JPH039813A - Infiltration method and its device for varnish - Google Patents

Abstract

PURPOSE:To perform uniformly and sufficiently infiltration of varnish into a base material by making removal of air before varnish infiltration perfect, by a method wherein the base material is opened physically with injection energy or nuclear boiling energy of a low viscosity solution in a steaming atmosphere of the low viscosity solution. CONSTITUTION:When a base material 1 is run at a fixed speed under a state where the inside of a base material treatment chamber 3 is held at an atmosphere of vapor of low viscosity solution and the same arrives at a sphere for an injection action, the low viscosity solution 12 is injected uniformly on both the surfaces of the same through a nozzle group 16. In this instance, since the base material is opened physically injection energy of the low viscosity solution 12, air in the base material 1 is replaced wholly with the low viscosity solution 12 for removal. Then the base material 1 brought to a sphere 6a for a heating action is heated to at least the boiling point of the low viscosity solution 12 with a heating roll 19 and the low viscosity solution 12 infiltrated into the base material 1 is evaporated for removal. Then the same is brought into varnish 8 of a varnish storage tank 2 from a base material outlet part 11 by passing through a base material discharge sphere 7a. In this instance, a space from the heating roll 19 extending to a liquid surface of the varnish on the inside of the outlet part 11 of the base material is held at a complete atmosphere of the vapor of the low viscosity solution.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a sheet-like base material made of a fibrous material such as paper or cloth used for manufacturing laminates such as electrical insulating boards and decorative boards. The present invention relates to a method and apparatus for impregnating water with varnish.

[Conventional technology]

Generally, when impregnating a sheet-like base material made of fibrous material with varnish, it is important that the varnish is impregnated into the inside of the fibers of the base material and that the amount of varnish is evenly distributed in each part. It is desirable to reduce the number of air bubbles remaining in the material as much as possible.

However, simply by dipping the base material in the varnish, it is difficult to uniformly and sufficiently impregnate the inside of the base material with the varnish, and it takes a long time to impregnate the base material with the varnish. Furthermore, it is difficult to sufficiently reduce the number of bubbles remaining in the base material. This problem becomes particularly noticeable when a high viscosity varnish is used.

Therefore, recently, a preliminary impregnation tank storing a low-viscosity liquid such as a solvent and a varnish impregnation tank storing varnish are placed side by side, and the substrate is made to pass through the preliminary impregnation tank and the varnish impregnation tank sequentially using guide rolls. things are being done.

According to this impregnation method, while the base material is passed through the low viscosity liquid, the air in the base material is replaced with the low viscosity liquid and removed, so that the base material can be passed through the low viscosity liquid impregnated with the low viscosity liquid. By bringing the liquid into the varnish while evaporating it, the varnish can be efficiently impregnated.

It is possible to reduce air bubbles.

[Problems to be Solved by the Invention] However, in such a method, air is replaced and eliminated by a low-viscosity liquid using capillary osmotic force, so there is a natural limit to the elimination of air. is difficult to completely eliminate. In particular, when the low viscosity liquid in the preliminary impregnation tank deteriorates due to contamination with impurities, the air removal effect due to capillary osmotic force is significantly reduced.

Therefore, in the conventional method, it is difficult to introduce the base material into the varnish in a state in which air is completely excluded, and the reality is that it is not possible to obtain a void-free, high-quality prepreg.

The present invention was made in view of these circumstances.

The object of the present invention is to provide a varnish impregnation method that can significantly improve the varnish impregnation properties and void-free effect in a base material, and a varnish impregnation apparatus that can suitably carry out the method.

[Means to solve the problem]

The varnish impregnation method of the present invention solves this problem by passing a sheet-like base material made of a fibrous material through a low-viscosity liquid vapor atmosphere and then passing it through a varnish.
In particular, air in the base material is removed by physically opening the base material while passing through a low-viscosity liquid vapor atmosphere.

