JPS6359642B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing coated seeds. More specifically, the present invention provides a novel method for producing coated seeds in which seeds are coated one by one with a coating powder material. Coating the seeds makes them easier to handle and allows them to withstand long-term storage.Also, by mechanically sowing, it is possible to reduce the amount of seeds to be sown, shorten the sowing time, and reduce the labor required for thinning.
Since the spacing between the plants is kept evenly spaced, growth will be uniform, which can also be expected to have the advantage of uniformity in the shape and quality of the harvest, as well as less waste. In order to facilitate mechanical sowing, it is necessary to increase the bulk of the seeds by coating them with an inorganic substance. Traditionally, coated seeds have been produced using an aqueous solution of water-soluble binders such as starch, PVA, CMC, MC, HPC, and gelatin, diatomaceous earth, aluminum hydroxide, barium hydroxide, magnesium hydroxide, calcium sulfate, and basic carbonate. Magnesium, silica, calcium sulfite, calcium carbonate, calcium silicate, illite, hallosite,
A coating method is known in which powder materials such as microsite, vermiculite, peat moss, sand, and clay are applied alternately to the surface of seeds. That is, seeds are placed in a coating container, and while the coating container is rotated, an aqueous binder solution is applied to the surface of the seeds by a spray method or the like, and then a powder material is added to bond the powder and seeds. It is known that by repeating this operation, the surface of the seeds can be coated with powder material to a desired thickness. However, the commonly known coating container is just a single-piece container, and when seeds are coated using the method of the coating container, since the coating container is slanted, the flow of the seeds tends to be uneven, and the seeds are separated into individual grains. It is difficult to coat each seed separately, the volume efficiency of the charged seeds is small compared to the internal volume of the coating container, and the flow of seeds becomes extremely poor when the rotation speed of the coating container is increased. Particle size distribution tends to occur, productivity is low, and the coating layer is soft, causing problems such as cracking of the coating layer during mechanical seeding, automatic filling, and transportation. Furthermore, coated seeds must absorb moisture in the soil and disintegrate easily, which naturally limits the amount of water-soluble binder used. The inventors of the present invention focused on the above-mentioned drawbacks, and as a result of intensive research to invent a coating device that does not have any drawbacks, the inventors of the present invention found that the inoculum surface is smooth in a manufacturing method in which seeds are coated using a powder material and a water-soluble binder. Coating is a device that combines a rotary plate-like part and a fixed cylindrical container, and the seeds are coated with the powder material by intermittently or continuously spraying the seeds with a water-soluble binder while introducing the powder material. Due to the seed manufacturing method, the particle size distribution is small,
The present invention was achieved based on the discovery that seeds having high productivity, appropriate hardness, and excellent disintegration in water, coated one by one, can be easily produced. A coating device used in the present invention and a coating method using the coating device will be described. As shown in FIG. 1, the coating device of the present invention, when seeds are placed in a rotary dish-shaped portion 1 with a smooth inocula surface and 1 is rotated at high speed, the coating device of the present invention smoothes the flow state of the seeds and prevents the seeds from falling. A spray gun 8 is equipped with a fixed cylindrical container 2 to prevent it from flying out due to centrifugal force.
While intermittently or continuously spraying the water-soluble binder onto the seeds, the powder material is intermittently or continuously fed from the powder material feeder 9, coating the surface of each seed with the powder material. This is the way to do it. The structure of the rotary plate-shaped part 1 having a smooth inoculator surface is preferably as shown in, for example, a flat plate (FIG. 2) and a plate having a gently curved structure at the tip (FIG. 3). It is not particularly limited. The rotational speed of the rotating plate-shaped part 1 with a smooth inoculator surface should naturally be selected to an optimal value depending on the size of the device, the amount of seeds purchased, the shape and size of the seeds, etc., but in general is less than 300r.pm,
Preferably 150 to 250 rpm. The rotational speed can be adjusted by means of a variable speed electric motor 3 or a suitable transmission. Further, the rotary plate-shaped portion 1 having a smooth inoculator surface is configured to be detachable from the drive shaft 4 of the variable speed electric motor 3. As mentioned above, it is necessary to select and use the shape of the rotary plate-shaped part 1 with a smooth inoculator surface depending on the amount of seeds to be prepared, the shape and size of the seeds, etc. In other words, when coating flat seeds such as lettuce and carrots one by one, using the rotary plate-shaped portion 1 shown in Fig. 3 allows the seeds to flow smoothly, thereby improving the particle size distribution of the product. This will ensure that each seed is coated one by one. The coating is coated for a certain period of time by the coating device shown in FIG. 1, and once it has reached a predetermined size, it can be taken out from a chute 6 into a saucer 7 via a damper 5 on the side wall of the fixed cylindrical container 2. The chute 6 can be provided on the side wall of the bottom of the fixed cylindrical container 2 as shown in FIG. 1, or it can be taken out from above as an overflow type when coating is to be carried out in continuous operation. The present invention is a method for producing coated seeds using a coating device having the structure as described above,
FIG. 4 shows the coating device in a stopped state, and the height of the effective volume H entering the fixed cylindrical container 2 is a value that increases as the seeds are coated. Further, FIG. 5 shows the state in which the coating device is in operation, in which the seeds rotate uniformly forming a vortex like a twisted "nawa" in the fixed cylindrical container 2, and the water-soluble binder Since the powder material is uniformly applied to the surface of each seed, local aggregation does not occur, so the particle size distribution of the coated seeds becomes narrower, and the coating container of the same diameter that is normally used can be used. compared to
Volumetric efficiency can be increased by 1.5 to 3 times. Furthermore, the feature of the present invention is that, as mentioned above, the water-soluble binder is applied to the powder surface, which makes the bond between the powder particles and between the seeds of the granules uniform, and because there are no local bond defects, the hardness is improved as a whole. The point is that highly coated seeds can be produced. The coated seeds produced by the method of the present invention have a coating layer that is easily destroyed by moisture in the soil during sowing, and does not affect germination and growth in any way compared to when regular uncoated seeds are sown. It was previously unknown that so many properties could be improved at the same time, and is truly surprising. The powder materials for coating used in the present invention are those commonly used as described above and are not particularly limited, but the average particle diameter thereof is preferably 10 μm or less, preferably 1 μm or less. The water-soluble binder used in the present invention is also commonly used, and the amount added can be from 0.1 to 20% by weight, but preferably from 0.5 to 5% by weight, based on the powder material for coating. Good. Examples will be shown below to further clarify the present invention, but these are merely illustrative and the present invention is not limited thereto. Example 1 500 g of Chinese cabbage seeds were grown using the coating device shown in FIG. 1, which has a smooth inoculum surface and a rotary plate of 200 mm diameter and the structure shown in FIG. 2, and a commonly used 200 mm diameter coating container. Coating was carried out until the average particle size of the particles was 3.0 mmφ. The powder material is 3500g of diatomaceous earth with an average particle size of 5μ.
On the other hand, the binder used was a 2% by weight aqueous solution of CMC (Celogen 6A Daiichi Kogyo Seiyaku) 1500 c.c. The results obtained are shown in Table 1.

