JP2004177277A - Tackiness testing device for prepreg and tackiness test method of prepreg - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a testing device and a test method capable of testing whether a prepreg does not slide and can be easily removed or not, when the surface of the sheet-shaped prepreg has proper tackiness and is stuck onto a die with an automatic laminating device. <P>SOLUTION: This tackiness testing device 10A for prepreg to be used is equipped with a pedestal 12 where a sheet-shaped prepreg is placed, an indenter 17 for pressure-contact applied vertically to the placed prepreg, and a load measuring means for measuring the load required for starting relative movement when the prepreg and the pedestal 12 are relatively moved mutually in the contact state. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an apparatus for testing the adhesiveness of the surface of a sheet-shaped prepreg used in producing a fiber-reinforced plastic molded product.
[0002]
[Prior art]
Fiber-reinforced plastics that are lightweight and have excellent mechanical properties are sometimes used for structural members such as aircraft.
When manufacturing these molded products from fiber reinforced plastic, first, prepreg, which is a precursor of fiber reinforced plastic, is laid in a mold, and a predetermined number of layers are laminated thereon as necessary, and then A method of curing a resin by heating, cooling, and releasing the mold is often used.
As the prepreg, for example, a resin or resin solution impregnated into a woven or knitted fabric made of fibers such as carbon fiber and glass fiber, or a resin or resin solution impregnated into many fibers aligned in one direction For applications such as aircraft described above, for example, about 300 carbon fiber bundles are impregnated with an epoxy resin at an impregnation rate of about 35% by mass, and the width (perpendicular to the carbon fiber bundles). In many cases, a tape having a length of about 150 mm and a thickness of about 0.2 mm is used. Such a prepreg tape is usually wound with a release paper on one side, since the impregnated resin usually has adhesiveness, thereby forming a roll.
[0003]
As an apparatus for pulling out a prepreg tape from such a roll, continuously laying it in a mold, and further laminating, there is an automatic laminating apparatus having a sticking mechanism unit 60 as shown in FIG. 7 (see Patent Document 1). .
The sticking mechanism unit 60 of this example presses the material supply reel 62 that continuously supplies the prepreg tape 61 from the roll and the prepreg tape 61 to a predetermined position on the surface of the mold, and impregnates the prepreg tape 61. A pressing roller 63 for applying to the die or a prepreg tape already laminated on the die by utilizing the adhesiveness of the resin, a winding roll 65 for winding the release paper 64 from the prepreg tape 61 attached, A cutting unit (not shown) for cutting the prepreg tape 61 at a predetermined location is attached to one stand (not shown). The pasting mechanism unit 60 further includes an automatic control unit 66, which moves the entire gantry along coordinate data input in advance, and continuously pastes or cuts the prepreg tape 61 at a predetermined position. And can be stacked.
[0004]
[Patent Document 1]
JP-A-5-254724
[Problems to be solved by the invention]
However, in such a pasting mechanism, by utilizing the adhesiveness of the resin impregnating the prepreg tape, the prepreg tape is attached to a mold or a prepreg tape already laminated on the mold. Therefore, depending on the type of the resin impregnated, the prepreg tape may slip due to insufficient adhesiveness at the time of application. If the prepreg tape slips, it cannot be stuck accurately according to the input coordinate data, and as a result, there is a problem that a molded product having desired physical properties cannot be obtained.
On the other hand, if the adhesiveness of the resin impregnated in the prepreg tape is too large, the prepreg tape does not slip, but foreign substances adhere to the prepreg tape while attaching or laminating the prepreg tape. However, there is a problem that the prepreg tape cannot be easily peeled off when it is necessary to repeat this step.
[0006]
Therefore, when applying the prepreg tape with an automatic laminating apparatus having an attaching mechanism as shown in FIG. 7, the prepreg tape is not sufficiently adhered and does not slip, and when it is necessary to peel it off, it can be easily peeled off. There is a demand for a prepreg tape having such appropriate adhesiveness.