The opening of such a base material is carried out by either of two primary methods.

That is, in the first method, a low viscosity liquid is injected onto the base material, the base material is opened by the energy of the jet, and air in the base material is replaced with the low viscosity liquid. The low viscosity liquid impregnated into the base material is heated and evaporated in a low viscosity liquid vapor atmosphere.

In the second method, a low viscosity liquid or its vapor is injected onto the base material while the base material is heated above the boiling point of the low viscosity liquid. This causes nucleate boiling in the base material, causes the base material to open with the nucleate boiling energy, and replaces the air in the base material with low viscosity liquid vapor.

On the other hand, the varnish impregnation device of the present invention for carrying out such a method includes a varnish reservoir for storing varnish, a base material inlet portion, and a base material outlet portion opened into the varnish of the varnish reservoir. a base material processing chamber; a traveling guide mechanism that guides a sheet-like base material made of in-fibrous material to travel sequentially through a base material inlet, a base material processing chamber, a base material outlet, and a varnish storage tank; A vapor atmosphere holding mechanism that maintains a low viscosity liquid vapor atmosphere in the material processing chamber. Particularly, in an apparatus for implementing the method that adopts the first method, a low viscosity liquid injection mechanism and a low viscosity liquid vapor atmosphere are further provided. a liquid evaporation mechanism;
The apparatus for implementing the method employing the method further includes a base material heating mechanism and a nucleate boiling generation mechanism.

The low viscosity liquid injection mechanism injects the low viscosity liquid onto the substrate in the substrate processing chamber, and the low viscosity liquid evaporation mechanism is located at the side of the substrate exit section from the injection action area of the low viscosity liquid injection mechanism. The base material is heated to a temperature higher than the boiling point of the low viscosity liquid in the heating action area.

Further, the base material heating mechanism heats the base material to a temperature higher than the boiling point of the low viscosity liquid in the base material processing chamber.

The nucleate boiling generation mechanism causes nucleate boiling to occur by injecting a low viscosity liquid or its vapor onto the base material in a heating action area of the base material heating mechanism.

[Effect]

The base material is caused to travel along a predetermined path by a travel guide mechanism and brought into the base material processing chamber from the base material inlet.

The base material brought into the base material processing chamber is opened by a low viscosity liquid injection mechanism, a base material heating mechanism, and a nucleate boiling generation mechanism, and air contained therein is removed.

That is, when the low viscosity liquid is injected onto the base material by the low viscosity liquid jetting mechanism, the base material is physically opened by the energy of the ejection. As a result, the air in the substrate is replaced with a low viscosity liquid and completely eliminated. The base material that has passed through this injection action area is heated to a temperature higher than the boiling point of the low viscosity liquid by the low viscosity liquid evaporation mechanism. As a result, the low viscosity liquid impregnated into the base material is evaporated and separated, and in combination with the fact that the base material processing chamber is maintained in a low viscosity liquid vapor atmosphere by the steam atmosphere retention mechanism, the base material becomes a low viscosity liquid. It is delivered to the substrate outlet in a state containing only steam.

Further, according to the base material heating mechanism and the nucleate boiling generation mechanism, the base material is heated to the boiling point or higher of the low viscosity liquid by the base material and the heating mechanism, and the nucleate boiling generation mechanism generates the low viscosity liquid or the like. Steam is injected. As a result, rapid nucleate boiling occurs in the base material, and the nucleate boiling energy physically opens the base material, replacing the air in the base material with low-viscosity liquid vapor and completely eliminating it. Ru. Thereafter, since the interior of the substrate processing chamber is maintained in a low-viscosity liquid-vapor atmosphere, the substrate is brought to the substrate outlet section in a state containing only low-viscosity liquid-vapor.

The substrate from which air has been excluded in this way is brought directly from the substrate outlet into the varnish in the varnish reservoir and is uniformly and thoroughly impregnated with the varnish during passage through the varnish.

