Test sample strip, detection device and mold

Abstract

The utility model discloses a test sample strip, a detection device and a mould, the test sample strip is used for testing the risk of tiger skin of an injection molding part, the test sample strip is an injection molding part and comprises a body part, and the body part is in a spiral line shape on the cross section perpendicular to the thickness direction of the test sample strip. According to the test sample strip disclosed by the utility model, the test sample strip is the injection-molded part and comprises the body part, and the body part is in the spiral line shape on the cross section perpendicular to the thickness direction of the test sample strip, so that the melt flow on the test sample strip is closer to the flow condition of the part, far away from a sprue gate, in the actual injection-molded part; therefore, the long-distance flowing process of the melt on the mold is simulated more truly, the accuracy of a test result is further improved, the position where the tiger stripes appear is obtained better in a quantified mode, and the risk of tiger stripe defects can be judged in the early stage of product development.

Description

Technical Field

[0001] This utility model relates to the field of vehicle trim testing technology, and in particular to a test strip, testing device and mold. Background Technology

[0002] To improve impact resistance, injection-molded parts such as vehicle bumpers, side skirts, door panels, and dashboards typically incorporate elastomers (e.g., EPDM rubber or polyolefin elastomers) into the material. However, under the combined effects of temperature, humidity, and sunlight in outdoor environments over a long period, the surfaces of these parts develop a pattern of alternating light and dark areas in a rounded shape, resembling tiger stripes, a feature known in the industry as tiger stripes.

[0003] The industry generally believes that tiger-skin patterns are caused by the viscoelasticity of polymer materials. When pressure is released, the volume expands. So when the melt enters the mold gate from the runner, the melt is compressed. When it reaches the part cavity from the gate, the pressure is released and the volume expands immediately, resulting in an expansion jump at the melt front. In particular, the expansion degree of the melt is greater and the jump is more obvious. Moreover, tiger-skin patterns often appear at the far end far from the gate.

[0004] In existing technologies, accelerated aging tests are typically conducted on injection-molded samples to assess the risk of tiger-stripe patterns appearing on the molded parts. However, the test samples are usually dumbbell-shaped or flat, which cannot accurately simulate the long-distance flow of melt on the mold, resulting in significant discrepancies with actual production and leading to certain errors in the test results. Utility Model Content

[0005] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a test strip that more realistically simulates the long-distance flow process of melt on a mold, thereby improving the accuracy of test results, better quantifying the location of tiger-stripe patterns, and enabling the assessment of the risk of tiger-stripe defects in the early stages of product development.

[0006] This invention also proposes a testing device for testing the aforementioned test strips.

[0007] This utility model also proposes a mold for injection molding the above-mentioned test strip.

[0008] According to an embodiment of the present invention, a test strip is used to test the risk of tiger stripe patterns appearing on injection molded parts. The test strip is an injection molded part and includes a body portion, which is spiral-shaped in a cross-section perpendicular to the thickness direction of the test strip.

[0009] According to the test strip of this utility model embodiment, the test strip is an injection molded part and includes a body portion. In a cross-section perpendicular to the thickness direction of the test strip, the body portion is spiral-shaped, making the melt flow on the test strip more closely resemble the flow pattern of the portion far from the gate in an actual injection molded part. This more realistically simulates the long-distance flow process of the melt in the mold, thereby improving the accuracy of the test results and better quantifying the location of tiger-stripe defects. The risk of tiger-stripe defects can be assessed early in product development. Simultaneously, this design achieves a longer flow path within a limited mold, simulating a longer injection channel without increasing the mold size and test chamber size, improving the space utilization efficiency of the mold and effectively reducing testing costs.

[0010] In some embodiments of this utility model, the outer surface of the body portion has a plurality of cleavage points, the plurality of cleavage points are evenly spaced along the length direction of the body portion, and the cleavage points are located on one of the two surfaces opposite each other in the thickness direction of the body portion.

