A method and verification mold for solving thick and thin print defects

Abstract

The application provides a method for solving thick-thin printing defects and a verification mold. The method for solving thick-thin printing defects comprises the following steps: step one, obtaining design and production parameters of a product; step two, obtaining verification products by using the verification mold according to the obtained design and production parameters of the product; and step three, judging whether the verification products have thick-thin printing defects. If the verification products have thick-thin printing defects, the design and production parameters of the product are modified, and the steps one to three are repeated until the verification products do not have thick-thin printing defects. The method for solving thick-thin printing defects can be applied to different stages of the product and is used for solving whether the verification product has thick-thin printing defects, and is used for providing a low-cost, comprehensive and acceptable optimal solution for solving thick-thin printing defects.

Description

Technical Field

[0001] This invention belongs to the technical field of surface defect solving for injection molded products, specifically relating to a method for solving thickness and thinness defects and a verification mold. Background Technology

[0002] Plastic products are becoming increasingly widely used due to their ease of processing and lightweight properties. With continuous upgrading of consumption, people have higher and higher requirements for product appearance. Thickness marks are a very typical surface defect in injection molded products. The occurrence of thickness marks greatly reduces the appearance quality of products and limits their application in exterior parts.

[0003] Current research on mitigating the appearance defects of thick and thin printing mainly focuses on modifying specific mold structures to suit specific products. There is a lack of a universal method to understand the extent and causes of thick and thin printing, so as to optimize and screen product structures during the design phase.

[0004] Therefore, designing a simple, efficient, and comprehensive method to solve the defects in thick and thin printing and verifying the mold is of great significance and value in the field of surface defect research. Summary of the Invention

[0005] In view of some or all of the above-mentioned technical problems existing in the prior art, a method and verification mold for solving the problem of thick and thin printing defects are provided. This mold is used to verify whether a product has thick and thin printing defects and to provide a low-cost, comprehensive, and acceptable optimal solution for solving the problem of thick and thin printing defects.

[0006] To solve the above-mentioned technical problems, one aspect of the present invention proposes the following technical solution:

[0007] A method for solving the problem of uneven printing includes:

[0008] Step 1: Obtain the product's design and manufacturing parameters.

[0009] Step two: Based on the obtained product design and production parameters, a verification sample is produced using a verification mold.

[0010] Step 3: Determine if the verification sample has a thickness difference print defect. If the verification sample has a thickness difference print defect, modify the product's design and production parameters, and repeat steps 1 to 3 until the verification sample is free of thickness difference print defects.

[0011] In one embodiment, in step one, the product design and manufacturing parameters include the product structure's thickness ratio, the product structure's transition length, and the product's material parameters.

[0012] In one embodiment, in step three, if the verification sample has a thickness-to-thickness print defect, one or more of the product structure's thickness ratio, the product structure's transition length, and the product's material parameters can be modified. The product's design and production parameters are prioritized according to increasing the product structure's thickness ratio, increasing the product structure's transition length, and decreasing the product's material shrinkage rate. If the thickness-to-thickness print defect still exists even after the previous level reaches its modification limit, the next level of the product's design and production parameters is then modified.

[0013] In one embodiment, in step one, the product is either a product that has already been manufactured and has a thickness-to-thickness print defect, or a product that has not been manufactured, is in the design stage, but has a structural design risk of thickness-to-thickness print defects.

[0014] In one embodiment, production using a verification mold includes:

[0015] Step one involves adjusting the verification mold to meet the design and production parameters of the obtained product, and then installing the verification mold into the injection molding machine.

[0016] In step two, an injection molding machine is used to produce a verification product.

[0017] In another aspect, the present invention provides a verification mold for use in the above-described method for resolving the thickness and thinness printing defects, comprising:

[0018] Front mold,

[0019] A rear mold, which is matched with the front mold, has a mounting groove on the rear mold facing the front mold.

[0020] Inserts are used to be disposed at the mounting slot, the inserts being used to adaptively change the thickness ratio or transition length of the product structure.

[0021] In one embodiment, the insert includes an insert for adjusting the thickness ratio and an insert for adjusting the transition length.

