JPH1076220A - Method for applying liquid to porous or gas permeable backing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a process in which the impregnation property of a liquid application material is improved to make it high quality and productivity is improved by heating a porous or gas permeable backing and applying liquid by extruding it from a die head. SOLUTION: A porous or gas permeable backing 1 is set in a feed mechanism 16 and fed with a speed controlled by a pinch roll 14. Hot air supplied from a hot air supply source 5 is sprayed from a hot air spraying nozzle 4 toward the backing 1, and the backing is heated at a prescribed temperature. Next, liquid supplied from a liquid supply apparatus 3 is contacted with the backing 1 to be applied on it by a die head 2 adjacent to the nozzle 4. The backing 1 which is impregnated with the liquid sufficiently is guided to a guide roll 15 and taken up by a take-up mechanism 17. In this way, a high quality product with a high impregnation property of the liquid application material is made, and productivity is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for applying a liquid material to a porous or air-permeable substrate.
More specifically, in the field of electronic equipment, for example, a porous material such as a printed circuit board or a screen having through holes is coated with an insulating material or a conductive material by applying and filling the holes, or a coating agent such as a moisture proof material is applied. And a method of applying a coating agent or an adhesive to a woven or nonwoven fabric, a breathable foam sheet, or the like. In the present invention, the liquid material includes a heated melt such as a hot melt adhesive or a viscous fluid such as a room temperature liquid or paste adhesive, a foamable liquid, or a room temperature liquid coating agent.

[0002]

2. Description of the Related Art As a method of applying a liquid material to a porous or air-permeable base material, a spray coating method or a coating method using a roll coater has been used for a long time. Recently, a coating method using a screen printing method and a vacuum together has been used for filling a hole in a printed circuit board or the like. In addition, as a method of further improving the filling property of the porous pores, an extruding slot nozzle is brought into contact with the base material, and the extruding pressure from the slot nozzle is directly applied, so that the liquid material is thinned. A method of press-fitting into a hole has also been proposed.

[0003]

The following problems have been encountered in the above-mentioned spray coating method and coating method using a roll coater as conventional methods for coating a liquid material on a porous or air-permeable base material. there were. In other words, when the liquid material is applied and impregnated on a porous or air-permeable substrate, there is almost no energy for press-fitting the liquid material, so that the liquid material is insufficiently penetrated into the pores of the porous substrate. . Therefore, in order to compensate for this, a method has been adopted in which a surfactant or a coupling agent is mixed into the liquid to improve the wettability of the liquid, thereby improving the permeability.

However, when a liquid material of an emulsion type having a particularly high viscosity is used for a back coating such as a fabric material as a porous or air-permeable base material to prevent fraying or strain, Substrate temperature,
There were many unstable factors such as the temperature and humidity of the coating material, and the quality was not stable, and the productivity was low. In addition, when a hot melt such as a hot melt adhesive is applied to a porous or air permeable base material and impregnated, the heat is rapidly removed when the melt is applied to the base material, and the viscosity increases or solidifies. Therefore, it was difficult to impregnate the substrate.

The pores of a printed circuit board or the like as a porous or air-permeable base material or the air-permeable portion of a fabric or the like lead to a pressure loss as the thickness of the base material becomes thicker. However, even at atmospheric pressure, the air impregnated in the base material hinders sufficient impregnation of the coating material.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has been made by heating a porous or air-permeable base material to a temperature suitable for a liquid material, that is, a coating material. An object of the present invention is to provide a method for applying a liquid material to a porous or air-permeable base material, which can provide a high-quality product with high material impregnation and high productivity.

[0007]

In order to solve the above-mentioned problems, the present invention provides a method for applying a liquid material to a porous or air-permeable substrate as described below. That is, a porous or air-permeable base material that moves relatively between the die head and the base material is heated to a predetermined temperature, and the heated base material is extruded and coated with a liquid material from the die head.
A method of applying a liquid material to a porous or air-permeable base material was adopted.

Further, a porous or air-permeable base material which moves relatively between the die head and the base material is heated to a predetermined temperature, and a liquid material is extruded from the die head onto the heated base material and applied thereto. A method of applying a liquid material to a porous or air-permeable substrate, characterized in that a vacuum mechanism is provided on the opposite side of and / or downstream of the applied surface and the application is performed while sucking.

Further, in the above method, the means for heating the base material is performed by blowing hot air or heated steam, and the means for heating the base material is formed by blowing the hot air or heated steam on the back side of the base material. Is performed in cooperation with the suction mechanism provided in the above, that the blowing nozzle outlet of the hot air or heating steam for heating the base material is provided in contact with the base material, and that the liquid material to be applied is foamed A method of applying a liquid material to a porous or air-permeable base material, which is characterized by being a liquid material.

Further, in the above method, it is characterized in that the suction means by a vacuum mechanism provided opposite to the die head is performed via a backup roll or a conveyor belt made of a porous material. And a method of applying a liquid material to a porous or air-permeable base material.

Further, a foamable liquid material is extruded from a die head onto a porous or air-permeable base material which moves relatively between the die head and the base material, and is coated on the opposite side of the coating surface facing the die head and / or downstream thereof. A method of applying a liquid material to a porous or air-permeable base material, which is provided with a vacuum mechanism and applied while sucking.

[0012]

Next, an embodiment of the present invention will be described. In the present invention, since the liquid material is applied to the porous or air-permeable base material by the means described above, a coating method of sufficiently high quality and high productivity can be obtained. That is, by heating a porous or air-permeable base material, the air in the air-permeable pores expands and escapes to the outside by heating, and the air density inside is reduced, so that the permeability of the liquid material to be applied is improved. .

Further, by preheating and maintaining the temperature of the liquid material, that is, the temperature suitable for the coating material, when the liquid material comes into contact with the base material, the temperature rapidly changes to increase the viscosity and lose the permeability. There is no. Therefore, the applied liquid material sufficiently penetrates into the pores of the porous or air-permeable base material.

Further, by extruding and applying the liquid material from the die head, the extruding pressure acts directly, so that the liquid material easily enters the inside of the pores of the porous or air-permeable base material, and is further opposed to the die head. By providing a vacuum mechanism on the opposite side of and / or downstream of the application surface and applying while suctioning, the liquid material can easily enter the pores.

In the case of a substrate having a relatively thin surface such as a film or paper, a heating means such as an infrared ray, a far-infrared ray, or a heating roll sufficiently heats and penetrates the inside of the substrate. The porous or air-permeable base material which is the object of the present invention and which is thick has properties close to those of a heat insulating material, so that only the surface of the base material is heated by heating means such as infrared rays, far infrared rays or a heating roll. And the inside cannot be sufficiently heated in a short time.
In this respect, in the heating method by blowing hot air or heated steam, the heat source penetrates into the inside of the base material through the pores of the base material, so that the inside of the base material can be sufficiently heated.

Further, the means for heating the substrate is more effectively performed by the cooperation of the blowing of the hot air or the heating steam and the suction mechanism provided on the back side of the substrate relative to the spray nozzle. Heating is performed to the inside of the substrate. Therefore, penetration of the liquid material applied thereafter becomes easy. This is particularly effective for emulsion coating materials.

Furthermore, by using a foaming liquid as the liquid to be applied, the foaming energy of the foaming liquid applied to the substrate amplifies the permeability and can be applied to a large area or inside with a small amount of application. Can be applied and permeated. Further, the use of the foamable liquid material can be applied without impairing the texture when the substrate is required to have flexibility like a fabric.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method for applying a liquid material to a porous or air-permeable base material of the present invention will be specifically described below with reference to the drawings showing the embodiments. FIG. 1 is an explanatory view of a first embodiment of a method for applying a liquid material to a porous or gas-permeable substrate of the present invention, and FIG. 2 is a diagram showing a liquid material applied to a porous or gas-permeable substrate of the present invention. FIG. 4 is an explanatory view of a second embodiment of a method of applying a liquid.

First, in FIG. 1, reference numeral 1 denotes a raw material of a porous or air-permeable base material set in a delivery mechanism 16. In this embodiment, a back coating of a fabric will be described as an example. Reference numeral 2 denotes a die head for extruding and applying a liquid material. The die head 2 applies the liquid material supplied from the liquid material supply device 3 to the application surface of the substrate 1 in a contact state.

A known liquid supply device 3 is used. For example, when a thermoplastic melt such as a hot melt adhesive is used, a device in which a heating and melting means and a pump means for pressure-feeding the molten melt are integrally incorporated is used. In the case where a melt is used, an apparatus incorporating a means for further mixing a foaming aid such as nitrogen gas into the melt at a high pressure is known. Alternatively, a foaming agent may be mixed in the melt in advance and foamed after application or application.

Reference numeral 4 denotes a hot air blowing nozzle provided immediately before the die head 2. The hot air blowing nozzle 4 blows hot air supplied from a hot air supply source 5 onto the substrate 1.
The temperature of the substrate is heated to a predetermined temperature. Usually, when a hot melt adhesive is used, the temperature is preferably 80 to 180 ° C. When a normal temperature liquid adhesive is used at normal temperature or heated, it is preferably 30 to 120 ° C.

Although the hot air heating method is employed in this embodiment, a steam heating method may be employed by replacing the hot air blowing nozzle 4 with a steam blowing nozzle and the hot air supply source 5 with a steam supply source. Further, when the tip of the nozzle 4 is configured to be in contact with the substrate 1, the effect of permeation heating by hot air pressure is further enhanced.

Numeral 6 denotes a vacuum hood provided on the back side of the substrate opposite to the nozzle 4 for blowing hot air. The hood 6 is connected to a blower 9 by a duct 8 via an adjusting valve 7. 6 is maintained at a negative pressure. The suction mechanism is constituted by the hood 6, the adjustment valve 7, the duct 8, the exhaust fan 9, and the like. By the cooperation of the hot air blowing nozzle 4 and the hood 6, the inside of the base material can be sufficiently heated.

Reference numeral 10 denotes a backup roll provided on the opposite side of the coating surface of the base material 1 from the die head 2, and the backup roll 10 is formed of a rigid porous air-permeable material or a metal net. . The inside of the fan-shaped part 12 partitioned by the partition plate 11 inside the backup roll 10 is communicated with the exhaust fan 9 through the adjustment valve 13 through the duct 8 in a ventilation state, and the inside of the fan-shaped part 12 is maintained at a negative pressure.

Reference numeral 14 denotes a pinch roll for controlling the feeding amount of the base material, and reference numeral 15 denotes a guide roll for the base material 1 to be wound by the winding mechanism 17. Adjustment valve 7
Is for adjusting the negative pressure generating force in the hood 6, and the adjusting valve 13 is for adjusting the negative pressure generating force in the backup roll 10.

In the coating apparatus configured as described above, first, the porous or air-permeable base material 1 is set on the delivery mechanism 16 and is delivered by the pinch roll 14 while controlling the delivery speed. Then, the hot air supplied from the hot air supply source 5 is blown from the hot air blowing nozzle 4 toward the substrate 1, and at the same time, the negative pressure in the hood 6 of the suction mechanism provided on the back surface of the substrate in communication with the exhaust fan. In cooperation, the substrate 1 is heated to a predetermined temperature.

When the substrate is heated, the air impregnated inside the pores of the substrate expands and escapes to the outside, and the air density inside decreases. Further, by the suction action of the hood 6, the air impregnated in the air-permeable pores is sucked and further reduced in density, which helps the liquid material in the next liquid material coating step.