〔Example〕

Hereinafter, the structure of the present invention will be specifically explained based on the embodiments shown in FIGS. 1 to 8.

FIG. 1 shows the first implementation of the varnish impregnation apparatus according to the present invention, in which 1 is a base material, 2 is a varnish storage tank, 3 is a base material processing chamber, 4 is a traveling guide mechanism, 5 is a low viscosity liquid injection mechanism, 6 is a low viscosity liquid evaporation mechanism, and 7 is a steam atmosphere holding mechanism.

The base material 1 is a sheet-like material made of a fibrous material.

Woven and non-woven fabrics consisting of synthetic, natural, organic and inorganic fibers, such as paper, glass fiber cloth, glass fiber non-woven fabrics.

Carbon fiber cloth, carbon fiber nonwoven fabric, aramid fiber cloth, aramid fiber nonwoven fabric, etc. are used.

The varnish storage tank 2 has an open top and stores a predetermined amount of varnish 8. As the varnish 8, a thermosetting resin varnish is generally used, but varnishes of thermoplastic resins, natural resins, etc., solvent-free liquid synthetic resins, liquid natural resins, etc. can also be used.

Note that the varnish 8 is maintained at a predetermined temperature by a temperature control device (not shown).

The substrate processing chamber 3 includes an inclined main body 9 , a substrate inlet 10 erected at the lower end thereof, and a vertically disposed upper end of the main body 9 and opened into the varnish 8 of the varnish storage tank 2 . The base material outlet part 11 is formed into an N-shaped cylinder. A low viscosity liquid storage tank 13 that stores a predetermined amount of low viscosity liquid 12 is connected to the lower end of the main body 9 . As the low viscosity liquid 12, one having sufficient wettability to the base material 1 is used. Specifically, the varnish has a lower viscosity than varnish 8 and varnish 1
A solvent having a viscosity of 00 cP or less is used, but it is preferable to use a solvent of the same quality as the solvent blended into the varnish to be impregnated. Note that the peripheral wall of the processing chamber including the peripheral wall of the low-viscosity liquid storage tank 13 is as follows.

It is composed of a heat insulating wall 3a.

The traveling guide mechanism 4 includes at least a guide roll 14 disposed at the lower end of the processing chamber main body 9, a plurality of guide rolls 15 disposed in the varnish 8 of the varnish storage tank 2, and the processing chamber main body 9. A heating roll 19 (described later) disposed at the upper end of the
The base material 1 is transferred from the base material inlet section 10 to the base material processing chamber 3.
Inside the material processing chamber 3, the material follows an N-shaped path that follows its shape, reaches the varnish storage tank 2 from the base material outlet section 11, and is guided so that it can pass through the varnish 8. be. Note that at least the negative roll 15 among the guide rolls 15 is configured as an expanded roll that can apply stretching force to the base material 1 in its width direction.

The low viscosity liquid injection mechanism 5 includes a nozzle group 16 disposed in the injection action area 5a on the lower end side of the processing chamber main body 9 and a low viscosity liquid supply pipe led to the nozzle group 16 from the low viscosity liquid storage tank 13. 17 and a pump 18 interposed therebetween. The nozzle groups 16 are arranged to face each other on both sides of the base material 1, and by operating the pump 18, the low viscosity liquid 12 from the low viscosity liquid storage tank 13 is uniformly sprayed onto both sides of the base material 1.

The low-viscosity liquid evaporation mechanism 6 includes a heating roll 19 rotatably provided in a heating area 6a on the upper end side of the processing chamber main body 9 to follow the rotation of the substrate 1. This heating roll 19 is
The base material 1 is heated to a temperature higher than the boiling point of the low viscosity liquid 12 to evaporate the low viscosity liquid 12 impregnated therein. Incidentally, the base material heating temperature by the heating roll 19 is controlled by a temperature control device (not shown), and its evaporation ability is determined by the maximum amount of low viscosity impregnated into the base material 1 and brought into the heating action area 6a. It is said to be sufficient to evaporate the liquid. Note that the heating roll 19 may be driven to rotate in the direction in which the base material 1 passes. in this case,
It goes without saying that the circumferential speed of the roll is made to match the traveling speed of the substrate 1. The steam atmosphere holding mechanism 7 mainly consists of a steam generating means that generates a low-viscosity liquid vapor 12a within the substrate processing chamber 3. However, in this example, further.

