Control method for improving forming deformation of plate-shaped rubber material

Abstract

The invention discloses a control method for improving the forming deformation of a plate-shaped sizing material, which comprises the following steps of: 1, performing shrinkage deformation simulation through mold flow analysis software based on product 3D (three-dimensional) data to obtain product deformation distribution data; 2, according to the product deformation distribution data obtained in the step 1, reverse pre-deformation compensation design is conducted on a mold cavity; 3, at least three glue inlets are formed in the top of the mold, the middle glue inlet corresponds to the middle section area of the top of the mold cavity, and the side glue inlets in the two sides correspond to the left section area and the right section area of the top of the mold cavity respectively; and 4, during injection molding, the opening and closing sequence of the pouring gate is controlled according to the following time sequence: in the first stage, the middle glue inlet is independently opened for glue injection, and the duration is T1; in the second stage, the side edge glue inlets in the two sides are opened, the side edge glue inlets and the middle glue inlet are made to conduct glue feeding synchronously so that residual glue injection can be completed jointly, and the synchronous glue feeding duration is T2; therefore, the deformation problem of the platy rubber material during injection molding is effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of plate-shaped rubber injection molding technology, in particular to a control method for improving the deformation amount of plate-shaped rubber. BACKGROUND

[0002] Taking a seat plate as an example, especially when the formed part uses PA6GF30 material, the rubber in the mold is injection molded, due to the limitation of the mold structure, the plastic part cannot shrink uniformly in the plane direction, which leads to the shrinkage of the plastic part in the thickness direction, which is one of the most common defects of plastic parts, and also one of the most difficult defects to solve. Generally, the warping deformation will cause the appearance gap to be inconsistent, there will be a gap, which will affect the appearance of the product. Consumers may feel that the product is too low-end and give up buying. Severe warping deformation will affect the assembly of the product, and even affect the function, performance and reliability of the product.

[0003] Specifically, the existing seat plate or other similar flat plate-shaped plastic parts use a central gate. The inventors of the present application analyzed that: 1. Due to the difference in shrinkage rate in the diameter direction and the circumferential direction, warping deformation will occur after forming. The position, form and number of the injection mold gate will affect the filling state of the plastic in the mold cavity, thereby causing the plastic part to deform. 2. In injection molding, the forming shrinkage rate of the plastic is different, and the anisotropy is obvious, that is, there is a difference in shrinkage between the flow direction and the non-flow direction of the rubber, which leads to large forming shrinkage and is prone to warping deformation. 3. The deformation caused by forming strain is mainly caused by the difference in forming shrinkage in the direction and the change in wall thickness. For example, the longer the flow distance, the greater the internal stress caused by the flow and feeding between the frozen layer and the central flow layer, which will also cause warping deformation. 4. The uneven flow and shrinkage difference caused by high glass fiber content of PA6GF30 material leads to the long-term pain point of PA6GF30 injection (such as high warping rate).

[0004] With the rapid development of today's furniture manufacturing industry, customers have higher awareness of product quality, and high-quality mold injection has become a demand in the high-end market. Therefore, it is urgent to develop a new technical solution to solve the above problems. SUMMARY

[0005] Therefore, the present application aims to solve the problems in the prior art, and the main purpose is to provide a control method for improving the deformation amount of plate-shaped rubber, which effectively improves the deformation problem of plate-shaped rubber during injection molding based on pre-deformation compensation and time-sharing glue injection control.

[0006] To achieve the above purpose, the present application adopts the following technical solutions: A control method for improving the deformation amount of plate-shaped rubber, comprising the following steps: Step 1, based on product 3D data, through the shrinkage deformation simulation of the mold flow analysis software, the product deformation distribution data is obtained; Step 2, according to the product deformation distribution data obtained in step 1, the mold cavity is reversely pre-deformed and compensated; Step 3, at least three glue inlets are arranged on the top of the mold, including a middle glue inlet and side glue inlets on both sides of the middle glue inlet; the middle glue inlet corresponds to the middle section area of the top of the mold cavity, and the side glue inlets on both sides correspond to the left section area and the right section area of the top of the mold cavity respectively; Step 4, during injection molding, the following timing control of gate opening and closing sequence is adopted: First stage, only the middle glue inlet is opened for glue injection, and the duration T1 is continued; Second stage, the side glue inlets on both sides are opened, and the glue is injected synchronously with the middle glue inlet to complete the remaining glue injection, and the synchronous injection duration T2 is 9-12 times of T1.

