A velocity measuring device, a velocity measuring method and application of a velocity measuring device

Abstract

The application provides a flow guide net speed measuring device, a speed measuring method and application. The speed measuring device comprises a flow guide device, a backflow prevention device and a vacuum pumping device connected in sequence. The flow guide device comprises two first flow guide pipes arranged in parallel on a glass plate. A flow guide net and a vacuum film are sequentially laid on the planes of the two first flow guide pipes. The two first flow guide pipes are respectively and independently connected with a second flow guide pipe and a third flow guide pipe extending outward. The second flow guide pipe is used for feeding. The third flow guide pipe is connected with the backflow prevention device. The speed measuring device is used to test the flow guide speed of the flow guide net through simple operation. The feasibility of the process can be quickly determined when the flow guide net or the resin is replaced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of vacuum assisted resin infusion molding, and relates to a flow guide net speed measuring device, a speed measuring method and application. BACKGROUND

[0002] The flow guide net is a net-shaped drainage medium made of polypropylene resin or polyethylene resin, which has the characteristics of easy paving, fast flow guide speed, less resin residue, cost saving and reduced labor intensity.

[0003] CN204801063U discloses a flow guide net with improved weaving method for wind power generation blade molding. The flow guide net body is woven by silk threads and has a grid structure. The mesh of the flow guide net body forms a resin flow channel. The warp threads and weft threads of the flow guide net body are respectively woven by different numbers of silk threads. When the warp threads of the flow guide net body are woven by at least three silk threads in a spiral structure, the weft threads of the flow guide net body are woven by no more than two silk threads. When the weft threads of the flow guide net body are woven by at least three silk threads in a spiral structure, the warp threads of the flow guide net body are woven by no more than two silk threads.

[0004] CN103802331A discloses a method for vacuum assisted resin infusion molding of resin-based composite materials without glue output. A glue input flow guide net and a resin traction layer are placed on a fiber reinforced preform, and a micro-permeable layer and a glue blocking layer are wrapped around the outer surface of the fiber reinforced preform.

[0005] The flow guide speed of the flow guide net is crucial in vacuum infusion and directly affects the infusion time and mold forming. The above-mentioned patents all use flow guide nets, which can make resin uniformly and quickly penetrate into any part of the product. Experiments have proved that the extruded flow guide net is easier to pave and less likely to curl than the woven flow guide net, and its flow guide speed is faster than that of the woven flow guide net. However, for flow guide nets with similar flow rates, it is almost impossible to distinguish the speed from experience.

[0006] Therefore, it is an important research direction in the field to develop a speed measuring device that can simply and quickly test the speed of the flow guide net. SUMMARY

[0007] The purpose of the present application is to provide a flow guide net speed measuring device, a speed measuring method and application that can be simply and quickly tested.

[0008] To achieve the purpose of the present application, the following technical solutions are adopted:

[0009] One of the purposes of the present application is to provide a flow guide net speed measuring device, which comprises a flow guide device, a backflow prevention device and a vacuum pumping device connected in sequence, the flow guide device comprises two first flow guide pipes arranged in parallel on a glass plate, a flow guide net and a vacuum film are laid on the plane of the two first flow guide pipes in sequence, the two first flow guide pipes are respectively and independently connected to a second flow guide pipe and a third flow guide pipe, the second flow guide pipe is used for feeding, and the third flow guide pipe is connected to the backflow prevention device.

[0010] The present application provides a simple and rapid device for testing a flow guide net, the backflow prevention device is used for collecting resin from the flow guide net area and preventing the resin from entering the vacuum pump, and the vacuum pumping device is used for pumping vacuum to ensure that the air pressure of the speed measuring device is far lower than the normal pressure or even in a vacuum state, the flow guide net and the vacuum film are laid on the plane of the two first flow guide pipes in sequence for testing the flow guide speed, the flow guide net is the main testing product of the method, and the main purpose is to guide the flow so that the fluid can pass through in a vacuum environment, and the vacuum film is arranged on the flow guide net and used for ensuring that the air pressure in the flow guide net is far lower than the normal pressure or even in a vacuum state. The present application uses the speed measuring device to realize the testing of the flow guide speed of the flow guide net through simple operation, and the feasibility of the process can be rapidly determined when the flow guide net or the resin is replaced.

[0011] As a preferred technical solution of the present application, a release agent layer is arranged between the plane of the two first flow guide pipes and the flow guide net.

[0012] The present application lays a release agent layer between the two first flow guide pipes and the flow guide net, and the flow guide net can be easily taken down after the testing is completed.

[0013] Preferably, the distance between the two first flow guide pipes is < the length of the flow guide net.

