Method for improving lack of glue accumulation in carbon fiber products with grooves

Abstract

The present invention discloses a method for improving glue deficiency in a carbon fiber product with grooves, comprising the following steps: (1) providing a carbon fiber preform, and placing the carbon fiber preform on a lower mold in a wind pressure forming mold; (2) providing a mold insert and a high-temperature glue, wherein the mold insert has a boss with a shape matching the groove, and an angle space is defined between the corresponding position of the mold insert and the boss, and the high-temperature glue is filled in the angle space, and the high-temperature glue in the angle space is bonded and fixed to the mold insert; (3) combining the mold insert coated with the high-temperature glue on the lower mold in the wind pressure forming mold; (4) covering the upper mold in the wind pressure forming mold with the lower mold in the wind pressure forming mold; and (5) placing the wind pressure forming mold on a forming table, and having the forming table blow air and heat and cure the carbon fiber preform in the wind pressure forming mold, thereby obtaining a carbon fiber product with grooves, so as to improve the yield rate and save the rework cost in the next finishing process.

Description

Technical Field

[0001] The invention relates to the field of bicycle frame manufacturing, and in particular to a method for improving glue deficiency of a carbon fiber product with grooves. Background Art

[0002] As we all know, the molding process of carbon fiber frames is inseparable from the use of carbon fiber cloth. First, the carbon fiber cloth is used to form a shape that is identical to the product (also known as a carbon fiber preform). Then, the carbon fiber preform is placed on the lower mold in the wind pressure molding mold. Then, the upper mold and lower mold of the wind pressure molding mold are covered. Finally, the wind pressure molding mold is placed on a molding table, and the molding table blows air into the carbon fiber preform, heats and cures it, and cools it to shape, thereby turning the carbon fiber preform into a carbon fiber frame.

[0003] Among them, there are grooves, steps and convex designs in the carbon fiber frame of the bicycle; due to the existence of the grooves, steps and convex designs, it is impossible to use carbon fiber cloth to stick to the product. Figure 1 The same shape, especially the inability to fit the groove or local protrusion shape, can generally only be pasted into a flat shape. Therefore, during the molding process, the carbon fiber preform cannot extend to the structural sharp corners used to form the groove in the wind pressure molding mold when blowing, resulting in easy glue shortage after molding. In order to solve the glue shortage, the applicant designed to stick the carbon fiber cloth on the mold insert to solve the glue shortage.

[0004] For example, for Figure 1 The groove 210 in the carbon fiber frame 200 shown in FIG. Figure 3 The mold insert 20 shown in FIG. 2 has a boss 21 that matches the groove 210, so that during the molding process, Figure 1 In the process of the carbon fiber frame 200 shown in FIG. Figure 3 The mold insert 20 shown is pasted with a carbon fiber cloth 40 covering the boss 21, and a carbon fiber composite sheet material 50 is pasted at the position of the carbon fiber cloth 40 corresponding to the angle space 22 of the mold insert 20. Figure 5 shown.

[0005] Similarly, for Figure 2 The groove 220 in the carbon fiber frame 200 shown in FIG. Figure 6 The mold insert 20' shown in FIG. 2 has a boss 21' that matches the groove 220, so that during the molding process, Figure 2 In the process of the carbon fiber frame 200 shown in FIG. Figure 6 The mold insert 20' is pasted with a carbon fiber cloth 40 covering the boss 21, and a carbon fiber composite sheet material 50 is pasted on the position of the carbon fiber cloth 40 corresponding to the angle space 22' of the mold insert 20'. Figure 7 shown.

[0006] However, the above-mentioned method has the defect of unstable operation. When the temperature of the wind pressure forming mold is relatively high, the carbon fiber cloth 40 cannot be closely attached to the surface of the mold insert 20 (20'), and about 50% of defective products still exist. It should be noted that the technical solution of this application is proposed based on the defects of the above-mentioned method, but it does not limit the above-mentioned method to be the existing technology in this field.

