JPH0131846B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a new paper for raising seedlings that facilitates the growth of roots of crops, and a pot for raising seedlings using this paper for raising seedlings. Conventionally, when manufacturing bottomless pots for raising seedlings such as paper tube aggregates, when paper is made from natural fibers, a predetermined amount of synthetic fibers, preservatives, etc. are mixed in to make a strong paper like kraft paper. It usually provides the moisture strength and rot resistance necessary for seedling raising. Recently, a porous, rot-resistant, wet-strength resin fiber nonwoven fabric is pasted on one or both sides of kraft paper to form a base paper.
It has been proposed to manufacture assembled paper tubes using this base paper. However, with kraft paper mixed with synthetic fibers, for example, in order to obtain the necessary wet strength of the pot body at the end of seedling raising, it is necessary to mix 15 to 25% of synthetic fibers into the kraft paper. After that, the roots of the plants are planted in the main field in their pots.
The wood pulp fibers remaining in the mesh-like pores of the synthetic fibers become an obstacle and inhibit root elongation. For this reason, in Chinese cabbage, Chinese orchid, etc., which have weak rooting ability, the growth after planting in the main field is delayed and the effectiveness of seedling transplantation is reduced. Therefore, in many cases, it is unavoidable to remove the paper pot body to form bare block seedlings at the time of planting in the main field, which not only results in a loss of labor, but also causes the soil blocks of the seedlings to collapse due to the removal of the paper pot. However, there were disadvantages such as the fact that the effect of raising seedlings using cut-cornered seedling pots was often lost. On the other hand, when creating seedling pots using seedling paper made of kraft paper with porous rot-resistant non-woven fabric, the porous areas of the non-woven fabric should be filled with rot-resistant material after the seedlings have been raised and planted in the main field. There are no debris left and the roots of the plants are not hindered in their growth, but a step is required to prepare seedling paper in advance. When laminating by heating, etc., the nonwoven fabric often wrinkles and the lamination is not uniform, and the kraft paper and the nonwoven fabric may be misaligned or cut, so they must be handled extremely carefully. As a result, the efficiency of the bonding work is poor. Furthermore, in order to improve the rooting ability of seedlings, the thinner the non-woven fabric is, the better, but the production limit for non-woven fabric is about 15g/ ^m2 , and the thinner it is, the more difficult it is to adhere to the kraft paper. The disadvantage is that work efficiency also deteriorates. As mentioned above, seedlings are grown in a collective pot made of a paper-like thin film and a large number of square or hexagonal prism-shaped bottomless pots glued together with water-soluble glue, and when transplanted, the seedlings are separated into individual paper pots and placed in pots. The method of planting seedlings in the main field is generally used as a labor-saving method for raising and transplanting seedlings, but the seedling paper that makes up the pot body is used to hold the roots of seedlings grown in the pot in the main field with the pot body attached. However, the reality is that the quality has not yet reached a level that satisfies the needs for full growth and very good growth. As a result of various studies in order to eliminate these drawbacks, the inventor found that the upper surface of paper made with natural fibers, such as kraft paper, was coated with rot-resistant synthetic fibers such as polypropylene, polyethylene, vinylon, etc. A small amount of fiber is uniformly dispersed and then integrated by adhesive or heat bonding to form a base paper, a square or hexagonal columnar pot body is formed from this base paper, and a large number of pot bodies are coated with water-soluble glue. The pot body is made of base paper made of kraft paper with rot-resistant synthetic fibers evenly distributed and glued together to form a paper tube assembly.
When the plant seedlings are grown for a specified period of time and then transplanted, they form a pot with extremely good moisture strength, and when transplanted directly to the main field, the roots of the seedlings naturally grow directly between the synthetic fibers of the pot. This invention was completed by discovering that The explanation will be given below based on the drawings. FIG. 1 is a schematic diagram of the manufacturing process of the seedling raising paper manufactured according to the present invention, in which 1 is paper made from natural fibers such as kraft paper, which is sequentially pulled out from one end of a roll. 2 is a hopper, 3 is a synthetic fiber, the hopper 2 is provided above the paper 1 that is successively pulled out, and inside is one or two types of rot-resistant synthetic fibers 3 such as vinylon, polyethylene, polypropylene, etc. I have stored more than that. The synthetic fiber in Hopper 2 usually has a thickness of around 3 denier and is 15 to 60 mm.