[0007] As a preferred scheme, in step 2, the product 3D data is modified reversely pre-deformed to compensate for the gauge block, and the modified product 3D data is simulated again by the mold flow analysis software to ensure that the product after simulated shrinkage deformation is within the drawing tolerance range of the initial standard product 3D, so that the final product 3D data obtained after the reverse pre-deformation compensation design is used as the mold cavity 3D data.

[0008] As a preferred scheme, in step 3, the top area of the mold cavity is divided into left section area, middle section area and right section area arranged from left to right, the middle glue inlet is arranged corresponding to the geometric center of the middle section area, the side glue inlet on the left is arranged corresponding to the geometric center of the left section area, and the side glue inlet on the right is arranged corresponding to the geometric center of the right section area.

[0009] As a preferred scheme, in step 3, for the mold cavity of the plate-shaped glue with left small and right large, the middle glue inlet is provided with more than one, the side glue inlet on the left is provided with one, and the side glue inlet on the right is provided with more than two.

[0010] As a preferred scheme, in step 3, for the mold cavity of the plate-shaped glue with left large and right small, the middle glue inlet is provided with more than one, the side glue inlet on the left is provided with more than two, and the side glue inlet on the right is provided with one.

[0011] As a preferred scheme, in step 4, T1 is 1.5 to 2.0 seconds, and T2 is 15 to 18 seconds.

[0012] As a preferred solution, in step 3, the intermediate glue inlet corresponds to the position of the center of gravity of the product, and the distance between the side glue inlets on both sides and the edge of the product is 1 / 5-1 / 3 of the length of the product.

[0013] As a preferred solution, in step 2, the determination method of the pre-deformation compensation amount of the reverse pre-deformation compensation design is that the simulation deformation amount is multiplied by a correction coefficient K, K=1+α×(Tm-Tg) / Tg, wherein α is the material shrinkage rate, Tm is the measured molding temperature, and Tg is the glass transition temperature of the material.

[0014] As a preferred solution, in step 4, in the second stage, the injection pressure of the intermediate glue inlet is 10%-15% lower than that of the side glue inlets on both sides.

[0015] As a preferred solution, the mold is provided with a plurality of independently controlled injection glue valve groups and a time sequence controller, and a pressure compensation module is also provided for the side glue inlets on both sides.

[0016] Compared with the prior art, the present application has obvious advantages and beneficial effects. Specifically, from the above technical solution, it can be seen that the deformation problem of the plate-shaped glue during injection molding is effectively improved based on pre-deformation compensation and time-sharing injection control through the settings of steps 1 to 4. The pre-deformation compensation corrects the injection molded part within the drawing tolerance range, so that the injection molded product meets the higher standard. The multi-glue inlet setting (such as selecting appropriate gate position and number) and the time-sharing injection control filling mode further reduce the injection molding deformation amount, maximize the improvement of the deformation problem of the plate-shaped glue during injection molding, greatly improve the product molding yield, improve the product quality, and better meet the higher product quality demand.

[0017] To more clearly illustrate the structural features and effects of the present application, the present application will be described in detail below with reference to the drawings and specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a step schematic diagram of a control method for improving the deformation amount of plate-shaped glue of the present application; Figure 2 is a deformation result schematic diagram of a seat plate (PA6GF30 material) of an embodiment of the present application obtained by MF software analysis; Figure 3 is a schematic diagram of the number and position of the glue inlets set in the mold cavity of the seat plate (PA6GF30 material) of the embodiment of the present application.