[0007]
However, the prepreg tape is actually pasted on a mold or already laminated prepreg tape using such an automatic laminating apparatus, and at a stage before lamination, the prepreg tape does not slip, and the mold or A test apparatus and a test method for accurately determining whether or not the prepreg tape can be easily peeled off from a prepreg tape laminated on a mold have not been known yet, and are not disclosed in the literature.
For this reason, conventionally, a worker at a prepreg tape manufacturing site had to sensuously judge from the sense of tackiness and the like. However, in such a method, even if the prepreg tape judged to be usable due to variations in the judgment criteria by the operator, etc., when actually used in an automatic laminating apparatus, it slips or sticks excessively. And sometimes, it could not be used. That is, in most cases, whether or not a prepreg tape can be used in an automatic laminating apparatus can be determined only after actually using the tape in an automatic laminating apparatus.
[0008]
In addition, since such an automatic laminating apparatus is very expensive, it is costly for a prepreg tape manufacturing site or a design site to own the prepreg tape for the purpose of determining whether the prepreg tape can be used in the automatic laminating apparatus. It was difficult from the side. Therefore, in a prepreg tape manufacturing site or a design site, what kind of resin-impregnated prepreg tape is suitable for use in an automatic laminating apparatus, and under what conditions the bonding process is performed It was also difficult to collect data on whether or not it was appropriate.
[0009]
The present invention has been made in view of the above circumstances, the surface of a sheet-like prepreg such as prepreg tape has an appropriate degree of adhesiveness, and was laminated on a mold or a mold by an automatic laminating apparatus. To provide a test device and a test method that can easily and easily test whether or not it can be peeled off when pasted on a prepreg tape under conditions close to actual pasting and laminating steps. As an issue.
[0010]
[Means for Solving the Problems]
The prepreg adhesiveness test apparatus of the present invention includes a pedestal on which a sheet-shaped prepreg is placed, an indenter vertically pressed against the placed prepreg, and a prepreg and the pedestal that are in contact with each other while being in contact with each other. And a load measuring means for measuring a load required to start the relative movement when moving.
It is preferable that the apparatus further includes fixing means for fixing the prepreg, and the load measuring means measures the tensile load when the pedestal starts moving by pulling the pedestal.
Alternatively, the prepreg may include a fixing unit for fixing the pedestal, and the load measuring unit may measure a tensile load when the prepreg starts moving by pulling the prepreg. At this time, the indenter may move together with the prepreg while keeping the pressure contact.
The contact surface of the pedestal with the prepreg may be release-molded.
The adhesiveness test method of the prepreg of the present invention is such that a sheet-like prepreg is placed on a pedestal, and the prepreg and the pedestal are kept in contact with the indenter pressed vertically against the placed prepreg. It is characterized by moving relative to each other and measuring the load required to start the relative movement.
In another method for testing the adhesiveness of a prepreg of the present invention, a sheet-shaped first prepreg is fixed to a pedestal, a sheet-shaped second prepreg is placed on the fixed first prepreg, and placed. The first prepreg and the second prepreg are moved relative to each other while keeping the indenter pressed vertically against the second prepreg, and the load required to start the relative movement is measured. It is characterized by doing.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
The adhesiveness test device (hereinafter, referred to as a test device) of the present invention includes a prepreg formed in a sheet shape such as a prepreg tape and has a sticking mechanism 60 as described with reference to FIG. It is tested for its adhesiveness to see if it is suitable for use in automated laminating equipment.
Hereinafter, the test apparatus of the present invention will be described in detail by exemplifying embodiments.
[0012]
1 and 2 are a perspective view and a front view showing a state in which a prepreg tape test piece (hereinafter, referred to as a test piece) 11 to be tested is arranged at a predetermined position of a test apparatus 10A according to the first embodiment. is there.
The test piece 11 to be tested in this example is obtained by cutting a prepreg tape used for a structural member of an aircraft or the like for a test, and a plurality of test pieces 11 are arranged substantially in parallel along the length direction of the prepreg tape. The prepreg layer is formed by impregnating the carbon fibers of the book with an epoxy resin and a release sheet such as release paper provided on one surface of the prepreg layer.
