Device and method for preparing carbon fiber multifilament tensile test specimens

Abstract

The present invention discloses a device for preparing carbon fiber multifilament tensile test specimens, which is used to press a reinforcing sheet onto a carbon fiber multifilament wound on a sample frame. The sample frame is surrounded by a cylindrical frame and includes: a first clamping plate, a second clamping plate covering the first clamping plate, and a locking structure for fixing the first clamping plate to the second clamping plate; the first clamping plate and / or the second clamping plate are provided with a limiting groove, and the limiting groove can respectively accommodate the symmetrical two side frames of the sample frame to achieve relative fixation between the first clamping plate and / or the second clamping plate and the sample frame, and the first clamping plate and the second clamping plate also have a pressing surface for pressing the reinforcing sheet onto the carbon fiber multifilament. The present invention also provides a method for preparing carbon fiber multifilament tensile test specimens. The device of the present invention has a simple structure, fast operation, and cost savings, and realizes the one-step curing of the carbon fiber multifilament impregnated with resin and the reinforcing resin.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer material testing, and in particular relates to a device and method for preparing a carbon fiber multifilament tensile test specimen. Background Art

[0002] Carbon fiber is lightweight and high-strength, and is widely used in aerospace, rail transportation and other fields. It is an emerging strategic national defense material.

[0003] Tensile performance is one of the most critical performance indicators of carbon fiber. The preparation of carbon fiber multifilament tensile test specimens in China is mainly divided into two steps. The first step is to impregnate the carbon fiber multifilament by hand or equipment, then wrap it around the sample preparation frame and put it into an oven or the equipment's own heating device for curing. The purpose is to cure the resin system impregnated with the carbon fiber multifilament; the second step is to remove the cured specimen on the sample preparation frame, paste reinforcement sheets on both ends, and then put it into the oven for curing again. The purpose is to cure the reinforcing resin. The two-step curing process to prepare carbon fiber multifilament specimens is time-consuming. Each step usually takes 60 minutes to 90 minutes, and the two steps take at least 120 minutes to 180 minutes.

[0004] In order to shorten the spline preparation time, the present invention provides a device and method for preparing carbon fiber multifilament tensile test splines by a one-step curing method, which avoids repeated curing, effectively shortens the time, and improves the spline preparation efficiency. Summary of the Invention

[0005] The object of the present invention is to provide a device and method for preparing carbon fiber multifilament tensile test specimens to solve the problems in the prior art.

[0006] In order to achieve the above-mentioned purpose, the technical solution provided by one embodiment of the present invention is as follows:

[0007] In one embodiment, a device for preparing a carbon fiber multifilament tensile test specimen is provided, which is used to press a reinforcing sheet onto a carbon fiber multifilament wound on a sample preparation frame, wherein the sample preparation frame is enclosed by a cylindrical frame and includes:

[0008] A first card plate, a second card plate covering the first card plate, and a locking structure for fixing the first card plate and the second card plate;

[0009] The first card plate and / or the second card plate are provided with limiting grooves, and the limiting grooves can respectively accommodate the two symmetrical side frames of the sample preparation frame to achieve relative fixation between the first card plate and / or the second card plate and the sample preparation frame. The first card plate and the second card plate also have a pressing surface for pressing the reinforcement sheet onto the carbon fiber multifilament.

[0010] As a further improvement of the present invention, there are multiple first clamping plates and they are arranged at intervals, and an adjustment structure is provided between adjacent first clamping plates.

[0011] As a further improvement of the present invention, the adjustment structure includes an adjustment rod, and both ends of the adjustment rod are respectively fixed to different first clamping plates.

[0012] As a further improvement of the present invention, the first clamping plate and the second clamping plate are snap-connected.

[0013] As a further improvement of the present invention, one end of the first clamping plate and the second clamping plate are hinged, and the other end is detachably connected.

[0014] As a further improvement of the present invention, the locking structure includes a matching hook structure and a slot structure; a hook structure is provided on the first card plate, and a matching slot structure is provided on the second card plate; or a hook structure is provided on the second card plate, and a matching slot structure is provided on the first card plate, and the first card plate and the second card plate are connected by a hook and a slot.

[0015] As a further improvement of the present invention, the hook structure includes a fixed sheath and a hook, and the hook is movably connected to the first clamping plate or the second clamping plate through the fixed sheath. The hook can rotate relative to the first clamping plate or the second clamping plate with the fixed sheath as the axis.

[0016] As a further improvement of the present invention, after the first clamping plate and the second clamping plate are covered, the cross-sectional area of ​​the limiting groove is not less than the cross-sectional area of ​​the frame.