[0019] The figure mark explanation: the intermediate glue inlet G1; the side glue inlet G2 on the left side; the side glue inlet G3 on the right side. DETAILED DESCRIPTION

[0020] In the description of the present application, it should be noted that the terms "upper", "lower", "left", "right" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0021] Please refer to Figures 1 to 3 The control method for improving the deformation amount of a plate-shaped rubber material is an injection molding method based on pre-deformation compensation and time-sharing injection control, and specifically establishes a systematic solution of simulation analysis, quantitative compensation and time sequence control, which includes the following steps: Step 1: Based on the product 3D data, the shrinkage deformation simulation is carried out by using the mold flow analysis software to obtain the product deformation distribution data; Step 2: According to the product deformation distribution data obtained in step 1, the mold cavity is designed with reverse pre-deformation compensation; specifically, in step 2, the product 3D data is modified with reverse pre-deformation to compensate for the gauge, and the modified product 3D data is simulated again by using the mold flow analysis software to ensure that the product after simulated shrinkage deformation is within the tolerance range of the original standard product 3D drawing, so that the final product 3D data obtained after reverse pre-deformation compensation is used as the mold cavity 3D data. In this way, the injection molded part is corrected within the drawing tolerance range, reaching a higher standard. Generally, by performing steps 1 and 2, the deformation amount can be improved by about 50-60%.

[0022] Step 3: At least three injection ports are provided on the top of the mold, including a middle injection port and side injection ports on both sides of the middle injection port; the mold is provided with a plurality of independently controlled injection valve groups and a time sequence controller, and is also provided with a pressure compensation module for the side injection ports on both sides; the middle injection port corresponds to the middle section area of the top of the mold cavity, and the side injection ports on both sides correspond to the left section area and the right section area of the top of the mold cavity, respectively; Step 4: During injection molding, the center priority injection method is adopted to establish a more stable melt flow path and change the melt flow balance, and the gate opening and closing sequence can be controlled according to the following time sequence: First stage, only the middle injection port is opened for injection, and the duration is T1; The second stage is to open the side glue inlet on both sides and synchronize the glue inlet with the middle glue inlet to jointly complete the remaining glue injection, and the synchronization glue injection lasts for T2, which is 9-12 times of T1. Taking a conventional single seat plate as an example, the plate-shaped glue is injection molded, and the gate opening and closing sequence is controlled during injection molding, deformation data analysis is performed to obtain the optimal deformation amount, the mold is opened first to the middle glue inlet G1, and the glue is injected for 1.5-2 seconds, then the side glue inlet G2 on the left and the side glue inlet G3 on the right are opened, at this time, the three points, the middle glue inlet G1, the side glue inlet G2 on the left and the side glue inlet G3 on the right, simultaneously inject glue for about 15-18 seconds. Since the center is preferentially injected, the second stage of glue injection flows under the constraint of the melt flow path / skeleton formed in the first stage, effectively reducing the difference in molecular orientation, effectively solving the long-term pain points of PA6GF30 injection molding caused by uneven flow and shrinkage difference of PA6GF30 material due to high glass fiber content (such as high warpage rate).

[0023] The mold flow analysis software (such as MF software) can be used to simulate and analyze the plastic molding process, such as flow, cooling, shrinkage, etc., to predict the filling, pressure maintaining, cooling of plastic melt in the mold cavity, and to predict the stress distribution, molecular and fiber orientation distribution, shrinkage and warpage deformation of the molded part, etc. For plate-shaped glue of seat plate, especially using glue PA6GF30, which cannot uniformly shrink in the plane direction, resulting in shrinkage and warpage deformation of the plastic part in the thickness direction, especially at the edge position. In the present application, by pre-deformation compensation, selecting appropriate gate position and number and injecting glue at different times, the filling mode is controlled, and the product yield strength is increased by about 15% (tested by ASTM D638), the deformation problem of plate-shaped glue during injection molding is improved to the maximum extent, the product molding yield is greatly improved, and the deformation of the molded product is within a controllable range.

