A winding unidirectional plate forming method and forming tool

Abstract

The application provides a winding unidirectional plate forming method and forming tool, and the winding unidirectional plate forming method comprises the following steps: winding fibers and pressurizing to form two-layer blank plates on the forming tool; pre-curing the blank plates, cutting off the fibers connecting the two-layer blank plates, and finally curing the blank plates; cutting the blank plates into unidirectional plates according to preset sizes; cutting reinforcing sheets; bonding the reinforcing sheets on the unidirectional plates and curing; and cutting the unidirectional plates into unidirectional plate standard test samples. The application adopts a sectional forming method, pre-cures the blank plates first, cuts off the fibers connecting the two-layer blank plates after pre-curing, and finally cures the blank plates, so that the problem of warping deformation caused by the fact that the fiber stress is not released in time is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fiber winding unidirectional plate, and particularly relates to a winding unidirectional plate forming method and forming tool. BACKGROUND

[0002] The fiber winding solid engine shell is applied more and more widely in missile weapons or rocket engines. Along with this, the performance verification and testing of the raw material are more and more urgent. The fiber filament sample can directly reflect the good and bad of the fiber single filament performance, and the fiber winding unidirectional plate performance can directly reflect the strength and weakness of the matching of the fiber and the resin. The carbon fiber unidirectional plate performance is the "gold standard" of the fiber performance examination of the winding product and an important index for evaluating the product performance. The unidirectional plate production and testing are accurate, and the unidirectional plate production and testing can truly reflect the fiber performance and the resin matching type. The carbon fiber unidirectional plate performance test includes 0° tensile strength, 0° tensile modulus, 90° tensile strength, 90° tensile modulus, 0° compression strength, 0° compression modulus, 90° compression strength, 90° compression modulus, 0° bending strength, 0° bending modulus and interlaminar shear strength. If the fiber winding unidirectional plate performance test result is abnormal due to the sample production, the use of the raw material is directly affected, and finally the product performance and use are affected.

[0003] The existing fiber winding unidirectional plate adopts the method of one-time curing forming and segmented bonding of the reinforcing sheet to form the unidirectional plate test sample, and has the problems of easy warping deformation of the unidirectional plate, low bonding strength of the reinforcing sheet and easy pulling off during the test due to the deflection. SUMMARY

[0004] The present application aims at the defects of the prior art, and provides a winding unidirectional plate forming method and forming tool. The segmented forming method is adopted, the blank plate is pre-cured, the fiber connecting the two layers of blank plates is cut off after the pre-curing, and the blank plate is finally cured, so that the warping deformation problem caused by the untimely release of the fiber stress is reduced.

[0005] In order to solve the above technical problems, in a first aspect, the present application provides a winding unidirectional plate forming method, comprising:

[0006] The fiber winding is performed on the forming tool, and two layers of blank plates are formed by pressing;

[0007] The blank plates are pre-cured, the fiber connecting the two layers of blank plates is cut off, and the blank plates are finally cured;

[0008] The blank plates are cut and processed into unidirectional plates according to the preset size;

[0009] The reinforcing sheet is cut and processed;

[0010] The reinforcing sheet is bonded on the unidirectional plate and cured;

[0011] The unidirectional plate is cut into a standard test specimen of the unidirectional plate.

[0012] In some embodiments, the method of fiber winding on a forming tool includes that the distance between the starting point of fiber winding and the two side boundaries of the winding area of the forming tool is a.

[0013] In some embodiments, the method of pre-curing the blank plate includes that the forming tool and the blank plate fixed on the forming tool are put into a curing oven, a heating system is started, the temperature rising rate is adjusted to 1-2 ℃ / min, the temperature is first heated to 80-90 ℃, and then the temperature is kept for 1-3 h, the temperature is heated to 100-120 ℃, and then the temperature is kept for 3-5 h, the heating is stopped, and the forming tool is cooled to below 50 ℃ and taken out.

[0014] Further, the method of cutting off the fibers connecting the two blank plates includes that a pneumatic sander is used to cut off all the fibers exposed on the outside along the side of the tool.

[0015] Further, the method of final curing the blank plate includes that the cut unidirectional plate and the tool are again placed flat in the curing oven, the heating system is started, the temperature rising rate is adjusted to 1-2 ℃ / min, the corresponding curing system is selected according to the type of resin, after the temperature rising and keeping, the oven is cooled to below 50 ℃ and taken out.

