An injection molded housing process and injection molded housing

Abstract

The application relates to an injection-molding shell process and an injection-molding shell, which comprises the following steps: obtaining the center fabric thickness of a five-surface shell, the thickness of the five-surface shell after the side wall is thinned based on a proportionality coefficient K; obtaining a melt glue flow equipotential map of the center fabric melt glue equipotential line step distance; obtaining a melt glue flow equipotential line map of the side wall melt glue equipotential line step distance after the side wall of the five-surface shell is thinned, confirming that there is no trapped gas information after the side wall is thinned; confirming that there is no trapped gas information between the gate and the side surface in the melt glue flow equipotential map of the center fabric melt glue equipotential line step distance; and confirming the numerical values of the center fabric thickness of the five-surface shell and the thickness of the five-surface shell after the side wall is thinned. The application has the beneficial effects that the problems of difficult elimination of trapped gas and influence of elimination of trapped gas on products in the prior art are overcome, and the injection-molding efficiency of the shell part is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of injection molding technology, and in particular to an injection molding shell process and an injection molded shell. Background Technology

[0002] In the injection molding industry, products are generally designed with uniform wall thickness. However, for shell-shaped or shell-like injection molded parts using side gates, air trapping can easily occur on the opposite side of the product during injection molding. That is, during injection molding, the molten plastic flow lines of products with uniform wall thickness enter at the same consistent pitch, ultimately trapping gas from the mold cavity inside the product, creating air trapping. Under injection pressure, this trapped gas generates high temperatures, leading to plastic degradation and a "burnt" appearance, resulting in surface defects such as yellowing or blackening. To solve this problem, ventilated inserts are installed at the air trapping points. These inserts are typically made of ventilated steel, utilizing the micropores in the steel to expel the trapped gas. This can alleviate the air trapping problem to some extent. However, this inlay structure can lead to the following problems in the product line: 1. Products are prone to wire trapping; 2. It weakens the mold strength, leading to the risk of cracking when the mold is under heavy load; 3. It can only solve the problem when the amount of trapped air is small. When the product size is large and the trapped air is severe, the trapped air cannot be removed in time; 4. Because the position of trapped air in the injection shell is not precise, the position of the inlay structure is difficult to predict accurately, which leads to frequent modifications of the insert, increasing the cost of trial molding and the development cycle.

[0003] To address these issues, existing technologies use "flow-retarding grooves" on the side of the product to slow down the flow rate of the molten adhesive on the sidewall, preventing air entrapment. MOLDFLOW and other membrane flow simulation software are then used to confirm whether the air entrapment has been eliminated. However, adding "flow-retarding grooves" can easily affect the product's appearance quality. Furthermore, there is no quantitative method for designing the depth of the "flow-retarding grooves," requiring frequent data modifications and membrane flow simulations to confirm the elimination of air entrapment. Frequent iterative calculations of the membrane flow require significant manpower and time, reducing efficiency and increasing labor costs.

[0004] Therefore, it is essential to provide an injection molding process and an injection molding shell to solve the technical problem of trapped air not being properly discharged from the injection molding shell. Summary of the Invention

[0005] This invention provides an injection molding shell process and an injection molded shell, which can solve the problem in related technologies where, during injection molding of shell injection parts or shell-like parts using side gates, air trapping easily forms on the opposite side of the product, and existing technologies cannot effectively solve the problem of air trapping.

[0006] On the one hand, embodiments of the present invention provide an injection molding shell process, Includes the following steps: Obtain the ratio K between the flow length of the melt at the center surface and the flow length on the sidewall surface; Obtain the center fabric thickness of the five-sided shell ; Based on the ratio coefficient K between the flow length of the melt center surface and the flow length of the sidewall surface, and the thickness of the center surface of the five-sided shell. Obtain the thickness of the five-sided shell sidewalls after thinning. ; Based on the thickness of the central fabric Obtain the center plane melt equipotential line step distance Isometric diagram of melt flow; Based on the thickness after thinning of the five-sided shell sidewall Obtain the step distance of the equipotential line of the sidewall melt after the sidewall of the five-sided shell is thinned. The equipotential lines of the melt flow were plotted, and it was confirmed that there was no trapped air after the sidewall was thinned. Confirm the center surface melt equidistant line spacing Information on untrapped gas on the side of the gate in the equipotential mapping of melt flow; Confirm the thickness of the center fabric of the five-sided shell. and the thickness of the five-sided shell sidewalls after thinning The value.