[0022] The adjustable transition length inserts are multiple and are selectively disposed at the mounting slot, and at least two of the adjustable transition length inserts have different transition lengths.

[0023] In one embodiment, the thickness adjustment inserts are multiple and selectively disposed at the mounting slot, and at least two of the thickness adjustment inserts have different heights.

[0024] Alternatively, an extension mechanism may be provided directly between the adjusting thickness ratio insert and the rear mold to adjust the height of the adjusting thickness ratio insert.

[0025] In one embodiment, the extension mechanism is configured as an extension screw extending through the wall of the mounting groove toward the thickness adjustment insert, the extension screw being threadedly connected to the rear mold, and the upper end of the extension screw being intermittently inserted into the lower end of the thickness adjustment insert.

[0026] In one embodiment, a plurality of mounting slots are provided on the rear mold, and the inserts are selectively provided at each of the mounting slots.

[0027] Compared with the prior art, the advantages of the present invention are: the method for solving the thick and thin printing defects can be applied to different stages of the product without being limited to a certain product, and can be used to verify whether the product has thick and thin printing defects, and to provide a low-cost, comprehensive and acceptable optimal solution for solving the thick and thin printing defects. Attached Figure Description

[0028] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, in which:

[0029] Figure 1 The illustration schematically shows a verification mold with an adjustable thickness ratio insert according to an embodiment of the present invention;

[0030] Figure 2 The illustration schematically shows a verification mold with an adjustable transition length insert according to an embodiment of the present invention;

[0031] Figure 3 The flowchart illustrates a method for resolving the thickness and thinness printing defects according to an embodiment of the present invention.

[0032] In the accompanying drawings, the same parts use the same reference numerals. The drawings are not drawn to scale. Detailed Implementation

[0033] To make the technical solutions and advantages of the present invention clearer, exemplary embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not an exhaustive list of all embodiments. Furthermore, without conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0034] This application provides a verification mold for verifying defects in thick and thin printing. For example... Figure 1 and 2 As shown, the verification mold includes a front mold 1, a rear mold 2, and an insert 3. The front mold 1 and rear mold 2 are the main body of the mold and are fitted together. The rear mold 2 has a mounting groove 21 facing the front mold 1. The insert 3 is positioned at the mounting groove 21 to adaptably change the thickness ratio or transition length of the product structure.

[0035] In one embodiment, the insert 3 includes an insert 31 for adjusting the thickness ratio and an insert 32 for adjusting the transition length.

[0036] like Figure 2 As shown, multiple adjustable transition length inserts 32 are selectively positioned at the mounting groove 21. The chamfers on both sides of the upper end of the adjustable transition length insert 32 characterize the transition length. At least two adjustable transition length inserts 32 have different transition lengths. That is, based on the product's design and production parameters, a suitable adjustable transition length insert 32 is selected and positioned at the mounting groove 21 to produce a pre-defined verification sample. When it is necessary to change the product's design and production parameters to produce verification samples with different transition lengths, simply replacing the adjustable transition length insert 32 is sufficient. For example, the adjustable transition length insert 32 can be constructed as a series, such as with transition ratios of 5 / 1, 10 / 1, 15 / 1, etc. Preferably, the adjustable transition length insert 32 is connected to the rear mold 2 by screws 34 for easy replacement. In use, the screws 34 sequentially pass through the rear mold 2 and the adjustable transition length insert 32 at the mounting groove 21 and are threadedly connected to the adjustable transition length insert 32.

[0037] Multiple thickness ratio adjusting inserts 31, each with varying heights, are used. In operation, these inserts are selectively positioned in the mounting slot 21 to adjust the thickness ratio of the verification sample and verify its impact on thickness markings. To simplify the structure and reduce the number of inserts 31, an ejector mechanism 33 is directly positioned between the insert 31 and the rear mold 2 to adjust the height of the insert. Adjusting the height of the insert allows for adjustment of the thickness ratio of the verification sample. This design simplifies the structure; only one insert 31 is needed to achieve thickness variation, and this variation can be adjusted freely within a certain range, not limited to a fixed value.

