JP3032029B2 - Method and apparatus for producing fiber-reinforced thermoplastic resin sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for producing a fiber-reinforced thermoplastic resin sheet in which continuous fibers are impregnated with a thermoplastic resin.

[0002]

2. Description of the Related Art As a method for producing a fiber-reinforced thermoplastic resin sheet by hot-melt impregnating a thermoplastic resin into a fiber, a fiber sheet as disclosed in JP-A-1-61561 is used. A method of impregnating a thermoplastic resin by passing between a pair of belts, including a belt having a thermoplastic resin coating film, which is heated to a temperature higher than the softening point of the resin and is known.

However, Japanese Patent Application Laid-Open No.
In the method described in Japanese Patent Application Laid-Open No. H10-157, a thermoplastic resin is supplied in a thin film form from a film forming die connected to an extruder on a belt. In the case of processing into a thin film, resin gelled material, solid foreign matter such as thermal degradation products of the resin, bubbles due to the pyrolysis gas of the resin are generated in the film, and in the process of impregnating the fibers, This is a cause of impregnation failure of the fiber, which is a problem. In addition, when extruding a super-heat-resistant thermoplastic resin by melting and extruding, the operating temperature of the extruder is set to exceed 400 ° C., and when operating for a long time, the resin stagnation portion in the extruder thermally decomposes, There is a restriction that normal film formation becomes impossible and the continuous operation time is shortened.

[0004]

SUMMARY OF THE INVENTION The present invention provides a fiber-reinforced thermoplastic resin sheet in which the above-mentioned disadvantages of the prior art have been solved. That is, a method for producing a fiber-reinforced thermoplastic resin sheet according to the present invention is a method for producing a fiber-reinforced thermoplastic resin sheet by hot-melting and impregnating a reinforcing fiber with a thermoplastic resin fine powder. The method is characterized in that the thermoplastic resin fine powder supplied from the supply section is supplied with a uniform thickness to the lower belt surface by vibrating, and then is thermally melted to impregnate the reinforcing fibers. [Configuration of Fine Powder Resin Supply Unit] A storage tank for storing the fine powder resin, a quantitative supply device for supplying the fine powder resin in the storage tank, and a lower belt for supplying the fine powder resin quantitatively supplied from the quantitative supply device A fine powder resin supply unit comprising: a supply tray for supplying to the surface; and a shaker for continuously vibrating the supply tray. In a preferred embodiment of the method for producing a fiber-reinforced thermoplastic resin sheet according to the present invention, the average particle size of the thermoplastic resin fine powder is 300 μm or less, and the reinforcing fibers are continuous fibers.

Further, in the apparatus for producing a fiber-reinforced thermoplastic resin sheet according to the present invention, the apparatus for producing a fiber-reinforced thermoplastic resin sheet by impregnating a thermoplastic resin with a hot melt by a hot melt method comprises the steps of: In this case, a fine powder resin supply unit having the following configuration for supplying a uniform thickness to the lower belt surface is provided. [Configuration of Fine Powder Resin Supply Unit] A storage tank for storing the fine powder resin, a quantitative supply device for supplying the fine powder resin in the storage tank, and a lower belt for supplying the fine powder resin quantitatively supplied from the quantitative supply device A fine powder resin supply unit comprising: a supply tray for supplying to the surface; and a shaker for continuously vibrating the supply tray.

In the present invention, the particle size refers to the diameter of a sphere, and in the case of a shape other than a sphere, is calculated by converting the projected area into a circle.

[0007]

DETAILED DESCRIPTION OF THE INVENTION The reinforcing fibers used in the present invention are those which are known as rovings, yarns and tows, which are aggregates of filaments constituting the fibers, singly or in combination. And the filaments are sufficiently long and have sufficient strength to pull in contact with the molten thermoplastic resin coating under the conditions used. Preferred materials include glass fibers and carbon fibers, and metal fibers such as inorganic fibers such as silicon carbide fibers, alumina fibers, titanium fibers, boron fibers, and stainless steel fibers can be used.

The glass fiber or carbon fiber may be coated with a surface treatment agent such as a silane-based or titanium-based coupling agent on the fiber surface in order to improve the adhesion to the resin in accordance with the thermoplastic resin used. Is preferred. It is preferable in handling to use a sizing agent so that roving or tow is not loosened during handling.