[0007] Further, the ratio K of the flow length on the center surface of the melt to the flow length on the sidewall surface is obtained, specifically including the following steps: Obtain the length O and height I of the five-sided shell; Based on the length O and height I of the five-sided shell, obtain the melt flow length data of the center surface. ; Based on the length O and width P of the five-sided shell, obtain the melt flow length data of the side wall surface. ; Based on the melt flow length data of the center plane Data on melt flow length of sidewall The ratio of the flow length at the center of the melt to the flow length at the sidewall is used to obtain the proportionality coefficient K.

[0008] Furthermore, the thickness of the central fabric of the five-sided shell is obtained. The specific steps are as follows: Obtain the product's basic parameters and preset the center fabric thickness of the five-sided shell. Thus, the thickness of the central fabric of the five-sided shell is obtained. .

[0009] Furthermore, based on the ratio coefficient K between the flow length of the melt center surface and the flow length of the sidewall surface, and the thickness of the center fabric of the five-sided shell... Obtain the thickness of the five-sided shell sidewalls after thinning. Specifically, it includes the following steps: Based on obtaining the central fabric thickness of the five-sided shell And the proportionality coefficient K, to obtain the thickness of the five-sided shell sidewall after thinning. numerical value Furthermore, based on the thickness of the central fabric Obtain the center plane melt equipotential line step distance The isotope diagram of melt flow specifically includes the following steps: Set the center fabric thickness of the five-sided shell The numerical value is imported into the computer software, and the computer software is used to draw the step distance of the melt equipotential line on the center plane. Isotope diagram of melt flow.

[0010] Furthermore, based on the thickness of the five-sided shell sidewalls after thinning... Obtain the step distance of the equipotential line of the sidewall melt after the sidewall of the five-sided shell is thinned. The equipotential mapping of melt flow specifically includes the following steps: Thickness of the five-sided shell sidewall after thinning The value; Thickness after thinning the sidewalls of the five-sided shell The numerical values ​​are imported into the computer software, and the step size of the equipotential lines of the sidewall melt is drawn using the computer software. Isotropic diagram of melt flow.

[0011] Further, confirming that there is no air entrapment after sidewall thinning, specifically includes the following steps: Based on the fact that the melt boundary point coincides with the melt flow equipotential map, the melt flow equipotential line is the gas outlet path at this time. Starting from the gate at a certain rate, molten plastic is injected along the center surface and sidewalls from the gate. The spacing of the equipotential lines of the molten plastic on the sidewalls after the five-sided shell sidewalls have been thinned is... The step distance between the equipotential line of the melt flow and the equipotential line of the center plane melt flow The entrapped air is discharged from the molten plastic equipotential line on the center surface after passing through the molten plastic equipotential line on the side wall.

[0012] Furthermore, confirm the spacing of the equipotential bonding lines on the center surface. The information on the untrapped gas on the side of the gate in the molten adhesive flow equipotential diagram includes the following steps: Obtain the location information of the gate and the information of the gate's position relative to the side; Obtain the center plane melt equipotential line step distance The equipotential diagram of melt flow confirms the points where trapped gas is likely to form. If these points are located between the equipotential lines, the trapped gas is eliminated, and the housing part is free of trapped gas.

[0013] Furthermore, the steps to eliminate drowsiness are as follows: Since the melt flow boundary point coincides with the melt flow equipotential line, the melt flow equipotential line is the venting position, and the position opposite the gate on the center surface is the point where trapped air is likely to form. When the point where trapped air is likely to form is located on the melt flow equipotential line, i.e. the venting position, the trapped air is eliminated. If molten adhesive is injected from the gate at a certain rate along the center plane, the air trapping point is located at the air outlet, and the air trapping point is eliminated.

[0014] On the one hand, an injection molded housing obtained by the injection molding process described in any of the above claims is provided, comprising a center surface and a side wall, wherein the thickness of the side wall is obtained based on the thickness of the center surface 1 and the ratio coefficient K of the flow length of the molten core on the center surface to the flow length of the side wall surface.