[0017] As a further improvement of the present invention, there are two limiting grooves on the first clamping plate and / or the second clamping plate, which are symmetrically arranged at both ends of the first clamping plate and / or the second clamping plate along the length direction.

[0018] In one embodiment, a method for preparing a carbon fiber multifilament tensile test specimen is provided, which is performed using the above-mentioned device for preparing a carbon fiber multifilament tensile test specimen, and is characterized in that:

[0019] s1: Adjust the distance between adjacent first pallets according to the spline length requirements;

[0020] s2: Place the reinforcing sheet coated with hot melt adhesive on the first cardboard;

[0021] s3: Place the sample preparation rack onto the first clamping plate, and the frame of the sample preparation rack symmetrical along the multifilament stretching direction falls into the first limiting groove;

[0022] s4: Lay the reinforcing sheet coated with hot melt adhesive symmetrically on the carbon fiber multifilament spline with the reinforcing sheet on the first cardboard;

[0023] s5: Snap the second card onto the first card, lock it, and heat and cure it.

[0024] As a further improvement of the present invention, in step s2, the reinforcing sheet is placed between the two limiting grooves, with the side with the hot melt adhesive away from the first clamping plate.

[0025] As a further improvement of the present invention, in step s4, the side of the reinforcing sheet with the hot melt adhesive is placed against the carbon fiber multifilament spline.

[0026] Compared with the prior art, the advantage of the present invention is that the carbon fiber multifilament is wound on the sample preparation frame and impregnated with resin, or the carbon fiber multifilament impregnated with resin is wound on the sample preparation frame and then installed in two pairs of clamps with limiting grooves and locked. A reinforcing sheet coated with hot melt adhesive is laid on the clamp in advance and cured, thereby realizing one-step curing of the carbon fiber multifilament impregnated with resin and the reinforcing resin, avoiding repeated curing, greatly shortening the preparation time of the spline, and improving the efficiency of the spline preparation. In addition, the device provided by the present invention has a simple structure, is quick to operate, and saves costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 This is a schematic structural diagram of a device for preparing carbon fiber multifilament tensile test specimens in Example 1 of the present application;

[0029] Figure 2 This is a structural diagram of the first clamping plate in a device for preparing carbon fiber multifilament tensile test specimens in Example 1 of the present application;

[0030] Figure 3 This is a structural diagram of the second clamping plate in a device for preparing carbon fiber multifilament tensile test specimens in Example 1 of the present application;

[0031] Figure 4 This is a cross-sectional view perpendicular to the tensile direction of the multifilaments of a device for preparing a carbon fiber multifilament tensile test specimen in Example 1 of the present application;

[0032] Figure 5 This is a cross-sectional view of a device for preparing carbon fiber multifilament tensile test strips in Example 2 of the present application, perpendicular to the tensile direction of the multifilament. DETAILED DESCRIPTION

[0033] The present invention will be described in detail below with reference to the various embodiments shown in the accompanying drawings. However, these embodiments do not limit the present invention, and any structural, methodological, or functional modifications made by a person skilled in the art based on these embodiments are all within the scope of protection of the present invention.

[0034] Example 1

[0035] refer to Figures 1 to 4 As shown, this embodiment provides a device for preparing carbon fiber multifilament tensile test specimens, which is used to press a reinforcing sheet onto a carbon fiber multifilament wound on a sample preparation frame 1. The sample preparation frame 1 is surrounded by a cylindrical frame. The device includes two first clamping plates 2, an adjusting rod 3 and two second clamping plates 4. The adjusting rod 3 is fixed between the two first clamping plates 2 and is used to adjust the distance between the first clamping plates 2. The second clamping plate 4 can be snapped onto the first clamping plate 2 and snap-connected with the first clamping plate 2.

[0036] The sample preparation rack 1 is constructed as a rectangular structure with a length of 300mm-400mm and a width of 200mm-300mm. The sample preparation rack 1 is enclosed by a cylindrical frame made of stainless steel with a diameter of 4mm-8mm.

[0037] The material of the first card plate 2 is stainless steel. The first card plate 2 is also a rectangular structure with a length of 220mm-320mm, a width of 30mm-40mm, and a thickness of 6mm-10mm. A group of first limiting grooves 21 are recessed on the top surface of the first card plate 2 toward the bottom surface. The first limiting grooves 21 are 10mm away from the edges of both ends of the first card plate 2. The cross-section of the first limiting grooves 21 is semicircular, the length is consistent with the width of the first card plate 2, which is 30mm-40mm, and the cross-sectional radius is 1mm-3mm The first limiting groove 21 can respectively accommodate the two side frames of the sample preparation rack 1 on the long side, so as to realize the relative fixation between the first clamping plate 2 and the sample preparation rack 1; the short sides of the first clamping plate 2 are respectively provided with a hook structure 22, and the hook structure 22 includes a fixed sheath 221 and a hook 222 provided on the first clamping plate 2. The hook 222 is movably connected to the first clamping plate 2 through the fixed sheath 221. The hook 222 can rotate relative to the first clamping plate 2 with the fixed sheath 221 as the axis. The hook 222 can be made of a material with a certain degree of flexibility.

