconut shell which is easily biodegradable.
A seedling made of a biodegradable plastic mixed with coconut shell fiber produced by vacuum forming a sheet formed by kneading a material formed by mixing 0% by weight with a biodegradable plastic such as aliphatic polyester. Containers have also been proposed (eg, Plastic Age 43, 1997, April)
Monthly, see page 159).

[0006]

The conventional seedling raising container has the following problems.

[0007] In the case of a seedling container made of a biodegradable aliphatic polyester or lactic acid-based plastic, a period of several months is required to disintegrate in soil, so that the growth of the seedling root during that period is not hindered. To
It is necessary to provide a plurality of rectangular holes. And, the size of this hole is more effective as it is larger from the viewpoint of promoting the growth of seedlings, but on the other hand, it becomes difficult to maintain the shape of the container itself as a factor that reduces the strength of the container for raising seedlings. There was a problem. Furthermore, during the raising of seedlings, there is a problem that the soil in the container easily flows out due to irrigation or movement, and the roots are easily exposed from the holes, thereby damaging the roots.

[0008] In the case of a seedling container made of biodegradable plastic mixed with coconut shell fiber, it takes three weeks to start disintegration in the soil even if the thickness is 80 µm. There is a problem that it is not preferable to keep the seedlings in the container for three weeks from the viewpoint of the growth of the seedlings. If the thickness is reduced to shorten the collapse in the soil, the strength becomes weak, and the seedlings are raised. There were also problems such as damaging the roots.

[0009] Therefore, as compared with the conventional seedling raising container, the applicant has water resistance and strength enough to withstand irrigation and movement during the seedling raising period, and after transplanting to the soil together with the seedlings, rapidly collapses by biodegradation. As such a seedling raising container, a container formed by a molding material containing at least paper fiber and a water-soluble binder has been proposed.

[0010] The present invention provides a seedling raising container in which at least a part of the container body is easily broken down by biodegradation promptly after transplantation into soil, so that the growth of the seedling root is not hindered. It is intended to be.

[0011]

In order to solve the above problems, in the seedling raising container of the present invention, a container body is formed by using a biodegradable material containing paper fiber and a water-soluble binder. In addition, a thin wall portion which is easily broken by biodegradation is dispersed and formed on the side wall of the container body.

In this way, since the container itself is formed in a state where the paper fibers firmly bound by the binder are entangled with each other, the container has strength enough to withstand movement and the like.
Moreover, since it has a large number of pores and pores and is air-permeable and water-permeable, even if the container gets wet when watering the seedlings,
Water evaporates quickly from the surface and dries, and can exhibit water resistance that does not collapse by irrigation. Also,
The paper fiber and the water-soluble binder are easily softened by absorbing rainwater or moisture in the soil, and then are decomposed and disintegrated by bacteria and microorganisms in the soil. Since the thinned portion is easily broken down more quickly, the growth of the seedling is not hindered.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The biodegradable seedling raising container of the present invention is formed by dispersing a thin portion on a side wall portion of a container main body formed of a material containing at least a paper fiber and a water-soluble binder. It is.

Since the material containing the paper fiber and the water-soluble binder is water-absorbing and biodegradable, it absorbs rainwater and the like in the soil and becomes wet, causing bacteria and microorganisms to form. It is easier to breed and biodegraded faster. In addition, since the thin portions that are more easily broken and easily collapsed are formed dispersedly, the growth of the seedlings in the soil is not hindered. Further, since the container itself is formed in a state in which the paper fibers firmly bound by the binding material are entangled, it has strength enough to withstand movement during the seedling raising period, and has many pores and through holes. Even if the container gets wet when watering the seedlings, the water is quickly evaporated and dried from the surface of the container, and the water resistance that does not collapse by watering can be exhibited. The strength, water resistance, and disintegration that the seedling raising container should have depends on the type of seedling to be raised, but when used for raising seedlings in general, the strength and water resistance must be at least about one month during the seedling raising period. It is preferable to keep it, and to disintegrate within at least about one month after transplantation.

In order to grow the seedlings uniformly around the thin roots, it is effective to disperse the thin roots symmetrically with respect to the central axis of the container body. The shape should be substantially rectangular from the bottom of the container body to the upper side of the side wall, which is effective for uniform growth from thin roots to thick roots.

