Combined polymer mold as well as preparation method and application thereof

Abstract

The invention relates to a combined polymer mold as well as a preparation method and application thereof. The combined polymer mold comprises a mold and a gap filling rope, wherein the mold is formed by combining at least two polymer mold main bodies with cavity structures; the gap filling ropes are used for filling gaps between the adjacent polymer mold main bodies; the polymer mold body and the joint filling rope are both made of shape memory polymers. The combined polymer mold has a shape memory function, is easy to demold, not only effectively reduces the manufacturing difficulty of a large mold, but also realizes simple, efficient and low-cost manufacturing of large composite material components, especially wing components.

Description

Technical Field

[0001] The present invention relates to the technical field of mold design, in particular to the technical field of composite material forming, and particularly to a combined polymer mold, a preparation method thereof and an application thereof. Background Art

[0002] In the manufacturing industry, molds are important tools for component forming and play an irreplaceable important role. With the technological revolution in manufacturing engineering, there are higher requirements for the design and production of complex components. Traditional manufacturing technologies are difficult to achieve the production of complex components with characteristics such as variable structure, variable curvature, and variable cross-section, and there are problems such as difficult demolding, complex design, and heavy self-weight of the mold, which seriously restricts the development of complex components. Therefore, developing new molds that are easy to demold and have fast production has become an urgent problem to be solved in the manufacturing industry. Summary of the Invention

[0003] In order to solve one or more technical problems existing in the prior art, the present invention provides a combined polymer mold, a preparation method thereof and an application thereof. The combined polymer mold proposed by the present invention has a shape memory function and is easy to demold, which not only effectively reduces the manufacturing difficulty of large molds, but also realizes the simple, efficient and low-cost manufacturing of large composite components, especially wing components.

[0004] In a first aspect, the present invention provides a combined polymer mold, comprising: a mold formed by combining at least two polymer mold bodies with cavity structures and caulking ropes; the caulking ropes are used to fill the gaps between adjacent polymer mold bodies; both the polymer mold bodies and the caulking ropes are made of shape memory polymers.

[0005] Preferably, the shape memory polymer includes styrene-based shape memory polymer, shape memory epoxy resin, shape memory silicone rubber or shape memory cyanate resin.

[0006] More preferably, the polymer mold bodies and the caulking ropes are made of the same shape memory polymer.

[0007] Preferably, the wall thickness of the polymer mold body is 1-50 mm.

[0008] Preferably, when using the combined polymer mold to prepare a component with a cavity, the number of caulking ropes is the same as the number of contact surfaces between the combined polymer mold and the component.

[0009] Preferably, when using the combined polymer mold to prepare a plate-shaped component, the difference between the number of contact surfaces between the combined polymer mold and the component and the number of caulking ropes is 1.

[0010] Second aspect, the present invention also provides a preparation method of the combined polymer mold described in any of the above first aspects, including:

[0011] Determine the structure, material type and material parameters of the component to be prepared;

[0012] According to the component to be prepared, simulate the deformation and stress conditions of each part during mold shaping, and simulate the load-bearing conditions of the mold during the curing process of the component to be prepared;

[0013] According to the deformation condition, the stress condition and the load-bearing condition, divide the mold to determine the number of polymer mold bodies and the number of caulking ropes, and perform the first simulation optimization on the combined polymer mold to obtain the first simulation result;

[0014] According to the first simulation result, determine the material system of the mold, and adjust the mold parameters for the second simulation optimization to determine the combined polymer mold.

[0015] Third aspect, the present invention also provides a preparation method of the combined polymer mold described in any of the above first aspects, including:

[0016] Determine the structure, material type and material parameters of the component to be prepared;

[0017] According to the component to be prepared and the metal outer mold, simulate the deformation and stress conditions of each part during mold shaping;

[0018] According to the deformation condition and the stress condition, divide the mold to determine the number of polymer mold bodies and the number of caulking ropes, and perform the first simulation optimization on the combined polymer mold to obtain the first simulation result;

[0019] According to the first simulation result, determine the material system and mold parameters of the mold to obtain the combined polymer mold.

[0020] Preferably, the material parameters include curing shrinkage rate, elastic modulus, Poisson's ratio, density.

[0021] Preferably, the mold parameters include the material type and wall thickness of the combined polymer mold.

[0022] Preferably, the dividing the mold to determine the number of polymer mold bodies and the number of caulking ropes includes:

[0023] Divide the mold according to the preset stress fluctuation range threshold, the preset strain fluctuation range threshold and the actual productivity of the factory to obtain the number of divided regions; wherein, the stress fluctuation of the polymer mold body is within the preset stress fluctuation range threshold, and the strain fluctuation is within the preset strain fluctuation range threshold;

[0024] Determine the number of polymer mold bodies and the number of caulking ropes according to the number of the regions.

[0025] More preferably, the number of polymer mold bodies is not less than the number of the regions and not less than the ratio of the size of the member to be prepared to the maximum dimension of the size of the member actually produced in the factory.

