JPH02305829A - Method and apparatus for impregnation with resin - Google Patents

Abstract

PURPOSE:To impregnate a fiber sheet with a resin smoothly and uniformly in good efficiency without encountering any squeezing phenomenon by rolling many spheres on a laminate of the fiber sheet with the resin under specified conditions. CONSTITUTION:Many spheres are rolled on a laminate of a fiber sheet (e.g. carbon fiber sheet) with a resin (e.g. epoxy resin) while keeping the spheres in contact with the sheet under pressure.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention mainly applies to fiber reinforced plastics (hereinafter referred to as FRP).
It is abbreviated as ), in particular, a novel resin impregnation method and apparatus for manufacturing flat materials consisting of sheet-like reinforcing fibers and a matrix resin.

(Prior Art) One form of FRP or a form of intermediate material for obtaining FRP is a structure in which a sheet-like material made of reinforcing fibers is impregnated with resin.

The above-mentioned material is generally known as prepreg, and the present invention primarily relates to a high-speed resin impregnation method and apparatus for manufacturing this prepreg.

In resin impregnation in this field, regardless of whether the resin is thermosetting or thermoplastic, the common element is to fluidize the resin using a solvent or heating to impregnate the resin into the fiber layer. The method that is currently widely used is the hot melt roller impregnation method, in which the resin is fluidized by heating and then impregnated into the fiber sheet by the pressure of a roller.

Representative examples of this method are shown in FIGS. 6 and 7.

In FIG. 6, the material to be impregnated 51 has various sheet forms, such as a unidirectional sheet in which reinforcing fibers are aligned in parallel in one direction, or a fabric obtained by weaving reinforcing fibers.

The sheet is laminated onto a resin 53 coated on a release paper 52 and passed between a pair of heated nip rollers 54, 55 to be impregnated with resin. In such roller nip systems, it is common to heat the resin with a heater plate or the like before reaching the nip point in order to promote fluidization of the resin.

The biggest drawback of such a roller nip method is that the resin to be impregnated is squeezed forward by the rollers before it is impregnated into the sheet layer, making it impossible to impregnate it uniformly. In order to avoid this squeezing phenomenon, the nip row 9
The gauge is set between 54 and 55 to prevent squeezing. However, such means cause a pressure drop in the nip and cannot increase the rate of resin impregnation. Therefore, in order to increase productivity, one method is used in which multiple nip rollers are used to sequentially apply pressure.

In addition, the method shown in FIG. 7 is such that a release paper 52, a resin 53, and a sheet material 51 to be impregnated are sequentially laminated on a heater plate 56 to the extent that squeezing does not occur on a roll 57 in which one or several rolls are combined. This is a method in which impregnation is carried out by applying pressure of 100 mL and moving it back and forth on the laminate.

Although this method can increase the impregnation speed more than the method shown in FIG. 6, it is still not possible to expect a large speed increase.

(Problem to be solved by the invention) In any case, in the conventional resin impregnation method for FRP manufacturing, it is difficult to increase the speed to avoid the squeezing phenomenon of the resin, resulting in poor productivity. was.

Therefore, the purpose of the present invention is to develop an impregnation mechanism that does not cause the resin squeezing phenomenon even during high-speed operation, and thereby
The objective is to improve the efficiency and speed of resin impregnation in the production of.

(Means and effects for solving the problem) As a result of various studies to achieve this objective, the feature is that a large number of spherical bodies are rotated and moved onto a laminate of a fiber sheet and a resin in a pressurized contact state. The present invention has been achieved, which comprises a resin impregnation method and apparatus.

Hereinafter, the present invention will be explained in detail along with its operation based on the drawings.

FIG. 1 is a schematic diagram showing an example of the mechanism of the present invention.

An object to be impregnated, for example, a tow alignment sheet (hereinafter abbreviated as sheet-like material) 1 is laminated on a matrix resin film 3 coated on the surface of a release paper 2, and is supplied to a heating roll 4. .

The matrix resin 3 is fluidized by heating to a level that allows it to be impregnated into the sheet-like material 1.

The sheet-like material l used here is mainly made of reinforcing fibers used in FRP production, and may be a sheet made by aligning the above-mentioned reinforcing fibers in one direction, a woven fabric obtained by weaving reinforcing fibers, or It is a fibrous porous body such as a braided fabric or a nonwoven fabric.

The resin 3 to be impregnated is a resin that can be fluidized by heating, such as a B-stage thermosetting resin of an epoxy resin ring, a thermoplastic resin such as polyamide or polyester, or a resin that can be fluidized by a solvent or the like. The resin 3 is supplied separately from the sheet material as illustrated in FIG. 1, and is laminated prior to impregnation.
The impregnation method of the present invention is generally carried out in a form in which the sheet-like material 1 and the resin 3 are laminated in a layered manner. It is true.