When the thin portion is present on the inner surface side of the container body and a concave portion is present on the outer surface, it is effective in maintaining strength and water resistance during the seedling raising period and disintegration after transplantation. Become That is, since the inner surface of the container body is smooth, during the seedling raising period, stress from the inside generated when the culture soil is packed in the container body or when watering is performed, does not concentrate on the thin portion, This is advantageous in terms of maintaining strength. In addition, after transplanting in soil, the surface area is increased due to the presence of the concave portion, so that it becomes susceptible to the action of bacteria and the like from the outside, and as a result, easily collapses.

On the other hand, if the thickness of the thin portion to be formed is too thick, it takes time for breakage and collapse in the soil, and if it is too thin, it collapses during seedling raising or loses the strength to withstand movement. During the required period, it has water resistance that can withstand irrigation and strength that can withstand movement, and after transplanting in soil together with seedlings, in order to be easily broken down by biodegradation,
0.05-0.50 mm, preferably 0.07-0.
A range of 30 mm is effective.

Further, the larger the area ratio of the thin portion, the more preferable it is that the growth of the seedlings in the soil is not hindered. However, if the size is too large, the container body will be weak in strength, so it is easy to damage the seedlings due to movement during seedling, etc.On the other hand, if it is too small, even if it collapses, some of the roots of the seedlings will be trapped in the seedling container. And hinder root growth. Therefore, in order to provide a certain degree of strength during the period required for raising seedlings and not to hinder the growth of roots after transplanting in soil, 5-30% of the surface area of the container body, preferably 10% ~ 20%
Range is effective.

Since the seedlings do not grow in the portion corresponding to the upper portion of the seedling growing container, it is not necessary to form a thin portion in this portion, and the strength of the container body is maintained, and the thin shoots and the thick seedlings are maintained. In order for the roots to effectively grow outside the container main body, the thin portion is preferably formed in a range from the bottom of the container main body and the lower end of the side wall portion to a height of 2/3 above.

Further, the biodegradable seedling raising container is made of paper fiber 60.
To 80 parts of a mixture of 20 to 40 parts of a water-soluble binder obtained by mixing starch with polyvinyl alcohol,
A molding material obtained by adding 0.5 to 1.5 parts of a non-alkali metal long-chain fatty acid salt to 100 parts of the mixture to which 150 to 150 parts has been added and heating the mixture to 140 to 200 ° C. Having a cavity in which the parting surfaces of the fixed mold and the movable mold are in close contact with each other, and a gap of 0.1 to 0.2 mm is formed between the parting surfaces;
The water vapor in the cavity is released and removed from the gap to dry and solidify the molding material. As the molding method, both the injection molding method and the compression molding method can be used.

[0021] The seedling container molded from the molding material blended as described above has water resistance to withstand irrigation during the seedling raising period, and strength not to damage the seedlings during movement and the like.
After transplanting together with the seedling into the soil, it is moistened by absorbing rainwater and the like, and germs and the like can be propagated and easily and quickly biodegraded to be broken down from the thin portion. Also, when filling the molding material, it is filled into a cavity that has been heated and closed, so that when the filling pressure is increased, the flowability of the molding material due to the large amount of water added causes the cavity to be filled. It is possible to reliably fill even a narrow portion forming a thin portion in the above. Furthermore, the water added to the molding material filled in the cavity is easily turned into water vapor due to the heating of the mold, and is quickly released and dissipated from the gap formed between the parting surfaces to dry and solidify. Therefore, the molding cycle can be shortened.

The seedling raising container is formed with a thin portion so as to be easily broken down in the soil by biodegradation so that the growth of the seedling root is not hindered. In the case, by reducing the amount of water added within the range of the mixing ratio of the molding material, the density of the container body is increased to relatively reduce water absorption, and sufficient strength and water resistance during the seedling raising period. Is preferably maintained. Also,
When used for seedlings that have a short seedling raising period, strength and water resistance during the seedling raising period are not necessary, so starch that is easily biodegradable as a water-soluble binder is added to promote disintegration in soil. It is preferable to use a material having a higher ratio and increase the amount of water to facilitate collapse of the thin portion.

Next, the embodiment will be specifically described.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described in detail with reference to FIG. 1 showing a top view of a seedling raising container and FIG. 2 showing a side view in which a main part of the seedling raising container is cut away.