[0007] Therefore, there is an urgent need for a method for improving glue deficiency in carbon fiber products to overcome one or more of the above-mentioned defects. Summary of the Invention

[0008] The object of the present invention is to provide a method for improving glue deficiency in carbon fiber products, which improves the yield rate and is simple to operate.

[0009] To achieve the above-mentioned purpose, the method for improving glue deficiency in a carbon fiber product with grooves of the present invention comprises the following steps: (1) providing a carbon fiber preform, and placing the carbon fiber preform in a lower mold in a wind pressure forming mold; (2) providing a mold insert and a high-temperature glue, wherein the mold insert has a boss with a shape matching the groove, and an angle space is defined between the corresponding position of the mold insert and the boss, and the high-temperature glue is filled in the angle space, and the high-temperature glue in the angle space is bonded and fixed to the mold insert; (3) combining the mold insert coated with the high-temperature glue in the lower mold of the wind pressure forming mold; (4) covering the upper mold in the wind pressure forming mold with the lower mold in the wind pressure forming mold; and (5) placing the wind pressure forming mold on a forming table, and the forming table blows air and heats the carbon fiber preform in the wind pressure forming mold to cure it, so that the cured high-temperature glue and the carbon fiber preform together form a carbon fiber product with grooves.

[0010] Preferably, in step (2), the corresponding positions of the mold inserts and the side surfaces of the bosses jointly define an angle space.

[0011] Preferably, the side surface of the boss is a closed annular side surface or an open side surface, and the high-temperature glue filled in the angle space continuously or discontinuously surrounds the boss with the annular side surface.

[0012] Preferably, the high temperature adhesive is a one-component epoxy resin adhesive.

[0013] Preferably, the high temperature adhesive is an aluminum-filled and thixotropic one-component epoxy resin adhesive.

[0014] Preferably, in step (5), the wind pressure is 180-300 PSI, the heating temperature is 145±5 degrees Celsius, and after heating for 40-50 minutes, the wind pressure forming mold is moved away from the forming table after cooling with liquid below 10 degrees Celsius for 10-20 minutes.

[0015] Preferably, in step (5), the wind pressure is 180-220 PSI, and after a heating time of 43-48 minutes, the wind pressure forming mold is moved away from the forming table after cooling with a liquid below 5 degrees Celsius for 13-18 minutes.

[0016] Preferably, in step (5), the wind pressure is 200 PSI, and after heating for 45 minutes, the wind pressure forming mold is cooled with 0 degrees Celsius ice water for 15 minutes, and then the wind pressure forming mold is moved away from the forming table.

[0017] Preferably, the angle defined by the corresponding position of the mold insert and the side surface of the boss is a right angle, an acute angle or an obtuse angle.

[0018] Preferably, the carbon fiber product is a carbon fiber frame.

[0019] Compared with the prior art, the present invention's method for improving glue shortage in carbon fiber products with grooves is to fill high-temperature glue in the angle space defined by the boss of the mold insert and the corresponding position of the mold insert, and also to make the high-temperature glue in the angle space bonded and fixed to the mold insert, replacing the method of sticking carbon fiber cloth on the mold insert, solving the existing problem of unstable quality; this is because when the temperature of the wind pressure forming mold is relatively high, the high-temperature glue can still be tightly attached to the mold insert, solving the problem that the carbon fiber cloth cannot be tightly attached to the surface of the mold insert when the temperature of the wind pressure forming mold is relatively high; at the same time, the present invention's method for improving glue shortage in carbon fiber products with grooves is to fill high-temperature glue in the angle space, rather than sticking carbon fiber cloth to the mold insert and then sticking carbon fiber composite sheet material, so the operation is simpler and the reproducibility is high. Furthermore, the present invention's method for improving glue shortage in carbon fiber products with grooves improves the yield rate, and the yield rate can be close to 100%, saving the rework cost in the next finishing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a perspective view of a carbon fiber frame with grooves.