[0038] Specifically, the extension mechanism 33 is constructed as an extension screw. This extension screw extends through the wall of the mounting groove 21 towards the thickness adjustment insert 31. The extension screw is threadedly connected to the rear mold 2. Furthermore, the upper end of the extension screw is intermittently inserted into the lower end of the thickness adjustment insert 31. During the tightening of the extension screw, the screw, through its threaded engagement with the rear mold 2, extends or retracts towards the thickness adjustment insert 31, thereby raising or lowering the thickness adjustment insert 31, thus adjusting the thickness difference.

[0039] In production, the mounting groove 21 can be constructed as a through hole. An adjusting thickness ratio insert 31 is disposed in the mounting groove 21. Furthermore, the adjusting thickness ratio insert 31 has a first stepped surface 35, which is distributed opposite to a second stepped surface 22 disposed on the mounting groove 21. During the upward movement of the adjusting thickness ratio insert 31 driven by the ejector screw, the first stepped surface 35 and the second stepped surface 22 abut against each other, limiting the position of the adjusting thickness ratio insert 31. Additionally, a mounting plate 4 is provided at the bottom end of the through hole to block the opening of the through hole away from the front mold 1. This mounting plate 4 is fixedly connected to the rear mold 2. For ease of connection, a third stepped surface 23 is provided on the rear mold 2, and a fourth stepped surface 41 is provided on the mounting plate 4. The third stepped surface 23 and the fourth stepped surface 41 abut against each other for positioning and mounting the mounting plate 4. Thus, the ejector screw passes through the mounting plate 4 and is threadedly connected to it.

[0040] To improve verification efficiency, multiple verification samples are produced at once. Multiple mounting slots 21 are provided on the rear mold 2. Based on the design and production parameters of the product to be verified, appropriate thickness ratio adjusting inserts 31 and / or transition length adjusting inserts 32 are selected and installed one-to-one in the corresponding mounting slots 21. This arrangement ensures that multiple verification samples are produced in a single injection molding process, improving efficiency. For example, if there are four mounting slots 21, four thickness ratio adjusting inserts 31 with different thickness ratios can be installed, or two thickness ratio adjusting inserts 31 with different thickness ratios and two transition length adjusting inserts 32 with different transition lengths can be installed. In short, the number of mounting slots 21 and the corresponding types of inserts 3 can be set according to actual usage requirements.

[0041] Furthermore, the thickness of the main body of the cavity after the front mold 1 and the rear mold 2 are closed can be set to different sizes as needed. For example, the thickness of the main body of the cavity after mold closing can be 1mm, 2mm, 3mm, 10mm, etc. The ratio between the thickness of the thin-walled area formed by the thin-walled insert 31 and the front mold 1 after mold closing and the thickness of the main body of the cavity is the thickness ratio. By setting the structure as needed, the thickness ratio can be 0.2, 0.5, 0.7, 0.9, etc. The above values ​​are only one embodiment, but this application is not limited to this. That is, multiple inserts 3 can be set as needed to change the thickness ratio or transition length of the product mechanism to meet the usage requirements.

[0042] This application also relates to a method for resolving the issue of thick and thin printing defects.

[0043] like Figure 3 As shown, firstly, it is necessary to obtain the product's design and manufacturing parameters. Of course, this product can be a product that has already been manufactured and has thickness variations in the printing process, that is... Figure 3 The production stage. Alternatively, the product could be an unproduced product in the design stage, but with structural design risks related to thickness variations. Figure 3This method is applicable to a wide range of stages, including the design phase. Therefore, it can be used to verify thickness and thinness printing defects at various stages of product development and provide experimental evidence for improving these defects.

[0044] The design and manufacturing parameters of a product include its thickness ratio, transition length, and material parameters. In other words, the presence of thickness-increase defects in a product is primarily determined and influenced by these three factors: the thickness ratio, the transition length, and the material. Understandably, modifying one, two, or all three factors can improve or eliminate thickness-increase defects.

[0045] Secondly, based on the obtained product design and production parameters, a verification product is obtained by using the aforementioned verification mold. Specifically, firstly, the verification mold is adjusted, a suitable insert 3 is selected, and the verification mold is installed on the injection molding machine. Secondly, the front mold 1 and the rear mold 2 are closed to form a cavity. Molten plastic is injected into the cavity of the verification mold. After injection molding is completed, the verification mold is opened, and the formed verification product is removed.