[0013]
The illustrated test apparatus 10A has a flat pedestal 12 arranged horizontally, and a test piece 11 is placed on the upper surface of the pedestal such that the release sheet side faces upward. The pedestal 12 of this example is provided with a thrust bearing (not shown) on its lower surface, and moves on the base 13 along the length direction (the left-right direction in FIG. 2) of the placed test specimen 11. I can do it. Further, in this example, a force gauge 14 is connected as a load measuring means to one end of the pedestal 12 in the moving direction, and the other end of the test piece 11 is placed on the base 13 by a clamp 15 which is a fixing means. Fixed to. Therefore, by pulling the force gauge 14 in the direction of the arrow in FIGS. 1 and 2, only the pedestal 12 moves while the test piece 11 and the pedestal 12 are in contact with each other, and the tensile load required to start the movement is reduced by the force gauge 14. It can be measured with.
[0014]
Note that, in this example, a release sheet 16 made of a fluororesin such as ethylene tetrafluoride is stuck on the upper surface of the pedestal 12, the upper surface of the pedestal 12 is subjected to release processing, and the test piece 11 is placed thereon. It is placed. Therefore, the release sheet 16 is in contact with the prepreg layer of the test piece 11. This is because when the prepreg tape is actually pasted on the mold using an automatic laminating apparatus having the pasting mechanism unit 60 as shown in FIG. This is because a release sheet made of fluororesin such as ethylene tetrafluoride is spread on the mold in advance so that the molded product can be easily removed from the mold, and a prepreg sheet may be pasted on this. In view of such a case, in order to test the test piece 11 under conditions that are as practical as possible, the release sheet 16 is also arranged on the pedestal 12 in this test apparatus 10A.
As a method of the mold release processing, in addition to the method of providing the mold release sheet 16 on the contact surface (upper surface) of the pedestal 12 with the test piece 11 as described above, a method of applying a mold release agent to the contact surface And so on. Further, the release processing may be performed on at least a portion corresponding to an indenter described later on the upper surface of the pedestal 12.
[0015]
The test apparatus 10A of this example has a cylindrical indenter 17 that is vertically pressed against the test piece 11 placed on the pedestal 12.
An air cylinder (not shown) is connected to the indenter 17, and the air pressure supplied to the air cylinder is adjusted so that the indenter 17 moves vertically (up and down in the figure) with respect to the upper surface of the test piece 11 to perform a test. The test piece 11 is pressed against the test piece 11 at a desired pressure or separated from the test piece 11. Further, the test apparatus 10A of this example tests whether or not the prepreg tape to be tested has adhesiveness suitable for use in an automatic laminating apparatus having an attaching mechanism 60 as shown in FIG. Since the indenter 17 is provided, the indenter 17 simulates the sticking roller 63 shown in FIG. 7 and has an iron cylindrical shape having a diameter of about 20 mm and a thickness of about 40 mm. It comes into pressure contact. Here, the indenter 17 may be a rotatable roller.
[0016]
Next, a method of testing the test piece 11 with the test apparatus 10A of this example will be described.
First, the test piece 11 is placed so that the upper surface of the pedestal 12 to which the release sheet 16 is adhered is in contact with the prepreg layer side. Next, a force gauge 14 is connected to one end of the pedestal 12 in the moving direction, and the other end of the test piece 11 is fixed by being clamped by a clamp 15.
Then, an air cylinder (not shown) is operated, and the indenter 17 is vertically pressed against the test piece 11 as shown in FIG. The pressure to be pressed may be appropriately set, for example, to be equal to the pressure applied when the prepreg tape is actually pasted on the mold by the automatic laminating apparatus. In this example, the pressure is set to 20N.
Then, with the indenter 17 kept pressed, the force gauge 14 connected to the pedestal 12 is pulled in the direction of the arrow, that is, in the length direction of the carbon fiber. Then, when the tensile load indicated by the force gauge 14 reaches a certain value, a slip occurs between the release sheet 16 on the pedestal 12 and the test piece 11, and the pedestal 12 starts to move on the base 13. . At this time, the tensile load when the pedestal 12 starts moving is read as a measured value.