It has a certain length. Synthetic fibers that are too short cannot be used because they lack wet strength, and synthetic fibers that are too long impair workability, so synthetic fibers of around 30 mm are preferred. Reference numeral 4 denotes a fiber feeding roller provided at the bottom of the hopper 2 with needles planted on its surface.The rotational speed of this feeding roller 4 is linked to the transfer speed of the kraft paper 1, and the feeding amount can be adjusted by adjusting the rotational speed. An amount of usually 20 g/m ² or less, preferably 3 to 15 g/m ² is evenly dispensed and laminated on the kraft paper 1. When the synthetic fibers 3 are intertwined with each other, they are fed out to form a dispersion band 3' with a uniform thickness. The kraft paper 1 on which the dispersion zone 3' is placed moves and reaches between the heating rollers 5 and 5', but since the heating rollers 5 and 5' are heated to about 100 to 200°C,
The synthetic fiber 3 placed on the top surface of the paper 1 is pinched and pressed, and the paper 1 is
The synthetic fibers 3 are laminated all at once on top, and the whole is wound up by a winder 6 to form seedling raising paper. The above description describes the method of thermal adhesion, but the heating rollers 5 and 5' are used as rollers that only apply pressure, and a water-resistant adhesive is applied to the surface of the paper 1 in advance before the pressure roller. Synthetic fiber 3
The seedling growing paper of the present invention can also be produced by placing a homogeneously dispersed band 3' on the paper, pressing it with a pressure roller, and winding it up. As shown in Figure 2, the seedling-raising paper obtained in this way has a layer 3'' of synthetic fibers 3 bonded to the top surface of the paper 1, making it an integral part. It has excellent wet tensile strength, and an example of this will now be explained using an experimental example.In the experiment, 3 denier thick polypropylene fibers cut into 30 mm pieces were fused to 60 g/ ^m2 kraft paper in various proportions. , the amount of synthetic fiber and wet tensile strength were tested.The results are shown in Table 1.However,
Wet tensile strength is the result of testing a 6 cm wide piece buried in the soil for 2 weeks and folded into 4 pieces.

[Table] That is, the wet tensile strength increases with the amount of synthetic fiber, but if the amount is less than 3 g/m ² , the strength of the paper is insufficient, and it is practically impossible to uniformly disperse such a small amount. Moreover, even if it exceeds 20 g/m ² , the strength will be more than necessary, which is not practical. When manufacturing a seedling-raising container using the above-mentioned seedling-raising paper, the layer 3'' of the synthetic fibers 3 itself is either fused to each other or glued together with glue, so the seedling-raising paper is cut into a predetermined width. Cut the pieces, stack the cut pieces so that the layer 3'' is inside each other, and heat-seal the two sides or glue them with water-resistant glue to form a hexagonal, square, etc. pot body (see Figure 3). do. Such pot bodies may be used alone or may be bonded together with water-soluble glue to form a collective pot body. In addition, when manufacturing the collective pot bodies, the outside of each pot body may be subjected to antiseptic treatment, root entanglement treatment, etc. as appropriate. When seedlings are filled with soil in seedling pots manufactured in this way and planted in the main field after seedlings are raised, the roots of the seedlings are free to move through the interstitial pores of the highly porous synthetic fiber layer 3, just as in natural conditions. Table 2 shows the root elongation properties depending on the amount of synthetic fiber 3 used in Table 1.As a control, 18% vinylon was mixed with conventional wood pulp. The elongation of seedlings in seedling pots using synthetic fiber paper is also described.

[Table] As is clear from the above table, the rooting index of paper bonded with 30 g/m ² of synthetic fibers and vinylon mixed paper is extremely poor. The seedling raising paper obtained by this invention has sufficient tensile strength when wet while creating an ultra-thin synthetic fiber layer of 20 g/m ² or less on the paper, which is impossible to produce using ordinary nonwoven fabric manufacturing technology. The following is shown in Table 1. As a result, the fifth seedling block when transplanting after raising seedlings.