1 and 2, reference numeral 1 denotes a container body,
2 is a side wall of the container body 1, 3 is a bottom part of the container body 1, 4
Is a circular pedestal formed on the bottom portion 3 and 5 is a thin portion formed on the side wall portion 2 of the container body 1. The thin portion 5 exists on the inner surface side of the side wall portion 2 of the container body 1, and the concave portion 7
Is formed so that the side wall 2 of the container body 1 is formed.
Container body 1 upward from a pedestal 4 corresponding to the lower end of
Are formed in a substantially rectangular shape up to a portion corresponding to a height of 2/3 of the height of the container body 1, and eight pieces are arranged symmetrically with respect to the center axis of the container body 1 and distributed at equal intervals. Reference numeral 6 denotes a thin portion formed on the bottom portion 3 of the container body 1. This thin part 6
Is formed on the inner surface side of the bottom portion 3 of the container body 1 and is formed so that the concave portion 7 exists on the front surface side, and the base 4 extends from the base 4 corresponding to the lower end of the side wall portion 2 of the container body 1 to the center of the bottom portion 3. It is formed in a substantially rectangular shape toward the portion, and four pieces are arranged at equal intervals so as to be continuous with the thin portion 5. 8
Is a drain hole formed in the bottom portion 3. Since the thin portion 5 and the thin portion 6 are provided on the inner surface side of the container body 1 by providing the recess 7 on the front surface side, the container body 1
Has a smooth inner surface.

As a material of the molding material for molding the container body 1, sliced powder, which is generated when assembling a milk pack, so-called paper powder, is used as paper fiber, and corn starch is used as a water-soluble binder [Oji Cornstarch Co., Ltd.] Corn Y] and polyvinyl alcohol [Gohsenol NM14 manufactured by Nippon Synthetic Chemical Industry Co., Ltd.] are used, and zinc stearate [Kishida Chemical Co., Ltd.] is used as a long-chain fatty acid salt of a non-alkali metal. . The long-chain fatty acid salt of the non-alkali metal functions as an internal lubricant.

Next, the preparation of the molding material will be described. In this example, a molding material for forming a seedling container having a high density and a low water absorption, and having sufficient strength is prepared so that the seedling can be used for a seedling requiring a long period of time for seedling raising. .

The material is paper fiber: starch: polyvinyl alcohol: water in a weight ratio of 7: 2.1: 0.9: 5.
And 1 part of zinc stearate is added to 100 parts of the mixture. At this mixing ratio, the ratio of the solid component / water is 10/5 and the amount of water is relatively small, so that the density of the seedling raising container is about 0.70 to 0.75 g / c.
m ³ , resulting in low water absorption and high strength.

In a so-called polyethylene bucket having an internal volume of about 20 liters, the above-mentioned paper fiber, starch, polyvinyl alcohol, water and zinc stearate were added in a total amount of 1 k.
g and then stirred and mixed. Then, the mixture was extruded by a co-rotating, twin-screw kneading extruder manufactured by BorgWana Co., Ltd., and then compressed to about 70 mm in diameter.
A tablet for molding weighing about 28 g was obtained. This twin-screw kneading extruder has a screw diameter of 28 mm, L / D32
The kneading conditions include a cylinder and die temperature of 7
The screw rotation speed is 200 rpm at 0 ° C.

Next, a seedling container having a shape as shown in FIGS. 1 and 2 was molded by a compression molding method using a molded tablet made of the molding material described above. In this seedling raising container, the upper inner diameter of the container body 1 is 98 mm, and the lower inner diameter is 80 mm.
mm, height 76 mm, internal volume of about 470 cm ³ , surface area of about 270 cm ² , side wall 2 and bottom 3
Has a thickness of 1.00 mm, and the thin portions 5 and 6 have a thickness of 0.0
3 mm (Comparative Example 1), 0.05 mm (Example 1), 0.
07 mm (Example 2), 0.10 mm (Example 3),
0.20 mm (Example 4), 0.30 mm (Example 5), 0.50 mm (Example 6), and 0.70 mm (Comparative Example 2) were produced, respectively. The eight thin portions 5 formed on the side wall portion 2 have a lower end in contact with the pedestal 4 and an upper end having 2/3 of the height of the container body 1, that is, 51 m.
The part corresponding to the height of m is formed with a width of 10 mm, and the length is 61 mm. The four thin portions 6 formed inside the pedestal 4 of the bottom portion 3 are:
It is formed with a width of 10 mm and a length of 14 mm.