Condensation prevention means that maintains the heating action area 6a and the substrate discharge area 7a extending from the area 6a to the end of the substrate outlet section 11 at a temperature higher than the condensation temperature of the low viscosity liquid vapor 12a, and and low viscosity liquid recovery means for condensing and recovering the viscous liquid vapor 12a.

The steam generating means includes a nozzle group 22 disposed at the base material outlet section 11, a steam generating tank 23 equipped with a heater 23a, and a steam generating tank 23 guided from the steam generating tank 23 to the nozzle group 22... A steam supply pipe 24 is provided. The low viscosity liquid 12 in the steam generation tank 23 is heated and evaporated by the heater 23a, and the low viscosity liquid vapor 12a is supplied to the substrate processing chamber 3 from the nozzle group 22 through the steam supply pipe 24. . Further, the low-viscosity liquid evaporation mechanism 6 generates a low-viscosity liquid vapor 12a within the substrate processing chamber 3, and constitutes a part of the vapor generation means. Therefore, the inside of the substrate processing chamber 3 is filled with the low-viscosity liquid vapor 12a by the vapor supplied from the nozzle group 22 and the vapor generated by the low-viscosity liquid evaporation mechanism 6. Note that the steam generation tank 23 is connected to the low viscosity liquid storage tank 1 by a low viscosity liquid supply pipe 25 with a pump 25a interposed therein.
The low viscosity liquid 12 of No. 3 is replenished as appropriate.

The condensation prevention means is formed by forming the upper end portion of the processing chamber main body portion 9 and the peripheral wall of the substrate outlet portion 11 into a double wall structure consisting of a heat transfer wall 20a serving as an inner wall and a heat insulating wall 20b serving as an outer wall. Supply appropriate heating medium to.

By causing the fluid to flow, the heating action area 6a and the base material discharge area 7a are heated to a temperature higher than the condensation temperature of the low viscosity liquid vapor 12a,
Constructed to retain heat. In particular, the base material outlet section 11
The open end portion 11a of the opening end portion 11a is configured in a nozzle shape, and is made as narrow as possible within a range through which the substrate l can smoothly pass through the substrate passage in the portion 11a. Note that the varnish liquid level within this open end portion 11a is located at the heat transfer wall 20.
The low viscosity liquid 12 is heated to a temperature higher than its boiling point by a. By the way, the end of the base material outlet section 11.

As shown in FIG. 2, the opening end portion 1 is composed of a metal nozzle-shaped body 21 having heat medium flow holes 21a...
The varnish liquid level in 1a may be heated above the boiling point of the low viscosity liquid 12. In this case, the outer surface of the nozzle shaped body 21 is provided with heat insulation to prevent the varnish 8 around it from being heated. The low viscosity liquid recovery means preferably includes the low viscosity liquid storage tank 13 and the cooler 26.2 disposed in the storage tank 13 and the base material inlet section 10.
7. The cooling capacity of the coolers 26 and 27 is set so that the amount of steam condensed on the base material inlet portion 10 side by the single cooler 26 and 27 and the amount of steam generated by the steam generating means are in equilibrium, It is devised to maintain the steam pressure within the substrate processing chamber 3 within a certain range.

