JPS5935276B2 - Spraying equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for spraying a curable liquid material such as a foamable polyurethane stock solution, and particularly to a device suitable for continuous spraying.

The present inventor previously discovered a method for uniformly dispersing a foaming polyurethane stock solution and filed a separate patent application (Japanese Patent Application No.
3-26633). The present invention relates to improvements in this spraying method, and particularly to a spraying device suitable for continuous spraying. In the previous invention, the foaming polyurethane stock solution was sprayed intermittently or continuously using two rolls (spreading rolls) and two brush rolls in contact with the rolls, but when a continuous spraying method was used,
A need for further improvements arose. One of them is that if it takes time to spread the foaming polyurethane stock solution, the stock solution will start to foam, and it will be difficult to uniformly spread the foaming stock solution. Therefore, it is necessary to perform the spraying quickly so that the sprayed undiluted solution adheres to the object to be sprayed by the end of the cream time of the undiluted solution. The second problem is with the brush roll. A brush roll is a roll with a large number of filaments, such as metal wires, arranged in the radial direction, and is used to spread the stock solution attached to the filaments using centrifugal force. However, the undiluted solution that adheres to the streaks tends to not be completely scattered and remain in small amounts, and since the undiluted solution hardens in a relatively short period of time, the entire brush roll tends to be stuck to the resin, so it is difficult to spray. Time was limited and cleaning for reuse was difficult. Therefore, the present inventor shortened the time required for spraying,
In addition, we conducted research and study to create a roll for spraying that is unlikely to retain the undiluted solution or can be used for a long time even if it remains. As a result, the first problem was solved by rotating the spreading roll at a relatively high speed and immediately spreading the stock solution supplied to this roll, and the second problem was solved by using the spreading roll as a spray roll. The problem was solved by providing a thin fibrous layer on the surface. The gist of the present invention is to provide two spreading rolls that are arranged in parallel and rotate inward, and two rolling rolls that are in contact with each of the spreading rolls and that rotate at high speed in the same direction as the touching spreading rolls. In a device for dispersing a material to be spread into fine particles, the device comprises a spreading roll and a supply nozzle positioned above a gap between two spreading rolls and supplying the material to be spread to the spreading roll, in which the spreading roll rotates at a high speed; and a spreading device characterized in that the spreading roll is a roll having on its surface a relatively thin fibrous layer made of an aggregate of fibers having a large number of filaments in a direction other than the radial direction of the spreading roll. FIG. 1 shows a perspective view of the spraying device of the present invention.

In a device consisting of two spreading rolls 1, 2, two spreading rolls 3, 4, and a curable liquid supply nozzle 5, the curable liquid supplied from the nozzle 5 is directed inward (as indicated by the arrow). It passes through the gap between developing rolls 1 and 2, which rotate at high speed, and is spread onto the surface of these rolls.

The narrower the gap between the two spreading rolls 1 and 2, the thinner and more uniformly the spread will be made on the rolls. )
By reciprocating, the curable liquid material is spread more uniformly over the entire surface of the spreading roll.

This gap is usually less than 107 nm, especially 5 m77! The rotation speed of the developing rolls 1 and 2 is preferably at least 200 revolutions per minute or more, but especially 50 revolutions per minute or more.
0 rotation or more is suitable. Next, the curable liquid material on the surfaces of the spreading rolls 1 and 2 is stripped off by the spreading rolls 3 and 4 and dispersed into fine particles by centrifugal force.

The rotation direction of the scattering rolls 3 and 4 is the same direction as that of the contacting developing roll as shown by the arrow, and the spreading rolls 3 and 4 rotate inwardly with respect to each other. As a result, the curable liquid material is spread downward, and a portion of the curable liquid material sprayed from each of the spreading rolls 3 and 4 intersects with each other, achieving more uniform spreading. The spreading rolls 3 and 4 rotate at a speed of at least 500 revolutions per minute or more, preferably 1000 revolutions or more, and usually several thousand revolutions per minute in order to achieve the spreading by centrifugal force. One of the points of the present invention is to rotate the spreading rolls 1 and 2 at high speed as described above, and another point is related to the surface material of the spreading rolls 3 and 4.