In the present invention, a plurality of continuous fibers are arranged in parallel in, for example, one direction in the machine direction, are controlled so as not to cross each other, are spread in the width direction, are adjusted to an appropriate thickness, and are formed into a sheet shape. Formed. More specifically, continuous fibers are wound on a plurality of bobbins, and the fibers are fed out from each bobbin while applying an appropriate tension, and are arranged in a line in a line with a suitable width in a machine direction. It is preferable to arrange them in a sheet through a machine.

Although the thickness of the sheet depends on the thickness of the fibers used, it can be controlled by the arrangement and density of rovings and tows in the width direction. Since the thickness accuracy affects the variation of the impregnation state, it is preferably within ± 10% of the target thickness. In particular, when the thickness is between 10 μm and 1000 μm, there is no breakage of the fiber, good impregnation, few voids, and no molding defects. In the sheet thus obtained, it is necessary that a uniform tension is applied to each roving or tow so that each roving or tow does not cross.

Next, when the sheet is impregnated with a heat-resistant thermoplastic resin, the heat-resistant thermoplastic resin used includes, but is not limited to, polyethersulfone, polyetheretherketone, and polyimide. These resins have an average particle size of 500 μm or less, preferably 300 μm
It is desirable that the particle size is not more than the above, and if it cannot be produced with the particle size smaller than this, it is necessary to perform a mechanical pulverizing treatment. When using these resins, it is preferable to carry out drying in advance.

The heat-resistant thermoplastic resin is supplied in the form of fine powder to the surface of the heated lower belt. Since the fine powder resin is liable to aggregate and no longer flow, it is necessary to provide a mechanism for continuously applying vibration to prevent aggregation. Means for supplying the fine powder resin to the lower belt surface is performed by a fine powder resin supply unit having the following configuration. [Configuration of Fine Powder Resin Supply Unit] A storage tank for storing the fine powder resin, a quantitative supply device for supplying the fine powder resin in the storage tank, and a lower belt for supplying the fine powder resin quantitatively supplied from the quantitative supply device This is a configuration having a supply tray to be supplied to the surface and a shaker for continuously vibrating the supply tray. The supply to the lower belt surface needs to be performed so as to have the same width and uniform thickness as the fiber sheet, and the thickness corresponds to the thickness of the fiber sheet. The value is experimentally determined by the target setting of the resin content in the medium, but is preferably ± 10%, more preferably ± 5%, with respect to the set thickness because it greatly affects the resin content.

Thus, the fiber sheet is pressed into contact with the roll via the lower belt provided with the resin coating, and the impregnation of the fiber with the resin is started. Impregnation is achieved when the resin coating passes between the filaments constituting the fiber sheet and reaches the back surface of the fiber sheet.

The resin-coated fiber sheet is then pressed against, for example, one or more heating rolls while being sandwiched between the upper and lower belts to improve impregnation, and then pulled out of the impregnating device. The temperature of these heating rolls is equal to or higher than the softening point of the resin to be impregnated. In the present specification, the softening point refers to the lowest temperature that can be measured with a load of 5 kg using a melt index measuring device. The fiber content of the fiber sheet thus obtained is usually from 60 to 90% by weight.

Next, the details of the present invention will be described with reference to a typical embodiment shown in the drawings.

FIG. 1 is a schematic side view showing an embodiment of the present invention.

As shown in FIG. 1, the manufacturing apparatus for carrying out the method of the present invention comprises a fiber feeding section 1, a supply section 2, a resin impregnating section 3, and a take-up section 4.

The fiber feeding section 1 has a function of feeding a required number of continuous fibers 8 wound on a plurality of bobbins 7 attached to a gantry 6. The continuous fibers 8 are horizontally arranged by guide rolls 9, and are arranged at an arbitrary fiber interval and an arbitrary thickness by an aligning machine 10 so that a fiber sheet 11 is formed.
To form The aligning machine 10 has a frame-like frame on which a number of steel wires are stretched, and the continuous fibers 8 are aligned by passing through the gaps between the steel wires one by one.