[0011] In some embodiments of this utility model, the distance between two adjacent puncture points is 5mm-20mm.

[0012] In some embodiments of this utility model, the length of the main body is 500mm-1000mm; and / or, the thickness of the main body is 1.8mm-3mm.

[0013] In some embodiments of this utility model, the radius at the midpoint of the width direction of one end of the main body is 18mm-20mm; and / or, the width of the main body is 15mm-20mm; and / or, the distance between any two adjacent spiral rings of the main body is the same.

[0014] In some embodiments of this utility model, it further includes: a gate portion, which is directly connected to one end of the body portion located at the center, wherein the size of the gate portion is a along the width direction of the body portion and the size of one end of the body portion at the center is b, wherein a = 1 / 2b; and / or, the size of the gate portion is c along the thickness direction of the body portion and the size of the body portion is d, wherein c = 2 / 3d.

[0015] According to an embodiment of the present invention, a detection device is used to test the above-mentioned test strip. The detection device includes: a test chamber, in which the test strip is located; and a xenon lamp, which is located in the test chamber and connected to the top wall or side wall of the test chamber.

[0016] The detection device according to an embodiment of this utility model is used to test test strips. The detection device includes a test chamber, inside which the test strip is located. The test chamber provides a closed and controllable environment for the test strip, isolating external interference factors and ensuring the accuracy of the test results. Simultaneously, the spiral design of the main body on the cross-section perpendicular to the thickness direction of the test strip increases the complexity and directional change of the melt flow, making the melt flow on the test strip more closely resemble the flow situation far from the gate in actual injection molded parts. This more realistically simulates the long-distance flow process of the melt on the mold, thereby improving the accuracy of the test results. Furthermore, this setup allows for the simulation of a longer injection runner without increasing the size of the test chamber, effectively reducing testing costs. A xenon lamp located inside the test chamber and connected to the top or side wall of the chamber simulates the lighting conditions in the natural environment, thereby accelerating the aging process of the test strip to assess the risk of tiger-stripe patterns and improve the accuracy of the test results.

[0017] According to an embodiment of the present invention, a mold is used for injection molding the above-mentioned test strip. The mold includes: an upper mold; a lower mold, and a cavity is provided between the lower mold and the upper mold. The cavity is spiral-shaped.

[0018] According to the present invention, a mold is used for injection molding test strips. The mold includes an upper mold and a lower mold, and a cavity is provided between the lower mold and the upper mold. The cavity is spiral-shaped, thereby forming a spiral body. At the same time, the spiral cavity makes the melt flow more closely resemble the flow situation far from the gate in the actual injection molded part, thereby more realistically simulating the long-distance flow process of the melt on the mold, and thus improving the accuracy of the test strip test results.

[0019] In some embodiments of this utility model, at least one of the upper mold and the lower mold has a plurality of protrusions that bulge toward each other or a plurality of recesses that are recessed toward each other.

[0020] In some embodiments of this utility model, at least one of the upper mold and the lower mold has a gating gate communicating with the cavity, and the gating gate is located at one end of the center of the cavity.

[0021] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0023] Figure 1This is a top view of a test strip according to an embodiment of the present invention, wherein the scale points are not shown;

[0024] Figure 2 This is a partial view of the test strip according to an embodiment of the present utility model;

[0025] Figure 3 This is a structural diagram of the mold according to an embodiment of the present utility model;

[0026] Figure 4 This is a cross-sectional view of the mold according to an embodiment of the present utility model.

[0027] Figure label:

[0028] 100. Test spline;

[0029] 1. Body section; 111. Markings; 2. Sprue section;

[0030] 200. Mold;

[0031] 3. Upper mold; 31. Sprue; 4. Lower mold; 5. Cavity; 6. Locating ring; 7. First mounting plate; 8. Second mounting plate; 9. Square iron; 10. Upper ejector plate; 11. Lower ejector plate. Detailed Implementation

[0032] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0033] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this utility model 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 this utility model. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0034] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0035] The test strip 100 according to an embodiment of the present invention is described below with reference to the accompanying drawings.