[0015] The beneficial effects of the technical solution provided by this invention include: By using the ratio of the flow length on the center surface to the flow length on the sidewalls and the thickness of the center surface of the five-sided shell, the thickness of the sidewalls after thinning can be preliminarily determined. Furthermore, by utilizing the larger step size of the equipotential lines on the center surface compared to the sidewalls, the flow velocity on the center surface is faster than that on the sidewalls, thus eliminating the conditions for trapped air formation. Simultaneously, combining the equipotential line diagram of the melt flow reveals the absence of trapped gas on the side opposite the gate. This ensures that trapped air in the injection-molded shell parts has been eliminated. The sidewall thickness obtained at this ratio can eliminate the trapped air problem, significantly improving the injection molding efficiency of shell parts. This overcomes the problem of trapped air easily forming on the opposite side of the product during injection molding of shell parts or shell-like parts using side gates in existing technologies, and the fact that existing technologies cannot effectively solve the trapped air problem. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of a five-sided shell in an injection molding shell process according to the present invention; Figure 2 This is a schematic diagram showing the unfolded five-sided shell in an injection molding shell process according to the present invention; Figure 3 This is a schematic diagram of the equipotential mapping of melt flow in an injection molding shell process according to the present invention; Figure 4 This is a front view of an injection-molded housing according to the present invention; Figure 5 for Figure 4 Cross-sectional view at point AA; Figure 6 for Figure 5 Enlarged view of point B in the middle. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] See Figures 1 to 3 As shown, this embodiment of the invention provides an injection molding housing process, including the following steps: Obtain the ratio K between the flow length of the melt at the center surface and the flow length on the sidewall surface; Obtain the center fabric thickness of the five-sided shell ; Based on the ratio coefficient K between the flow length of the melt center surface and the flow length of the sidewall surface, and the thickness of the center surface of the five-sided shell. Obtain the thickness of the five-sided shell sidewalls after thinning. ; Based on the thickness of the central fabric Obtain the center plane melt equipotential line step distance Isometric diagram of melt flow; Based on the thickness after thinning of the five-sided shell sidewall Obtain the step distance of the equipotential line of the sidewall melt after the sidewall of the five-sided shell is thinned. The equipotential lines of the melt flow were plotted, and it was confirmed that there was no trapped air after the sidewall was thinned. Confirm the center surface melt equidistant line spacing Information on untrapped gas on the side of the gate in the equipotential mapping of melt flow; Confirm the thickness of the center fabric of the five-sided shell. and the thickness of the five-sided shell sidewalls after thinning The value.

[0020] See Figure 1 As shown, in some embodiments, obtaining the ratio K between the flow length on the center surface of the melt and the flow length on the sidewall surface specifically includes the following steps: Obtain the length O and height I of the five-sided shell; Based on the length O and height I of the five-sided shell, obtain the melt flow length data of the center surface. ; Based on the length O and width P of the five-sided shell, obtain the melt flow length data of the side wall surface. ; Based on the melt flow length data of the center plane Data on melt flow length of sidewall The ratio of the flow length at the center of the melt to the flow length at the sidewall is used to obtain the proportionality coefficient K.

[0021] In this embodiment, the melt flow length data of the center surface is as follows: Sidewall melt flow length data: The ratio coefficient K between the flow length on the center surface and the flow length on the sidewall surface of the melt is: .

[0022] In some embodiments, the center fabric thickness of the five-sided shell is obtained. The specific steps are as follows: Obtain the product's basic parameters and preset the center fabric thickness of the five-sided shell. Thus, the thickness of the central fabric of the five-sided shell is obtained. .

[0023] In some embodiments, the ratio K between the flow length of the melt center surface and the flow length of the sidewall surface, and the thickness of the center fabric of the five-sided shell are used as the basis. Obtain the thickness of the five-sided shell sidewalls after thinning. Specifically, it includes the following steps: Based on obtaining the central fabric thickness of the five-sided shell And the ratio K of the flow length of the melt center surface to the flow length of the sidewall surface, to obtain the thickness of the five-sided shell after sidewall thinning. The value.

[0024] In this embodiment, the thickness of the five-sided shell sidewall after thinning is... .

[0025] In some embodiments, based on the thickness of the central fabric Obtain the center plane melt equipotential line step distance The isotope diagram of melt flow specifically includes the following steps: Set the center fabric thickness of the five-sided shell The numerical value is imported into the computer software, and the computer software is used to draw the step distance of the melt equipotential line on the center plane. Isotope diagram of melt flow.