Subsequently, the liquid material supplied from the liquid material supply device 3 is applied to the base material 1 by the die head 2 provided adjacent to the heating means. At the same time that the liquid material is applied from the die head 2, the liquid material applied by the vacuum action of the backup roll 10 provided on the back surface of the base material 1 penetrates deeply into the base material 1. Then, the base material sufficiently impregnated with the liquid material is guided by the guide roll 15 and wound up by the winding mechanism 17 to become a product.

The liquid material, in particular, the fabric which is a substrate to which the hot melt adhesive is applied, has a high quality as a material for preventing the hot melt adhesive from penetrating into the fabric and preventing fraying and distortion. A back coating is applied.

When a foamable melt is used as the liquid material to be applied, the foaming energy of the foamable melt applied to the substrate amplifies the permeability, and can be applied over a wide area with a small application amount. Further, when the base material requires flexibility like a fabric, the foamable melt can be applied without impairing the texture.

Next, a second embodiment shown in FIG. 2 will be described. The second embodiment has a main purpose of applying a liquid material to a printed circuit board having through holes and the like in the field of electronic devices and the like so that the applied liquid material easily penetrates into the inside of the through holes and the like. It is. That is, in FIG. 2, reference numeral 21 denotes a porous or air-permeable base material, and the base material is placed on a conveyor belt 34 stretched around rotating shafts 31 and 32,
Move continuously or intermittently. The conveyor belt 34 is made of a gas permeable porous body or a metal net, and at least one of the rotating shafts 31 and 32 is forcibly driven by a motor or the like.

A die head 22 extrudes and applies the liquid material. The die head 22 applies the liquid material supplied from the liquid material supply device 23 to the application surface of the substrate 21 in a contact state. As the liquid material supply device 23, a known device is used as in the first embodiment.

Reference numeral 24 denotes a hot air blowing nozzle provided immediately before the die head 22. The hot air blowing nozzle 24 blows hot air supplied from a hot air supply source 25 onto the base material 21 to lower the temperature of the base material 21. Heat to a predetermined temperature.

Numeral 26 denotes a vacuum hood provided on the back side of the substrate 21 and the conveyor belt 34 opposite to the hot-air blowing nozzle 24. Connected to the hood 2
6 is maintained at a negative pressure. The suction mechanism is constituted by the hood 26, the adjustment valve 27, the duct 28, the exhaust fan 29, and the like.
The inside of the substrate 21 can be sufficiently heated by the cooperation of the hot air blowing nozzle 24 and the hood 26 described above.

Numeral 30 denotes a substrate 21 facing the die head 22.
And a vacuum hood provided on the opposite side of the conveyor belt 34, and the vacuum hood 30
The inside of the vacuum hood 30 is maintained at a negative pressure by being communicated with the duct 28 via the duct 3 through the duct 28. The adjusting valve 27 is for adjusting the negative pressure generating force in the hood 26, and the adjusting valve 33 is for adjusting the vacuum hood 3.
This is for adjusting the negative pressure generating force within zero.

In the coating apparatus configured as described above, first, the porous or air-permeable base material 21 is placed on the conveyor belt 34 and moves continuously or intermittently in the traveling direction of the conveyor. Then, when the substrate 21 advances to the heating area, the hot air supply source 2
The hot air supplied from the nozzle 5 is blown toward the substrate 21 from the nozzle 24 for blowing hot air, and at the same time, the hood 26 of the suction mechanism provided on the back surface of the substrate 21 and the air-permeable conveyor belt 34 in communication with the exhaust fan. In cooperation with the negative pressure in the
1 is heated to a predetermined temperature.

Due to the heating of the base material and the suction action of the hood 26, the air originally impregnated in the porous or air-permeable pores is reduced in density, and the permeability of the liquid material in the next liquid material application step is reduced. Help.

Subsequently, the liquid material supplied from the liquid material supply device 23 is applied to the base material 21 by the die head 22 provided adjacent to the heating means. At the same time that the liquid material is applied from the die head 22, the liquid material applied by the vacuum action of the vacuum hood 30 provided on the back surface of the base material 21 penetrates deeply into the base material 21. In this way, a substrate sufficiently impregnated with the liquid material is continuously produced.