[0038] The two ends of the adjusting rod 3 are respectively fixed to the two first clamping plates 2. The adjusting rod 2 can be the existing technology, specifically, it can be a nested telescopic rod, wherein the telescopic rod arranged on the outer ring is also provided with a tightening nut for achieving relative fixation of the telescopic rod.

[0039] refer to Figure 4As shown, the second card plate 4 can be covered with the first card plate 2 and is made of stainless steel. The second card plate 4 is also a rectangular structure with a length of 220mm-320mm, a width of 30mm-40mm, and a thickness of 6mm-10mm. A group of second limiting grooves 41 are recessed on the bottom surface of the second card plate 4 towards the top surface. The second limiting grooves 41 are 10mm away from the two end edges of the second card plate 4 respectively. The cross-section of the second limiting grooves 41 is semicircular, and the length is consistent with the width of the second card plate 4, which is 30mm-40mm, and the cross-sectional radius is 1mm-3mm. The second limiting grooves 41 can respectively accommodate the two side frames of the sample preparation rack 1 on the long side to achieve relative fixation between the second card plate 4 and the sample preparation rack 1; a card slot structure is respectively provided on both sides of the short side of the second card plate 4, including a card slot 42 fixed to the second card plate, and the card slot structure cooperates with the hook structure of the first card plate 2 to achieve a snap connection between the first card plate 2 and the second card plate 4.

[0040] The first clamping plate 2 and the second clamping plate 4 are aligned up and down. When the side with the first limiting groove 21 and the side with the second limiting groove 41 overlap and dock, the hook 222 can just hook the groove 42 to lock the first clamping plate 2 and the second clamping plate 4. At this time, the cross-sectional area of ​​the slot hole enclosed by the first limiting groove 21 and the second limiting groove 41 is not less than the cross-sectional area of ​​the sample preparation rack frame.

[0041] The second card board 4 is an independent card board.

[0042] Example 2

[0043] Different from the embodiment 1, in this embodiment, the portion between the two first limiting grooves 21 of the first clamping plate 2 can protrude from the portions at both ends of the first limiting groove 21. Figure 5 As shown, the portion between the two second limiting grooves 41 of the second clamping plate 4 can protrude from the portions at both ends of the second limiting grooves 41. This arrangement can strengthen the pressing force between the multifilament and the reinforcing sheet and achieve a better pressing effect.

[0044] Example 3

[0045] The difference from Example 1 or Example 2 is that, in this embodiment, one end of the first clamping plate 2 and the second clamping plate 4 are hinged, and the other ends are connected by a hook and a slot buckle.

[0046] Example 4

[0047] Different from the embodiment 1, in this embodiment, the limiting groove is only provided on the first clamping plate 2 or the second clamping plate 4, and the size of the limiting groove can completely accommodate the frame of the sample preparation rack.

[0048] The present invention also provides a method for preparing a carbon fiber multifilament tensile test specimen, comprising:

[0049] Step 1: Prepare two first and two second card plates 2 and 4, and adjust the distance between the two first card plates 2 to 150 mm to 250 mm using the adjustment rod 3, with the side with the first limiting groove 21 facing upwards;

[0050] Step 2: Place two reinforcing sheets coated with hot melt adhesive between the two first cardboards 2, with the hot melt adhesive side facing up. The reinforcing sheets can be made of metal or cardboard with a certain thickness, with a length of 200mm-300mm and a width of 30mm-40mm. The hot melt adhesive can be made of blue adhesive film.