[0026] In some embodiments, the thickness is based on the reduced thickness of the five-sided shell sidewalls. Obtain the step distance of the equipotential line of the sidewall melt after the sidewall of the five-sided shell is thinned. The equipotential mapping of melt flow specifically includes the following steps: Thickness of the five-sided shell sidewall after thinning The value; Thickness after thinning the sidewalls of the five-sided shell The numerical values ​​are imported into the computer software, and the step size of the equipotential lines of the sidewall melt is drawn using the computer software. Isotropic diagram of melt flow.

[0027] In this embodiment, the sidewall melt equipotential line spacing is... .

[0028] In some embodiments, confirming that there is no air entrapment information after sidewall thinning specifically includes the following steps: Based on the fact that the melt boundary point coincides with the melt flow equipotential map, the melt flow equipotential line is the gas outlet path at this time. Starting from the gate at a certain rate, molten plastic is injected along the center surface and sidewalls from the gate. The spacing of the equipotential lines of the molten plastic on the sidewalls after the five-sided shell sidewalls have been thinned is... The step distance between the equipotential line of the melt flow and the equipotential line of the center plane melt flow The entrapped air is discharged from the molten plastic equipotential line on the center surface after passing through the molten plastic equipotential line on the side wall.

[0029] In this embodiment, the step size of the equipotential bonding line of the sidewall melt after the sidewall of the five-sided shell is thinned is... The step distance between the equipotential line of the melt flow and the equipotential line of the center plane melt flow Non-overlapping .

[0030] In some embodiments, confirm the center plane melt equidistant line step distance. The information on the untrapped gas on the side of the gate in the molten adhesive flow equipotential diagram includes the following steps: Obtain the location information of the gate and the information of the gate's position relative to the side; Obtain the center plane melt equipotential line step distance The equipotential diagram of melt flow confirms the points where trapped gas is likely to form. If these points are located between the equipotential lines, the trapped gas is eliminated, and the housing part is free of trapped gas.

[0031] In some embodiments, the elimination of drowsiness specifically includes the following steps: Since the melt flow boundary point coincides with the melt flow equipotential line, the melt flow equipotential line is the venting position, and the position opposite the gate on the center surface is the point where trapped air is likely to form. When the point where trapped air is likely to form is located on the melt flow equipotential line, i.e. the venting position, the trapped air is eliminated. If molten adhesive is injected from the gate at a certain rate along the center plane, the air trapping point is located at the air outlet, and the air trapping point is eliminated.

[0032] See Figures 4 to 6As shown, on one hand, an injection molded housing obtained by the injection molding process described in any of the above claims is provided, comprising: Center plane 1; The thickness of the sidewall 2 is obtained based on the thickness of the center surface 1 and the ratio K between the flow length of the melt center surface and the flow length of the sidewall surface.

[0033] The beneficial effects of this invention are as follows: By using the ratio of the flow length on the center surface to the flow length on the sidewalls and the thickness of the center surface of the five-sided shell, the thickness of the sidewalls after thinning can be preliminarily determined. Furthermore, by utilizing the characteristic that the equipotential line spacing on the center surface is larger than that on the sidewalls, the flow velocity on the center surface is faster than that on the sidewalls, thus eliminating the conditions for trapped air formation. Simultaneously, combining the equipotential line diagram of the melt flow reveals the absence of trapped gas on the side opposite the gate. This ensures that trapped air in the injection-molded shell parts has been eliminated. The sidewall thickness obtained at this ratio can eliminate the trapped air problem, significantly improving the injection molding efficiency of shell parts. This overcomes the problem of trapped air easily forming on the opposite side of the product during injection molding of shell parts or shell-like parts using side gates in existing technologies, and the fact that existing technologies cannot effectively solve the trapped air problem.

[0034] In the description of this invention, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Unless otherwise expressly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0035] It should be noted that, in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the term "comprising," or any other variation thereof, is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0036] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features of the invention herein.