[0026] Preferably, the first simulation optimization of the combined polymer mold includes:

[0027] Conduct the first simulation optimization according to the divided polymer mold bodies and the caulking ropes, and determine the first simulation results including the number, structure and size of the polymer mold bodies and the number of the caulking ropes.

[0028] Preferably, the second simulation optimization by adjusting the mold parameters includes:

[0029] Determine the maximum deformation amount of the combined polymer mold according to the precision requirement of the member to be prepared, and determine the elastic modulus of each part in the combined mold according to the load-bearing condition, so as to determine the mold parameters of the combined polymer mold.

[0030] More preferably, the maximum deformation amount does not exceed the product of the precision requirement and the size of the member to be prepared.

[0031] Fourthly, the present invention also provides an application of the combined polymer mold according to any one of the first aspects above, including:

[0032] Determine the combined polymer mold for preparing the member to be prepared;

[0033] Lay an isolation layer and a prepreg on the surface of the combined polymer mold in sequence, then place it in a vacuum bag for curing and forming. After the curing is completed, take out the combined polymer molds one by one to obtain the member to be prepared.

[0034] Preferably, for the combined polymer mold obtained by the preparation method of the second aspect, the temperature of the curing and forming is lower than the glass transition temperature of the combined polymer mold; the combined polymer mold deforms when heated to the deformation temperature to take out the combined polymer mold; wherein, the deformation temperature is 10-30 °C higher than the glass transition temperature.

[0035] Preferably, for the combined polymer mold obtained by the preparation method of the third aspect, it further includes: placing the combined polymer mold with an isolation layer and prepreg laid on its surface in a metal outer mold, then closing the mold and placing it in a vacuum bag for curing; wherein, the temperature of the curing is higher than the glass transition temperature of the combined polymer mold.

[0036] Preferably, the isolation layer includes a release agent layer, a release cloth or a polytetrafluoroethylene layer.

[0037] The present invention has at least the following beneficial effects compared with the prior art:

[0038] The combined polymer mold provided by the present invention is composed of multiple polymer mold bodies, and the adjacent polymer mold bodies are filled with caulking ropes, so that the molding of large-sized and complex composite components can be realized. At the same time, the combined polymer mold uses shape memory polymer, which can realize automatic demolding of the mold and is more convenient for demolding. In addition, compared with other molds such as metal combined molds and water-soluble molds, the combined polymer mold reduces the self-weight of the mold, and significantly reduces the self-weight of the mold by setting a cavity structure. Moreover, the combined polymer mold can be recycled and has low cost. The components prepared by it have good molding quality, which can promote the development of the molding technology of large-sized wing components and realize cost reduction and efficiency increase. Description of the Drawings

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to these drawings without creative efforts.

[0040] Figure 1 It is a schematic structural diagram of a combined polymer mold provided by an embodiment of the present invention;

[0041] Figure 2 It is a schematic structural diagram of a plate-shaped combined polymer mold provided by the present invention;

[0042] Figure 3 It is a schematic structural diagram of a composite component provided by an embodiment of the present invention;

[0043] Figure 4 It is a schematic diagram of using a combined polymer mold to mold a composite component during curing provided by an embodiment of the present invention;

[0044] Figure 5 It is a schematic structural diagram of a plate-shaped composite component provided by the present invention;

[0045] Figure 6 Schematic diagram of forming a plate-shaped composite material component using a combined polymer mold during the curing process provided by the present invention;

[0046] Reference numerals: 10 - Polymer mold body; 20 - Caulking rope; 30 - Component to be prepared. Detailed implementation manners

[0047] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0048] As Figure 1 shown, an embodiment of the present invention provides a combined polymer mold, including: a mold formed by combining at least two polymer mold bodies 10 with cavity structures and a caulking rope 20; the caulking rope 20 is used to fill the gaps between adjacent polymer mold bodies 10; both the polymer mold body 10 and the caulking rope 20 are made of shape memory polymers.

[0049] In the embodiment of the present invention, the combined polymer mold is composed of multiple polymer mold bodies, and the gaps between adjacent polymer mold bodies are filled with caulking ropes, so that the forming of large-size and complex composite material components can be realized. At the same time, the combined polymer mold uses shape memory polymers, which can realize automatic demolding of the mold, making the demolding more convenient. In addition, compared with other molds such as metal combined molds and water-soluble molds, the combined polymer mold reduces the self-weight of the mold, and significantly reduces the self-weight of the mold by setting cavity structures. Moreover, the combined polymer mold can be recycled and has a low cost. The components prepared by it have good forming quality and can realize the forming of large-size and complex components.

[0050] In the present invention, the caulking rope is mainly used to fill the gaps between each polymer mold body in direct contact with the surface of the composite material component to improve the quality and integrity of the surface of the composite material component.