[0017]
In this case, if the measured value of the test piece 11 in such a test is in advance in any range, the test piece 11 is actually molded by an automatic laminating apparatus having an attaching mechanism 60 as shown in FIG. The correlation should be grasped so as not to slip on the mold when sticking to the mold and to easily peel off the mold. Then, a test piece 11 was cut out from the newly produced prepreg tape, and the test was performed in the same manner as described above to determine whether the prepreg tape was suitable for use in an automatic laminating apparatus. Can be determined. If the measured value is less than the specified range, the possibility of slipping on the mold is insufficient due to insufficient adhesiveness, and if it exceeds the specified range, the adhesiveness is too large and cannot be easily peeled from the mold. The possibilities are great. In this example, if the measured value is in the range of 40-50N, the prepreg tape is suitable for use in an automatic laminating apparatus.
[0018]
In addition, when such a test apparatus 10A is used, not only can it be determined whether the prepreg tape can be used in the automatic laminating apparatus, but also the correlation between the composition of the resin used in the prepreg layer and the adhesiveness can be obtained. It is also possible to obtain design guidelines for the resin used for the prepreg tape. In addition, by performing tests under various conditions such as changing the temperature, it is also possible to determine the optimum conditions for actually applying the prepreg tape on the mold by the automatic laminating apparatus, and to manufacture the prepreg tape, The design becomes more efficient.
[0019]
Next, a second embodiment will be described.
FIG. 4 is a front view of the test apparatus 10B of this example. In this test apparatus 10B, not the pedestal 12 but the test piece 11 is pulled to measure the tensile load when the test piece 11 starts moving. It differs from the test apparatus 10A of FIG. Therefore, in the test apparatus 10B of this example, the pedestal 12 is not provided with a thrust bearing, but is fixed on the base 13, and the force gauge 14 is connected to the end of the test piece 11 instead of the pedestal.
When a test is performed using the test apparatus 10B of this example, the test is performed so that the upper surface of the pedestal 12 to which the release sheet 16 is adhered and the prepreg layer side are in contact with each other as in the case of the test apparatus 10A of FIG. The test piece 11 is placed, and then a force gauge 14 is connected to one end of the test piece 11 in the moving direction. Thereafter, an air cylinder (not shown) is operated to press the indenter 17 vertically against the test piece 11, and in this state, the force gauge 14 connected to the test piece 11 is pulled in the direction of the arrow. Then, the tensile load indicated by the force gauge 14 when the test piece 11 starts to slide and move on the pedestal 12 is measured.
[0020]
As described above, even when the test apparatus 10B of the second embodiment is used, the measured value of the tensile load when the test piece 11 starts to slide and move on the pedestal 12 and the use in the automatic laminating apparatus By determining the correlation with the suitability of the prepreg tape and testing a prepreg tape or the like produced on the basis of the correlation, it can be determined whether or not the prepreg tape has adhesiveness suitable for use in an automatic laminating apparatus. Also, as in the case of the test apparatus 10A of the first embodiment, the optimum conditions for obtaining the design guidelines for the resin used for the prepreg tape and for attaching the prepreg tape to the mold by an automatic laminating apparatus. You can also ask for.
[0021]
As described above, by using the test devices 10A and 10B of the first and second embodiments, it is possible to reduce the adhesiveness of the prepreg tape, which has been difficult to determine until it is actually used in an automatic laminating device. Although a test can be easily performed with a simple device, a test device 10C shown in FIG. 5 may be used in order to more accurately determine whether or not the use in the attaching mechanism unit 60 shown in FIG. 7 is appropriate.
[0022]
A test apparatus 10C according to the third embodiment shown in FIG. 5 has a pedestal 12 fixed to a base 13 as in the case of the test apparatus 10B according to the second embodiment, and performs a test on the fixed pedestal 12. The test piece 11 is moved and the tensile load at that time is measured. In the test apparatus of this example, the indenter 17 can move along with the test piece 11. Therefore, by using the test apparatus 10C of this example, the pressing and sticking roller 63 shown in FIG. 7 that presses the prepreg tape to a predetermined position on the surface of the mold moves together with the prepreg tape. With respect to a prepreg tape which is assumed to be used in an automatic laminating apparatus having the attaching mechanism section 60, it is possible to accurately test whether or not the prepreg tape is used under conditions closer to actual conditions.