[0016] In some embodiments, the method of bonding the reinforcing sheet on the unidirectional plate and curing includes that

[0017] The bonding area of the reinforcing sheet and the corresponding bonding area of the unidirectional plate are sandblasted to be rough;

[0018] The unidirectional plate and the reinforcing sheet are cleaned and dried;

[0019] The adhesive film is cut;

[0020] The adhesive film is pasted;

[0021] The reinforcing sheet is bonded on the unidirectional plate.

[0022] Further, the method of bonding the reinforcing sheet on the unidirectional plate and curing includes that

[0023] The unidirectional plate with the bonded reinforcing sheet is wrapped in a vacuum bag and subjected to vacuumizing treatment;

[0024] The unidirectional plate that passes the vacuumizing is transferred to a curing oven for curing.

[0025] In the second aspect, the application provides a winding unidirectional plate forming tool, comprising a winding plate and two pressing plates, recesses and fixing holes are arranged on the upper and lower surfaces of the winding plate, the fixing holes are arranged on both sides of the recesses, the recesses are used for winding fibers, and the fixing holes are used for fixing the pressing plates on the winding plate, bosses are arranged on the pressing plates, the bosses are arranged correspondingly with the recesses, and the bosses are used for extruding the fibers wound on the winding plate.

[0026] Further, counter top holes are arranged on the pressing plates, and the counter top holes are used for separating the pressing plates from the winding plate.

[0027] Further, a gasket is arranged between the winding plate and the pressing plate, and the gasket is arranged at the fixing hole.

[0028] The application has the following beneficial effects:

[0029] 1. The application adopts a segmented forming method, the embryo plate is pre-solidified first, then the fibers connecting the two layers of embryo plates are cut off, after the cutting, the embryo plate clamped on the forming tool releases a certain stress and shrinks, and finally the embryo plate is solidified, so that the problem of warping deformation caused by the fact that the fiber stress is not released in time is reduced.

[0030] 2. When the fibers are wound, the winding starting point and the winding end point of the fibers are reserved a certain distance from both sides of the winding area of the forming tool, so that when the tool extrudes the fibers, the resin on the fibers is prevented from gathering to the edge, the fiber resin content at the edge is prevented from being higher, and the manufacturing requirements of the unidirectional plate are met.

[0031] 3. The application directly bonds the reinforcing plate to the large-size unidirectional plate, and then cuts the unidirectional plate bonded with the reinforcing plate into a unidirectional plate standard test sample, compared with the method of cutting first and then bonding the reinforcing plate, the unidirectional plate standard test sample is more square, and the reinforcing plate is accurately bonded at both ends of the unidirectional plate standard test sample, so that the problem that the subsequent test result is inaccurate due to the bonding deviation of the reinforcing plate is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 It is a front view of the application.

[0033] Figure 2 It is a top view of the application.

[0034] Figure 3 It is a front view of the winding plate of the application.

[0035] Figure 4 It is a top view of the winding plate of the application.

[0036] Figure 5 It is a front view of the pressing plate of the application.

[0037] Figure 6 The top view of the pressing plate of the present application.

[0038] Reference signs: winding plate 1; pressing plate 2; handle 3; gasket 4; bolt 5; counter top hole 6; groove 7; boss 8; fixing hole 9. DETAILED DESCRIPTION

[0039] In order to make the technical problems to be solved by the present application, technical solutions and beneficial effects more clear and explicit, the present application will be further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and not used to limit the present application.

[0040] As shown in Figure 1 , the present application provides a winding unidirectional plate forming tool, which comprises a winding plate 1 and two pressing plates 2, as shown in Figure 2 , 3 , the upper and lower surfaces of the winding plate 1 are provided with grooves 7 and fixing holes 9, the grooves 7 are provided in the middle of the winding plate 1, the fixing holes 9 are arranged on both sides of the grooves 7, close to the edges of the winding plate 1, the grooves 7 are used for winding fibers, and the fixing holes 9 are used for fixing the pressing plates 2 on the winding plate 1, as shown in Figure 5 , 6 , the pressing plates 2 are provided with bosses 8, the bosses 8 are arranged correspondingly to the grooves 7, and the bosses 8 are used for extruding the fibers wound on the winding plate 1.

[0041] As shown in Figure 6 , counter top holes 6 are provided on the pressing plates 2, the counter top holes 6 are used for separating the pressing plates 2 from the winding plate 1, that is, the pressing plates 2 can be lifted up by screwing bolts 5 into the counter top holes 6.