[0014] Preferably, the length of the first flow guide pipe is >= the width of the flow guide net.

[0015] Preferably, the first flow guide pipe is a threaded pipe.

[0016] The first flow guide pipe of the present application is a threaded pipe, and the resin can uniformly flow from one side of the flow guide net.

[0017] As a preferred technical solution of the present application, the two first flow guide pipes are respectively and independently fixed on the glass plate.

[0018] Preferably, the edges of the flow guide net are fixed on the glass plate.

[0019] Preferably, the edges of the vacuum film are fixed on the glass plate.

[0020] Preferably, the fixing mode comprises using a sealing tape for fixing.

[0021] Preferably, the glass plate is placed on the heating platform.

[0022] The flow guide device of the present application comprises a heating platform, which can heat the test process so that the resin has better flowability.

[0023] As a preferred technical solution of the present application, the backflow prevention device comprises a backflow prevention tank.

[0024] Preferably, the backflow prevention device and the vacuumizing device are connected by a fourth flow guide pipe.

[0025] Preferably, the vacuumizing device comprises a vacuum pump.

[0026] Preferably, the second flow guide pipe, the third flow guide pipe and the fourth flow guide pipe are all vacuum pipes.

[0027] The second object of the present application is to provide a flow rate measuring method of a flow guide net, which uses the flow rate measuring device of the first object, and the flow rate measuring method comprises:

[0028] After the flow rate measuring device is vacuumized, resin is injected into the flow guide device through the second flow guide pipe, and when the resin flows to the third flow guide pipe, the weight of the fed resin and the feeding time are recorded, and then the flow rate of the flow guide net is equal to the weight of the resin / (feeding time*area of the resin flowing through the flow guide net).

[0029] The present application realizes the test of the flow rate of the flow guide net through simple operation, and can quickly determine the feasibility of the process when the flow guide net or the resin is replaced.

[0030] As a preferred technical solution of the present application, the vacuumizing method comprises: sealing the port of the second flow guide pipe, and vacuumizing the flow rate measuring device by the vacuumizing device.

[0031] After the vacuumizing of the present application, the glass plate, the flow guide net and the vacuum film are completely attached.

[0032] As a preferred technical solution of the present application, the pressure of the vacuumizing is greater than or equal to 0.96Mpa, and the pressure can be 0.96Mpa, 0.97Mpa, 0.98Mpa or 0.99Mpa, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0033] If the pressure of the vacuum degree is too small, the resin cannot flow to the other side, which leads to the failure of the experiment.

[0034] Preferably, the holding time of the vacuum extraction is 15-20 min, wherein the holding time can be 15 min, 16 min, 17 min, 18 min, 19 min or 20 min, etc., but is not limited to the listed values, and other values not listed in the range are also applicable.

[0035] The holding time of the present application is too short to well determine whether the vacuum film leaks, and air is not allowed to enter the resin during the vacuum infusion process. If the air leakage is less than or equal to 3%, it is considered to meet the vacuum extraction standard.

[0036] Preferably, the viscosity of the resin is 1100-1700 mPa·s, wherein the viscosity can be 1100 mPa·s, 1200 mPa·s, 1300 mPa·s, 1400 mPa·s, 1500 mPa·s, 1600 mPa·s or 1700 mPa·s, etc., but is not limited to the listed values, and other values not listed in the range are also applicable.

[0037] In the present application, the resin is a non-crystalline resin. If the resin crystallizes before use, the resin needs to be heated at about 60°C and stirred at intervals.

[0038] Preferably, the temperature of the resin is 25-60°C, wherein the temperature can be 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C or 60°C, etc., but is not limited to the listed values, and other values not listed in the range are also applicable.

[0039] Preferably, the area of the resin flowing through the flow guide net is equal to the width of the flow guide net multiplied by the distance between the two first flow guide pipes.

[0040] The third object of the present application is to provide an application of the flow guide net speed measuring device according to any one of the objects, which is applied to the field of vacuum assisted infusion molding technology.

[0041] Compared with the prior art, the present application has the following beneficial effects:

[0042] The application utilizes a speed measuring device to realize the test of the guide net guide speed through simple operation, and the feasibility of the process can be quickly determined when the guide net or resin is replaced. The application provides a simple and rapid guide net testing device, a backflow prevention device is used to collect the resin from the guide net area, prevent the resin from entering the vacuum pump, and a vacuum pumping device is used to pump vacuum to ensure that the air pressure of the speed measuring device is far lower than the normal pressure, and even in a vacuum state, the guide net and the vacuum film are sequentially laid on the plane of the two first guide pipes for the test of the guide speed, the guide net is the main testing product of this method, and the main purpose is to guide the fluid to pass through in the vacuum environment, the vacuum film is arranged on the guide net to ensure that the air pressure in the guide net is far lower than the normal pressure, and even in a vacuum state. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 The speed measuring device of the guide net of the embodiment 1 of the application.