[0024] Further, in step 3, the top area of the mold cavity of the plate-shaped glue is divided into a left segment area, a middle segment area and a right segment area arranged in sequence from left to right, the middle glue inlet is arranged corresponding to the geometric center of the middle segment area, the side glue inlet on the left is arranged corresponding to the geometric center of the left segment area, and the side glue inlet on the right is arranged corresponding to the geometric center of the right segment area.

[0025] Further, in step 3, for the mold cavity of the plate-shaped rubber material with the left large and the right small, the intermediate rubber inlet is provided with more than one, the left side rubber inlet is provided with two or more, and the right side rubber inlet is provided with one.

[0026] Further, in step 3, the intermediate rubber inlet is arranged according to the position of the center of gravity of the product, and the distance between the side rubber inlets on both sides and the edge of the product is 1 / 5-1 / 3 of the length of the product.

[0027] Further, in step 2, the determination method of the pre-deformation compensation amount of the reverse pre-deformation compensation design is that the simulation deformation amount is multiplied by a correction coefficient K, K=1+α×(Tm-Tg) / Tg, wherein α is the material shrinkage rate, Tm is the measured molding temperature, and Tg is the glass transition temperature of the material. In this way, the coupling optimization of material properties and process parameters is realized through the dynamic compensation coefficient K.

[0028] Further, in step 4, in the second stage, the injection pressure of the intermediate rubber inlet is 10%-15% lower than that of the side rubber inlets on both sides.

[0029] Next, taking a seat plate (PA6GF30 material) as an example, as shown in Figure 2 , the original product deformation amount is shown, and the deformation result is obtained through MF software analysis. The original analysis deformation amount: the maximum product shape deformation amount is as high as 7.5mm, and the product intermediate deformation amount is as high as 2.5mm. After knowing the deformation condition as shown in Figure 2 , the mold 3D product is modified by the MF report value, the reverse pre-deformation is compensated (that is, the physical deformation of the product in the manufacturing or use stage is compensated in advance through digital means, so as to improve the quality and performance of the final product, and the geometry is adjusted in reverse in the 3D model in advance, so that the actual product after manufacturing meets the design expectation), so that the injection molding part is within the drawing tolerance range, and the deformation amount is improved by about 50-60%. Specifically, after pre-deformation, the deformation amount is improved: the maximum product shape deformation amount is 3.5mm, and the product intermediate deformation amount is 1.3mm. And according to the deformation condition as shown in Figure 2 , the number and position of the rubber inlets on the top of the mold are set, as shown in Figure 3As shown. When injection molding, control the opening and closing sequence of the gate, open the middle gate G1 first, inject for 1.5 seconds, then open the left side gate G2 and the right side gate G3, at this time the three points, middle gate G1, left side gate G2 and right side gate G3 inject at the same time for about 15 seconds. The last molded part obtained by opening the mold, the injection molding deformation is further reduced: the maximum product deformation is controlled within 1.5 mm, the product deformation is controlled within 0.5 mm, and the deformation is small, within the controllable range, meeting the high-quality product acceptance deformation: the maximum product deformation is 2 mm, and the product deformation is 1 mm.

[0030] As shown in the following table:

[0031] The design focus of the present application is that it mainly improves the deformation problem of the plate-shaped glue during injection molding through the setting of steps 1 to 4 based on pre-deformation compensation and time-sharing injection control. The pre-deformation compensation corrects the injection molding part within the drawing tolerance range, so that the injection molding product meets the higher standard. The multi-gate setting (such as selecting appropriate gate position and number) and time-sharing injection control filling mode further reduce the injection molding deformation, maximize the improvement of the deformation problem of the plate-shaped glue during injection molding, greatly improve the product molding yield, improve the product quality, and better meet the higher product quality demand. Therefore, compared with the traditional plate-shaped glue injection molding technology, the control method of the present application has the advantages of more accurate (offsetting deformation error, improving size consistency), more efficient (reducing trial and error and post-processing, accelerating mass production), more reliable (optimizing stress distribution, prolonging product life), more intelligent (promoting deep cooperation between simulation and manufacturing), and many other advantages, and is suitable for popularization and application.