Further, the cooler 26 prevents evaporation of the low viscosity liquid 12 in the low viscosity liquid storage tank 13, and the cooler 27 prevents the low viscosity liquid 12 from evaporating at the base material inlet portion 1.
Steam leakage from 0 is prevented. This prevention of steam leakage is better achieved in conjunction with the advancing action of the base material 1, and the base material passage in the base material inlet portion 10 is closed as much as possible within a range that does not obstruct the passage of the base material 1. By keeping it narrow, it can be done almost perfectly. Note that this low-viscosity liquid recovery means is provided as necessary, and is not necessarily required depending on conditions such as the properties of the low-viscosity liquid 12 used.

For example, it is also possible to discharge the low-viscosity liquid vapor 12a from the substrate inlet portion 10, or to install the low-viscosity liquid storage tank 13 separately from the substrate processing chamber 3.

According to the varnish impregnation apparatus configured as above, the varnish impregnation method according to the present invention is carried out as follows.

That is, the base material 1 is run at a predetermined speed while the inside of the base material processing chamber 3 is maintained in a low viscosity liquid vapor atmosphere.

Then, the base material 1 is brought into the base material processing chamber 3 from the base material inlet portion 10 and reaches the injection action area 5a.

The low viscosity liquid 12 is uniformly sprayed onto both surfaces from the nozzle group 16.

At this time, the base material 1 is physically opened by the injection energy of the low-viscosity liquid 12. Therefore, all the air in the base material 1 is replaced with the low viscosity liquid 12 and eliminated.

Next, the base material 1 brought to the heating action area 6a is heated by a heating roll 19 to a temperature higher than the boiling point of the low viscosity liquid 12, and the low viscosity liquid 12 impregnated in the base material 1 is evaporated and removed.

The substrate 1 from which the impregnating liquid has been evaporated passes from the heating action area 6a to the substrate discharge area 7a, and is brought into the varnish 8 of the varnish storage tank 2 from the substrate outlet section 11.

At this time, since the heating action area 6a and the base material discharge area 7a are kept warm at a temperature higher than the condensation temperature of the low viscosity liquid vapor 12a, this is combined with the supply of the low viscosity liquid vapor 12a from the nozzle group 22, etc. Thus, a complete low-viscosity liquid-vapor atmosphere is maintained from the heating roll 19 to the varnish liquid level in the substrate outlet section 11. Therefore, air does not re-enter the base material 1 and the low viscosity liquid vapor 12a does not condense and adhere to the base material 1.
is brought directly into the varnish 8 from the base material outlet section 11 in a state containing only a trace amount of low viscosity liquid vapor 12a.

Therefore, while the substrate 1 passes through the varnish 8 thereafter, the varnish 8 is evenly and sufficiently impregnated into the substrate 1. This impregnation with the varnish 8 is carried out more effectively when the base material 1 is subjected to the action of the expander type guide roll 15 in the varnish 8. As a result, a void-free prepreg of extremely high quality is obtained.

By the way, the temperature of the varnish 8 is generally lower than the saturated vapor temperature of the low viscosity liquid 12, so when the base material 1 enters the varnish 8, the low viscosity liquid vapor 12a contained therein will be condensed. . However, the liquid level part of the varnish 8 in the base material outlet part 11 is
) is heated to a temperature higher than the boiling point of the low-viscosity liquid 12, so that the condensed liquid accompanying the entry of the base material 1 will be re-evaporated. Therefore, together with the fact that the amount of vapor contained in the base material 1 is extremely small, the low viscosity liquid 12 hardly enters into the varnish 8 as the base material 1 enters, and the varnish 8 is diluted. There is no possibility of becoming Furthermore, there is a risk that the solvent etc. in the varnish 8 will evaporate due to the heating by the heat transfer wall 20a (or the nozzle shaped body 21) and enter the substrate processing chamber 3; Material outlet part 1
By making the opening end portion 11a of the substrate 1 narrow enough to allow the substrate 1 to pass through, and by minimizing the boundary area between the substrate discharge area 7a and the varnish 8, the substrate 1 can pass through the narrow opening end portion 11a. Combined with moving in the incoming direction, you can definitely avoid it.