[0023]
When the test is performed using the test apparatus 10C of this example, the prepreg layer is in contact with the pedestal 12 to which the release sheet 16 is attached, as in the case of the test apparatus 10B of the second embodiment. Is placed on the test piece 11. Then, an air cylinder (not shown) is operated to press the indenter 17 vertically against the test piece 11, and in this state, the force gauge 14 connected to the test piece 11 is pulled in the direction of the arrow. Then, a tensile load when the test piece 11 placed on the pedestal 12 and the indenter 17 accompanying the test piece 11 start to move in the horizontal direction is measured.
Thereafter, as in the case of the first and second embodiments, the correlation between the measured value of the tensile load and the suitability for use in the automatic laminating apparatus having the attaching mechanism unit 60 as shown in FIG. In light of this, it is determined whether the test piece 11 is suitable for use in an automatic laminating apparatus, a design guide for a resin to be used is obtained, and further, a prepreg tape is pasted on a mold by the automatic laminating apparatus. It is also possible to determine the optimal conditions at that time.
[0024]
Each of the first to third embodiments described above assumes a process of attaching a prepreg tape to a mold by an automatic laminating apparatus. In practice, however, a prepreg tape already attached to a mold is used. In many cases, another prepreg tape is laminated. Therefore, a method of testing the adhesiveness between prepreg tapes will be described below, assuming a step of laminating another prepreg tape on the prepreg tape attached to the mold.
For the adhesion test between such prepreg tapes, any of the test apparatus 10A shown in FIGS. 1 to 3, the test apparatus 10B shown in FIG. 4, and the test apparatus 10C shown in FIG. 5 can be used. 6, FIG. 6 illustrates and describes a case of testing the adhesiveness between prepreg tapes using the test apparatus 10A illustrated in FIGS.
[0025]
First, as shown in FIG. 6, the first prepreg tape 18 is fixed on the pedestal 12 using an adhesive or the like so as not to slip. The first prepreg tape 18 fixed here is usually peeled off before the release sheet is fixed, and is composed of only the prepreg layer. Further, the release sheet for release processing may or may not be attached to the pedestal 12, and FIG. 6 shows a state where the release sheet is not attached. Next, the test piece 11 made of the second prepreg tape is placed on the first prepreg sheet 18, and one end of the test piece 11 is fixed with the clamp 15. The test piece 11 is composed of a prepreg layer obtained by impregnating a plurality of carbon fibers aligned substantially in parallel along the length direction of the prepreg tape with an epoxy resin, and a release paper provided on one surface of the prepreg layer. The first prepreg tape 18 is in contact with the first prepreg tape 18.
Then, the indenter 17 is vertically pressed against the test piece 11, and in this state, the force gauge 14 connected to the pedestal 12 is pulled in the horizontal direction, and the pedestal 12 starts to move on the base 13. The tensile load when slippage occurs between the first prepreg tape 18 and the test piece 11 fixed to the test piece 11 is measured.
[0026]
Also in this case, if the measured value in such a test is in any range in advance, the adhesiveness between the prepreg tapes is appropriate, and the prepreg tapes do not slip each other in the actual lamination process, and are peeled off. If necessary, you can easily peel it off or grasp the correlation. Then, in actually laminating different types of prepreg tapes, it is possible to determine in advance whether or not the prepreg tapes do not slip with each other and adhere appropriately to each other simply by testing in this manner. Further, in the case of laminating a plurality of types of prepreg tapes in this manner, it is possible to obtain the design guidelines for the resin of each prepreg tape and the optimum conditions such as the temperature.
The first prepreg tape 18 and the second prepreg tape may be different types of prepregs having different types of fibers and resins, or may be the same type of prepregs.
