Preparation method of composite material forming mold and composite material forming mold

Abstract

The invention provides a preparation method of a composite material forming mold and the composite material forming mold, and particularly relates to the technical field of mold forming. The preparation method comprises the following steps: providing a lower mold; a cavity material layer is laid on the lower die, and the thickness of the cavity material layer is larger than that of the product to be formed; carrying out surface processing treatment on the cavity material layer according to the thickness of the to-be-formed product so as to obtain a cavity layer consistent with the to-be-formed product in thickness; pasting an upper mold on the lower mold so as to wrap the cavity layer between the upper mold and the lower mold; and after the upper mold is cured, demolding is conducted to remove the cavity layer, and the composite material forming mold is obtained. According to the forming die manufactured through the manufacturing method, the surface of a cavity is flat and smooth, the uniformity is good, and the defects of sinking, seams, uneven thickness and the like are greatly reduced, and the die manufacturing cost is greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of mold forming, and in particular to a preparation method of a composite material forming mold and the composite material forming mold. Background Art

[0002] FRP molds are widely used molding molds for composite glass fiber and resin products. When preparing the cavity of the product, the FRP mold of the traditional Light Weight Resin Transfer Molding (LRTM) process manually lays wax sheets on the lower mold of the mold, and the thickness of the wax sheets varies according to the thickness of the product. Sometimes, wax sheets of different thicknesses are even stacked to achieve the required product thickness. However, the uniformity of the thickness of the manually laid wax sheets is difficult to ensure. Affected by different workers and different techniques, the surface cannot be laid flat, and there are always defects such as dents, seams, and uneven thickness, which leads to defects on the surface of the mold cavity, thereby affecting the quality of the molded product. In addition, the price of wax sheets is expensive, and the price of wax sheets of different thicknesses increases exponentially, resulting in a significant increase in the production cost of the mold. Summary of the invention

[0003] In view of the above problems existing in the prior art, the present invention provides a method for preparing a composite material molding die and a composite material molding die, so as to improve the problem of surface defects of the cavity of the composite material molding die.

[0004] To achieve the above-mentioned object and other related objects, the present invention provides a method for preparing a composite material forming mold in a first aspect, comprising at least the following steps:

[0005] Provide lower mold;

[0006] Laying a cavity material layer on the lower mold, wherein the laying thickness of the cavity material layer is greater than the thickness of the product to be molded;

[0007] Performing surface processing on the cavity material layer according to the thickness of the product to be formed to obtain a cavity layer with the same thickness as the product to be formed;

[0008] Pasting an upper mold on the lower mold to cover the cavity layer between the upper mold and the lower mold;

[0009] After the upper mold is solidified, the cavity layer is removed by demoulding to obtain the composite material molding mold.

[0010] In one embodiment of the present invention, the lower mold is provided with a reserved product cutting edge and a cavity material laying boundary, the reserved product cutting edge corresponds to the boundary of the product to be formed, and the cavity material laying boundary exceeds the reserved product cutting edge by 10mm to 30mm.

[0011] In one embodiment of the present invention, the step of laying a cavity material layer on the lower mold comprises: using a glue pressing device to press the cavity material into a preset thickness, and then laying the cavity material on the surface of the lower mold along the cavity material laying boundary to form a cavity material layer.

[0012] In one embodiment of the present invention, the material of the cavity material layer is selected from substitute wood.

[0013] In one embodiment of the present invention, the thickness of the cavity material layer is 3 mm to 6 mm greater than the thickness of the product to be formed.

[0014] In one embodiment of the present invention, the surface processing of the cavity material layer is performed by using a CNC machining machine to process the cavity material layer.

[0015] In one embodiment of the present invention, the lower mold comprises one or more cavity areas, and each of the cavity areas is paved with the cavity material layer.

[0016] In one embodiment of the present invention, the lower mold comprises a lower mold body, a mold steel frame and a mold pulley, the lower mold body is fixed on the mold steel frame, and the mold pulley is installed at the bottom of the mold steel frame.

[0017] In one embodiment of the present invention, the step of pasting an upper mold on the cavity layer includes: spraying a mold gel coat layer on the surface of the lower mold with the cavity layer laid thereon; and pasting a laminated material of the upper mold on the cavity layer and the mold gel coat layer.