FIG. 3 shows a second embodiment. In this embodiment, the low viscosity liquid evaporation mechanism 6 is used to heat the substrate 1 by radiant heat transfer from the peripheral wall of the substrate processing chamber 3. It is configured to do so. That is, the peripheral walls of the heating action area 6a and the base material discharge area 7a extending from the vicinity of the injection action area 5a to the end of the base material outlet section 11 are made up of a heat transfer wall 20'a, which is an inner wall, and a heat insulating wall 20'b, which is an outer wall. By configuring the double wall structure and supplying and flowing a heating medium higher in temperature than the double walls 20a and 20b, the base material 1 that has passed through the injection action area 5a is heated to the heat transfer wall 20'a. The low viscosity liquid 12 is heated to the boiling point or higher by radiant heat transfer from the liquid 12. In this case, since the heating roll 19 is not required, a guide roll 28 is provided at the bent portion of the substrate processing chamber 3. Of course.

A heating roll may be used as the guide roll 28, but in that case, a roll having a small heat capacity may be used. In addition,
The functions of Structure 2 other than those described above are the same as those of the first embodiment.

In addition, FIGS. 4 and 5 show the third embodiment,
In this embodiment, in particular, the low viscosity liquid injection mechanism 5 is
A spray roll 29 which also serves as a guide roll is disposed at a bent portion of the substrate processing chamber 3 on the side of the substrate entrance 10, and the spray roll 29 is configured to spray the low viscosity liquid 12 onto the substrate 1. It is. That is, the injection roll 29 is a porous roll made of porous sintered metal or the like, and is fitted onto a hollow shaft 30 to which the low-viscosity liquid supply pipe 17 is connected. When the pump 18 is operated to supply the low viscosity liquid 12 from the low viscosity liquid storage tank 13 to the hollow shaft 30 from the low viscosity liquid supply pipe 17, the low viscosity liquid 12 flows through the communication hole group of the hollow shaft 30. 30
a... passes through the spray roll 29 and is uniformly sprayed onto the base material 1. The base material 1 is opened by this low viscosity liquid jet.

The air in the substrate 1 is replaced with a low viscosity liquid 12. At this time, a fluid 1 of the low-viscosity liquid 12 is formed between the base material 1 and the spray roll 29, and both 1 and 29 are maintained in a non-contact state. Therefore, the support structure of the spray roll 29 can guide the base material 1 well whether it is rotating or non-rotating. Note that the effects of configuration 2 other than those described above are the same as those of the second embodiment.

Further, in each of the above embodiments, the base material 1 is opened by the injection energy of the low viscosity liquid 12, but in the fourth embodiment shown in FIG. 6, the base material 1 is opened by the nucleate boiling energy. I have to.

That is, in this embodiment, the varnish impregnation apparatus includes a varnish storage tank 2, a substrate processing chamber 3, a traveling guide mechanism 4, a steam atmosphere holding mechanism 7, a substrate heating mechanism 31, and a nucleate boiling generation mechanism 32.
It is equipped with the following. Note that the functions of configuration 2 other than the base material heating mechanism 31 and the nucleate boiling generation mechanism 32 are the same as those in the first embodiment, so detailed explanation thereof will be omitted.

The substrate heating mechanism 31 includes a heating roll 33 disposed in a heating area 31a on the substrate outlet section 11 side of the substrate processing chamber 3. This heating roll 33 is similar to the heating roll 19 described above, and heats the base material 1 to a temperature higher than the boiling point of the low-viscosity liquid 12.

The nucleate boiling generation mechanism 32 includes a heating roll 3 that the base material 1 contacts.
A nozzle group 34 is provided on the peripheral wall of the substrate processing chamber 3 so as to face each other in three parts. Note that the nozzle group 34
... are arranged in parallel in the width direction of the base material 1. A low viscosity liquid supply pipe 17 led from the low viscosity liquid storage tank 13 is connected to the nozzle group 34..., and by operating the pump 18, water is supplied from the nozzle group 34... to the heating action area 31a. The low viscosity liquid 12 is sprayed uniformly onto a portion of the base material 1.