Further, the adhesiveness between such prepreg tapes can be similarly tested even when the test devices 10B and 10C of FIGS. 4 and 5 are used. In this case, instead of pulling the pedestal 12, the test piece 11 may be pulled.
[0027]
In the above example, a tape-like prepreg made of a solution of a carbon fiber and an epoxy resin is illustrated as a prepreg used for a structural member of an aircraft or the like, but it is used for a sheet-like prepreg to be tested. There are no particular restrictions on the types of fibers and resins used, and there is no particular limitation on the tape shape. For example, examples of the fiber include inorganic fibers such as glass and organic fibers such as aramid fiber, and examples of the resin include polyester resin, phenol resin, and bismaleimide resin. Further, as the sheet-shaped prepreg, in addition to a tape-shaped one in which fibers are aligned in one direction, a woven fabric, a knitted fabric, a braid, or the like made of fibers impregnated with a resin or a resin solution may be used.
[0028]
【The invention's effect】
As described above, according to the prepreg adhesion test apparatus and test method of the present invention, when a sheet-shaped prepreg is attached to a prepreg tape laminated on a mold or a mold by an automatic laminating apparatus. It can be easily tested whether it is slippery and can be easily peeled off.Furthermore, it is possible to obtain the design guidelines for the resin used for the prepreg, and to place the prepreg on a mold or on a mold with an automatic laminator. It is also possible to determine the optimum conditions for sticking on the laminated prepreg tape. Therefore, by using the prepreg adhesion test apparatus and test method of the present invention, it is possible to efficiently manufacture and design a fiber-reinforced composite material.
[Brief description of the drawings]
FIG. 1 is a perspective view of a prepreg adhesion test apparatus according to a first embodiment.
FIG. 2 is a front view of the adhesion test apparatus of FIG.
FIG. 3 is a front view showing a state in which an indenter is pressed against a test piece in the adhesion test apparatus of FIGS. 1 and 2;
FIG. 4 is a front view of a prepreg adhesion test apparatus according to a second embodiment.
FIG. 5 is a front view of a prepreg adhesion test apparatus according to a third embodiment.
FIG. 6 is a cross-sectional view showing a state in which the prepreg is tested for adhesion using the adhesion test apparatus of FIG. 1;
FIG. 7 is a perspective view of a pasting mechanism provided in a conventional automatic laminating apparatus.
[Explanation of symbols]
10A, 10B, 10C Adhesion test device 11 Pre-preg tape test piece 12 Pedestal 17 Indenter 18 First prepreg tape

Claims (7)

A pedestal on which a sheet-like prepreg is placed,
An indenter vertically pressed against the placed prepreg,
A load measuring means for measuring a load required to start the relative movement when the prepreg and the pedestal move relative to each other while being in contact with each other. Comprising fixing means for fixing the prepreg,
The prepreg adhesiveness test apparatus according to claim 1, wherein the load measuring unit measures the tensile load when the pedestal starts moving by pulling the pedestal. Comprising fixing means for fixing the pedestal,
The prepreg adhesiveness test apparatus according to claim 1, wherein the load measuring unit measures the tensile load when the prepreg starts moving by pulling the prepreg. The prepreg adhesiveness test apparatus according to claim 3, wherein the indenter moves together with the prepreg while being pressed. The prepreg adhesion test apparatus according to any one of claims 1 to 4, wherein a contact surface of the pedestal with the prepreg is subjected to release processing. The sheet-shaped prepreg is placed on a pedestal, and the prepreg and the pedestal are moved relative to each other with the indenter vertically pressed against the placed prepreg, and the relative movement is started. A method for testing the adhesiveness of a prepreg, comprising measuring a load required for the prepreg. The sheet-like first prepreg is fixed to the pedestal, the sheet-like second prepreg is placed on the fixed first prepreg, and the indenter is vertically attached to the placed second prepreg. A method for testing the adhesiveness of a prepreg, wherein the first prepreg and the second prepreg are moved relative to each other while being in contact with each other while being in contact with each other, and a load required to start the relative movement is measured.

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