[0042] As shown in Figure 1 , gaskets 4 are arranged between the winding plate 1 and the pressing plates 2, the gaskets 4 are arranged at the fixing holes 9, that is, close to the edges of the winding plate 1 on both sides, and the gaskets 4 can accurately control the thickness of the blank plate while ensuring that the pressing plates 2 pressurize the fibers.

[0043] The present application provides a winding unidirectional plate forming method, which comprises:

[0044] S1, winding and pressurizing fibers on a forming tool to form two layers of blank plates; specifically comprising:

[0045] S11, assembling the forming tool: cleaning the surfaces of the winding plate 1 and the pressing plate 2, then sticking polytetrafluoroethylene release cloth on the grooves 7 (i.e. unidirectional plate winding area) of the winding plate 1 and the bosses 8 of the pressing plate 2, connecting the winding plate 1 and the handle 3 into a whole through the bolts 5 and nuts, clamping the handle 3 on the winding machine chuck, and tightening the numerical control winding machine chuck;

[0046] S12, according to the demand, the corresponding fiber and resin are selected for fiber unidirectional plate winding: the corresponding fiber and resin are selected, the fiber is threaded through the yarn path of the numerical control winding machine, the resin is prepared according to the corresponding resin preparation proportion, the prepared resin is poured into the fiber impregnation glue tank, the appropriate tension is set, the tension control system of the numerical control winding machine is opened, the winding program is called, the fiber unidirectional plate is wound, the winding layer number is determined and adjusted according to the fiber yarn type, the fiber yarn strand number, the fiber yarn width and the winding layer thickness, the winding starting point is about 10mm from the side wall of one side of the groove 7, the ending point is about 10mm from the side wall of the other side of the groove 7, and the winding length is about 280mm. After winding, the cutting machine head yarn is cut.

[0047] It can be understood that, in the process of pressing the fiber by the pressing plate 2 after the fiber winding is completed, the resin on the fiber is extruded to both sides of the groove 7, if the fiber extends to both sides of the groove 7, the resin content in the fiber close to both sides of the groove 7 is more, which does not meet the forming requirement of the unidirectional plate. Therefore, the starting point and the ending point of the winding are reserved a certain distance from both sides of the groove 7, so that the resin content in the whole blank plate meets the requirement.

[0048] S13, using the pressing plate 2 to press: 10 M12 screws are used to assemble the pressing plate 2 and the winding plate 1 in place, before assembling the pressing plate 2, 1mm thick gaskets 4 (adjusted according to the thickness of the unidirectional plate) are used between the bolts 5 between the pressing plate 2 and the winding plate 1 to limit, then the two pressing plates 2 are tightened by the bolts 5 (the torque is required to be the same, the torque value is 40-90N·m, the bolts 5 are symmetrically tightened, the torque is increased by 10N·m step by step), and the thickness of the blank plate is uniform.

[0049] S2, pre-curing the blank plate, cutting the fiber connecting two layers of blank plates, and finally curing the blank plate; specifically including:

[0050] S21, pre-curing the blank plate: the forming tool and the blank plate fixed on the forming tool are put into the curing oven, the heating system is started, the temperature rising rate is adjusted to 1-2℃ / min, the temperature is first heated to 80-90℃, and then the temperature is heated to 100-120℃, and the temperature is kept for 3-5h, the heating is stopped, and the forming tool is cooled to below 50℃ and taken out.

[0051] S22, cutting the fiber connecting two layers of blank plates: a pneumatic sander is used to cut all the exposed fibers along the side edge of the tool.

[0052] S23, finally curing the blank plate: the unidirectional plate and the tool after cutting are put into the curing oven again, the heating system is started, the temperature rising rate is adjusted to 1-2℃ / min, the corresponding curing system is selected according to the type of resin, after the temperature rising and keeping, the oven is cooled to below 50℃ and taken out.

[0053] It can be understood that, by using the segmented molding method, the embryo plate is first pre-solidified, after pre-solidification, the fibers connecting the two layers of embryo plate are cut off, after cutting off, the embryo plate clamped on the molding tool releases a certain stress and shrinks, and finally the embryo plate is solidified, thereby reducing the warping deformation problem caused by the fact that the fiber stress is not released in time.