[0051] According to some preferred implementation manners, the shape memory polymer includes styrene-based shape memory polymers, shape memory epoxy resins, shape memory silicone rubbers, or shape memory cyanate resins.

[0052] It should be noted that the shape memory polymer includes, but is not limited to, the above types.

[0053] According to some more preferred implementation manners, the polymer mold body and the caulking rope are made of the same shape memory polymer.

[0054] In the present invention, in order to further ensure the forming accuracy of the component to be prepared and avoid the possible influence caused by the difference in the coefficient of thermal expansion between different types of shape memory polymers, the polymer mold body and the caulking rope are preferably made of the same type of shape memory polymer.

[0055] According to some preferred embodiments, the wall thickness of the polymer mold body is 1 to 50 mm (for example, it can be 1 mm, 2 mm, 3 mm, 5 mm, 8 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm or 50 mm).

[0056] According to some preferred embodiments, when using a combined polymer mold to prepare a component with a cavity, the number of caulking ropes is the same as the number of contact surfaces between the combined polymer mold and the component. For example, as Figure 1 shown, there are 2 surfaces of the polymer mold body 10 in contact with the inner surface of the component 30 to be prepared, so 2 caulking ropes are designed.

[0057] According to some preferred embodiments, when using a combined polymer mold to prepare a plate-shaped component, the difference between the number of contact surfaces between the combined polymer mold and the component and the number of caulking ropes is 1. For example, as Figure 2 shown, there are a total of 2 surfaces of the polymer mold body 10 in contact with the inner surface of the component 30 to be prepared, so 2 - 1 = 1 caulking rope should be designed.

[0058] In a second aspect, the present invention also provides a method for preparing a combined polymer mold according to any one of the first aspects, including:

[0059] S1: Determine the structure, material type and material parameters of the component to be prepared;

[0060] S2: Simulate the deformation and stress conditions of each part of the mold during the mold shaping process according to the component to be prepared, and simulate the load-bearing conditions of the mold during the curing process of the component to be prepared;

[0061] S3: Divide the mold according to the deformation, stress and load-bearing conditions to determine the number of polymer mold bodies and the number of caulking ropes, and perform the first simulation optimization on the combined polymer mold to obtain the first simulation result;

[0062] S4: Determine the material system of the mold according to the first simulation result, and adjust the mold parameters to perform the second simulation optimization to determine the combined polymer mold.

[0063] According to some preferred embodiments, the length or width of the component to be prepared is more than 200 mm.

[0064] Specifically, the component to be prepared is preferably a component with a large curvature, such as a wing component. Thus, the modular polymer mold of the present invention can be used to prepare large-sized and complex-configured components by dividing the mold into blocks, while ensuring the forming accuracy of the complex-configured components.

[0065] According to some preferred embodiments, the material parameters in step S1 include the curing shrinkage rate, elastic modulus, Poisson's ratio, density, etc.

[0066] In step S2, the component to be prepared is placed on the mold to simulate the deformation and stress conditions of each part of the mold, as well as the load-bearing conditions on each part of the mold during the curing process.

[0067] According to some preferred embodiments, in step S3, the mold is divided to determine the number of polymer mold bodies and the number of caulking ropes, including:

[0068] The mold is divided according to the preset stress fluctuation range threshold, the preset strain fluctuation range threshold, and the actual productivity of the factory to obtain the number of divided regions; wherein, the stress fluctuation of the polymer mold body is within the preset stress fluctuation range threshold, and the strain fluctuation is within the preset strain fluctuation range threshold;

[0069] The number of polymer mold bodies and the number of caulking ropes are determined according to the number of regions.

[0070] Specifically, the preset stress fluctuation range threshold is ±5 MPa; the preset strain fluctuation range threshold is ±10%. The actual productivity of the factory is the size of the mold that the factory can produce. For example, the difference between the maximum and minimum stresses in the divided region is 10 MPa, or the stress range of the region is the mean value of the maximum and minimum stresses ±5 MPa; and the strain range of the region is between 80% and 120% of the mean value of the maximum and minimum strains.

[0071] According to some more preferred embodiments, the number of polymer mold bodies is not less than the number of regions, and not less than the ratio of the size of the component to be prepared to the maximum dimension of the size of the component actually produced by the factory.

[0072] Specifically, in the modular polymer mold, the number of polymer mold bodies ≥ the number of divided regions, and ≥ the ratio of the maximum dimension of the size of the component to be prepared to the maximum dimension of the size of the component actually produced by the factory. And on the basis of meeting the above conditions, the number of polymer mold bodies should be as small as possible.