[0021] Figure 2 yes Figure 1 A perspective view of the carbon fiber frame shown from another angle.

[0022] Figure 3 A perspective view of a mold insert designed to match one of the grooves in a carbon fiber frame.

[0023] Figure 4 yes Figure 3 The mold insert is shown in an internal view cut through a longitudinal plane through its center and looking to the right.

[0024] Figure 5 yes Figure 4 An internal view showing carbon fiber cloth and carbon fiber composite plies.

[0025] Figure 6 A perspective view of a mold insert matching another groove in a carbon fiber frame.

[0026] Figure 7 yes Figure 6 The mold insert is shown as an interior view cut through a cross-sectional plane P and looking towards the left.

[0027] Figure 8 yes Figure 7 An internal view of the carbon fiber cloth and carbon fiber composite sheet material.

[0028] Figure 9 The present invention is a flow chart of a method for improving glue deficiency in a carbon fiber product with grooves.

[0029] Figure 10 yes Figure 4 The internal diagram shows the high temperature glue.

[0030] Figure 11 yes Figure 7 The internal diagram shows the high temperature glue.

[0031] Figure 12 This is a three-dimensional image of a carbon fiber frame being formed using a wind pressure forming mold.

[0032] Figure 13 yes Figure 12 3D exploded view of . DETAILED DESCRIPTION

[0033] Embodiments of the present invention will now be described with reference to the accompanying drawings, wherein like reference numerals represent like elements throughout the several views.

[0034] please Figures 3 and 4 , Figures 6 and 7 ,as well as Figures 9 to 13 The method for improving glue deficiency of carbon fiber products with grooves of the present invention is used to solve the quality instability problem of the existing carbon fiber frame 200; of course, according to actual needs, the method for improving glue deficiency of carbon fiber products with grooves of the present invention can also be used to solve the quality instability problem of other carbon fiber products with grooves, so it is not limited to Figure 1 、 Figure 2 and Figure 13 The carbon fiber frame 200 shown is limited. The method for improving glue deficiency of a carbon fiber product with grooves of the present invention comprises the following steps:

[0035] S001. Provide a carbon fiber preform, and place the carbon fiber preform on the lower mold 11 in the wind pressure forming mold 10. Since the production of the carbon fiber preform is well known in the art, it will not be described in detail here.

[0036] S002, provide a mold insert 20 (20') and a high temperature glue 30, the mold insert 20 (20') has a boss 21 (21') with a shape matching the groove 210 (220), the corresponding position of the mold insert 20 (20') and the boss 21 (21') define an angle space 22 (22'), the high temperature glue 30 is filled in the angle space 22 (22'), and the high temperature glue 30 in the angle space 22 (22') is also bonded and fixed to the mold insert 20 (20'). Specifically, when the molding Figure 1 The groove 210 shown is designed Figure 3 The mold insert 20 shown in FIG. 1 is an obtuse angle defined by the corresponding position of the mold insert 20 and the side surface 211 of the boss 21. Figure 4 As shown, the corresponding position of the mold insert 20 and the side surface 211 of the boss 21 jointly define an angle space 22. The side surface 211 of the boss 21 is a ring-shaped side surface closed at both ends. Figure 3 As shown; when forming Figure 2 The groove 220 shown is designed Figure 6 The mold insert 20' shown in the figure has an acute angle defined by the position of the mold insert 20' and the side surface 211' of the boss 21'. Figure 7 As shown, the corresponding position of the mold insert 20' and the side 211' of the boss 21' jointly define the angle space 22', and the side 211' of the boss 21' is also a ring-shaped side surface closed at both ends. Figure 7 As shown; at the same time, the high temperature glue 30 filled in the corner space 22 (22') continuously surrounds the boss 21 (21') with an annular side surface. Of course, according to actual needs, the side surface 211 (211') of the boss 21 (21') can also be an open side surface with both ends open. The high temperature glue 30 filled in the corner space 22 (22') can also intermittently surround the boss 21 (21') with an annular side surface. It should be noted that for the high temperature glue 30, the filling requirement in the corner space 22 (22') is to ensure that the filling in the corner space 22 (22') makes a smooth transition between the corresponding positions of the boss 21 (21') and the mold insert 20 (20') to avoid the existence of sharp corners.