[0044] In the figure: 1-glass plate; 2-first guide pipe; 3-guide net; 4-second guide pipe; 5-third guide pipe; 6-sealing tape; 7-backflow prevention tank; 8-fourth guide pipe; 9-vacuum pump. DETAILED DESCRIPTION

[0045] The technical solutions of the application will be further described through specific embodiments. Those skilled in the art should understand that the embodiments are only used to understand the application and should not be regarded as specific limitations on the application.

[0046] The application provides a speed measuring device for a guide net, as shown in Figure 1 .

[0047] The speed measuring device comprises a guide device, a backflow prevention device and a vacuum pumping device connected in sequence, the guide device comprises two first guide pipes 2 arranged in parallel on a glass plate 1, a guide net 3 and a vacuum film are sequentially laid on the plane of the two first guide pipes 2, the two first guide pipes are respectively and independently extended to connect a second guide pipe 4 and a third guide pipe 5, the second guide pipe 4 is used for feeding, and the third guide pipe 5 is connected with the backflow prevention device.

[0048] Further, a layer of release agent is arranged between the plane of the two first guide pipes 2 and the guide net 3.

[0049] Further, the distance between the two first guide pipes 2 is < the length of the guide net 3.

[0050] Further, the length of the first guide pipe 2 is ≥ the width of the guide net 3.

[0051] Further, the first guide pipe 2 is a threaded pipe.

[0052] Further, the two first flow guides 2 are independently fixed on the glass plate 1.

[0053] Further, the edges of the flow guide net 3 are fixed on the glass plate 1.

[0054] Further, the edges of the vacuum film are fixed on the glass plate 1.

[0055] Further, the fixed mode includes using sealing tape 6.

[0056] Further, the glass plate is placed on a heating platform.

[0057] Further, the backflow prevention device includes a backflow prevention tank 7.

[0058] Further, the backflow prevention device and the vacuum device are connected by a fourth flow guide 8.

[0059] Further, the vacuum device includes a vacuum pump 9.

[0060] Further, the second flow guide 4, the third flow guide 5 and the fourth flow guide 8 are all vacuum tubes.

[0061] Embodiment 1

[0062] The embodiment provides a flow rate measuring method of a flow guide net using the above flow rate measuring device. In the embodiment, the length of the flow guide net of the flow rate measuring device is 700 mm, the width is 300 mm, and the distance between the two first flow guides 2 is 500 mm. The flow rate measuring method comprises the following steps.

[0063] The second flow guide 4 is sealed, the third flow guide 5 is connected to the backflow prevention tank 7, the fourth flow guide 8 is connected to the vacuum pump 9, the flow rate measuring device is vacuumized, the pressure reaches 0.98 Mpa, the pressure is maintained for 15 min, the resin with a viscosity of 1500 mPa·s is injected into the flow guide device through the second flow guide 4, the temperature of the resin is maintained at 25℃ under the action of the heating platform, when the resin flows to the third flow guide 5, the weight of the feeding resin and the feeding time are recorded, and then the flow rate of the flow guide net 3 is equal to the weight of the resin / (feeding time×width of the flow guide net×distance between the two first flow guides).

[0064] The weight of the resin at the beginning of the feeding was 3680g, 3660g after 1min, 3645g after 2min, 3630g after 3min, 3615g after 4min, 3600g after 5min, 3580g after 6min, 3565g after 7min, 3555g after 8min, 3535g after 9min, 3520g after 10min, and the average calculation of the 10 sets of data showed that the resin consumed 16g per minute. The flow velocity of the guide net 3 was 106.67g / (m 2 *min).

[0065] Example 2

[0066] In this example, the pressure reached 0.8Mpa after the speed measuring device was vacuumized, and the pressure was maintained for 15min, and the other conditions were the same as in Example 1.

[0067] Example 3

[0068] In this example, the heating platform was not heated, which was the same as room temperature 13℃, the viscosity of the resin decreased, and the other conditions were the same as in Example 1.

[0069] Example 4

[0070] In this example, the resin was heated to 55℃ by using a heating platform, the resin did not exist in a crystalline state, and the flowability of the resin was enhanced, and the other conditions were the same as in Example 1.

[0071] Example 5

[0072] In this example, the threaded pipe of the first guide pipe 2 was replaced with a conventional vacuum pipe, and the other conditions were the same as in Example 1.

[0073] The results of the flow velocity of the guide net measured by the speed measuring method in Examples 1-5 are shown in Table 1 (all are the average values of the flow velocity of the guide net for 10 times).

[0074] Table 1

[0075] Velocity of the flow guide of the flow guide net Example 1 106.67 g / (m 2 *min) Example 2 83.69 g / (m 2 *min) Example 3 50.75 g / (m 2 *min) Example 4 210.87 g / (m 2 *min) Example 5 /

[0076] From the above table, it can be seen that the pressure of vacuumizing in Example 2 is too small, leading to slow flow speed. The curing speed of the resin at this temperature is greater than that at normal temperature, which may cause the resin to solidify before it flows through the flow net. In Example 3, the heating platform in the speed measuring device is replaced by a normal platform at normal temperature, which cannot heat the resin at a constant temperature. High-purity epoxy resin is prone to generate more crystal seeds when the temperature decreases, thus leading to slow flow speed. In Example 4, the resin is heated to 55°C by using a heating platform. At this time, the resin has no crystal seeds, and the flow speed is fast. In Example 5, the vacuum pipe is replaced by a threaded pipe, and the resin cannot flow, so the flow net speed cannot be tested.

[0077] The applicant declares that the above description is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto. It should be understood by those skilled in the art that any changes or replacements within the technical scope disclosed by the present application can be easily thought of by any person skilled in the art, and all such changes or replacements fall within the protection scope and disclosure scope of the present application.

Claims

1. A method of measuring the speed of a velocity control net, characterized in that, The velocity measurement method is performed by using the velocity measurement device of the flow guide net, and the velocity measurement method comprises the following steps: After the velocity measurement device of the flow guide net is vacuumized, the resin is injected into the flow guide device through the second flow guide pipe, and when the resin flows to the third flow guide pipe, the weight of the resin and the feeding time are recorded, and then the flow guide velocity of the flow guide net = the weight of the resin / (the feeding time × the area of the resin flowing through the flow guide net); The velocity measurement device of the flow guide net comprises a flow guide device, an anti-backflow device and a vacuumizing device connected in sequence, the flow guide device comprises two first flow guide pipes arranged in parallel on a glass plate, a flow guide net and a vacuum film are sequentially laid on the plane of the two first flow guide pipes, the two first flow guide pipes are respectively and independently connected with a second flow guide pipe and a third flow guide pipe extending outward, the second flow guide pipe is used for feeding, and the third flow guide pipe is connected with the anti-backflow device.

2. The method of claim 1, wherein, A layer of release agent is arranged between the plane of the two first flow guide pipes and the flow guide net.

3. The method of claim 1, wherein, The distance between the two first flow guide pipes is less than the length of the flow guide net.

4. The method of claim 1, wherein, The length of the first flow guide pipe is greater than or equal to the width of the flow guide net.

5. The method of claim 1, wherein, The first flow guide pipe is a threaded pipe.

6. The method of claim 1, wherein, The two first flow guide pipes are respectively and independently fixed on the glass plate.

7. The method of claim 1, wherein, The edge of the flow guide net is fixed on the glass plate.

8. The method of claim 1, wherein, The edge of the vacuum film is fixed on the glass plate.

9. The method of claim 6, wherein, The fixed mode comprises using a sealing tape for fixing.

10. The method of claim 1, wherein, The glass plate is placed on a heating platform.

11. The method of claim 1, wherein, The anti-backflow device comprises an anti-backflow tank.

12. The method of claim 1, wherein, The anti-backflow device and the vacuumizing device are connected by a fourth flow guide pipe.

13. The method of claim 1, wherein, The vacuumizing device comprises a vacuum pump.

14. The method of claim 1, wherein, The second flow guide pipe, the third flow guide pipe and the fourth flow guide pipe are all vacuum pipes.

15. The method of claim 1, wherein, The vacuumizing method comprises the following steps: sealing the port of the second flow guide pipe, and vacuumizing the velocity measurement device of the flow guide net by using the vacuumizing device.

16. The method of claim 1, wherein, The pressure of the vacuumizing is greater than or equal to 0.96 MPa.

17. The method of claim 1, wherein, The pressure maintaining time of the vacuumizing is 15-20 min.

18. The method of claim 1, wherein, The viscosity of the resin is 1100-1700 mPa·s.

19. The method of claim 1, wherein, The temperature of the resin is 25-60 DEG C.

20. The method of claim 1, wherein, The area of the resin flowing through the flow guide net = the width of the flow guide net × the distance between the two first flow guide pipes.

21. The method of claim 1, wherein, The velocity measurement device of the flow guide net is applied to the field of vacuum assisted resin transfer molding technology.

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