JPH0451905Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention is a coating header used when applying a mixture of pigments, adhesives, etc. to the surface of materials such as paper, plastic film, cloth, and metal foil. It is related to.

[Prior Art] In order to impart properties such as whiteness, gloss, smoothness, surface strength, and printability to materials such as paper, coating machines are used to apply paints formulated according to the respective purposes. Various types have been developed and used.

In a coating machine, a coating head is used to apply coating to a base paper or the like, measure it, and smooth it, and roll type, bar type, blade type, air knife, etc. are used depending on the purpose.

For example, a fountain blade coater, which is a type of blade-type header, as shown in Fig. 4, has a fountain manifold b placed below a bucking roll a whose outer circumferential surface is wrapped with an elastic material such as rubber. Arranged parallel to King Roll a,
A slit-shaped fountain lip c is provided at the top of the manifold b, and the paint supplied under pressure to the manifold b flows from the fountain lip c to the paper web d.
An excessive amount of paint is sprayed on the paint, and the excess paint is scraped off by a blade e and then measured.

[Problems to be solved by the invention] However, as shown in FIG. 5, when paint is supplied under pressure from both ends of the fountain manifold b using a variable speed pump,
In the vicinity of both ends of the manifold b, the velocity distribution of the paint in the pipe is obtained as shown in Fig. 6, but at the center of the manifold b, that is, where the flows of paint supplied from both sides collide, the velocity distribution is as shown in Fig. 7. Become.

The relationship between the viscosity μ of the paint and the shear rate γ is expressed as μ=A・γ ⁿ (A, n are constants), and in the case of paint applied to paper, as γ increases, μ increases as shown in Figure 8. becomes smaller.

Here, γ is expressed as γ=v ₁ −v ₂ /Δy, so as mentioned above, γ≈0 at the center in the width direction of fountain manifold b,
As a result, μ≒∞, and as shown in FIG. 5, a low portion occurs in the height of the ejected liquid f at the center, and the ejected height h becomes non-uniform in the width direction.

In addition, even in the case of a multi-head pipe type in which there are many paint supply pipes g to the fountain manifold b' as shown in Fig. 9, the middle part of the adjacent supply pipes g is depressed as described above, and the discharge height is low. In this case, the height becomes uneven.

Therefore, with the conventional fountain-type coating header, uniform coating could not be achieved, resulting in uneven coating.

[Means for solving the problems] The purpose of this invention is to solve the problems of the conventional fountain-type coating header described above, to make the paint discharge height uniform in the width direction, and to improve the quality of the product. In a fountain-type coating header that has a slit-like lip in the longitudinal direction of the tube body and connects multiple paint supply pipes, liquid is applied to the confluence point between the connections of adjacent paint supply pipes. The present invention relates to a coating header which is characterized by being connected to a withdrawal pipe.

[Operation] Paints supplied from adjacent paint supply pipes flow inside the pipe bodies, and a portion flows out from a drain pipe connected to a point where paint flows from both sides join.

Therefore, the flow of the paint is ensured even at the joining part, the viscosity of the paint does not increase excessively, and a uniform discharge height can be obtained.

[Example] Hereinafter, an example of the present invention will be described based on the drawings.

Figures 1 and 2 are an embodiment of the present invention,
1 is a fountain manifold, 2 is a slit-shaped fountain lip provided in the longitudinal direction of the manifold 1, and paint supply pipes 3, 3 are connected to both ends of the manifold 1, respectively, and a variable speed pump 4, etc. so that the paint can be supplied at equal pressure,
A liquid drain pipe 5 is connected to the top of the manifold 1, which is approximately central in the longitudinal direction of the surface and faces the lip 2, and the liquid drain pipe 5 is provided with a valve 6 for adjusting flow rate. The liquid draining pipe 5 has a diameter that allows it to draw out 5 to 10% of the amount of paint supplied into the manifold 1.

With the above configuration, the paint flowing from the paint supply pipes 3, 3 at both ends is transferred to the fountain lip 2.
The liquid flows toward the center while flowing out from the drain pipe 5, and a portion of the liquid flows out from the liquid drain pipe 5 at the confluence part.

The valve 6 of the drain pipe 5 is set to 2 to 5 of the paint supply amount.
By adjusting the opening so that % flows out,
A flow occurs in the paint at the merging portion as well, and an increase in the viscosity of the paint at the merging portion is suppressed to a low level.

Therefore, the discharge height h becomes uniform in the width direction without being indented even at the merging part, and uniform coating can be achieved.

FIG. 3 shows another embodiment of the present invention, in which three or more (four in this embodiment) paint supply pipes 3 are connected to the fountain manifold 1' at approximately equal intervals. A common supply header 7 is connected to the common supply header 7, and further, approximately in the middle of the connection part of each adjacent paint supply pipe 3,
This is an example in which drain pipes 5 each having a valve 6 are connected to each other. In FIG. 3, the same reference numerals as in FIGS. 1 and 2 indicate the same components.

Also in the case of the multi-head tube type coating header of this example,
It is possible to prevent the discharge height h of the paint merging portion from decreasing, and a uniform height h can be obtained.

It should be noted that the coating header of the present invention is not limited to the above-mentioned embodiments, but can be applied to paints of various compositions and viscosities, and the connection point of the liquid drain pipe is located midway between the connection part of the paint supply pipe. It goes without saying that various changes can be made without departing from the gist of the present invention, such as the fact that it can be used not only at a confluence point, but also for things made of other materials as well as paper webs.

[Effects of the invention] As described above, according to the coating header of the invention, a liquid drain pipe is connected to the confluence between the connecting parts of adjacent paint supply pipes, and a part of the paint is drawn out. As a result, fluidity is obtained even at the joining part of the paint, and an increase in the viscosity of the paint can be prevented.As a result, the discharge height of the paint is also constant in the width direction, and uniform coating can be achieved.
Various excellent effects such as improved product quality can be achieved.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of one embodiment of the coating header of the present invention, Fig. 2 is a view taken in the - direction arrow of Fig. 1, and Fig. 3 is an explanatory diagram of another embodiment of the coating header of the present invention. , FIG. 4 is an explanatory diagram showing an example of a conventional fountain blade coater, FIG. 5 is a view taken in the - direction arrow in FIG. , Fig. 7 is a diagram showing the velocity distribution in the pipe at the - cross section in Fig. 5, Fig. 8 is a diagram showing the relationship between paint viscosity and shear rate, and Fig. 9 is an explanation of a conventional multi-head pipe header. It is a diagram. 1 and 1' are fountain manifolds, 2 is a fountain lip, 3 is a paint supply pipe, 4 is a variable speed pump, 5 is a drain pipe, and 6 is a valve.

Claims (1)

[Scope of utility model registration request] In a fountain-type coating header that has a slit-like lip in the longitudinal direction of the pipe body and connects multiple paint supply pipes, a drain pipe is connected to the paint confluence point between the connections of adjacent paint supply pipes. A coated header characterized by: