A method for preparing a shape-controllable inflatable mandrel for braiding

Abstract

The present invention discloses a method for preparing a shape-controllable inflatable core shaft for weaving, comprising the following steps: preparing a periodic incision array on a non-elastic film after calculation according to the desired woven product; pouring an elastic material into a mold and curing it into an elastic film; after the elastic film is cured, fixing the non-elastic film on the surface of the elastic film; pouring a layer of elastomer on the non-elastic film and waiting for it to cure; after the elastomer is completely cured, a controllable deformation composite layer is obtained, which is removed from the mold and fixed into a cylindrical shell with viscose. The present invention can accurately control the inflated shape of the core shaft, ensure the shape of woven products with complex shapes, and improve the application range of fiber-reinforced composite components.

Description

Technical Field

[0001] The invention relates to the technical field of textiles, and in particular to a method for preparing a shape-controllable inflatable core shaft for weaving. Background Art

[0002] Mandrels are essential tools for fabricating fiber-reinforced composite reinforcements using braiding processes. However, in practical applications, the preparation of mandrels for special-shaped composite tubes remains a challenge. Special-shaped mandrels require high strength to ensure structural stability during braiding, while maintaining flexibility for easy demolding during injection molding.

[0003] To address this contradiction, numerous methods for producing special-shaped mandrels have been developed, but these methods still face challenges in their application. For example, cavity wax injection can be used for braiding mandrels, but the high temperature of the wax can damage and stain the braided material. Furthermore, the mold must be refilled with wax after each use. Therefore, the present invention proposes a method for producing a shape-controllable inflatable braiding mandrel to address these challenges. Summary of the Invention

[0004] In order to overcome the defects in the above-mentioned prior art, the present invention provides a method for preparing a shape-controllable inflatable mandrel for weaving, by which the weaving of the fiber reinforcement is achieved through the shape-controllable inflatable mandrel. The mandrel has high strength after being inflated, which can ensure that the final molded product has a more accurate size and appearance, and can be easily demolded after being deflated.

[0005] Technical Solution

[0006] A method for preparing a shape-controllable inflatable mandrel for braiding comprises the following steps:

[0007] Step 1: According to the required woven product, a periodic incision array is prepared on the non-elastic film through calculation;

[0008] Step 2: pouring the elastic material into the mold and solidifying it into an elastic film;

[0009] Step 3: After the elastic film is cured, the non-elastic film is fixed on the surface of the elastic film;

[0010] Step 4: Pour a layer of elastomer on the non-elastic film and wait for it to solidify;

[0011] Step 5: After the elastomer is completely cured, the controllable deformation composite layer is obtained, which is removed from the mold and fixed into a cylindrical shell with adhesive;

[0012] Step 6: Add an additional layer of elastic material to one end of the cylindrical shell for sealing;

[0013] Step 7: Covering the cylindrical shell on the surface of the metal shaft core with the inflation control component to form a shape-controllable braided inflatable core shaft;

[0014] Step 8: Connect the prepared braided inflatable mandrel to the robotic arm, inflate the braided inflatable mandrel and maintain the pressure, and then send it into the braiding machine to braid on the surface of the braided inflatable mandrel;

[0015] Step 9: After the weaving is completed, the weaved inflatable mandrel is placed into a mold for curing while maintaining the inflation pressure;

[0016] Step 10: After curing is completed, the braided inflatable core shaft is deflated, and the metal shaft core with the inflation control component and the cylindrical shell are removed in turn. Finally, the cured composite material is removed from the mold and post-processed by polishing and painting.

[0017] Furthermore, the step of preparing a periodic cut array on the non-elastic film in step 1 includes cutting a periodic cut array in the non-elastic film using a laser.

[0018] Furthermore, the mold in step 2 is a photo frame.

[0019] Furthermore, in step 4, a layer of elastomer is cast on the non-elastic film:

[0020] Then, a layer of elastic film is cast on the surface of the non-elastic film so that the non-elastic film is completely embedded in the elastic film.

[0021] Furthermore, the step 5 of fixing it into a cylindrical shell with glue is as follows: the controllable deformation composite layer is rolled into a cylindrical shell, and then two sides of the cylindrical shell are glued with glue to fix it.

[0022] Furthermore, in step six, an additional layer of elastic material is added to one end of the cylindrical shell for sealing: one end of the cylindrical shell is vertically placed in a mold filled with elastic material and waited for it to solidify.

[0023] Furthermore, the step nine of placing the braided inflatable mandrel into a mold for curing is as follows: placing the braided inflatable mandrel into a mold with a built-in resin for curing.

[0024] The present invention has beneficial effects:

[0025] The present invention adopts a method of embedding a non-elastic film in an elastic material to prepare an inflatable core shaft with controllable shape. On the one hand, when air is filled into the inflatable core shaft, the shape of the incision can be controlled to more accurately obtain a special-shaped core shaft for weaving of the desired shape; on the other hand, the internal core shaft can be conveniently removed from the cured special-shaped composite material by deflating, and can be reused and has a long service life. At the same time, the inflatable core shaft processed by using cured silicone rubber has the advantages of a smooth outer surface and the absence of bubbles, thereby better ensuring the perfect appearance of the woven product. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a cut array shape pattern of a method for preparing a shape-controllable inflatable mandrel for braiding according to the present invention;

[0027] Figure 2 This is a schematic diagram of casting the first layer of elastic film of the present invention;

[0028] Figure 3 This is a schematic diagram of casting the second layer of elastic film of the present invention;

[0029] Figure 4 It is a schematic diagram of the inflation pattern of the cylindrical shell of the present invention;

[0030] Figure 5 It is a schematic diagram of the preparation process of the present invention;

[0031] Figure 6 It is a schematic diagram of the curing process of the present invention.

[0032] Figure Numbers

[0033] Cylindrical shell 1, metal shaft core 2, braiding machine 3, beaker 4, 00-50 silicone 5, photo frame 6, mold 7, fiber reinforcement 8, incision array shape 9.

[0034] Specific implementation cases

[0035] To better illustrate the present invention, the following is a detailed description with reference to the accompanying drawings and implementation examples:

[0036] have Figures 1-6 As shown, the present invention discloses a method for preparing a shape-controllable inflatable mandrel for braiding, comprising the following steps:

[0037] Step 1: According to the required woven product, a periodic incision array is prepared on the non-elastic film through calculation;

[0038] Step 2: pouring the elastic material into the mold and solidifying it into an elastic film;

[0039] Step 3: After the elastic film is cured, the non-elastic film is fixed on the surface of the elastic film;

[0040] Step 4: Pour a layer of elastomer on the non-elastic film and wait for it to solidify;

[0041] Step 5: After the elastomer is completely cured, the controllable deformation composite layer is obtained, which is removed from the mold and fixed into a cylindrical shell with adhesive;

[0042] Step 6: Add an additional layer of elastic material to one end of the cylindrical shell for sealing;

[0043] Step 7: Covering the cylindrical shell on the surface of the metal shaft core with the inflation control component to form a shape-controllable braided inflatable core shaft;

[0044] Step 8: Connect the prepared braided inflatable mandrel to the robotic arm, inflate the braided inflatable mandrel and maintain the pressure, and then send it into the braiding machine to braid on the surface of the braided inflatable mandrel;

[0045] Step 9: After the weaving is completed, the weaved inflatable mandrel is placed into a mold for curing while maintaining the inflation pressure;

[0046] Step 10: After curing is completed, the braided inflatable core shaft is deflated, and the metal shaft core with the inflation control component and the cylindrical shell are removed in turn. Finally, the cured composite material is removed from the mold and post-processed by polishing and painting.

[0047] Furthermore, the step of preparing a periodic cut array on the non-elastic film in step 1 includes cutting a periodic cut array in the non-elastic film using a laser.

[0048] Furthermore, the mold in step 2 is a photo frame.

[0049] Furthermore, in step 4, a layer of elastomer is cast on the non-elastic film:

[0050] Then, a layer of elastic film is cast on the surface of the non-elastic film so that the non-elastic film is completely embedded in the elastic film.

[0051] Furthermore, the step 5 of fixing it into a cylindrical shell with glue is as follows: the controllable deformation composite layer is rolled into a cylindrical shell, and then two sides of the cylindrical shell are glued with glue to fix it.

[0052] Furthermore, in step six, an additional layer of elastic material is added to one end of the cylindrical shell for sealing: one end of the cylindrical shell is vertically placed in a mold filled with elastic material and waited for it to solidify.

[0053] Furthermore, the step nine of placing the braided inflatable mandrel into a mold for curing is as follows: placing the braided inflatable mandrel into a mold with a built-in resin for curing.

[0054] Specifically, in step 1, the non-elastic film selected is a PI film with a width of 17.5 mm, a length of 895 mm, and a thickness of 0.3 mm. A pattern is cut out on the PI film by laser. Figure 1 As shown, the pattern is slightly larger than the actual size so that the elastic material can be better embedded in the cut periodic array. As the incision array shape 9, the pattern selected by the present invention is an X shape with dimensions of a = 3 mm, b = 30 mm, and θ = 80°;

[0055] The production process of step 2 is as follows: the elastic material selected is 00-50 silicone 5, the 00-50 silicone 5 in the beaker 4 is poured into the photo frame 6, and evenly distributed under the action of gravity, filling the photo frame 6 to the edge, the thickness of the first layer of elastomer is controlled to 0.3mm, and it is waited for to be completely cured. The photo frame 6 is 18mm wide, 850mm long, and 12mm thick.

[0056] The operation process of step three is as follows: after curing is completed, the PI film is gently placed on the first layer of elastomer;

[0057] The operation process of step 4 is: pouring a second layer of elastomer on top of the PI film, the operation process is the same as step 2, the thickness of the second layer of elastomer is 0.4mm, so that the PI film is completely embedded in the elastomer, and after the operation is completed, wait for it to completely cure;

[0058] The operation process of step five is as follows: after the second layer of elastomer is completely cured, the controlled deformation composite layer is removed, and then the controlled deformation composite layer is rolled into a cylindrical shell 1 using a needle so that the two opposite edges are aligned. Then, 2-ethyl cyanoacrylate glue is used to glue the edges together. After the gluing process is completed, a layer of elastomer is deposited on the inside of the cylindrical shell 1, and the two edges are connected together. To ensure uniform thickness in this area, the elastomer is flattened by scraping off excess material that overflows from the groove formed by the previously cured elastomer. The same process is repeated on the outside of the cylindrical shell 1.

[0059] The operation process of step six is as follows: an acrylic cover is glued to the end of the cylindrical shell 1, and the end is also covered with an additional layer of elastomer to ensure its airtightness;

[0060] The operation process of step 7 shown is as follows: after curing is completed, the unsealed end of the cylindrical shell 1 is placed on the surface of the metal shaft core 2 with an inflation control component, thereby forming a shape-controllable braided inflatable core shaft. The metal shaft core 2 with an inflation control component has a diameter of 100 mm and a length of 800 mm.

[0061] The operation process of step eight is as follows: the shape-controllable braided inflatable mandrel is loaded into the robotic arm, the inflation switch of the metal shaft core 2 with the inflation control component is turned on, and the shape-controllable braided inflatable mandrel is inflated. The metal shaft core 2 with the inflation control component includes an air inlet and an air outlet; the air inlet can only take in air in one direction but not out, and it is connected to a hose; the air outlet can only outflow air in one direction but not take in air, and the port is normally closed and can be opened by a switch; the hose can extend into the braided inflatable mandrel, and when inflated, a constant air flow is filled into it from the air inlet, and the robotic arm is operated to send the shape-controllable braided inflatable mandrel into the braiding machine 3, and the movement trajectory of the robotic arm during the braiding process is designed according to the shape of the mandrel sleeve, and the braiding machine 3 is cooperated to braid the reinforcement body, and the fiber reinforcement body 8 is densely wrapped around the surface of the cylindrical shell 1;