[0073] In a more preferred embodiment, the number of polymer mold bodies is determined by the following formula:

[0074]

[0075] Wherein, N is the number of polymer mold bodies; N0 is the number of divided regions; L is the maximum dimension of the size of the component to be fabricated; k is the curvature segmentation coefficient, representing the ratio of the allowable curvature radius of each mold block to the segmentation length, and its value range is usually 0.1 to 0.5; R min is the minimum curvature radius of the component to be fabricated; l max is the maximum dimension of the size of the component actually produced in the factory; L i is the length of the i-th sub-region, ΣL i = L; i ∈ I, I is the sub-region divided according to the load distribution of the component to be fabricated. For example, the wing component is divided into 3 sub-regions: the wing root, the middle part, and the wing tip; σ i is the local maximum stress of the i-th sub-region; σ ref is the allowable stress of the mold material, which is determined by the material properties; α is the safety factor, usually taking 1.5 to 3.0, and is adjusted according to the material strength and process risk; N c 、N l 、N s respectively represent the curvature constraint term, the size constraint term, and the force constraint term.

[0076] In the present invention, for the force constraint term, in the high-stress region (such as the wing root), the segmentation length needs to be smaller to reduce the force concentration on a single mold block; in the low-stress region (such as the wing tip), the segmentation length can be appropriately increased to reduce the number of molds, so as to better meet the actual engineering requirements. Thus, by comprehensively considering the above parameters, the optimal number of blocks of the combined polymer mold is determined.

[0077] According to some preferred embodiments, in step S3, the combined polymer mold is subjected to the first simulation optimization, including:

[0078] Performing the first simulation optimization according to the divided polymer mold bodies and caulking ropes, and determining the first simulation result including the number, structure, and size of the polymer mold bodies and the number of caulking ropes.

[0079] It should be noted that the first simulation optimization is used to optimize the structure and size of the polymer mold bodies included in the combined polymer mold, and the first simulation result includes the structure and size of the polymer mold bodies included in the combined polymer mold.

[0080] According to some preferred embodiments, the mold parameters in step S4 include the material type and wall thickness of the combined polymer mold.

[0081] According to some preferred embodiments, in step S4, the mold parameters are adjusted for the second simulation optimization, including:

[0082] According to the precision requirements of the component to be prepared, determine the maximum deformation amount of the combined polymer mold, and according to the load-bearing situation, determine the elastic modulus of each part in the combined mold, so as to determine the mold parameters of the combined polymer mold.

[0083] According to some more preferred embodiments, the maximum deformation amount does not exceed the product of the precision requirement and the size of the component to be prepared.

[0084] Specifically, in step S4, based on steps S2 and S3, preliminarily select the material systems of each polymer mold body and each caulking rope, adjust the mold parameters including the material type and wall thickness of the combined polymer mold, and further optimize through simulation to finally determine the composition of the combined polymer mold. Among them, the basis for adjustment and selection in step S4 is: according to the precision requirements of the component to be prepared, determine the maximum deformation amount of the combined polymer mold, and combine the load borne by the combined polymer mold during the curing process, and then deduce the elastic modulus of each part of the material of the combined polymer mold, and finally determine the material type of each part in the combined polymer mold. More specifically, the allowable deformation amount of the combined polymer mold ≤ product precision (%) (i.e., strain) * size of the component to be prepared, and when there is no constraint, this strain = stress (i.e., the load borne by the combined polymer mold) / elastic modulus, so that the elastic modulus range of the selected shape memory polymer of the combined polymer mold can be roughly deduced, and thus a suitable material type can be selected. It should be noted that no constraint means that the deformation of the combined polymer mold is completely caused by the force applied by the prepreg, rather than by an external force (such as a metal outer mold). For example, taking the wing component to be prepared with a height of 20 cm as an example, the product precision is 0.5%, that is, the allowable strain is 0.5%, and at this time the allowable deformation amount is 20 cm * 0.5% = 1 mm. The load borne by the combined polymer mold is the sum of the load applied by the vacuum bag and the curing shrinkage load of the prepreg, which is not greater than 1 MPa. At this time, the elastic modulus E ≥ 1 MPa / 0.5% = 200 MPa. The calculation methods for the length and width dimensions are similar.

[0085] In a third aspect, the present invention also provides a preparation method for any combined polymer mold of the first aspect, including:

[0086] A1: Determine the structure, material type and material parameters of the component to be prepared; the material parameters include curing shrinkage rate, elastic modulus, Poisson's ratio, density;

[0087] A2: Simulate the deformation and stress conditions of each part during the mold shaping according to the component to be prepared and the metal outer mold;

[0088] A3: According to the deformation and stress conditions, divide the mold to determine the number of polymer mold bodies and the number of caulking ropes, and perform the first simulation optimization on the combined polymer mold to obtain the first simulation result, including:

[0089] Divide the mold according to the preset stress fluctuation range threshold, the preset strain fluctuation range threshold, and the actual productivity of the factory to obtain the number of divided regions; among them, the stress fluctuation of the polymer mold body is within the preset stress fluctuation range threshold, and the strain fluctuation is within the preset strain fluctuation range threshold;

[0090] Determine the number of polymer mold bodies and the number of caulking ropes according to the number of regions;

[0091] Conduct the first simulation optimization according to the divided polymer mold bodies and caulking ropes to determine the first simulation results including the number, structure, and size of the polymer mold bodies and the number of caulking ropes;

[0092] A4: Determine the material system of the mold and the mold parameters of the combined polymer mold according to the first simulation results; the mold parameters include the material type and wall thickness of the combined polymer mold.