Claims

1. A process for injection molding a housing, characterized in that, Includes the following steps: Obtain the ratio K between the flow length of the melt at the center surface and the flow length on the sidewall surface; Obtain the center fabric thickness of the five-sided shell ; Based on the ratio coefficient K between the flow length of the melt center surface and the flow length of the sidewall surface, and the thickness of the center surface of the five-sided shell... Obtain the thickness of the five-sided shell sidewalls after thinning. , ; Based on the thickness of the central fabric Obtain the center plane melt equipotential line step distance Isometric diagram of melt flow; Based on the thickness after thinning of the five-sided shell sidewall Obtain the step size of the equipotential lines of the sidewall melt after the sidewalls of the five-sided shell are thinned. Isotropic diagram of melt flow And confirmed that there was no air entrapment information after the sidewall thinning; Confirm the center surface melt equidistant line spacing Information on untrapped gas on the side of the gate in the equipotential mapping of melt flow; Confirm the thickness of the center fabric of the five-sided shell. and the thickness of the five-sided shell sidewalls after thinning The value; The ratio K between the flow length of the melt center surface and the flow length of the sidewall surface is obtained by the following steps: Obtain the length O and height I of the five-sided shell; Based on the length O and height I of the five-sided shell, obtain the melt flow length data of the center surface. , ; Based on the length O and width P of the five-sided shell, obtain the melt flow length data of the side wall surface. , ; Based on the melt flow length data of the center plane Data on melt flow length of sidewall The ratio of the flow length at the center of the melt to the flow length on the sidewall is used to obtain the proportionality coefficient K, K= ; After confirming that there is no air entrapment after sidewall thinning, the specific steps include: Based on the fact that the melt boundary point coincides with the melt flow equipotential map, the melt flow equipotential line is the gas outlet path at this time. Starting from the gate at a certain rate, molten plastic is injected along the center surface and sidewalls from the gate. The spacing of the equipotential lines of the molten plastic on the sidewalls after the five-sided shell sidewalls have been thinned is... The step distance between the equipotential line of the melt flow and the equipotential line of the center plane melt flow Non-overlapping The trapped gas is discharged from the equipotential line of the molten adhesive on the center surface, passing through the equipotential line of the molten adhesive on the side wall.

2. The injection molding shell process as described in claim 1, characterized in that, Obtain the center fabric thickness of the five-sided shell The specific steps are as follows: Obtain the product's basic parameters and preset the center fabric thickness of the five-sided shell. Thus, the thickness of the central fabric of the five-sided shell is obtained. .

3. The injection molding shell process as described in claim 1, characterized in that, Based on the thickness of the central fabric Obtain the center plane melt equipotential line step distance The isotope diagram of melt flow specifically includes the following steps: Set the center fabric thickness of the five-sided shell The numerical value is imported into the computer software, which is then used to draw the center plane melt equipotential line step distance. Isotope diagram of melt flow.

4. The injection molding shell process as described in claim 1, characterized in that, Based on the thickness after thinning of the five-sided shell sidewall Obtain the step size of the equipotential lines of the sidewall melt after the sidewalls of the five-sided shell are thinned. The equipotential mapping of melt flow specifically includes the following steps: Thickness of the five-sided shell sidewall after thinning The value; The thickness after thinning the sidewalls of the five-sided shell The numerical values ​​are imported into computer software, which is then used to draw the step size of the equipotential lines of the sidewall melt. Isotropic diagram of melt flow.

5. The injection molding shell process as described in claim 1, characterized in that, Confirm the center surface melt equidistant line spacing The information on the untrapped gas on the side of the gate in the molten adhesive flow equipotential diagram includes the following steps: Obtain the location information of the gate and the information of the gate's position relative to the side; Obtain the center plane melt equipotential line step distance The equipotential diagram of melt flow identifies points where trapped gas is likely to form. If these points are located between the equipotential lines, the trapped gas is eliminated, and there is no trapped gas in the shell parts.

6. The injection molding shell process as described in claim 5, characterized in that, The steps to eliminate drowsiness are as follows: Since the melt flow boundary point coincides with the melt flow equipotential line, the melt flow equipotential line is the venting position, and the position opposite the gate on the center surface is the point where trapped air is likely to form. When the point where trapped air is likely to form is located on the melt flow equipotential line, i.e. the venting position, the trapped air is eliminated. If molten adhesive is injected from the gate at a certain rate along the center plane, the air trapping point is located at the air outlet, and the air trapping point is eliminated.

7. An injection molded housing obtained by the injection molding process according to any one of claims 1 to 6, characterized in that, include: Center plane; The thickness of the sidewall is obtained based on the thickness of the center surface and the ratio K between the flow length of the melt center surface and the flow length of the sidewall surface.

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