[0054] S3, cutting the embryo plate into unidirectional plate according to the preset size; specifically including:

[0055] The embryo plate that has been completely cured and passed the inspection is processed according to the following sizes:

[0056] (1) 0° tensile unidirectional plate machining: (230±0.3) mm (fiber direction) × (250±0.5) mm × 1 mm (thickness size, not processed);

[0057] (2) 90° tensile test sample machining: (170±0.3) mm × (25±0.3) mm (fiber direction) × 2 mm;

[0058] (3) 0° compression unidirectional plate machining: (140±0.3) mm (fiber direction) × (250±0.5) mm × 2 mm (thickness size, not processed);

[0059] (4) 90° compression unidirectional plate machining: (140±0.3) mm (perpendicular to the fiber direction) × (250±0.5) mm × 2 mm (thickness size, not processed);

[0060] (5) 0° bending test sample machining: (80±0.3) mm (fiber direction) × 12.5 (±0.2) mm × 2 mm;

[0061] (6) interlaminar shear test sample machining: (30±1) mm (fiber direction) × 10 (±0.2) mm × 2 mm.

[0062] S4, cutting and processing the reinforcing sheet; specifically including:

[0063] The reinforcing sheet of the composite material with a size of 1020×2040×2 mm is processed into reinforcing sheets with sizes of 50×250×2 mm (tensile sample reinforcing sheet) and 63×250×2 mm (compression sample reinforcing sheet) respectively, and is ready for use.

[0064] S5, bonding the reinforcing sheet on the unidirectional plate and solidifying; specifically including:

[0065] S51, sandblasting the bonding area of the reinforcing sheet and the corresponding bonding area of the unidirectional plate to be rough, without damaging the fibers;

[0066] S52, clean the unidirectional plate and the reinforcing sheet and dry: use a lint-free paper to dip anhydrous ethanol or ethyl acetate to clean the whole surface of the unidirectional plate and the reinforcing sheet, and dry at room temperature for 10-20 min;

[0067] S53, cut the adhesive film: cut the adhesive film of corresponding size according to the size of each sample reinforcing sheet, 4 pieces of adhesive film (250 mm x 50 mm) for each 0° or 90° tensile unidirectional plate, 4 pieces of adhesive film (250 x 63 mm) for each 0° compression unidirectional plate and 90° compression unidirectional plate;

[0068] S54, paste the adhesive film: tear off the silicone oil paper on one side of the adhesive film, paste the adhesive film of corresponding size on the surface of the reinforcing sheet of corresponding size, then press the adhesive film to make it preliminarily adhere to the reinforcing sheet, tear off the adhesive film on the outside, and the layer of adhesive film on the outside is upward;

[0069] S55, bond the reinforcing sheet to the unidirectional plate: bond the 0° tensile sample reinforcing sheet and the 0° / 90° compression sample reinforcing sheet to the 0° tensile unidirectional plate and the 0° / 90° compression unidirectional plate respectively, and press them to make them adhere tightly after bonding.

[0070] S56, wrap the unidirectional plate with the bonded reinforcing sheet in a vacuum bag and perform vacuumizing treatment;

[0071] S57, transfer the unidirectional plate that has passed the vacuumizing to a curing oven for curing, take out the unidirectional plate from the curing oven after curing, clean the vacuum bag, air-permeable felt, and adhesive cloth, and gently tear off the positioning strip, pressure-sensitive adhesive, release cloth, and sealing black glue, and clean the surface of the unidirectional plate, without damaging the fibers during the cleaning process.

[0072] S6, cut and process the unidirectional plate into standard test samples of unidirectional plate.

[0073] Transfer the unidirectional plate with the bonded reinforcing sheet and the unidirectional plate that can be directly machined to a machine for machining standard test samples of unidirectional plate, and the sizes of the standard samples are as follows (the size standards are respectively implemented: tensile: GB / T3354; compression: GB / T3856; bending: GB / T3356; interlaminar shear strength: JC / T773):

[0074] 0° tensile sample ((230±0.3) mm (fiber direction) x (12.5±0.3) mm x 1 mm), 10 pieces;

[0075] 90° tensile sample ((170±0.3) mm x (25±0.3) mm (fiber direction) x 2 mm), 10 pieces;

[0076] 0° compression sample ((140±0.3) mm (fiber direction) x (6±0.3) mm x 2 mm)), 10 pieces;

[0077] 90° compression test sample (140±0.3)mm (vertical fiber direction) x (6±0.3)mm x 2mm), 7;

[0078] 0° bending test sample ((80±0.3)mm (fiber direction) x 12.5(±0.2)mm x 2mm), 7;

[0079] 0° interlaminar shear test sample ((30±1)mm (fiber direction) x 10(±0.2)mm x 2mm), 7.