Therefore, there are eight thin portions 5 having a width of 10 mm and a length of 61 mm, and thin portions 6 having a width of 10 mm and a length of 14 mm.
Are formed, the area of the thin portions 5 and 6 is about 54 cm ² , and the ratio is about the surface area of the container body 1, that is, about ² cm which is the area of the side wall 2 and the bottom 3.
It is about 20% for 70 cm ² .

The compression molding of the seedling raising container will be described. In addition, as an apparatus for compression-molding a nursery container,
Using a double-acting 50-ton compression press and a flash-type compression mold manufactured by Marushichi Tekkosho Co., Ltd., the excess supplied molding material is allowed to flow out of the parting surface, and the side wall of the container body 1 and The thickness of the bottom part and the thin part can be controlled accurately.

The molding tablet is charged and filled into the cavity of the mold, and the mold is closed. At the time when the filling of the molding tablet is completed, the parting surface is in close contact, but after the filling is completed, the water vapor generated by the water added to the molding tablet is released outside the mold. A gap of 0.2 mm is formed on the parting surface. The release of water vapor from this gap was completed 10 to 15 seconds after the filling was completed, and after 20 seconds, the mold was opened and the molded seedling raising container was taken out. The temperature of the mold was 195 ° C.
Set to.

The thin portions 5 and 6 can be formed by providing a convex portion having the same shape as the thin portion on the cavity wall surface of the mold. Seedlings having a thin portion as in Comparative Examples and Examples In order to form the container, first, a convex portion for forming a thin portion having a thickness of 0.03 mm is provided and molded, and then the convex portion is sequentially ground to reduce its height, thereby reducing the height to 0.05 mm. , 0.07 mm, 0.10 mm, 0.
20mm, 0.30mm, 0.50mm, 0.70mm
Each seedling raising container having a thin portion having a thickness of 5 mm was formed into a test container.

Table 1 shows the results of evaluating each of the seedling raising containers obtained as described above by the method described below.

To each of the seedling raising containers, 87 parts of horticultural soil [Super Garden 20 manufactured by Taiyo Shokusan Co., Ltd.], 10 parts of humus and 3 parts of cottonseed lees were added. About 400 cm ³ and placed in a vinyl house. Then, the irrigation was performed once a day, and the state of breakage of the thin portion at 1 month, 2 months, 3 months, and 6 months was examined to determine the state of breakage and collapse of the thin portion during the seedling raising period. In the case where the thin portion has not been damaged, that is, the case where it has water resistance and strength enough to withstand movement is indicated by a mark, and the thin portion has been partially damaged and the container body has been damaged. The state where the culture soil inside leaks out only by being lifted, that is, the state where it does not have the strength to withstand the movement, is indicated by a cross.

Each seedling container filled with the culture soil is embedded in the same culture soil as above. Then
Water was irrigated once a day, and the state of breakage of the thin-walled portion after 3, 7, 14, and 28 days was examined to determine the state of breakage and collapse of the thin-walled portion in the soil after transplantation. In addition, the case where the thin portion is not damaged, that is, the case where the growth of the seedling is hardly broken and the growth of the seedling is suppressed is indicated by an x mark, and the thin portion is damaged and collapsed, and the culture soil between the inside and the outside of the container is integrated. The state where the seedlings are transformed, that is, the case where the growth of the seedling roots is unrestricted and unhindered, is indicated by a mark.

[0038]

[Table 1]

In the case of Example 1, the thin part is preserved after one month of the seedling raising period, and part of the thin part starts to collapse after two months, and when lifted by hand, part of the culture soil falls off. 3 days after the transplantation, the decay had started, and it was difficult to distinguish the culture soil between the inside and the outside of the seedling raising container.