[0032] The above is only a preferred embodiment of the present application, and does not limit the technical scope of the present application in any way. Any slight modification, equivalent change and modification made according to the technical essence of the present application to the above embodiment are still within the scope of the technical solution of the present application.

Claims

1. A method for improving the deformation control of plate-shaped rubber materials, characterized in that: The following steps are involved: Step 1: Based on the product 3D data, perform shrinkage deformation simulation using mold flow analysis software to obtain product deformation distribution data; Step 2: Based on the product deformation distribution data obtained in step 1, reverse pre-deformation compensation design is performed on the mold cavity; Step 3: Set at least three glue inlets on the top of the mold, including a middle glue inlet and side glue inlets located on both sides of the middle glue inlet; the middle glue inlet corresponds to the middle area of ​​the top of the mold cavity, and the side glue inlets on both sides correspond to the left area and the right area of ​​the top of the mold cavity respectively; Step 4: During injection molding, control the gate opening and closing sequence according to the following timing: In the first stage, the middle glue inlet is opened alone for glue injection, which lasts for T1; In the second stage, the side glue inlets on both sides are opened to feed glue synchronously with the middle glue inlet to complete the remaining glue injection. The duration of synchronous glue feeding is T2, which is 9-12 times of T1.

2. A control method for improving deformation of plate-shaped rubber material according to claim 1, characterized in that: In step 2, the product 3D data is modified by reverse pre-deformation to compensate for the sample volume, and the modified product 3D data is simulated for shrinkage deformation again with the help of mold flow analysis software to ensure that the dimensions of the product after simulated shrinkage deformation are within the tolerance range of the original standard product 3D drawing. The final product 3D data obtained after the reverse pre-deformation compensation design is used as the mold cavity 3D data.

3. A control method for improving deformation of plate-shaped rubber material according to claim 1, characterized in that: In step 3, the top area of ​​the mold cavity is divided into a left section area, a middle section area and a right section area arranged from left to right. The middle glue inlet is set corresponding to the geometric center of the middle section area, the side glue inlet on the left is set corresponding to the geometric center of the left section area, and the side glue inlet on the right is set corresponding to the geometric center of the right section area.

4. A control method for improving deformation of plate-shaped rubber material according to claim 1, characterized in that: In step 3, for the mold cavity of the plate-shaped rubber material that is smaller on the left and larger on the right, there is more than one middle glue inlet, one side glue inlet on the left, and more than two side glue inlets on the right.

5. The method for improving the deformation of plate-shaped rubber material according to claim 1, characterized in that: In step 3, for the mold cavity of the plate-shaped rubber material that is larger on the left and smaller on the right, there is more than one middle rubber inlet, more than two side rubber inlets on the left side are provided, and one side rubber inlet on the right side is provided.

6. The method for improving the deformation of plate-shaped rubber materials according to claim 1, characterized in that: In step 4, T1 is 1.5 to 2.0 seconds, and T2 is 15 to 18 seconds.

7. The method for improving the deformation of plate-shaped rubber material according to claim 1, characterized in that: In step 3, the middle glue inlet is set corresponding to the center of gravity of the product, and the distance between the side glue inlets on both sides and the edge of the product is 1 / 5-1 / 3 of the length of the product.

8. A control method for improving deformation of plate-shaped rubber material according to claim 1 or 2, characterized in that: In step 2, the method for determining the pre-deformation compensation amount of the reverse pre-deformation compensation design is: multiply the simulated deformation amount by the correction coefficient K, K=1+α×(Tm-Tg) / Tg, where α is the material shrinkage rate, Tm is the measured molding temperature, and Tg is the material glass transition temperature.

9. The method for improving the deformation of plate-shaped rubber material according to claim 1, characterized in that: In step 4, during the second stage, the injection pressure of the middle glue inlet is 10%-15% lower than the injection pressure of the side glue inlets on both sides.

10. The method for improving the deformation of plate-shaped rubber material according to claim 1, characterized in that: The mold is provided with a multi-channel independently controlled injection valve group and a timing controller, and is also provided with a pressure compensation module set for the side glue inlets on both sides.

Images