[0037] S003, assemble the mold insert 20 (20') coated with high temperature glue 30 to the lower mold 12 in the wind pressure forming mold 10, and the state is shown in FIG. Figure 13 shown.

[0038] S004, the upper mold 12 in the wind pressure forming mold 10 is covered with the lower mold 11 in the wind pressure forming mold 10, and the state after covering can be seen in FIG. Figure 12 As shown, the wind pressure forming mold 10 is prepared for transporting to the forming table.

[0039] S005. Place the wind pressure forming mold 10 on a forming table. The forming table blows air onto the carbon fiber preform in the wind pressure forming mold 10. The forming table heats and cures the blown carbon fiber preform and the high temperature adhesive 30. Thus, the cured high temperature adhesive 30 and the carbon fiber preform together form a carbon fiber frame 200 with grooves. Figure 1 、 Figure 2 and Figure 13 As shown; wherein, in the carbon fiber frame 200 with grooves 210 (220), the high temperature glue 30 is mainly used to form the stepped sharp corner part of the product, and the carbon fiber preform is used to form the conventional part of the product. Specifically, in step S005, the wind pressure is 180-300 PSI (pounds force per square inch), the heating temperature is 145 ± 5 degrees Celsius, and after a heating time of 40-50 minutes, the wind pressure forming mold 10 is cooled with a liquid below 10 degrees Celsius for 10-20 minutes, and then the wind pressure forming mold 10 is removed from the forming table. Preferably, in step S005, the wind pressure is 180-220 PSI, after a heating time of 43-48 minutes, and then the wind pressure forming mold 10 is cooled with a liquid below 5 degrees Celsius for 13-18 minutes, and then the wind pressure forming mold 10 is removed from the forming table. More preferably, in step S005, the wind pressure is 200 PSI, after a heating time of 45 minutes, and then the wind pressure forming mold 10 is cooled with ice water at 0 degrees Celsius for 15 minutes, and then the wind pressure forming mold 10 is removed from the forming table. More specifically, as follows:

[0040] In the method for improving glue defects in carbon fiber products with grooves of the present invention, the high-temperature glue 30 is a one-component epoxy resin adhesive, preferably an aluminum-filled and thixotropic one-component epoxy resin adhesive, so that the formula of the high-temperature glue 30 has excellent tensile shear strength and impact resistance within a larger temperature range (for example, between 120° and 180°C). The high-temperature glue 30 can bond oily and other poorly pre-treated working surfaces and can be used to bond a variety of substrates; the high-temperature glue 30 is used to cure at a medium temperature, for example, the high-temperature glue 30 is cured at 121° to 177°C for 60 minutes, and its curing effect is best. When the temperature is lower than 121°C, the curing time varies depending on the shape of the product; in addition, the high-temperature glue 30 has a longer storage time at room temperature; due to the good thixotropy of the high-temperature glue 30, the high-temperature glue 30 can be easily sucked and applied on the component without collapsing.