[0080] It can be understood that, the present application directly bonds the reinforcing plate on the large-size unidirectional plate by making the large-size unidirectional plate, cutting the unidirectional plate bonded with the reinforcing plate into the unidirectional plate standard test sample, and the unidirectional plate standard test sample of the present application is more square, and the reinforcing plate is accurately bonded at both ends of the unidirectional plate standard test sample, avoiding the problem that the subsequent test result is inaccurate due to the bonding deviation of the reinforcing plate.

[0081] The above-processed unidirectional plate standard test sample is subjected to performance test according to the following standards:

[0082] 0° / 90° tensile strength and modulus are detected, and the execution standard is GB / T 3354-2014;

[0083] 0° / 90° compression strength and modulus are detected, and the execution standard is BG / T 3856-2005;

[0084] 0° bending strength is detected, and the execution standard is GB / T 3356-2014;

[0085] 0° bending modulus is detected, and the execution standard is GB / T 3356-2005;

[0086] The interlaminar shear strength is detected, and the execution standard is JC / T 773-2010.

[0087] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A method of forming a wound unidirectional sheet, characterized by, The method comprises the following steps: performing fiber winding on a forming tool and pressurizing to form two-layered preforms; pre-curing the preforms, cutting off the fibers connecting the two-layered preforms, and finally curing the preforms; cutting the preforms into unidirectional plates according to preset sizes; cutting the reinforcing sheets; bonding the reinforcing sheets to the unidirectional plates and curing them; cutting the unidirectional plates into unidirectional plate standard test samples; The method for performing fiber winding on a forming tool comprises the following steps: a certain distance is reserved between the winding starting point and ending point of the fibers and the two sides of the winding area of the forming tool.

2. The method of claim 1, wherein The method for pre-curing the preforms comprises the following steps: placing the forming tool and the preforms fixed on the forming tool into a curing oven, starting the heating system, adjusting the heating rate to 1-2 ℃ / min, first heating the temperature to 80-90 ℃, keeping the temperature for 1-3 h, then heating the temperature to 100-120 ℃, keeping the temperature for 3-5 h, stopping heating, cooling to below 50 ℃, and taking out the forming tool.

3. The method of claim 2, wherein The method for cutting off the fibers connecting the two-layered preforms comprises the following steps: using a pneumatic sander to cut off all the fibers exposed on the outside along the side of the tool.

4. The method of claim 3, wherein The method for finally curing the preforms comprises the following steps: placing the unidirectional plates and the tool after cutting again into a curing oven, starting the heating system, adjusting the heating rate to 1-2 ℃ / min, selecting the corresponding curing system according to the type of the resin, after completing the heating and keeping the temperature, cooling to below 50 ℃ in the oven and taking out.

5. The method of claim 1, wherein The method for bonding the reinforcing sheets to the unidirectional plates and curing them comprises the following steps: blasting the bonding area of the reinforcing sheets and the corresponding bonding area of the unidirectional plates to be rough; cleaning the unidirectional plates and the reinforcing sheets and drying them; cutting the adhesive film; bonding the adhesive film; bonding the reinforcing sheets to the unidirectional plates.

6. The method of claim 5, wherein the winding the unidirectional plies is performed by a winding machine. The method for bonding the reinforcing sheets to the unidirectional plates and curing them comprises the following steps: packing the unidirectional plates with the bonded reinforcing sheets into a vacuum bag and performing vacuumizing treatment; transferring the unidirectional plates that pass the vacuumizing to a curing oven for curing.

7. A winding unidirectional sheet molding tool according to the winding unidirectional sheet molding method according to any one of claims 1 to 6, characterized by, The device comprises a winding plate (1) and two pressing plates (2), the upper and lower surfaces of the winding plate (1) are provided with grooves (7) and fixing holes (9), the fixing holes (9) are arranged on the two sides outside the grooves (7), the grooves (7) are used for winding fibers, and the fixing holes (9) are used for fixing the pressing plates (2) on the winding plate (1), the pressing plates (2) are provided with protrusions (8), the protrusions (8) are arranged correspondingly with the grooves (7), and the protrusions (8) are used for extruding the fibers wound on the winding plate (1).

8. The winding unidirectional sheet molding tool according to claim 7, wherein, The pressing plates (2) are provided with reverse top holes (6), and the reverse top holes (6) are used for separating the pressing plates (2) from the winding plate (1).

9. The wrapping unidirectional sheet forming tooling of claim 7, wherein, The winding plate (1) and the pressing plate (2) are provided with a gasket (4), and the gasket (4) is arranged at the fixing hole (9).

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