[0018] On the other hand, the present invention also provides a composite material molding mold, which is prepared by any of the above-mentioned preparation methods. The composite material molding mold includes: a lower mold, an upper mold and a cavity. The upper mold is cooperatively connected with the lower mold. The cavity is located between the upper mold and the lower mold, and is used for molding the composite material.

[0019] The preparation method of the composite material forming mold of the present invention comprises the following steps: laying an easily processable cavity material on the lower mold, and performing surface processing on the cavity material according to the thickness of the product to be formed to obtain a cavity layer with the same thickness as the product to be formed, and removing the cavity layer after the upper mold is solidified and formed, so as to obtain a forming mold with a flat, smooth, and uniform cavity surface. The preparation method eliminates the wax sheet laying process, replaces the wax sheet with an easily processable cavity material, and lays it directly according to a preset thickness, thereby reducing the seams, uneven thickness, depressions, and errors caused by manual laying of the wax sheet, and greatly reducing the mold manufacturing cost and product surface defects.

[0020] The invention uses substitute wood as cavity material and adopts CNC machine tool positioning processing, which greatly improves the accuracy of cavity processing and can be applied to cavity molds with complex shapes in special fields.

[0021] The preparation method of the present invention is not limited by the number of mold cavities, and a one-mold multi-cavity mold can be manufactured according to actual production, which is more conducive to controlling production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying creative work.

[0023] Figure 1 is a flow chart of a method for preparing a composite material forming mold in one embodiment of the present invention;

[0024] Figure 2 It is a structural schematic diagram of a lower mold in one embodiment of the present invention;

[0025] Figure 3 It is a schematic diagram of the structure of laying a cavity material layer on a lower mold in one embodiment of the present invention.

[0026] Component number description

[0027] 100. lower mold; 110. lower mold body; 111. lower mold flange; 112. reserved product cutting edge; 113. cavity material laying boundary; 114. cavity material layer; 120. mold steel frame; 130. mold pulley. DETAILED DESCRIPTION

[0028] The following is an explanation of the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the features in the following embodiments and the embodiments can be combined with each other without conflict. It should also be understood that the terms used in the embodiments of the present invention are intended to describe specific embodiments, rather than to limit the scope of protection of the present invention. The test methods for which specific conditions are not specified in the following examples are usually carried out under conventional conditions or according to the conditions recommended by the manufacturers.

[0029] When numerical ranges are given in the embodiments, it should be understood that unless otherwise specified in the present invention, both endpoints of each numerical range and any value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention are familiar to those skilled in the art and the description of the present invention, and any method, device and material of the prior art similar or equivalent to the method, device and material in the embodiments of the present invention can also be used to implement the present invention.

[0030] It should be noted that the terms such as "upper", "lower", "left", "right", "middle" and "one" etc. used in this specification are only for the convenience of description and are not intended to limit the scope of implementation of the present invention. Changes or adjustments to their relative relationships, without substantially changing the technical content, should also be regarded as the scope of implementation of the present invention.

[0031] When preparing the cavity of a conventional LRTM mold, it is often necessary to manually lay wax sheets on the surface of the lower mold. The thickness of the wax sheets is relatively thin, and generally has specifications such as 0.5 / 1 / 1.5 / 2mm. The cost of thicker wax sheets increases exponentially. For example, if the product thickness is 4mm, at least two layers of 2mm wax sheets are required. It is not easy to stick the layers firmly, and gaps are easily left, resulting in inconsistent thickness. Especially at the R corners with shapes, it is more difficult to stick a smooth R corner, which is time-consuming and labor-intensive. In addition, the wax sheets have a certain hardness and are not easy to stick. After sticking the wax sheets, the joints between the wax sheets need to be filled with putty, which makes the mold surface uneven and not smooth, thus affecting the quality of the product.

[0032] Based on this, the present invention provides a method for preparing a composite material molding mold and a composite material molding mold, which utilizes easy-to-process cavity material layers for seamless paving to replace traditional wax sheet splicing and paving, and performs surface processing on the cavity material according to production needs, thereby obtaining a mold cavity with a flat, smooth and highly uniform surface, which greatly reduces the surface defects of the mold cavity and the mold manufacturing cost.

[0033] See also Figures 1 to 3 The first aspect of the present invention provides a method for preparing a composite material forming mold, the preparation method comprising at least the following steps:

[0034] S1, providing a lower mold 100;

[0035] S2, laying a cavity material layer 114 on the lower mold 100, and the thickness of the cavity material layer 114 is greater than the thickness of the product to be molded;

[0036] S3, performing surface processing on the cavity material layer 114 according to the thickness of the product to be molded to obtain a cavity layer with the same thickness as the product to be molded;

[0037] S4, pasting an upper mold on the lower mold 100 to cover the cavity layer between the upper mold and the lower mold 100;

[0038] S5, after the upper mold is solidified, demoulding is performed to remove the cavity layer to obtain a composite material molding mold.

[0039] Specifically, the specific structure of the lower mold 100 in step S1 can be selected according to the type of product to be processed in actual production, and is not limited here. The lower mold 100 in this step can be prepared according to the conventional process flow in the art.

[0040] See also Figure 2 In one embodiment, the lower mold mold 100 includes: a lower mold body 110, a mold steel frame 120 and a mold pulley 130, wherein the lower mold body 110 is the main part of the lower mold mold 100, and plays the role of bearing the product appearance surface and the product molding structure. Therefore, the outer contour of the lower mold body 110 depends on the appearance structure of the product to be produced, which is not limited here. The outer edge of the lower mold body 110 is provided with a lower mold flange 111, which is used to form a flow channel and vacuum pressure; the lower mold body 110 is fixed on the mold steel frame 120, and the mold steel frame 120 plays the role of bearing and fixing the lower mold body 110. There is no limit to the fixing method of the lower mold body 110 and the mold steel frame 120. For example, the lower mold body 110 can be directly formed on the mold steel frame 120, or it can be fixed by a connecting structure. The mold pulley 130 is installed at the bottom of the mold steel frame 120 to facilitate the movement and transfer of the mold.

[0041] See also Figure 2 and Figure 3, further, the lower mold 100 is provided with a reserved product cutting edge 112 and a cavity material laying boundary 113, wherein the reserved product cutting edge 112 corresponds to the boundary of the product to be molded, and the cavity material laying boundary 113 extends outward along the reserved product cutting edge 112 for a distance. This is because the edge of the product after the LRTM process is molded is uneven, and there are defects such as burrs. After the product is molded, its edge needs to be cut and corrected to make its edge flat. Therefore, the cavity size (length and width) of the LRTM mold is slightly larger than the product size to leave a processing allowance for the product. The position of the reserved product cutting edge 112 corresponds to the edge area of ​​the final product, and the position of the cavity material laying boundary 113 corresponds to the edge position of the mold cavity. The area between the reserved product cutting edge 112 and the cavity material laying boundary 113 is the processing allowance of the molded product. In the present application, the cavity material laying boundary 113 exceeds the reserved product cutting edge 112 by at least 10mm to ensure sufficient processing allowance for the molded product. Furthermore, the cavity material laying boundary 113 exceeds the reserved product cutting edge 112 by 10 to 30 mm, for example, 10 mm, 20 mm, or 30 mm, etc., to prevent excessive processing allowance and material waste.

[0042] See also Figure 1 and Figure 3 , step S2 is to lay a cavity material layer 114 on the lower mold 100. Since the cavity material layer 114 is laid in order to form a mold cavity, the thickness of the mold cavity, that is, the thickness of the product to be formed, needs to be determined before laying the cavity material layer 114, and the surface of the cavity material layer 114 needs to be processed after laying to obtain a cavity layer with a smooth surface and no defects. Therefore, the laying thickness of the cavity material layer 114 is greater than the thickness of the product to be formed. As for the difference between the thickness of the cavity material layer 114 and the thickness of the product to be formed, it can be determined according to the type of product actually produced. In one embodiment, the thickness of the cavity material layer 114 is 3 to 6 mm greater than the thickness of the product to be formed, such as 3 mm, 4 mm, 5 mm or 6 mm, etc., so that there will not be too much waste while leaving a processing allowance.

[0043] See also Figure 3The specific process of laying the cavity material layer 114 includes: using a glue pressing device to press the cavity material into a preset thickness, and then laying the cavity material along the cavity material laying boundary 113 on the surface of the lower mold 100 to form a cavity material layer 114. Among them, the glue pressing device is, for example, a glue pressing machine, and the cavity material is selected from materials that are easy to process, such as wood. First, use a glue pressing machine to press the cavity material into a preset thickness, and then lay it on the surface of the lower mold 100 along the cavity material laying boundary 113 to form a cavity material layer 114. The cavity material layer 114 can be formed by laying a whole piece of cavity material, or it can be formed by splicing multiple pieces of cavity material. When the cavity material layer 114 is laid by splicing multiple pieces of cavity material, no gap is used between adjacent cavity materials.

[0044] See also Figure 1 and Figure 3 After the cavity material layer 114 laid in step S2 is solidified and formed, step S3 is executed to perform surface processing on the cavity material layer according to the thickness of the product to be formed.

[0045] In one embodiment, a CNC machine tool is used to perform surface processing on the cavity material layer 114. A CNC machine tool, i.e., a computer numerical control machine tool, is an automated machine tool that controls the movement and operation of the machine tool through a computer program to achieve high-precision and high-efficiency processing. The surface of the cavity material layer 114 is processed by a CNC machine tool, so that the surface of the cavity layer is smoother, thereby making the outer contour accuracy of the product higher. Specifically, before CNC processing, it is necessary to set a positioning reference line on the lower mold 100, transfer the lower mold 100 with the cavity material layer 114 to the CNC machine tool, and fix the lower mold 100 by a four-point positioning method to ensure that the lower mold 100 will not move during the processing; then, the surface of the cavity material layer 114 is processed according to the positioning reference line until the thickness of the cavity material layer 114 is consistent with the thickness of the product to be formed. Furthermore, the CNC machine tool uses a small tool to make the cavity surface texture finer and denser, and the cavity surface state is better.

[0046] See also Figure 1 After step S3 is completed, a cavity layer with a flat and smooth surface is obtained. Then, step S4 is performed to paste an upper mold on the lower mold 100 to cover the cavity layer between the upper mold and the lower mold 100.

[0047] The process of paste-making the upper mold can be paste-made according to the conventional preparation process in the art. As an example, the paste-making upper mold includes:

[0048] A mold gel coat layer is sprayed on the surface of the lower mold 100 with the cavity layer, and the mold gel coat layer is sprayed on the cavity layer. The mold gel coat layer can provide a smooth and bright surface and protect the mold from chemical erosion and wear.

[0049] After the mold gel coat is cured, the laminating material of the upper mold is pasted, that is, the glass fiber and resin are stacked and laid layer by layer to form the main structure of the upper mold. In this step, the combination of glass fiber and resin needs to be laid according to the design requirements to ensure the strength and rigidity of the mold. During the lamination process, reinforcing materials such as alkali-free chopped strand mat and surface mat can be used. The selection of mold resin is very important. Commonly used ones are RM2000 (fast curing, fast mold manufacturing, low shrinkage, and reduced mold cost) and F-010 (epoxy modified vinyl resin, with good strength and heat resistance, as well as low shrinkage), etc. The specific selection can be made according to actual production needs.

[0050] After the paste making of the upper mold in step S4 is completed, step S5 is executed to demould after the upper mold of the mold is solidified, remove the cavity layer between the upper and lower molds, clean it up, and obtain a complete molding mold.

[0051] It should be noted that the molding mold prepared by the present invention may include one or more cavities. When the molding mold includes multiple cavities, the corresponding lower mold 100 includes multiple cavity areas, each cavity area is paved with a cavity material layer 114, and then the cavity material layer 114 of each cavity area is surface processed according to the thickness of the product to be molded. That is, the preparation method of the present invention is not limited by the number of mold cavities, and a mold with multiple cavities can be manufactured, which is more conducive to cost control.

[0052] The above steps not described in detail can all be completed according to conventional processes in the art.

[0053] Compared with the conventional wax sheet laying method, the preparation method of the composite material forming mold of the present invention can greatly reduce the mold manufacturing cost and product surface defects, obtain a mold cavity with a flat, smooth and uniform surface, and the entire preparation process does not use special materials or tools, and is easy to process and manufacture. It can be applied to the production and processing of complex molds in various fields.

[0054] Based on the same inventive concept, the present invention also provides a composite material forming mold, which is prepared by the above-mentioned preparation method of the present invention.

[0055] The composite material forming mold comprises a lower mold 100, an upper mold and a cavity. The upper mold is connected to the lower mold 100, and the cavity is located between the upper mold and the lower mold 100 for forming a product.

[0056] The molding die may include one or more cavities, each of which is formed by laying out a layer of cavity material that is easy to process and then processing it through a CNC processing machine.

[0057] The preparation method of the composite material forming mold provided by the present invention comprises the following steps: laying an easily processable cavity material on the lower mold, and performing surface processing on the cavity material according to the thickness of the product to be formed to obtain a cavity layer consistent with the shape of the product to be formed, and removing the cavity layer after the upper mold is solidified and formed, so as to obtain a forming mold with a flat, smooth and uniform cavity surface. The preparation method eliminates the wax sheet laying process, replaces the wax sheet with an easily processable cavity material, and lays it directly according to a preset thickness, thereby eliminating the seams, uneven thickness, depressions and errors caused by manual laying of the wax sheet, and greatly reducing the mold manufacturing cost and defects on the product surface. Therefore, the present invention effectively overcomes some practical problems in the prior art and thus has a high utilization value and use significance.

[0058] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for preparing a composite material forming mold, characterized in that: At least the following steps are included: Provide lower mold; Laying a cavity material layer on the lower mold, wherein the thickness of the cavity material layer is greater than the thickness of the product to be molded; Performing surface processing on the cavity material layer according to the thickness of the product to be formed to obtain a cavity layer with the same thickness as the product to be formed; Pasting an upper mold on the lower mold to cover the cavity layer between the upper mold and the lower mold; After the upper mold is solidified, the cavity layer is removed by demoulding to obtain the composite material molding mold.

2. The method for preparing a composite material forming mold according to claim 1, characterized in that: The lower mold is provided with a reserved product cutting edge and a cavity material laying boundary, the reserved product cutting edge corresponds to the boundary of the product to be formed, and the cavity material laying boundary exceeds the reserved product cutting edge by 10mm to 30mm.

3. The method for preparing a composite material forming mold according to claim 2, characterized in that: The step of laying a cavity material layer on the lower mold comprises: using a glue pressing device to press the cavity material into a preset thickness, and then laying the cavity material on the surface of the lower mold along the cavity material laying boundary to form a cavity material layer.

4. The method for preparing a composite material forming mold according to claim 1, characterized in that: The material of the cavity material layer is selected from wood substitutes.

5. The method for preparing a composite material forming mold according to claim 1, characterized in that: The thickness of the cavity material layer is 3 mm to 6 mm greater than the thickness of the product to be formed.

6. The method for preparing a composite material forming mold according to claim 1, characterized in that: The cavity material layer is subjected to surface processing by using a CNC machining machine to process the cavity material layer.

7. The method for preparing a composite material forming mold according to claim 1, characterized in that: The lower mold comprises one or more cavity areas, and each of the cavity areas is paved with the cavity material layer.

8. The method for preparing a composite material forming mold according to claim 1, characterized in that: The lower mold comprises a lower mold body, a mold steel frame and a mold pulley. The lower mold body is fixed on the mold steel frame, and the mold pulley is installed at the bottom of the mold steel frame.

9. The method for preparing a composite material forming mold according to claim 1, characterized in that: The step of pasting the upper mold on the lower mold comprises: spraying a mold gel coat layer on the surface of the lower mold with the cavity layer laid; and pasting the laminated material of the upper mold on the cavity layer and the mold gel coat layer.

10. A composite material forming die, characterized in that: The composite material is prepared by the preparation method according to any one of claims 1 to 9, and the composite material forming mold comprises: Lower mold, An upper mold, connected to the lower mold; The mold cavity is located between the lower mold and the upper mold.

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