In the case of Example 2, the disintegration started after 3 months of the seedling raising period, and the disintegration started 7 days after transplantation. In the case of Example 3, the seedling raising period was 6 months. The disintegration started later, and the disintegration started 7 days after transplantation. In the case of Example 4, the seedling raising period was 6
Collapse started after one month, and the collapse started 14 days after transplantation. In the case of Example 5, the thin part was preserved even after 6 months from the seedling raising period.
Disintegration started in 4 days, and in the case of Example 6, the thin-walled portion was preserved even after 6 months from the nursery period, and disintegration started 28 days after transplantation. .

Therefore, although the state of collapse differs depending on the thickness of the thin portion, the seedling raising containers of Examples 1 and 2 are suitable for seedlings having a relatively short seedling raising period and a high growth rate, such as garden plants and vegetables. The seedling containers of Examples 5 and 6 are suitable for seedlings having a long seedling raising period and a low growth rate, such as trees.
The seedling raising containers of Examples 3 and 4 are suitable for the seedling raising period and the growth rate which are intermediate between the above.

On the other hand, in the case of Comparative Example 1, the thickness of the thin-walled portion was too thin, so that the culture soil inside spilled out after one month, and the seedling raising period could not be sufficiently maintained. I can't stand it. In addition, in the case of Comparative Example 2, since the collapse of the thin portion does not start even after 4 weeks from the transplantation, the container is not suitable for general purpose use as a seedling raising container that does not hinder the growth of roots. In addition, in the case of Comparative Example 2, the seedling raising container which does not form a thin portion (thickness of thin portion 1.
(Equivalent to 00 mm)
Since there was not much difference in the situation of collapse, it can be seen that the effect is not so large when the thin portion is thickened.

Next, the surface area of the container body 1, that is, the ratio of the area of the thin portions 5 and 6 to the area of the bottom portion 3 and the side wall portion 2 was examined as described below. is there.

Thickness 0.10 mm, width 10 mm, length 61
8 thin parts 5 mm, thickness 0.10mm, width 10m
m, four thin portions 6 each having a length of 14 mm are formed,
The ratio of the area of the thin portions 5 and 6 is about 20% with respect to the surface area of the container body 1, that is, the area of the side wall 2 and the bottom 3.
The study was conducted by changing the area ratio with reference to the case of the third embodiment.

Then, the width of the thin portions 5 and 6 is set to 15 mm
Example 7 where the area ratio was 30% and the width was 5
Example 8 in the case where the area ratio was 10% and the area ratio was 10%, and Example 9 in the case where the width was 5 mm and the length was almost halved and the area ratio was 5%, the width was 3 mm and the length was approximately Comparative Example 3 and Example 7 in which the area ratio was reduced to 3% by half.
In the central part between the thin parts 5, 5, a thickness of 0.10
Comparative Example 4 is a comparative example 4 in which eight thin portions of mm, width 5 mm, and length 32 mm are arranged and the area ratio is 35%, and Comparative Example 5 is a case of direct sowing. Example 9 and Comparative Example 3
In the above, the length of the thin portions 5 and 6 is set to approximately half, and the length of the thin portions 5 is set to 31 mm and the length of the thin portions 6 is set to 7
mm. In Comparative Example 4, the thin portions 5, 5
The upper end of the thin-walled portion disposed between them is aligned with the upper end of the thin-walled portion 5, that is, the position of の of the height of the container body 1.

In each of the seedling raising containers in Examples 3, 7 to 9 and Comparative Examples 3 and 4, horticultural soil [Taiyo Shokusan Co., Ltd.
Super Garden 20] was added to 87 parts, 10 parts of humus and 3 parts of cottonseed meal were added, and aged for about one month was filled as culture soil, soybeans were sown on July 1, and July 15th. The plant was transplanted to the same culture soil as above together with the seedling raising container. Watering is carried out every day during the seedling raising period, and every three days after transplantation. One month after seeding, one month after July, two months after August, three months after September, four months after October, and one month after five months
At the end of January, each growth situation was compared and examined. In addition,
In the case of Comparative Example 5, soybeans were sown directly on soil on July 1.

The growth status and the yield after transplantation were evaluated by comparing the case of Comparative Example 5 with that of the comparative example, and the growth status was judged to be inferior, and the growth was judged to be slightly inferior.た indicates that the growth was clearly delayed, and × indicates that the growth was clearly delayed, and the yield of Comparative Example 5 was 100%.