[0062] The operation process of step nine is as follows: after the braiding is completed, the inflation switch of the metal shaft core 2 with the inflation control component is kept open, the braided inflatable mandrel is inflated and the pressure is maintained, and the robotic arm is operated to place the shape-controllable braided inflatable mandrel into the mold 7 with the built-in resin for curing;

[0063] The operation process of step 10 is as follows: after the curing is completed, the shape-controllable braided inflatable mandrel is taken out from the robot arm, the inflation switch of the metal shaft core 2 with the inflation control component is turned off, the metal shaft core 2 with the inflation control component is first removed, and then the cylindrical shell 1 is taken out, and finally the cured composite material is taken out from the mold 7. Figure 1 The elastic deformation ability of the middle pattern is studied. The present invention simulates the shape of a woven fabric. The pattern sizes of the rows cut in front and behind the PI film are a=3mm, b=30mm, θ=60°, and the size of the middle pattern is changed to a=3mm, b=30mm, θ=90°. As expected by the present invention, when inflated, the cylindrical shell 1 begins to expand. This structure deforms uniformly along its soft axis and most of it is elongated. The lower end of the cylindrical shell 1 is affected by the pattern size on the PI film, so the deformation change is stronger and the expansion size is significantly increased.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the technical solutions of the present invention have been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for preparing a shape-controllable inflatable mandrel for braiding, characterized in that: The steps include: Step 1: According to the required woven product, a periodic incision array is prepared on the non-elastic film through calculation; Step 2: pouring the elastic material into the mold and solidifying it into an elastic film; Step 3: After the elastic film is cured, the non-elastic film is fixed on the surface of the elastic film; Step 4: Pour a layer of elastomer on the non-elastic film and wait for it to solidify; Step 5: After the elastomer is completely cured, the controllable deformation composite layer is obtained, which is removed from the mold and fixed into a cylindrical shell with adhesive; Step 6: Add an additional layer of elastic material to one end of the cylindrical shell for sealing; Step 7: Covering the cylindrical shell on the surface of the metal shaft core with the inflation control component to form a shape-controllable braided inflatable core shaft; Step 8: Connect the prepared braided inflatable mandrel to the robotic arm, inflate the braided inflatable mandrel and maintain the pressure, and then send it into the braiding machine to braid on the surface of the braided inflatable mandrel; Step 9: After the weaving is completed, the weaved inflatable mandrel is placed into a mold for curing while maintaining the inflation pressure; Step 10: After curing is completed, deflate the braided inflatable core shaft, remove the metal shaft core with the inflation control component and the cylindrical shell in turn, and finally remove the cured composite material from the mold for polishing and painting.

2. The method for preparing a shape-controllable inflatable mandrel for braiding according to claim 1, characterized in that: The step 1 of preparing a periodic cut array on the non-elastic film is as follows: a periodic cut array is cut in the non-elastic film using a laser.

3. The method for preparing a shape-controllable inflatable mandrel for braiding according to claim 2, characterized in that: The mold in step 2 is a photo frame.

4. The method for preparing a shape-controllable inflatable mandrel for braiding according to claim 3, characterized in that: The step 4 of casting a layer of elastomer on the non-elastic film is as follows: casting a layer of elastic film on the surface of the non-elastic film so that the non-elastic film is completely embedded in the elastic film.

5. The method for preparing a shape-controllable inflatable mandrel for braiding according to claim 4, characterized in that: The step 5 of fixing it into a cylindrical shell with glue is as follows: the controllable deformation composite layer is rolled into a cylindrical shell, and then both sides of the cylindrical shell are glued with glue to fix it.

6. The method for preparing a shape-controllable inflatable mandrel for braiding according to claim 5, characterized in that: In step 6, an additional layer of elastic material is added to one end of the cylindrical shell for sealing: one end of the cylindrical shell is placed vertically into a mold filled with elastic material and waited for it to solidify.

7. The method for preparing a shape-controllable inflatable mandrel for braiding according to claim 6, characterized in that: The step nine of placing the braided inflatable mandrel into a mold for curing is as follows: placing the braided inflatable mandrel into a mold with a built-in resin for curing.

Images