[0036] like Figure 1 and Figure 2 As shown, the test strip 100 according to the embodiment of the present invention is used to test the risk of tiger stripe pattern on injection molded parts. The test strip 100 is an injection molded part and includes a body part 1. On the cross-section perpendicular to the thickness direction of the test strip 100, the body part 1 is spiral-shaped.

[0037] Therefore, on the cross-section perpendicular to the thickness direction of the test specimen 100, the spiral design of the body part 1 increases the complexity and direction change of the melt flow, making the melt flow on the test specimen 100 closer to the flow situation far from the gate in the actual injection molded part. This more realistically simulates the long-distance flow process of the melt on the mold 200, thereby improving the accuracy of the test results and better quantifying the location of the tiger stripe pattern.

[0038] Meanwhile, since tiger-stripe defects are difficult to resolve through later processes, they are mostly addressed by changing materials. However, changing materials requires redoing material and component verification, incurring significant testing costs and time, which is detrimental to agile vehicle development. Therefore, this application more realistically simulates the long-distance flow of melt on mold 200 to ensure the accuracy of test results. It can identify the risk of tiger-stripe defects early in product development, thereby guiding component design, material selection, process design, and mold 200 design. This allows testing personnel to provide appropriate solutions based on the location of the defects, reducing the verification costs and time associated with material replacement.

[0039] Specifically, the flow length ratio is calculated by dividing the distance from the center end of the body part 1 where the tiger-stripe pattern appears by the thickness of the body part 1. This flow length ratio can be used to assess the risk of tiger-stripe pattern formation during subsequent production. For example, a flow length ratio greater than the center end of the body part 1 indicates a higher risk of tiger-stripe pattern formation. If a part with a flow length ratio greater than the center end needs to be injection molded, adding more gates can help avoid tiger-stripe pattern formation. Conversely, if the distance from the center end of the body part 1 where the tiger-stripe pattern appears is small, it means that the product design and mold design 200 cannot be addressed by adding multiple gates. This indicates that the current injection molding material is unsuitable, and a material change is necessary in the early stages. Furthermore, if no tiger-stripe pattern appears on the entire body part 1, it means that the material is risk-free, and the part design does not require special treatment; it can be designed according to general requirements.

[0040] In addition, this setup enables a longer flow path within the limited mold 200, simulating a longer injection flow channel without increasing the size of the mold 200 and the test chamber, thus improving the space utilization efficiency of the mold 200 and effectively reducing testing costs.

[0041] According to the test strip 100 of this embodiment, the test strip 100 is an injection molded part and includes a body portion 1. In a cross-section perpendicular to the thickness direction of the test strip 100, the body portion 1 is spiral-shaped, making the melt flow on the test strip 100 more closely resemble the flow pattern of the portion far from the gate in an actual injection molded part. This more realistically simulates the long-distance flow process of the melt on the mold 200, thereby improving the accuracy of the test results and better quantifying the location of tiger-stripe defects. The risk of tiger-stripe defects can be assessed early in product development. Simultaneously, this design achieves a longer flow path within the limited mold 200, simulating a longer injection channel without increasing the size of the mold 200 and the test chamber, improving the space utilization efficiency of the mold 200 and effectively reducing testing costs.

[0042] In some embodiments of this utility model, such as Figure 2 As shown, the outer surface of the body part 1 has a plurality of cleavage points 111, which are evenly spaced along the length of the body part 1. Thus, by using the cleavage points 111 on the outer surface of the body part 1 as a reference, the distance where tiger stripes appear can be measured more quickly, and the accuracy and repeatability of the measurement results can be guaranteed. Whether it is manual measurement or machine inspection, precise calibration and comparison can be performed based on the cleavage points 111.