In Figure d, the pot body is held with a certain strength;
There is no possibility that the layer 3'' of the synthetic fibers 3 will shift and the block will collapse.As described above, the seedling raising paper according to the present invention has high wet strength and good root elongation, and moreover, the amount of synthetic fiber used is low. Not only has it become possible to achieve savings that would not be possible with conventional methods, but it has also become possible to reduce
In the method of laminating paper to paper during subsequent processing, the nonwoven fabric has extremely poor rigidity, so the working speed is within about 10 m/min, and the nonwoven fabric layer is prone to wrinkles, the quality is poor, and it is extremely uneconomical. In comparison, in this invention, the bonding process of the paper layer 1 and the synthetic fiber layer 3'' can be carried out at a speed of 300 m/min, which is a remarkable improvement.This outer synthetic fiber layer 3'' is free from wrinkles. There is no risk of product deterioration resulting in non-uniformity of the product. These seedling raising papers of the present invention utilize paper that has sufficient tensile strength, and induce a homogeneously distributed band 3' of ultra-thin synthetic fibers on the paper surface, which would otherwise be impossible to withstand pulling out. At the stage where the synthetic fibers are pressed with glue or heated by rollers 5 and 5', the synthetic fibers are pinched and pressed all at once without forming a fabric, so the entire fabric is corrected without wrinkles. At that moment, the synthetic fibers are also fused or glued together to form an ultra-thin film with the necessary wet strength, and when bonded to paper, it has the same rigidity as paper. It is possible to form a collective pot body, and is also suitable for later seedling raising operations. As described above, the present invention makes it possible to obtain an ultra-thin synthetic fiber thin film that allows roots to extend extremely well at the lowest economical limit, and also to obtain the necessary and sufficient wet tensile strength, thereby reducing the unit price. It is particularly effective for raising and transplanting cheap crop seedlings using paper tube aggregates, and the benefits in terms of productivity are enormous. This will be explained below using examples. Example 1 A piece of 60 g/ ^m2 kraft paper with a width of 60 cm and a length of 2500 m was pulled out from one end of the roll and connected to the outlet of a hopper containing a mixture of equal amounts of 3 denier 30 mm polypropylene fibers and polyethylene fibers as synthetic fibers. A homogeneous dispersion band of fibers at a rate of 8 g/m ² is guided from the fed-out roll 4, placed on the surface of the paper, and then passed between rollers 5 and 5' heated to 160°C to melt the whole. The winding was carried out with the entire machine running at a speed of 150 m/min.
The resulting seedling paper made of paper and synthetic fibers is extremely suitable for making seedling pots, and has a diameter of 5 cm and a height of 5 cm.
A hexagonal paper cylinder with no lid and bottom (see Figure 3) was made, and then a total of 60 cluster pots, 6 rows horizontally and 10 rows vertically, were made with water-soluble glue. The collective pot was filled with soil, and seeds of Citrus orchid were sown, and the seedlings were raised in a hot bed for 35 days, and then planted in the main field. During transplantation, separating the seedlings from the collective pot into individual seedlings was extremely easy because there was almost no penetration of roots from the sides. Furthermore, the rooting ability from the side wall of the pot after planting was extremely good, with 15 roots growing on the third day and 32 roots growing on the fifth day. Target vinylon fiber 18%
When we raised seedlings in the same manner as above in pots made from synthetic fiber paper made by mixing them with pulp, we found that with synthetic fiber paper, no roots formed on the 3rd day, 3 on the 5th day, and 12 on the 7th day. Compared to books, the seedling raising paper of the present invention showed an overwhelming advantage, and the subsequent growth was also extremely good. Example 2 Using the same method as in 1), synthetic fibers were mixed fibers of vinylon and polypropylene each with a length of 3 denier and 25 mm.
Using a 50% paper, instead of heat fusing, apply a 12% aqueous solution of PVA117 (trade name) on the surface of the kraft paper in advance, then place the homogeneously dispersed band 3' of the above synthetic fiber on it and use rollers 5 and 5'. After being lightly pressed, it was dried and rolled up to complete the seedling raising paper of the present invention. Using this paper for raising seedlings, we made a grouping pot similar to that in Example 1, and tested the raising and transplanting of C. orchid in the same manner as in Example 1, and found that the seedlings in the paper tube pots used in the product of the present invention were suitable for handling. After planting in the main field, the rooting ability of the canola from the side wall surface was extremely good.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of a device for attaching synthetic fibers, Figure 2 is a partial side sectional view of the seedling raising paper of the present invention, and Figures 3b and a show examples of pots made with the seedling raising paper of the present invention. FIG. 4 is a perspective view of the collective pot shown in FIG. 3b, and FIG. 5 is a perspective view of the pot at the time of transplantation. 1...Paper, 3...Synthetic fiber, 4...Feeding roll, 5,
5'...Heating roller.

Claims (1)

[Claims] 1 Synthetic fibers having a thickness of about 3 denier and a length of about 15 to 60 mm are evenly distributed and bonded in the range of 3 to 20 g/m ² on the upper surface of paper made of natural fibers. A paper for raising seedlings that is integrated into one. 2 Plant seedling paper made by gluing synthetic fibers of around 3 denier thickness and 15 to 60 mm length evenly in the range of 3 to 20 g/m ² to the upper surface of paper made of natural fibers, and cut into a specified size. A pot for raising seedlings, which is made by cutting the cut pieces, stacking the cut pieces on top of each other, and heat-sealing both sides or gluing them with water-resistant glue to form an independent pot. 3 Plant seedling paper with synthetic fibers approximately 3 denier thick and 15 to 60 mm long adhered evenly in the range of 3 to 20 g/m ² to the upper surface of paper made of natural fibers, cut into a specified size. 1. A pot for raising seedlings, characterized in that the cut pieces are cut, overlapped and glued on both sides to form a pot, and a large number of the pot bodies are adhered with a water-soluble glue to form an aggregate.