In each of the first and second embodiments, the die head is fixed and the substrate is applied while moving the substrate. However, the substrate is fixed on the vacuum structure and the die head is mounted. You may comprise so that it may apply while moving.

[0040]

According to the present invention, a liquid material is applied to a porous or air-permeable substrate as described above.
By maintaining the porous or air-permeable base material at a temperature suitable for the liquid material, that is, the coating material, a high-quality product with improved impregnation of the liquid material, that is, the coating material, can be obtained, and the productivity is high. A method for applying a liquid material to a porous or air-permeable substrate can be provided.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a first embodiment of a method for applying a liquid material to a porous or air-permeable base material of the present invention.

FIG. 2 is an explanatory view of a second embodiment of the method for applying a liquid material to a porous or air-permeable substrate according to the present invention.

[Explanation of symbols]

1, 21 ... substrate, 2, 22 ... die head, 4, 24 ... hot air blowing nozzle, 10 ... backup roll, 34 ...
Conveyor belt,

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location B29C 65/40 B29C 65/40 // B29K 105: 04 B29L 9:00

Claims (12)

[Claims] 1. A method according to claim 1, wherein a porous or air-permeable base material relatively moving between the die head and the base material is heated to a predetermined temperature, and a liquid material is extruded from the die head onto the heated base material. Applying a liquid material to a porous or air-permeable substrate. 2. The method for applying a liquid material to a porous or air-permeable substrate according to claim 1, wherein the means for heating the substrate is performed by blowing hot air or heated steam. . 3. The method according to claim 1, wherein the means for heating the substrate is performed by blowing hot air or heated steam and cooperating with a suction mechanism provided on the back side of the substrate relative to the blowing nozzle. Item 1. The method for applying a liquid material to a porous or air-permeable substrate according to Item 1. 4. The method according to claim 2, wherein an outlet of a hot air or heating steam spray nozzle for heating the substrate is provided in contact with the substrate. The method for applying a liquid material to a porous or air-permeable substrate as described above. 5. A liquid material to be applied to a porous or air-permeable substrate according to claim 1, wherein the liquid material to be applied is a foamable liquid material. how to. 6. A porous or air-permeable base material relatively moving between a die head and a base material is heated to a predetermined temperature, a liquid material is extruded from the die head to the heated base material, and the die head and the base material are coated. A method for applying a liquid material to a porous or air-permeable substrate, wherein a vacuum mechanism is provided on the opposite side of and / or downstream of the opposed application surface and the application is performed while sucking. 7. The method for applying a liquid material to a porous or air-permeable substrate according to claim 6, wherein the means for heating the substrate is performed by blowing hot air or heating steam. Method. 8. The method according to claim 1, wherein the means for heating the base material is performed by blowing hot air or heated steam and cooperating with a suction mechanism provided on the back side of the base material relative to the blowing nozzle. Item 6. The method for applying a liquid material to a porous or air-permeable substrate according to Item 6. 9. The method according to claim 7, wherein an outlet for blowing hot air or heating steam for heating the substrate is provided in contact with the substrate. A method of applying a liquid material to a porous or air-permeable base material. 10. A suction means by a vacuum mechanism provided on the opposite side of the application surface facing the die head and / or downstream of the application surface is formed through a backup roll or a conveyor belt made of a gas-permeable porous material. The method according to any one of claims 6 to 9, wherein the liquid material is applied to a porous or air-permeable substrate. 11. The liquid material to be applied to a porous or air-permeable base material according to claim 6, wherein the liquid material to be applied is a foamable melt. how to. 12. A foamable liquid material is extruded from a die head onto a porous or air-permeable substrate relatively moving between a die head and a substrate, and is applied to the opposite side of the application surface facing the die head and / or downstream thereof. A method for applying a liquid material to a porous or air-permeable base material, comprising applying a suction while providing a vacuum mechanism.