In order to spread the hardening liquid adhered to the surface of the spreading roll using centrifugal force or to peel it off from the surface of the spreading roll,
It is more effective if the surface of the scattering roll has fine irregularities.
However, when a brush roll is used as described above, the curable liquid that adheres to the brush roll and remains hardens, gradually filling the spaces between the brush lines and fixing the entire brush roll. In particular, there is a tendency for the curable liquid substance to remain from the portion near the core of the brush roll, and a brush roll having long filaments is disadvantageous. So I used a brush roll with short bristles and it had some effect. For example, it has been found that a brush roll with a bristly length of 1 cm or less can be used. However, upon further investigation, it was discovered that the curable liquid material can be sprayed even if the spray roll is not necessarily a brush roll whose surface has many filaments. In other words, it is sufficient to have a fibrous layer on the surface of the roll, and the fibrous layer does not necessarily have to have many fluffs in the radial direction of the roll. Preferably, the fibrous layer on the surface of the spreading roll is brought into contact with the surface of the spreading roll under some compression. This makes it possible to effectively spread the cured liquid material even on fibers present in a direction other than the radial direction of the spreading roll. Therefore, the spreading roll in the present invention is not a so-called brush roll, but is a roll having on its surface a relatively thin fibrous layer made of an aggregate of fibers having a large number of filaments in directions other than the radial direction. The thickness of the fibrous layer depends on the size of the spreading roll, but is usually between 5 and 10 in diameter.
The thickness of cTrL's spreading roll is 3CT! L
Below, 1.5 CTIL or less is particularly preferable. Specifically explaining the fibrous layer in the scattering roll, animal and plant fibers,
Mats made of synthetic fibers or other fiber materials;
A layer is formed by wrapping or gluing cloth, netting, rope, string, or other fiber aggregates around the roll surface. For example, since mats (non-woven fabric) and cloth are wide, they are constructed by wrapping them one or more times over the entire length of the roll, and ropes and strings are constructed by winding them around the roll from one side to the other. others,
The fibrous layer can be provided on the surface of the roll by any appropriate method, such as forming a bag and covering the roll or aligning the fibers in the axial direction of the roll. It is preferable that the surface of the fibrous layer has a so-called rough surface, and thick or hard fibers (for example, thick synthetic fibers, fibers such as hemp, etc.) are used, or fabrics with fluff or loops on the surface or coarsely woven fabrics are used. Ivy cloth is suitable. The material of the fibers is preferably one to which the curable liquid material does not easily adhere, and in this respect metal fibers are not very suitable. Preferably, synthetic fibers such as nylon, polyvinyl chloride, polypropylene, etc., and vegetable fibers such as hemp (shoot, manila hemp, hemp, etc.), and cocoon are suitable. The spraying device of the present invention is mainly composed of four rolls as shown in FIG. 1, but it is preferable to further include supplementary and auxiliary spraying rolls in order to adjust the spraying direction and to ensure uniform spraying. .

This auxiliary spreading roll is provided close to the bottom of each spreading roll, preferably slightly outside, and rotates at high speed without contacting the spreading rolls. FIG. 2 shows a side view of a spreading device equipped with this auxiliary spreading roll. Similar to FIG. 51, the device is composed of spreading rolls 1, 2, spreading rolls 3, 4, and a nozzle 5 for supplying a curable liquid, with auxiliary spreading rolls 6, 7 is provided. The auxiliary spreading rolls 6 and 7 rotate at high speed in the same direction as the three neighboring spreading rolls 3 and 4, respectively.
The role of the auxiliary scattering rolls 6 and 7 is to
The main purpose of this device is to scatter the fine particles of the hardening liquid that have adhered to the inside and outside of the fine particles that have been scattered toward the inside and outside again. Since the diameter of the fine particles scattered toward the outside tends to be relatively large, it is also effective to divide the relatively large fine particles into even smaller pieces and scatter them. For reference, FIG. 2 shows part of the trajectory of fine particles of the curable liquid material. The auxiliary scattering rolls 6 and 7 have a small amount of hardened liquid matter attached to them, so they do not have the same problems as the scattering rolls, so long-bristled brush rolls can be used, and they have a high scattering effect. It is recommended to use a long brush roll. Of course, a roll having a fibrous layer similar to the spreading roll can also be used. The spraying device of the present invention is most suitable for spraying a foamable polyurethane stock solution, but is not limited thereto, and is also suitable for spraying curable liquid materials such as liquid effective resins and paints.