[0093] It should be noted that the number of polymer mold bodies can also be determined by the above formula.

[0094] In the present invention, the preparation methods of the polymer mold body and the caulking rope include, but are not limited to, perfusion molding, hand lay-up molding, injection molding, 3D / 4D printing, etc. After the polymer mold body and the caulking rope are prepared, it also includes shaping the polymer mold body and the caulking rope, and then performing post-treatment; among them, shaping includes, but is not limited to, negative pressure molding, blow molding, airbag pressurization, etc. above the glass transition temperature of the polymer mold body and the caulking rope; post-treatment includes, but is not limited to, screening, grinding, and polishing.

[0095] Fourthly, the present invention also provides an application of the combined polymer mold of any one of the above first aspects, including:

[0096] Determine the combined polymer mold for preparing the component to be prepared;

[0097] Lay an isolation layer and prepreg on the surface of the combined polymer mold in sequence, and then place it in a vacuum bag for curing and molding. After curing is completed, take out the combined polymer molds one by one to obtain the component to be prepared.

[0098] According to some preferred embodiments, according to the relationship between the glass transition temperature of the combined polymer mold and the curing and molding temperature, there are two application cases for the combined polymer mold. The first application case of the combined polymer mold obtained based on the second aspect:

[0099] The curing temperature is lower than the glass transition temperature of the modular polymer mold; the modular polymer mold deforms when heated to the deformation temperature to remove the modular polymer mold; wherein, the deformation temperature is 10-30 °C higher than the glass transition temperature (for example, it can be 10 °C, 12 °C, 15 °C, 16 °C, 18 °C, 20 °C, 22 °C, 25 °C, 28 °C or 30 °C).

[0100] Specifically, (1) place and assemble the polymer mold body and the caulking rope according to the design to obtain a modular polymer mold;

[0101] (2) Lay an isolation layer on the surface of the modular polymer mold;

[0102] (3) Lay the prepreg on the surface of the modular polymer mold as required;

[0103] (4) Put the modular polymer mold with the prepreg and the isolation layer laid in step (3) into a vacuum bag as a whole and perform vacuum bag molding;

[0104] (5) Use a heating device to heat to a temperature suitable for curing the prepreg (lower than the glass transition temperature of the modular polymer mold) and execute according to the curing procedure of the prepreg;

[0105] (6) After curing, continue to heat up to the deformation temperature of the modular polymer mold, and the modular polymer mold actively changes its stiffness, so that it is easy to take out each part of the modular polymer mold one by one to obtain a composite component (i.e., the component to be prepared);

[0106] (7) Reshape each part of the removed modular polymer mold for reuse in step (1) in a cycle to achieve recycling.

[0107] In the embodiment of the present invention, the modular polymer mold is shaped before reaching the deformation temperature, and the stiffness in the glass state is used to form the composite component, and then the modular polymer mold is demolded by changing the stiffness after reaching the deformation temperature.

[0108] Based on the second application case of the modular polymer mold obtained in the third aspect: after successively laying an isolation layer and a prepreg on the surface of the modular polymer mold, it further includes: putting the modular polymer mold with the isolation layer and the prepreg successively laid on the surface into a metal outer mold, and then placing it in a vacuum bag for curing and molding after closing the mold; wherein, the curing and molding temperature is higher than the glass transition temperature of the modular polymer mold.

[0109] Specifically, (1) place and assemble the polymer mold body and the caulking rope according to the design to obtain a modular polymer mold;

[0110] (2) Lay an isolation layer on the surface of the combined polymer mold;

[0111] (3) Lay the prepreg on the surface of the combined polymer mold as required;

[0112] (4) Put the combined polymer mold with the prepreg and the isolation layer laid in step (3) as a whole into the metal outer mold, then after closing the mold, place the whole in a vacuum bag for vacuum bag molding;

[0113] (5) Use a heating device to heat to a temperature suitable for curing the prepreg (higher than the glass transition temperature of the combined polymer mold), and execute according to the curing procedure of the prepreg;

[0114] (6) After curing, take out each part of the combined polymer mold one by one to obtain a composite component (i.e., the component to be prepared);

[0115] (7) Reshape each part of the taken-out combined polymer mold and prepare for repeating step (1), and cycle repeatedly to achieve recycling.

[0116] In the present invention, since the curing temperature is higher than the glass transition temperature of the combined polymer mold, before curing, the metal outer mold and the combined polymer mold in the glass state shape the component to be prepared. During the curing process, the combined polymer mold is in the high elastic state. At this time, as a flexible inner mold, it can play a role in promoting the uniform dispersion of the resin during the curing of the composite material, which is beneficial to improving the molding quality and making its thickness evenly distributed.