Next, the fiber sheet 11 is controlled to have a uniform tension over the entire width by a tension adjusting roll 13 having a brake 12, and is supplied to the resin impregnated section 3. The surface of the tension adjusting roll 13 is preferably made of rubber or the like so that the tension can be easily adjusted by frictional resistance. The tension is not particularly limited, and it is sufficient that the fiber sheet 11 does not disturb the fibers during the impregnation process of the resin impregnation portion 3. The fiber sheet 11 enters the resin impregnated section 3. On the other hand, the fine-powder thermoplastic resin conveyed from the storage tank 5 is guided to the fine-powder resin supply unit 14. FIG. 2 shows a schematic diagram of the fine powder resin supply section 14, and the supply tray 30
The feed tray 30 is fixed to the gantry 31 at an angle of 5 to 20 ° via a leaf spring 32, and the rear center of the supply tray 30 is connected to a shaker capable of continuously vibrating the tray up and down within a range of ± 1 mm. Have been. Shaking is 1000-300 per minute
It is preferable to have zero-time vibration capability. The gap between the supply tray 30 and the lower belt 15 must be changed depending on the particle size distribution of the fine powder resin used and the belt speed, but is usually adjusted in the range of 0.1 to 0.5 mm. The fine powder resin is guided from the storage tank 5 to the supply tray 30 from the fixed-quantity supply device 34, and the supply tray is normally vibrated at a rate of 1200 times per minute so that the fine powder resin is reduced to a width equal to the fiber sheet width. 15. The supplied resin is melted by the heat of the heating roll 23 to form a resin film. The fiber sheet 11 is pressed into contact with the heating roll 17 via the lower belt 15 to impregnate the resin, and then the heating roller 18 via the upper belt 16 and the lower belt 1.
5 and is pressed against the heating roll 19 to completely impregnate the resin. Heating rolls 17, 18, 19, 20,
Heats 21, 22, and 23 are heated to a temperature corresponding to the melt viscosity of the thermoplastic resin to be used, and a heat transfer heater or an induction heating roll is suitable as a heating method. The rolls 24 and 25 adjust the tension of the belt.
No heating is required. A pair of rolls facing each of the rolls 17 and 20, the rolls 18 and 21, and the rolls 19 and 22 are provided with a mechanism capable of adjusting the interval therebetween.
The interval can be changed according to the type of reinforcing fiber used and the content of the reinforcing fiber.

The two rolls 19 and 22 are driven by a motor 26, each roll rotates at the same peripheral speed, and the upper and lower belts are conveyed by the rotation of these rolls.

Next, the fiber-reinforced thermoplastic resin sheet thus obtained is taken up by the take-up roll 2 of the take-up section 4.
At 7, it is taken up while applying tension, and is taken up on a take-up shaft 28. 29 is a take-up roll 27 and a take-up shaft 2
9 drive motor.

[0022]

The present invention will be described below with reference to examples.

Example 1 The specifications of each part of the apparatus shown in FIG. 1 were 100 bobbins, the width of extruder 30 mmφ rolls 17 to 25 was 400 mm, the roll diameter was 240 mm, and the thickness of upper and lower belts 15 and 16 was 0.6 m.
m and a width of 350 mm were used. Heat rolls 17 and 2
The gaps between 3, 18 and 21 and 19 and 22 were adjusted to make the gap between the upper belt and the lower belt 0.25 mm. As the continuous fiber, a carbon fiber (filament diameter 7 μm, bundle of 6000 fibers: Toray T-300) was used, and a polyetheretherketone resin (VICTREX 150P manufactured by ICI) pulverized to an average particle diameter of 50 μm was used as a fine thermoplastic resin. . The continuous fibers fed from the 100 bobbins were aligned to form a 200 mm wide fiber sheet. On the other hand, the fine powdered polyetheretherketone resin supplied to the fine powder resin supply unit 14 is placed on the surface of a lower belt moving at a speed of 2 m / min on a roll 23 heated to 400 ° C.
It was fed at a rate equal to the fiber sheet at a rate of g / min. 10
The fiber sheet to which 0 kg tension is applied passes between the rolls 17 to 22 heated to 400 ° C. while being sandwiched between the upper and lower belts 15 and 16 in the state shown in FIG. An ether ether ketone resin was impregnated, and a fiber-reinforced thermoplastic resin sheet was wound up on a take-up roll 34. The fiber content of the fiber-reinforced thermoplastic resin sheet thus obtained was 62% by volume, and the impregnation property was good. The operation was performed continuously for 24 hours, but the operation could be performed smoothly without any problem such as thermal deterioration of the resin.

Example 2 Instead of polyetheretherketone, a polyimide resin having an average particle size of 30 μm (NEW manufactured by Mitsui Toatsu Chemicals, Inc.)
-TPI) and carbon fiber (filament diameter 5μ)
m, 12,000 bundles: a fiber-reinforced thermoplastic resin sheet was produced in the same manner as in Example 1 except that Toray T-800H) was used. The sheet thus obtained is
The impregnation was good at a fiber content of 58% by volume.