[0051] Step 3: Place the carbon fiber multifilament sample frame 1 wrapped with the impregnated resin on the two first clamping plates 2, so that the long side of the sample frame 1 will fall exactly into the first limiting groove 21;

[0052] Step 4: Place the other two reinforcement sheets coated with hot melt adhesive on the carbon fiber multifilament spline symmetrically with the reinforcement sheet on the first card plate 2, with the hot melt adhesive facing downwards. Figure 4 The upper and lower position relationship shown;

[0053] Step 5: Place two second clamping plates 4 on the upper reinforcing sheet symmetrically with the first clamping plate 2, so that the second limiting grooves 41 of the second clamping plates 4 fall on the long sides of the sample preparation rack 1;

[0054] Step 6: Engage the hook 222 in the slot 42 to lock the second card plate 4 and the first card plate 2;

[0055] Step 7: Place the sample preparation frame with the locking card plate and the reinforcement sheet into the oven, and the carbon fiber multifilament impregnated resin and the reinforcement resin will be cured at one time;

[0056] Compared with the prior art, the advantage of the present invention is that the carbon fiber multifilament is wound on the sample preparation frame and impregnated with resin, or the carbon fiber multifilament impregnated with resin is wound on the sample preparation frame and then installed in two pairs of clamps with limiting grooves and locked. A reinforcing sheet coated with hot melt adhesive is laid on the clamp in advance and cured, thereby realizing one-step curing of the carbon fiber multifilament impregnated with resin and the reinforcing resin, avoiding repeated curing, greatly shortening the preparation time of the spline, and improving the efficiency of the spline preparation. In addition, the device provided by the present invention has a simple structure, is quick to operate, and saves costs.

[0057] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0058] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A device for preparing carbon fiber multifilament tensile test specimens, used for pressing a reinforcing sheet onto a carbon fiber multifilament wound on a sample preparation frame, wherein the sample preparation frame is enclosed by a cylindrical frame, characterized in that: include: A first card plate, a second card plate covering the first card plate, and a locking structure for fixing the first card plate and the second card plate; The first clamping plate and / or the second clamping plate are provided with limiting grooves, and the limiting grooves can respectively accommodate the two symmetrical frame bodies of the sample preparation rack to achieve relative fixation between the first clamping plate and / or the second clamping plate and the sample preparation rack, and the first clamping plate and the second clamping plate further have a pressing surface for pressing the reinforcement sheet onto the carbon fiber multifilament; There are two limiting grooves on the first clamping plate and / or the second clamping plate, which are symmetrically arranged at both ends of the first clamping plate and / or the second clamping plate along the length direction; The portion between the two limiting grooves of the first clamping plate protrudes from the portions of the limiting groove toward both ends, and the portion between the two limiting grooves of the second clamping plate protrudes from the portions of the limiting groove toward both ends.

2. The device for preparing carbon fiber multifilament tensile test specimens according to claim 1, characterized in that: There are multiple first clamping plates and they are arranged at intervals, and an adjustment structure is provided between adjacent first clamping plates.

3. The device for preparing carbon fiber multifilament tensile test specimens according to claim 2, characterized in that: The adjustment structure includes an adjustment rod, and both ends of the adjustment rod are respectively fixed to different first clamping plates.

4. The device for preparing carbon fiber multifilament tensile test specimens according to claim 1, characterized in that: The first clamping plate and the second clamping plate are snap-connected.

5. The device for preparing carbon fiber multifilament tensile test specimens according to claim 4, characterized in that: The locking structure includes a matching hook structure and a slot structure; the first card plate is provided with a hook structure, and the second card plate is provided with a matching slot structure; or the second card plate is provided with a hook structure, and the first card plate is provided with a matching slot structure, and the first card plate and the second card plate are connected by a hook and a slot.

6. The device for preparing carbon fiber multifilament tensile test specimens according to claim 5, characterized in that: The hook structure includes a fixed sheath and a hook. The hook is movably connected to the first clamping plate or the second clamping plate through the fixed sheath. The hook can rotate relative to the first clamping plate or the second clamping plate with the fixed sheath as an axis.

7. The device for preparing carbon fiber multifilament tensile test specimens according to claim 1, characterized in that: After the first clamping plate and the second clamping plate are covered, the cross-sectional area of ​​the limiting groove is not less than the cross-sectional area of ​​the frame.

8. A method for preparing a carbon fiber multifilament tensile test specimen, using the device for preparing a carbon fiber multifilament tensile test specimen according to any one of claims 1 to 7, characterized in that: s1: Adjust the distance between adjacent first pallets according to the spline length requirements; s2: Place the reinforcing sheet coated with hot melt adhesive on the first cardboard; s3: Place the sample preparation rack onto the first clamping plate, and the frame of the sample preparation rack symmetrical along the multifilament stretching direction falls into the first limiting groove; s4: Lay the reinforcing sheet coated with hot melt adhesive symmetrically on the carbon fiber multifilament spline with the reinforcing sheet on the first cardboard; s5: Snap the second card onto the first card, lock it, and heat and cure it.

9. The method for preparing a carbon fiber multifilament tensile test specimen according to claim 8, characterized in that: In step s2, the reinforcing sheet is placed between the two limiting grooves, with the side with the hot melt adhesive facing away from the first clamping plate.

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