[0117] It should be noted that for the second application case, since a metal outer mold is also required, when determining the combined polymer mold as the inner mold, there is no need to simulate the load-bearing situation of the mold during the curing process, nor is it necessary to perform a second simulation optimization, that is, the combined polymer mold can be determined.

[0118] According to some preferred embodiments, the isolation layer includes a release agent layer, a release cloth or a polytetrafluoroethylene layer.

[0119] It should be noted that the reshaping method during recycling is the same as the shaping method when preparing the combined polymer mold.

[0120] In the present invention, the "and / or" appearing between multiple technical features means that these technical features are all connected in an "and / or" relationship, indicating that any one of these technical features, or any two or more combinations of these technical features can be used.

[0121] The present invention will be further described by way of examples below, but the protection scope of the present invention is not limited to these embodiments.

[0122] Example 1

[0123] For a large composite wing component with a width of 40 cm and a length of 60 cm (as shown in Figure 3 ), a preparation method of a combined polymer mold includes:

[0124] S1: The wing component is prepared by epoxy prepreg, and its curing temperature is 90 °C;

[0125] S2: Considering the productivity of a certain factory, the mold is roughly divided into two polymer mold bodies and two caulking ropes; models of the wing component and each part of the roughly divided combined polymer mold are established in simulation software, and parameters such as the elastic modulus, density, and curing shrinkage rate of the epoxy prepreg are input to simulate the deformation and stress conditions of each part during the profiling of the combined polymer mold, and the load-bearing situation of the combined polymer mold during the curing process of the prepared component.

[0126] S3: According to the preset stress fluctuation range threshold of ±5 MPa and the preset strain fluctuation range threshold of ±10% for each region, the mold is determined to be two polymer mold bodies and two caulking ropes. Then, the parameter design of the two polymer mold bodies and two caulking ropes is optimized. Combining the accuracy requirements of the wing component, a styrene-based shape memory polymer with a suitable load-bearing capacity (elastic modulus of 1 GPa), deformation amount (300%+) and glass transition temperature (110 °C) is determined, and the wall thickness of the combined mold body is determined. Finally, after simulation confirmation, the drawing is designed.

[0127] S4: Since the styrene-based shape memory polymer has a low viscosity, perfusion molding is used, and then curing and demolding are carried out. Each part prepared is placed in the corresponding profiling mold, its temperature is raised to 120 °C, and it is profiled by blow molding, and the pressure is maintained until it cools to room temperature. After demolding, each part of the combined polymer mold is obtained, and the polymer mold body and caulking rope are polished and buffed, and then assembled into the combined polymer mold as shown in Figure 1 .

[0128] Example 2

[0129] An application of the combined polymer mold described in Example 1, as shown in Figure 4 , includes:

[0130] Step 1, spray a release agent on the surface of the combined polymer mold. After the volatilization is complete, cut the epoxy prepreg and lay it on the surface of the combined polymer mold as required. After laying, place it in a vacuum bag, evacuate, raise the temperature to 90 °C and cure for 12 h, and maintain the negative pressure state until the curing is completed. At this time, the combined polymer mold is in a glassy state and can support the prepreg to maintain the shape required for the product until the curing is completed;

[0131] Step 2: After the curing is completed, raise the temperature to 120°C. The modular polymer mold undergoes a variable stiffness transformation, and the modulus drops sharply. At this time, the mold can be easily removed to obtain a large composite wing component.

[0132] Step 3: Place the removed parts of the mold in their corresponding profiling molds respectively, raise the temperature to 120°C, and use the blow molding method to re-profile them. Keep the pressure until it cools to room temperature, then demold to obtain the modular polymer mold, and transfer to Step 1 for recycling.

[0133] Example 3

[0134] For a large composite wing component with a width of 40 cm and a length of 60 cm (as Figure 3 shown), a preparation method for a modular polymer mold includes:

[0135] S1: The wing component is prepared using epoxy prepreg, and its curing temperature is 120°C.

[0136] S2: Considering the productivity of a certain factory, roughly divide the mold into two polymer mold bodies and two caulking ropes. Establish models of the wing component and each part of the roughly divided modular polymer mold in simulation software, input parameters such as the elastic modulus, density, and curing shrinkage rate of the epoxy prepreg, and simulate the deformation and stress conditions of each part during the profiling of the modular polymer mold, as well as the load-bearing conditions of the modular polymer mold during the curing process of the prepared component.

[0137] S3: According to the preset stress fluctuation range threshold of ±5 MPa and the preset strain fluctuation range threshold of ±10% for each region, determine that the mold is two polymer mold bodies and two caulking ropes. Then optimize the parameter design of the two polymer mold bodies and two caulking ropes. Combining with the accuracy requirements of the wing component, determine to use a styrene-based shape memory polymer with a load-bearing capacity (elastic modulus of 0.8 GPa), a deformation amount (300%+), and a suitable glass transition temperature (95°C), and determine the wall thickness of the modular mold body. Finally, confirm through simulation and design the drawings.