Note that the base material heating mechanism 31 and the nucleate boiling generation mechanism 32 also generate the low viscosity liquid vapor 12a in the base material processing chamber 3, and constitute a part of the steam atmosphere holding mechanism 7.

According to the varnish impregnating apparatus configured as above, the varnish impregnating method according to the present invention is carried out as follows.

That is, when the base material 1 reaches the heating action area 31a, the low viscosity liquid 12 is injected from the nozzle group 34 onto the base material 1 which has been heated by the heating roll 33 to a temperature higher than the boiling point of the low viscosity liquid 12. , rapid nucleate boiling occurs in the base material 1. Then, the base material 1 is physically opened by this nucleate boiling energy. As a result, air in the base material 1 is completely eliminated.

Thereafter, as in the first embodiment, the base material 1 is introduced into the varnish 8 in a state containing only the low viscosity liquid vapor 12a, so that the base material 1 is evenly and sufficiently impregnated with the varnish 8. That will happen.

Further, FIG. 7 shows a fifth embodiment, in which the substrate heating mechanism 31 is configured to utilize radiant heat transfer from the peripheral wall of the substrate processing chamber 3. That is,
The peripheral wall portion of the processing chamber excluding the substrate entrance portion 10 side is configured to have a double wall structure 20'a, 20'b similar to the second embodiment, and an appropriate heating medium is supplied and made to flow therein. , the base material 1 that has passed through the guide roll 14 is placed on the heat transfer wall 20'a.
The low viscosity liquid 12 is heated to the boiling point or higher by radiant heat transfer from the low viscosity liquid 12. In addition, the nucleate boiling generation mechanism 32 includes the double structure wall 20'a
, 20'b, the low viscosity liquid vapor 12a is injected onto the base material 1 in the heating action area 31a. That is, an injection roll 35 which also serves as a guide roll is disposed in the heating action area 31a. This injection roll 35 has the same structure as the injection roll 29 in the third embodiment, and the low viscosity liquid vapor 12a supplied from the steam supply pipe 24 to the hollow shaft 36 is connected to the communication hole group (not shown) of the hollow shaft 36. figure)
The liquid then passes through a porous roll 35 and is uniformly sprayed onto the heated substrate 1 . As a result, nucleate boiling occurs as in the fourth embodiment, and the base material 1 is opened. A fluid film of low viscosity liquid vapor 12a is formed between the base material 1 and the spray roll 35, and the two 1° 34 are kept in a non-contact state.

Furthermore, in this embodiment, the base material outlet section 11 is configured with only a nozzle-shaped portion, that is, a portion corresponding to the open end portion 11a in the above embodiment, and from the heating action area 3'l a to the end of the base material outlet section 11. Let the distance be minimal. Therefore, the nozzle group 22 that supplies the low viscosity liquid vapor 12a...
is not particularly necessary and is obsolete. That is, in this embodiment, no special configuration is required as the steam generation means and condensation prevention means of the steam atmosphere holding mechanism 7, and these means are replaced by the base material heating mechanism 31 and the nucleate boiling generation mechanism 32. This configuration is also possible in the embodiments described above.

Note that the effects of configuration 2 other than those described above are the same as those of the fourth embodiment.

Further, FIG. 8 shows a sixth embodiment, in which the nucleate boiling generation mechanism 32 is connected to the heating action area 31.
A nozzle group 37... is arranged at a.

The low viscosity liquid vapor 12a is uniformly injected from the nozzle group 37 onto both sides of the base material 1 heated above the boiling point of the low viscosity liquid 12 in the heating action area 31a, thereby causing nucleate boiling in the base material 1. It is configured as follows. The other functions of the configuration 9 are the same as those of the fifth embodiment except that a guide roll 38 is provided in place of the injection roll 35.