The molding material used for molding the container body 1 has a compounding composition having excellent water resistance and strength, so that the container body does not collapse during the seedling raising, but the thin portions 5 and 6 are not damaged. Depending on the area ratio, the strength is slightly insufficient, and there are some cases that require careful handling at the time of movement, etc., so that there is no problem on the strength, strength A, which is somewhat soft but practically usable is strength B, A material that is too soft to be practically used is designated as strength C.

[0049]

[Table 2]

From Table 2, the area ratio of the thin portions 5 and 6 is
In the case of Examples 3, 7 to 9, which are in the range of 5 to 30% of the surface area of the container body 1, the growth status and the yield of the seedlings, and the container body during the seedling raising period, as compared with Comparative Examples 3 and 4. It can be seen that 1 is excellent in water resistance, strength and the like. In addition, in the case of Examples 8 and 9, the growth condition and the yield are slightly inferior to those of Examples 3 and 7, but the area ratio of the thin portion is small, and the strength retention during the seedling raising period is low. Because it is excellent, it may be more preferable than the case of Example 7 depending on the purpose of use.
It can be seen that a range of 5 to 30% of the surface area of the container body is effective. In the case of Comparative Example 3, since the area ratio is small, the growth status and the yield are inferior to those of the Example, and in the case of Comparative Example 4, the area ratio is too large, and handling such as movement during seedling raising is easy. It turns out that there is a problem.

[0051]

The present invention is embodied in the form described above and has the following effects.

During the growing period, the seedlings have strength not to damage the roots due to movement, etc., and water resistance not to be destroyed by irrigation, etc. After transplantation, they are easily broken down by biodegradation and hinder the growth of the roots. No seedling containers can be provided.

[Brief description of the drawings]

FIG. 1 is a top view of a seedling raising container according to an embodiment of the present invention.

FIG. 2 is a side view in which a main part of the seedling raising container is cut away.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Container main body 2 Side wall part 3 Bottom part 5, 6 Thin part 7 Recess

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kosuke Yagi 1-3-7 Oinmachi, Moriguchi-shi, Osaka Daiho Kogyo Co., Ltd. (72) Inventor Masahiko Funaki 1-3-3 Oinmachi, Moriguchi-shi, Osaka No. 7 F-term in Taiho Kogyo Co., Ltd. (reference) 2B027 NB03 NC02 NC23 NC24 NC36 NC40 NC52 ND03 ND09 ND11 NE05 QC07 QC23 4L055 AG34 AG47 AG64 AH37 BF07 BF08 EA08 EA15 EA17 EA20 EA32 FA13 FA20 FA30 GA25

Claims (8)

[Claims] 1. A biodegradable seedling raising container formed by dispersing a thin portion on a side wall portion of a container body formed of a material containing at least a paper fiber and a water-soluble binder. 2. The biodegradable seedling raising container according to claim 1, wherein a thin portion having a concave portion is formed on an outer surface of the container body. 3. The thickness of the thin portion is 0.05 to 0.50 m
2. The biodegradable seedling raising container according to claim 1, wherein m is m. 4. The thickness of the thin portion is 0.07 to 0.30 m
2. The biodegradable seedling raising container according to claim 1, wherein m is m. 5. The biodegradable seedling raising container according to claim 1, wherein an area ratio of the thin portion is 5 to 30% of a surface area of the container body. 6. The biodegradable seedling raising container according to claim 1, wherein an area ratio of the thin portion is 10 to 20% of a surface area of the container body. 7. The biodegradable seedling raising container according to claim 1, wherein a thin-walled portion is formed at least in a range from a lower end of a side wall portion of the container body to a height of 2/3 upward. 8. A mixture of 60 to 80 parts of paper fiber and 20 to 40 parts of a water-soluble binder obtained by mixing starch with polyvinyl alcohol, and 100 parts of a mixture obtained by adding 40 to 150 parts of water, The long-chain fatty acid salt of the non-alkali metal is added to 0.1%.
5 to 1.5 parts of the molding material added and mixed,
Heated to 00 ° C., having a thin wall forming part, filling the cavity with the parting surfaces of the fixed mold and the movable mold in close contact with each other, and then 0.1 to 0.1 cm between the parting surfaces.
A method for forming a biodegradable seedling-growing container in which a gap of 0.2 mm is formed, and water vapor in the cavity is released and removed from the gap to dry and solidify the molding material.