[0138] S4: Since the styrene-based shape memory polymer has a low viscosity, perfusion molding is used, and then curing and demolding are carried out. Place the prepared parts in their corresponding profiling molds respectively, raise the temperature to 110°C, and use the blow molding method to profile them. Keep the pressure until it cools to room temperature, then demold to obtain each part of the modular polymer mold, and perform grinding and polishing on the polymer mold body and caulking ropes. Then assemble them according to the drawings into a modular polymer mold as Figure 1 shown.

[0139] Example 4

[0140] Application of the combined polymer mold described in Embodiment 3, comprising:

[0141] Step 1: Spray a mold release agent on the surface of the combined polymer mold. After the mold release agent has volatilized completely, cut the epoxy prepreg and lay it on the surface of the combined polymer mold as required. After laying, place it in the metal outer mold, then close the mold, place the whole in a vacuum bag and put it into an oven (the cavity of the combined polymer mold is connected to the atmospheric pressure, and the metal outer mold, the prepreg, and the solid part of the combined polymer mold are all in the vacuum bag), evacuate the air, heat up to 120 °C and cure for 5 h, and maintain the negative pressure state until the curing is completed;

[0142] Step 2: Since the curing temperature is higher than the glass transition temperature of the combined polymer mold, the combined polymer mold is in a highly elastic state during the curing process, and it can evenly distribute pressure during the curing and forming process, promoting the discharge of air and excess resin in the prepreg. After curing is completed, the mold can be easily removed to obtain a large composite wing component;

[0143] Step 3: Place the removed parts of the mold in the corresponding shaping molds respectively, raise their temperature to 110 °C, and reshape them by blow molding, keep the pressure until it cools down to room temperature, demold to obtain the combined polymer mold, and transfer to Step 1 for recycling.

[0144] Embodiment 5

[0145] For a large composite wing component with a width of 40 cm and a length of 60 cm (as Figure 5 shown), a preparation method of a combined polymer mold, comprising:

[0146] S1: The wing component is prepared with an epoxy prepreg, and its curing temperature is 90 °C;

[0147] S2: Considering the productivity of a certain factory, roughly divide the mold into two polymer mold bodies and a caulking cord; establish models of the wing component and each part of the roughly divided combined polymer mold in simulation software, input parameters such as the elastic modulus, density, and curing shrinkage rate of the epoxy prepreg, and simulate the deformation and stress conditions of each part during the shaping of the combined polymer mold, and the load-bearing conditions of the combined polymer mold during the curing of the prepared component;

[0148] S3: According to the preset stress fluctuation range threshold of ±5 MPa and the preset strain fluctuation range threshold of ±10% for each region, determine that the mold consists of two polymer mold bodies and two caulking ropes. Then optimize the parameter design of the two polymer mold bodies and two caulking ropes. Combining with the precision requirements of the wing component, determine to use a styrene-based shape memory polymer with a bearing capacity (elastic modulus of 1 GPa), a deformation amount (300%+), and a suitable glass transition temperature (110°C), and determine the wall thickness of the combined mold body. Finally, confirm through simulation and design the drawing well.

[0149] S4: Since the styrene-based shape memory polymer has a low viscosity, perfusion molding is used, and then curing and demolding are carried out. Place each part obtained in the corresponding shaping mold, raise its temperature to 120°C, and use blow molding to shape it. Keep the pressure until it cools to room temperature, and demold to obtain each part of the combined polymer mold. Then, grind and polish the polymer mold body and the caulking rope, and then assemble them into the combined polymer mold as shown in Figure 2 the combined polymer mold shown.

[0150] Example 6

[0151] An application of the combined polymer mold described in Example 5, as shown in Figure 6 shown, includes:

[0152] Step 1, spray a release agent on the surface of the combined polymer mold. After waiting for it to volatilize completely, cut the epoxy prepreg and lay it on the surface of the combined polymer mold as needed. After laying, place it in a vacuum bag, evacuate the air, raise the temperature to 90°C and cure for 12 h, and maintain the negative pressure state until the curing is completed. At this time, the combined polymer mold is in a glassy state and can support the prepreg to maintain the shape required for the product until the curing is completed;

[0153] Step 2, after the curing is completed, raise the temperature to 120°C, and the combined polymer mold realizes a variable stiffness transition, and the modulus drops sharply. At this time, the mold can be easily removed to obtain a large composite wing component;

[0154] Step 3, place each part of the removed mold in the corresponding shaping mold, raise its temperature to 120°C, and use blow molding to reshape it. Keep the pressure until it cools to room temperature, and demold to obtain the combined polymer mold, and then transfer to Step 1 for recycling.

[0155] 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 present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention. The parts of the present invention that are not described in detail are well-known technologies to those skilled in the art.