However, other forms include a state in which the resin to be impregnated is dispersed in lumps in a sheet-like object, a state in which the resin to be impregnated is in the form of fibers and is aligned together with reinforcing fibers in a sheet-like object,
Alternatively, there are various forms in which the sheet-like material may be a woven fabric made of reinforcing fibers and a yarn material made of the resin to be impregnated, and in the present invention, the form in which the sheet-like material and the resin to be impregnated are supplied prior to impregnation is limited. It's not a thing. However, in the present invention, all of these supply forms will be referred to as "laminates". FIG. 1 shows, as an example, a supply form in which resin 3 and sheet-like material 1 are laminated.

The laminate of the sheet-like material 1, the resin 3, and the release paper 2 is impregnated by a large number of spherical bodies 5 which rotate and move under pressure via the film-like material 8.

That is, in FIG. 1, a cylindrical body (hereinafter referred to as a roll) 6
has a large number of spherical bodies 5 on its surface, and the spherical bodies 5 are fixed to the surface of the roll 6 by a carrier 7. However, the spherical body 5 can freely rotate on the surface of the roll 6.

Such a structure is similar to that of a ball guide bearing for a guisette, for example, and the individual spherical bodies 5 are positioned relative to each other by a carrier 7.

The arrangement of the spherical bodies 5 on the roll surface is such that the spherical bodies 5 are arranged in a spherical shape, for example, as shown in the developed view of FIG. A large number of bodies 5 are arranged in one row at equal pitches perpendicular to the circumferential direction of the roll 6, and the positions of the spherical bodies are slightly shifted between adjacent rows. Note that the arrow in the figure indicates the axial direction of the roll 6 (the direction perpendicular to the paper surface in FIG. 1). A roll 6 having a large number of freely rotating spherical bodies 5 on its surface (hereinafter collectively referred to as an impregnation roll) is placed under pressure on the laminate through a film material 8, and the roll 6 is When rotated in the direction of the arrow in the figure, each spherical body 5 rotates in the direction of the arrow in the figure and moves in the direction of the arrow 9 at the same time. This situation will be explained with reference to FIG. FIG. 3 shows a cross section taken along line A-A' in FIG.

The laminate consisting of the sheet material 1, resin 3, and release paper 2 is subjected to local pressure by the spherical bodies 5, but since there are non-pressure areas between the spherical bodies, the fluidized resin is Spheroid 5
At the same time as it flows into the surrounding non-pressurized area, impregnation into the fiber layer is promoted.

When the surface speed of the roll 6 is set higher than the moving speed of the laminate, the laminate can be repeatedly impregnated by a large number of spherical bodies 5.5-.

The impregnation effect due to the repeated pressure generated by the movement of the spherical bodies is calculated as follows: the surface speed of the roll 6 is V''/min, the speed of the laminate is v''''/min, and the density of the spherical bodies is 1 piece/aa.
The number of repeated pressure cycles per square centimeter for the laminate is 50 (v-2v)n times/-, which is the reason why the present invention achieves a high-speed impregnation effect.

In such an impregnation method, since there is a non-pressure part between the heating roll 4 and the impregnation roll, the resin to be impregnated is not squeezed out in front of the nip point (to the right in the drawing). Note that the rotation direction of the heating roll 4 is not particularly limited, but it is generally rotated in the same direction as the laminate. Further, in FIG. 1, the film-like material 8 is for preventing contamination of the spherical bodies 5, and is not necessarily essential for the impregnation mechanism.

The present invention can also be realized by the impregnation roll shown in FIG. That is, the spherical bodies 5 on the surface of the roll 4 are maintained at intervals by spacers 10, and their entire outer peripheral surface is covered with a cylindrical rubber elastic film 11. Such a structure ensures smooth rotation of the impregnating roll. and is effective in preventing dust.

The present invention can also be practiced with the impregnation mechanism shown in FIG. A bell 12 is disposed along a part of the circumferential surface of the heating roll 4 and is driven to rotate at a predetermined distance from the circumferential surface. The interval is the diameter of the spherical body 5 and the laminated body (1, 2,
The length of the belt 12 is set to be approximately equal to the length plus the thickness of 3), and the belt 12 is driven by a drive roll. While moving, the laminated body (
1, 2, 3) and move the spherical bodies 5, 5-. Reference numeral 13 is a casing, and a part of its inner surface has a guide surface for moving the spherical body 5 along the rotating portion of the belt 12.

A film-like material 8 is layered on a laminate (1, 2, 3) of sheet-like materials to be impregnated with matrix resin coated on a release paper, and the film-like material 8 is guided onto a heating roll 4 to fluidize the matrix resin. urge

The spherical bodies 5 are pressurized and rotated against the laminate (1, 2, 3) by the belt 12, and at this time, the spherical bodies 5 impregnate the sheet material and then fall from the upper part of the belt 12. It is transported again to the point of action.