[0041] Compared with the prior art, the carbon fiber product with grooves of the present invention improves the glue shortage method by filling the high temperature glue 30 into the angle space 22 (22') defined by the boss 21 (21') of the mold insert 20 (20') and the position corresponding to the mold insert 20 (20'), and also makes the high temperature glue 30 in the angle space 22 (22') bonded and fixed to the mold insert 20 (20'), replacing the method of sticking the carbon fiber cloth 40 on the mold insert 20 (20'), thereby solving the problem of unstable quality of the prior art; this is due to the wind pressure. When the temperature of the mold 10 is relatively high, the high-temperature glue 30 can still be closely attached to the mold insert 20 (20'), thereby solving the problem that the carbon fiber cloth 40 cannot be closely attached to the surface of the mold insert 20 (20) when the temperature of the wind pressure forming mold 10 is relatively high; at the same time, in the method for improving glue shortage of the carbon fiber product with grooves of the present invention, the high-temperature glue 30 is filled in the angle space 22 (22'), rather than sticking the carbon fiber cloth 40 to the mold insert 20 (20') and then sticking the carbon fiber composite sheet material 40, so the operation is simpler and the reproducibility is high. Furthermore, the method for improving glue shortage of the carbon fiber product with grooves of the present invention improves the yield rate, and the yield rate can be close to 100%, saving the rework cost in the next finishing process.

[0042] The above disclosure is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.

Claims

1. A method for improving glue deficiency in a carbon fiber product with grooves, characterized in that: The steps include: (1) Providing a carbon fiber preform, and placing the carbon fiber preform on the lower mold of the wind pressure forming mold; (2) providing a mold insert and a high-temperature adhesive, wherein the mold insert has a boss with a shape matching the groove, and an angle space is defined between the corresponding position of the mold insert and the boss, and the high-temperature adhesive is filled in the angle space, and the high-temperature adhesive in the angle space is bonded and fixed to the mold insert; (3) Assemble the mold insert coated with high temperature glue to the lower mold in the wind pressure forming mold; (4) closing the upper mold in the wind pressure forming mold with the lower mold in the wind pressure forming mold; and (5) The wind pressure forming mold is placed on a forming table, and the forming table blows air and heats the carbon fiber preform in the wind pressure forming mold to solidify it, so that the cured high-temperature glue and the carbon fiber preform together form a carbon fiber product with grooves.

2. The method for improving glue deficiency of a carbon fiber product with grooves according to claim 1, characterized in that: In step (2), the corresponding position of the mold insert and the side surface of the boss jointly define an angle space.

3. The method for improving glue deficiency of a carbon fiber product with grooves according to claim 2, characterized in that: The side surface of the boss is a closed annular side surface or an open side surface, and the high-temperature glue filled in the angle space continuously or discontinuously surrounds the boss with the annular side surface.

4. The method for improving glue deficiency of a carbon fiber product with grooves according to claim 1, characterized in that: High temperature adhesive is a one-component epoxy resin adhesive.

5. The method for improving glue deficiency of a carbon fiber product with grooves according to claim 4, characterized in that: High temperature adhesive is an aluminum filled and thixotropic one-component epoxy resin adhesive.

6. The method for improving glue deficiency of a carbon fiber product with grooves according to claim 1, characterized in that: In step (5), the wind pressure is 180-300 PSI, the heating temperature is 145±5 degrees Celsius, and after heating for 40-50 minutes, the wind pressure forming mold is moved away from the forming table after cooling with liquid below 10 degrees Celsius for 10-20 minutes.

7. The method for improving glue deficiency of a carbon fiber product with grooves according to claim 6, characterized in that: In step (5), the wind pressure is 180-220 PSI. After heating for 43-48 minutes, the wind pressure forming mold is moved away from the forming table after cooling with liquid below 5 degrees Celsius for 13-18 minutes.

8. The method for improving glue deficiency of a carbon fiber product with grooves according to claim 6, characterized in that: In step (5), the wind pressure is 200 PSI. After heating for 45 minutes, the wind pressure forming mold is removed from the forming table after cooling with 0 degrees Celsius ice water for 15 minutes.

9. The method for improving glue deficiency of a carbon fiber product with grooves according to claim 1, characterized in that: The angle defined by the corresponding position of the mold insert and the side surface of the boss is a right angle, an acute angle or an obtuse angle.

10. The method for improving glue deficiency of a carbon fiber product with grooves according to claim 1, characterized in that: Carbon fiber products are carbon fiber frames.

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