Claims

1. A combined polymer mold, characterized in that, Comprising: A mold and a caulking rope formed by combining at least two polymer mold bodies with cavity structures; the caulking rope is used to fill the gaps between adjacent polymer mold bodies; both the polymer mold bodies and the caulking rope are made of shape memory polymers.

2. The combined polymer mold according to claim 1, characterized in that: The shape memory polymer includes styrene-based shape memory polymer, shape memory epoxy resin, shape memory silicone rubber or shape memory cyanate resin; preferably, the polymer mold bodies and the caulking rope are made of the same kind of shape memory polymer; and / or, The wall thickness of the polymer mold body is 1 - 50 mm.

3. The combined polymer mold according to any one of claims 1 to 2, characterized in that: When using the combined polymer mold to prepare a member with a cavity, the number of caulking ropes is the same as the number of contact surfaces between the combined polymer mold and the member; and / or, When using the combined polymer mold to prepare a plate-shaped member, the difference between the number of contact surfaces between the combined polymer mold and the member and the number of caulking ropes is 1.

4. A method for preparing a combined polymer mold according to any one of claims 1 to 3, characterized in that, Comprising: Determining the structure, material type and material parameters of the member to be prepared; According to the member to be prepared, simulating the deformation and stress conditions of each part during mold shaping, and simulating the load-bearing conditions of the mold during the curing process of the member to be prepared; According to the deformation conditions, stress conditions and load-bearing conditions, dividing the mold to determine the number of polymer mold bodies and the number of caulking ropes, and performing the first simulation optimization on the combined polymer mold to obtain the first simulation result; According to the first simulation result, determining the material system of the mold and adjusting the mold parameters for the second simulation optimization to determine the combined polymer mold.

5. A method for preparing a combined polymer mold as described in any one of claims 1 to 3, characterized in that, Comprising: Determining the structure, material type and material parameters of the member to be prepared; According to the member to be prepared and the metal outer mold, simulating the deformation and stress conditions of each part during mold shaping; According to the deformation conditions and stress conditions, dividing the mold to determine the number of polymer mold bodies and the number of caulking ropes, and performing the first simulation optimization on the combined polymer mold to obtain the first simulation result; According to the first simulation result, determining the material system and mold parameters of the mold to obtain the combined polymer mold.

6. The preparation method according to claim 4 or 5, characterized in that: The material parameters include curing shrinkage rate, elastic modulus, Poisson's ratio, density; and / or, The mold parameters include the material type and wall thickness of the combined polymer mold.

7. The preparation method according to claim 4 or 5, characterized in that: The dividing the mold to determine the number of polymer mold bodies and the number of caulking ropes includes: Dividing the mold according to a preset stress fluctuation range threshold, a preset strain fluctuation range threshold and the actual productivity of the factory to obtain the number of divided regions; wherein, the stress fluctuation of the polymer mold body is within the preset stress fluctuation range threshold, and the strain fluctuation is within the preset strain fluctuation range threshold; Determining the number of polymer mold bodies and the number of caulking ropes according to the number of regions; Preferably, the number of polymer mold bodies is not less than the number of regions and not less than the ratio of the size of the member to be prepared to the maximum dimension of the size of the member actually produced by the factory; and / or, The performing the first simulation optimization on the combined polymer mold includes: Perform the first simulation optimization according to the divided polymer mold body and the caulking rope, and determine the first simulation result including the quantity, structure, and size of the polymer mold body and the quantity of the caulking rope.

8. The preparation method according to claim 4, characterized in that: Adjust the mold parameters to perform the second simulation optimization, including: According to the precision requirements of the component to be prepared, determine the maximum deformation amount of the combined polymer mold, and according to the load-bearing situation, determine the elastic modulus of each part in the combined mold to determine the mold parameters of the combined polymer mold; preferably, the maximum deformation amount does not exceed the product of the precision requirements and the size of the component to be prepared.

9. Use of a combined polymer mold as described in any one of claims 1 to 3, characterized in that, Including: Determine the combined polymer mold for preparing the component to be prepared; Sequentially lay an isolation layer and prepreg on the surface of the combined polymer mold, then place it in a vacuum bag for curing and forming. After curing is completed, take out the combined polymer molds one by one to obtain the component to be prepared.

10. The application according to claim 9, characterized in that: The temperature of the curing and forming is lower than the glass transition temperature of the combined polymer mold; the combined polymer mold deforms when heated to the deformation temperature to take out the combined polymer mold; wherein, the deformation temperature is 10-30 °C higher than the glass transition temperature; and / or, It also includes: putting the combined polymer mold with an isolation layer and prepreg sequentially laid on its surface into a metal outer mold, then closing the mold and placing it in a vacuum bag for curing and forming; wherein, the temperature of the curing and forming is higher than the glass transition temperature of the combined polymer mold; preferably, the isolation layer includes a release agent layer, a release cloth or a polytetrafluoroethylene layer.

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