Comparative Example The same apparatus as in Example 1 was used, but the fine powder resin supply section 14 was not used. Instead, a coat hanger die connected to an extruder was provided at the position of the supply section 14. The extruder heats and melts the polyetheretherketone resin at 380 ° C. from the extruder. The fiber sheet is coated on a lower belt moving at a speed of 2 m / min on a roll 23 heated at 400 ° C. from a coat hanger die. The operation was carried out in the same manner as in Example 1 except that the coating was performed with a width equal to the width and a thickness of 90 μm. After 3 hours from the start of the operation, the gelled product resulting from the thermal deterioration came to be extruded from the die onto the coating film. Six hours after the start of the operation, the gelled product clogged the lip of the coat hanger die and could not form a coating film, and further operation was impossible. 3 from operation start
The fiber reinforced thermoplastic resin sheet up to the time point had a fiber content of 63% by volume and good impregnation. However, the fiber reinforced thermoplastic resin sheet after 3 hours from the start of operation had a fiber content of 67 to 77% by volume, and had a problem in impregnation.

[0026]

According to the present invention, a fiber-reinforced resin sheet excellent in impregnation can be stably obtained for a long time.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing one embodiment of the present invention.

FIG. 2 is a schematic side view showing a fine powder thermoplastic resin supply unit.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 fiber feeding section 2 supply section 3 resin impregnated section 4 take-up section 5 fine powder thermoplastic resin storage tank 6 gantry 7 bobbin 8 continuous fiber 9 guide roll 10 aligning machine 11 fiber sheet 12 brake 13 tension adjusting roll 14 fine powder thermoplastic resin Supply unit 15 Lower belt 16 Upper belt 17 to 23 Heating roll 24 to 25 Belt tension adjusting roll 26 Drive motor 27 Take-up roll 28 Take-up shaft 29 Drive motor 30 Supply tray 31 Mount 32 Plate spring 33 Shaking device 34 Quantitative supply device

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor: Masashi Masuda, 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Inside of Mitsui Toatsu Chemical Co., Ltd. (72) Inventor Satoshi Kishi 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa (72) Inventor Chiaki Maruko 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Inside Mitsui Toatsu Chemical Co., Ltd. (72) Inventor Hiroshi Tanabe 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Mitsui Toatsu Chemical Co., Ltd. 56) References JP-A-48-73476 (JP, A) JP-A-64-60517 (JP, A) JP-A-64-61561 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , (DB name) B29C 43/00-43/58 B29C 70/00-70/88

Claims (4)

(57) [Claims] 1. A method for producing a fiber-reinforced thermoplastic resin sheet by hot-melting and impregnating a reinforcing fiber with a thermoplastic resin fine powder, wherein the thermoplastic resin fine powder supplied from a fine powder resin supply section having the following constitution is provided. A method for producing a fiber-reinforced thermoplastic resin sheet, comprising supplying a uniform thickness to the surface of a lower belt by vibrating, and then thermally melting and impregnating the reinforcing fibers. [Configuration of Fine Powder Resin Supply Unit] A storage tank for storing the fine powder resin, a quantitative supply device for supplying the fine powder resin in the storage tank, and a lower belt for supplying the fine powder resin quantitatively supplied from the quantitative supply device A fine powder resin supply unit comprising: a supply tray for supplying to the surface; and a shaker for continuously vibrating the supply tray. 2. An average particle size of the thermoplastic resin fine powder is 300 μm.
2. The method for producing a fiber-reinforced thermoplastic resin sheet according to claim 1, wherein m is equal to or less than m. 3. The method for producing a fiber-reinforced thermoplastic resin sheet according to claim 1, wherein the reinforcing fibers are continuous fibers. 4. A reinforcing fiber is hot-melt-impregnated with a thermoplastic resin,
In an apparatus for producing a fiber-reinforced thermoplastic resin sheet,
An apparatus for manufacturing a fiber-reinforced thermoplastic resin sheet, comprising: a fine powder resin supply section having the following configuration to supply a uniform thickness to the lower belt surface by vibrating thermoplastic resin fine powder. [Configuration of Fine Powder Resin Supply Unit] A storage tank for storing the fine powder resin, a quantitative supply device for supplying the fine powder resin in the storage tank, and a lower belt for supplying the fine powder resin quantitatively supplied from the quantitative supply device A fine powder resin supply unit comprising: a supply tray for supplying to the surface; and a shaker for continuously vibrating the supply tray.