2. Description of the Related Art As a paint spraying device, a device is known in which paint flowing down on an inclined plate is sprayed using a brush roll rotating at high speed.
However, this known method is not suitable for dispersing highly viscous liquids that are difficult to flow down on an inclined plate, and the device of the present invention for forcibly spreading and dispersing liquids is suitable. The method of the present invention is also suitable for spraying liquid curable resins whose viscosity changes drastically. That is, the liquid material supplied to the device is dispersed within an extremely short period of time. Furthermore, it is of course possible to spray general liquid materials, and is particularly suitable for spraying highly viscous fluid materials such as resin solutions, resin emulsions, and cement milk. Furthermore, plastic solids and powders such as gels can be spread on the spreading roll, and substances that can adhere to the spreading roll can also be spread. However, as explained above, the spraying device of the present invention is particularly suitable for spraying curable liquid materials, and among these, liquid curable materials such as foamed polyurethane stock solutions that have relatively high viscosity and harden rapidly. Most suitable for spraying resin. The foamable polyurethane stock solution is mainly produced by mixing an active hydrogen compound-containing component and a polyisocyanate compound-containing component.

Immediately after this mixing, the liquid becomes milky white and then foaming begins. The time until just before foaming begins is called cream time, and the time until the liquid level stops rising due to foaming is called rising time. In the case of spraying the foamed polyurethane stock solution, it is preferable that the spraying is completed within this cream time, but sufficient spraying is possible even at the beginning of the rising time. Polyurethane foams include hard foams, soft foams, semi-hard foams, etc., and since the apparatus of the present invention is suitable for continuous spraying, it is mainly used for manufacturing hard foams and soft foams. For example, it is used for spraying to obtain a slab-like foam or to form a foam layer on a substrate. Of course, it can also be used to fill a mold with a wide surface with stock solution. The spraying device of the present invention can spray evenly and extremely thinly, so it is suitable for applications where this feature can be effectively utilized. Suitable for manufacturing insulation boards such as slate. That is, the stock solution can be applied uniformly and extremely thinly onto the surface of a substrate having irregularities such as a corrugated asbestos slate plate or a folded iron plate. With conventional spray methods, it is impossible to apply a thin layer, and it tends to be applied thinly on the crests of waves and thickly on the troughs, but with the device of the present invention, it is possible to apply a uniform thickness even on the crests of waves. Is possible.
Note that the device of the present invention can be modified in various ways other than those shown in the drawings, and is not limited to these.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of the spraying device of the present invention,
It is composed of two spreading rolls 1, 2, two spreading rolls 3, 4, and a supply nozzle 5 for the material to be spread.

Claims (1)

[Scope of Claims] 1. Two spreading rolls arranged in parallel and rotating inwardly, two spreading rolls in contact with each of the spreading rolls and rotating at high speed in the same direction as the touching spreading roll, and 2. In a device for distributing a material to be spread into fine particles, which is composed of a supply nozzle that supplies the material to a spreading roll for books, the spreading roll rotates at high speed, and the spreading roll is rotated in a direction other than the radial direction of the spreading roll. A spreading device characterized in that it is a roll having on its surface a relatively thin fibrous layer made of an aggregate of fibers having a large number of directional filaments. 2. A spreading device according to claim 1, wherein the spreading roll rotates at least 200 revolutions per minute. 3. The spraying device according to claim 1, wherein the supply nozzle supplies the material to be spread while reciprocating above the gap between the two spreading rolls parallel to the axis of the rolls. 4. The spraying device according to claim 1, wherein the material to be sprayed is a curable liquid material. 5. The spraying device according to claim 4, wherein the curable liquid material is a foamable polyurethane stock solution. 6 Two spreading rolls arranged in parallel and rotating inward, two spreading rolls that are in contact with each of the spreading rolls and rotate at high speed in the same direction as the touching spreading rolls, and a spreader roll that is covered by the two spreading rolls. In a device for dispersing a material to be spread into fine particles, which is composed of a supply nozzle that supplies a material to be spread, the spreading roll rotates at a high speed, and the spreading roll has a large number of filaments in a direction other than the radial direction of the spreading roll. The roll has a relatively thin fibrous layer made of an aggregate of fibers on its surface, and two auxiliary spreading rolls that are close to each other below each of the two spreading rolls and rotate at high speed without contacting the spreading rolls. A spreading device characterized by being equipped with rolls.