〔Effect of the invention〕

As can be easily understood from the above explanation, according to the method of the present invention, the base material is physically opened by injection energy or nucleate boiling energy of a low viscosity liquid in a low viscosity liquid vapor atmosphere. Therefore, air removal before varnish impregnation can be completely carried out, and the substrate can be brought into the varnish in a state containing only low viscosity liquid vapor. therefore,
The base material is uniformly and thoroughly impregnated with varnish, and a void-free prepreg of extremely high quality can be obtained.

Moreover, according to the apparatus of the present invention, the above method can be carried out suitably, and the base material can be efficiently impregnated with varnish.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a first embodiment of the varnish impregnating device according to the present invention, FIG. 2 is an enlarged sectional view of a main part showing a modification thereof, and FIG. 3 is a sectional view showing a second embodiment. Figure 4.
The figure is a cross-sectional view of the main part showing the third embodiment, FIG.
FIG. 7 is a sectional view showing the fifth embodiment, and FIG. 8 is a sectional view showing the main parts of the sixth embodiment. Air atmosphere holding mechanism, 8... Varnish, 1o... Base material inlet part, 11... Base material outlet part, 12... Low viscosity liquid, 1
2a...Low viscosity liquid vapor, 31...Base material heating mechanism, 3
1a... Heating action area by base material heating mechanism, 32...
- Nucleate boiling generation mechanism.

Claims (4)

[Claims] (1) A sheet-like base material made of a fibrous material is passed through a low viscosity liquid vapor atmosphere and then passed through a varnish. A low viscosity liquid is jetted, and the jet energy opens the base material, replaces the air in the base material with the low viscosity liquid, and heats and evaporates the low viscosity liquid impregnated into the base material. A varnish impregnation method characterized by: (2) A sheet-like base material made of a fibrous material is passed through a low viscosity liquid vapor atmosphere and then passed through a varnish. This is heated above the boiling point of the low viscosity liquid, and the low viscosity liquid or its vapor is injected to cause nucleate boiling, and the nucleate boiling energy opens the base material and removes the air in the base material. A varnish impregnation method characterized in that varnish is replaced with low viscosity liquid vapor. (3) A varnish storage tank that stores varnish, a base material processing chamber that includes a base material inlet and a base material outlet that opens into the varnish in the varnish reservoir, and a sheet-like base made of a fibrous material. a travel guide mechanism that guides the material to travel sequentially through the base material inlet, the base material processing chamber, the base material outlet, and the varnish storage tank;
A steam atmosphere holding mechanism that maintains a low-viscosity liquid vapor atmosphere in the substrate processing chamber, a low-viscosity liquid injection mechanism that injects a low-viscosity liquid onto the substrate in the substrate processing chamber, and an injection action area by the low-viscosity liquid injection mechanism. A varnish impregnation device comprising: a low viscosity liquid evaporation mechanism that heats the base material to a temperature higher than the boiling point of the low viscosity liquid in a heating action area on the base material outlet side. (4) A varnish storage tank that stores varnish, a base material processing chamber that includes a base material inlet and a base material outlet that opens into the varnish in the varnish reservoir, and a sheet-like base made of a fibrous material. a travel guide mechanism that guides the material to travel sequentially through the base material inlet, the base material processing chamber, the base material outlet, and the varnish storage tank;
A vapor atmosphere holding mechanism that maintains a low viscosity liquid vapor atmosphere in the substrate processing chamber, a substrate heating mechanism that heats the substrate to a temperature above the boiling point of the low viscosity liquid in the substrate processing chamber, and a heating action area by the substrate heating mechanism. 1. A varnish impregnating device comprising: a nucleate boiling generating mechanism that injects a low viscosity liquid or its vapor onto a base material to cause nucleate boiling.