This method allows the use of a significantly larger number of spheres and allows faster impregnation than the apparatus shown in FIGS. 1-4 above.

(Example) Hereinafter, the present invention will be specifically explained with reference to Examples.

Example 1 150g/d of 12 carbon fiber tows drawn in parallel
The unidirectional carbon fiber sheet was layered on a matrix resin film coated with 82 g/l epoxy resin on release paper and guided onto a 1 m diameter heat drum heated to 120°C and rotating at a surface speed of 1 m/min. Ta. At a position 500H from the point where the laminate came into contact with the heat drum, the impregnation roll shown in Figure 1 was applied through a 20 micron thick polypropylene film to a linear pressure of 1 kg/cm, and the surface of the heating drum and the spheroidized bottom were heated to 1 kg/cm. Set the minimum distance (gap) to the vertex to 0
35n+, and the rotational speed of the roll 6 was set to 200 revolutions/minute in the direction of the arrow. In addition, an impregnating roll with a linear pressure of 5 kg/min and a gap of 0.25 m and a rotation speed of 200 rpm was placed 250 m behind the impregnating roll (left side in Fig. 1), and an impregnating roll with a rotation speed of 200 rpm was placed behind the impregnating roll. 500n
At a position of 7,501 m, a sinew roll with a diameter of 100 mm, a sinew roll with a shallow groove of 1 pinch on the surface, a sinew roll with a shallow groove of 1 pinch on the surface, and a roll with a flat surface are placed. It was pressurized at a pressure of 10 kg/cra.

The impregnation roll used here has a structure in which the roll 6 in FIG. 1 has a diameter of 100 mm, and spherical bodies 5 having a diameter of 6 nm are arranged on the surface thereof in a staggered manner at a pitch of 8 nm. Due to the spherical bodies 5, the laminate consisting of reinforcing fibers, matrix resin, release paper and top film is subjected to discontinuous non-abrasive pressure of about 2,000 times/d per impregnated roll.

Under the above conditions, no squeezing of the resin occurred, and the obtained prepreg was completely impregnated with resin, and its appearance was extremely good.

On the other hand, when all rolls with flat surfaces are used, it is necessary to operate at a lower linear pressure to prevent the resin from squeezing out, and the speed must be lowered to 1.317 minutes to obtain a good impregnation state. I couldn't get it.

Example 2 Instead of the impregnating roll used in Example 1, impregnation was carried out using the apparatus shown in FIG.

A 6fi steel ball is used as the spherical body 5, molybdenum disulfide powder is sprinkled to reduce rotational friction between the steel balls, and one top film is further layered to prevent contamination of the top film 8. Impregnation was performed. The conveyor bell H2 was made of rubber and was tensioned by drive rolls to create pressure on the steel balls. Furthermore, the gap between the conveyor belt 12 and the heating roll 4 widens at the entrance of the stack. It was designed to gradually narrow towards the exit.

The surface speed of the conveyor belt 12 is set to 50a+/min.
Soaked. At this time, satisfactory impregnation could be achieved by applying a calculated continuous non-abrasive pressure of 5,200 times/cd to the laminate.

(Effects of the Invention) As described above in detail, according to the present invention, since point-like pressure is applied by the spherical body over the entire surface of the sheet-like object without any scratches, a non-pressing part is instantly created around the pressing part. I can,
As the resin flows here, it is smoothly impregnated into the sheet-like material, so that uniform and efficient impregnation is realized, and processing speed can be increased.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing an example of an apparatus for embodying the present invention, Fig. 2 is a surface development view of the same impregnating roll, Fig. 3 is a cross-sectional view taken at A- in Fig. 1, and Fig. 4 is a schematic diagram showing an example of an apparatus for embodying the present invention. FIG. 5 is a side view showing another impregnation roll, FIG. 5 is a schematic diagram showing still another example of the apparatus, and FIGS. 6 and 7 are schematic diagrams for explaining conventional impregnating properties. Explanation of the main parts of the diagram 1 - Sheet material 3 - Resin 4 - Heating roll 5 - Spherical body 11 - Elastic coating 12 - Belt Fig. 1 Fig. 4 Fig. 1

Claims (1)

[Scope of Claims] 1. A resin impregnation method characterized by rotating and moving a large number of spherical bodies onto a laminate of a fiber sheet and a resin in a pressurized contact state. 2. An apparatus for use in the resin impregnation method according to claim 1, characterized by having a large number of rotatable spherical bodies on the roll surface. 3. Used in the resin impregnation method according to claim 1, characterized in that a large number of freely rotatable and freely movable spherical bodies are placed in pressure contact between the laminate and a belt-like object that is driven and rotated. device to do.