[0046] Next, the presence of uneven printing defects on the verification sample is determined through experience. If no uneven printing defects are found, the risk of uneven printing defects is eliminated, proving that the product's design and manufacturing parameters are feasible. If the verification sample has uneven printing defects, the product's design and manufacturing parameters are modified, and the above steps are repeated until the verification sample is free of uneven printing defects.

[0047] Specifically, if the verification sample exhibits a thickness-to-thickness print defect, one or more of the following parameters can be modified: the product structure's thickness ratio, the transition length of the product structure, and the product's material parameters. The modification of the product's design and manufacturing parameters should be prioritized according to the following order: increasing the product structure's thickness ratio, increasing the product structure's transition length, and decreasing the material's shrinkage rate. If the thickness-to-thickness print defect persists even after reaching the upper limit of the previous level, then the next level of design and manufacturing parameters should be modified. For example, if the verification sample exhibits a thickness-to-thickness print defect, first consider increasing the product structure's thickness ratio, then increasing the product structure's transition length, and finally reducing the material's shrinkage rate. If the product structure's thickness ratio has reached its upper limit and cannot be modified, then consider increasing the product structure's transition length. If neither the product structure's thickness ratio nor the product structure's transition length can be modified, then consider reducing the material's shrinkage rate. In practice, the magnitude of the increase or decrease is determined based on experience. For example, when considering increasing the thickness ratio of a product structure, one can judge from experience whether the thickness difference defect is serious. If it is serious, the thickness ratio can be increased slightly more, for example, from 0.5 to 0.7, within the upper limit. If it is not serious, the thickness ratio can be increased slightly less, for example, from 0.5 to 0.6, within the upper limit.

[0048] Finally, design and production parameters are provided to verify that the sample does not have thickness or thinness defects, in order to guide production.

[0049] The following are several practical production examples that verify and resolve the issue of uneven printing thickness.

[0050] Example 1

[0051] A product is in the design stage with high appearance requirements. Due to shape and functional needs, there is uneven thickness in the structural design. Reviewing the design drawings, the main body wall thickness is 2.6mm, the thickness ratio at key structural points is 0.7, and the transition length is 5mm, posing a risk of uneven thickness marks. The injection molding material is specified as a particular grade of polycarbonate (PC) with a shrinkage rate of approximately 0.55%. To verify whether this product will produce uneven thickness marks, the mold cavity thickness was adjusted to 2.6mm, and an adjusting transition length insert 32 with a 0.7 thickness ratio and 5mm transition length was selected. The specified grade of PC was used for injection molding. After injection molding, no obvious uneven thickness marks were observed on the verification product. Based on the verification results, this product has no risk of uneven thickness marks under the current conditions, and the design is feasible and requires no modification.

[0052] Example 2

[0053] A product is in the design stage with high appearance requirements. Due to shape and functional requirements, there is uneven thickness in the structural design. Reviewing the design drawings, the main body wall thickness is 2.5mm, and the thickness ratio at key structural points is 0.5 with no transition, posing a significant risk of thickness mark defects. The injection molding material has been determined to be a specific polypropylene (PP) material. To verify whether this product will produce thickness mark defects, the mold cavity thickness was adjusted to 2.5mm, and a thickness ratio adjustment insert 31 with a 0.5 thickness ratio and no transition length was selected. Injection molding was performed using the specified grade of PP. After injection molding, observation revealed that due to the high shrinkage rate of this PP and the lack of transition in the abrupt wall thickness areas, obvious thickness mark defects appeared on the verification product. To optimize the thickness difference defect, the thickness ratio in this area was initially increased to 0.7. However, after injection molding, thickness difference marks were still observed on the surface of the verification plastic part. Since the structural design requirements prevented further increases in the thickness ratio, a transition zone was created in the area of ​​abrupt wall thickness changes. The transition lengths were adjusted to 2mm, 5mm, and 7mm. After injection molding, it was observed that the surface of the verification plastic part was better with a transition length of 7mm, and thickness difference marks were almost invisible. For this product, verification revealed a significant risk of thickness difference marks in the original structural design. It is recommended to modify the structure at the local features, specifically increasing the thickness ratio from 0.5 to 0.7 and the transition length from 0 to 7mm, while keeping the material unchanged.

[0054] Example 3

[0055] A product is in the design stage with high appearance requirements. Due to shape and functional needs, there is uneven thickness in the structural design. The design drawings show a main body wall thickness of 3mm, a thickness ratio of 0.7 at key structural points, and a transition length of 5mm, indicating a risk of uneven thickness marks. The injection molding material is not specified. To verify whether this product will produce uneven thickness marks, the mold cavity thickness was adjusted to 3mm, and an adjusting transition length insert 32 with a 0.7-thickness-5mm transition length was selected. Two types of PP with shrinkage rates around 0.8% and 0.6% were selected for injection molding. After injection molding, it was observed that obvious uneven thickness marks appeared on the product when using a material with a shrinkage rate of 0.8%, while the defects were not obvious when using a material with a shrinkage rate of 0.6%. Since the production material for this product is not specified, based on the verification results, it is recommended to use a material with a shrinkage rate below 0.6% for production.

[0056] Example 4

[0057] During the production of a certain product, severe thickness variation defects appeared on the surface. Structural examination revealed significant thickness differences at the defect site, with a thickness ratio as low as 0.4 and no transition. The currently used material is a PC material with a shrinkage rate of around 0.65%. To ensure product functionality, the customer requires no additional transition length and the thickness ratio cannot exceed 0.7. To optimize the thickness variation defect, the thickness ratio on the verification product was initially increased to 0.5 and 0.7. Injection molding with the same material revealed that even with the thickness ratio increased to 0.7, significant thickness variation defects remained. Due to the customer's restrictions on structural modifications, further structural optimization was not possible. Furthermore, injection molding was performed using PC materials with shrinkage rates around 0.55%, 0.6%, and 0.65%. Injection molding showed that the thickness variation defect was better when using shrinkage rates of 0.55% and 0.6%. Based on the verification, it is recommended to modify the structure of the local features, specifically increasing the thickness ratio from 0.5 to 0.7, and switching to a material with a shrinkage rate below 0.6% for injection molding.

[0058] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and / or modifications falling within the scope of the invention, and all changes and / or modifications made according to embodiments of the invention should be covered within the protection scope of the invention.

Claims

1. A method for solving the defect of thick and thin printing, characterized in that, include: Step 1: Obtain the product's design and manufacturing parameters. Step two: Based on the obtained product design and production parameters, a verification sample is produced using a verification mold. Step 3: Determine if the verification sample has a thickness / thickness print defect. If the verification sample has a thickness / thickness print defect, modify the product's design and manufacturing parameters, and repeat steps 1 to 3 until the verification sample is free of thickness / thickness print defects. Step four: Provide the design and production parameters for verifying that the sample does not have thickness or thinness printing defects. In step one, the product's design and manufacturing parameters include the product's thickness ratio, the product's transition length, and the product's material parameters. In step three, if the verification sample has a thickness-to-thickness print defect, one or more of the product's thickness ratio, the product's transition length, and the product's material parameters are modified. The modification of the product's design and manufacturing parameters is prioritized according to the following order: increasing the product's thickness ratio, increasing the product's transition length, and decreasing the product's material shrinkage rate. If the thickness-to-thickness print defect still exists even after the previous level has been modified to its upper limit, the next level of the product's design and manufacturing parameters is then modified.

2. The method for solving the problem of thick and thin printing defects according to claim 1, characterized in that, In step one, the product is either a product that has already been manufactured and has a thickness-to-thickness print defect, or a product that has not been manufactured and is in the design stage but has a risk of thickness-to-thickness print in its structural design.

3. The method for solving the problem of thick and thin printing defects according to claim 1 or 2, characterized in that, In step two, the production process using the verification mold includes: Step one involves adjusting the verification mold to meet the design and production parameters of the obtained product, and then installing the verification mold into the injection molding machine. In step two, an injection molding machine is used to produce a verification product.

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