[Table] Example 2 Carrot seeds were coated using the coating device shown in FIG. 1, which had a rotary plate-like part with a smooth inoculum surface of 200 mmφ and the structure shown in FIG. 3, and a commonly used 200 mmφ coating container. 200g was charged and coating was performed until the average particle size was 3.5mm. In addition,
The powder material used was 2500 g of diatomaceous earth with an average particle size of 5 μm, and the binder used was 1200 c.c. of a 2% by weight aqueous solution of CMC (Celogen 6A Daiichi Kogyo Seiyaku). The results obtained are shown in Table 2.

【table】

[Table] There it was.
** Sheare test method, 100 grains x 4 series, 20
~25℃ (bare seeds: 81%)

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the coating device of the present invention;
FIGS. 2 and 3 are cross-sectional views showing the structure of the rotary dish-shaped portion, and FIGS. 4 and 5 are cross-sectional views for explaining the coating state of seeds according to the present invention. 1... Rotating dish-shaped part, 2... Fixed cylindrical container, 3...
... variable speed electric motor, 4 ... drive shaft, 5 ... damper, 6 ... chute, 7 ... saucer, 8 ... spray gun, 9 ... powder material feeder.

Claims (1)

[Claims] 1. In a manufacturing method in which seeds are coated with a powder material and a water-soluble binder, a device that combines a rotating plate-like part with a smooth inoculator surface and a fixed cylindrical container,
A method for producing coated seeds, which comprises coating the seeds with the powder material by introducing a powder material while spraying the seeds with a water-soluble binder intermittently or continuously.