[0043] In some embodiments of this invention, the clef 111 is located on one of the two opposing surfaces of the body portion 1 in the thickness direction. This arrangement facilitates the measurement of the distance where the tiger-stripe pattern appears while reducing the impact of the clef 111 on the body portion 1, allowing the body portion 1 to be better simulated during injection molding and improving overall reliability.

[0044] In some embodiments of this invention, the distance between two adjacent markings 111 is 5mm-20mm. Therefore, by limiting the distance between two adjacent markings 111, it is easier to measure the distance at which tiger stripes appear, thus improving the reliability of the test strip 100. Optionally, the distance between two adjacent markings 111 can be 5mm, 10mm, 15mm, or 20mm.

[0045] In some embodiments of this utility model, the length of the body portion 1 is 500mm-1000mm. It is understood that tiger-stripe patterns often appear at locations far from the pouring gate. By limiting the length of the body portion 1, the risk of tiger-stripe patterns appearing in the test specimen 100 is effectively ensured, improving overall reliability. Optionally, the length of the body portion 1 can be 500mm, 600mm, 700mm, 800mm, 900mm, or 1000mm. It should be noted that the length of the body portion 1 can be measured along its inner diameter, outer diameter, or central axis; this application does not impose any limitations on this.

[0046] In some embodiments of this utility model, the thickness of the body portion 1 is 1.8mm-3mm. It is understood that since a larger thickness of the injection molded part allows for a lower injection pressure and injection speed, a lower injection speed reduces the risk of tiger-stripe patterns. Therefore, the minimum thickness of the body portion 1 is limited to 1.8mm to better simulate the risk of tiger-stripe patterns. Simultaneously, the maximum thickness of the body portion 1 is limited to 3mm to better simulate vehicle injection molded parts, further ensuring the accuracy of the test results using the test strip 100 of this application. Optionally, the thickness of the body portion 1 can be 1.8mm, 2mm, 2.2mm, 2.4mm, 2.6mm, 2.8mm, or 3mm.

[0047] In some embodiments of this utility model, the radius at the midpoint of the width direction of one end of the main body 1 is 18mm-20mm (e.g., Figure 1(as shown in L1). Therefore, this dimensional constraint makes the melt flow on the body 1 more closely resemble the flow pattern of a portion of the injection molded part far from the gate, further simulating the long-distance flow process of the melt on the mold 200 and improving the accuracy of the test results using the test strip 100 of this application. Optionally, the radius at the midpoint in the width direction of one end of the body 1 located at the center is 18 mm, 19 mm, or 20 mm.

[0048] In some embodiments of this utility model, the width of the body portion 1 is 15mm-20mm (e.g., Figure 1 (as shown in L2). This configuration ensures that each spiral ring of the body 1 has the same width, maintaining a consistent flow path and conditions, making it easier to observe and evaluate the appearance of the tiger-stripe pattern. Simultaneously, this dimensional constraint makes the melt flow on the body 1 more closely resemble the flow pattern in an actual injection-molded part away from the gate, further simulating the long-distance flow of the melt on the mold 200 and improving the accuracy of the test results obtained using the test strip 100 of this application. Optionally, the width of the body 1 can be 15mm, 16mm, 17mm, 18mm, 19mm, or 20mm.

[0049] In some embodiments of this invention, the distance between any two adjacent spiral rings of the body portion 1 is the same. This arrangement ensures consistent flow paths and conditions, making it easier to observe and evaluate the appearance of tiger-stripe patterns, further simulating the long-distance flow of melt on the mold 200, and improving the accuracy of test results obtained using the test strip 100 of this application.

[0050] In some embodiments of this utility model, such as Figure 1 and Figure 2 As shown, the test specimen 100 also includes a gate portion 2. The gate portion 2 is directly connected to the central end of the body portion 1. It is understood that, since the test specimen 100 is an injection molded part, the gate portion 2 facilitates the molten material entering the cavity 5 of the mold 200 and filling the cavity 5 to form the body portion 1, thus improving reliability.

[0051] In some embodiments of this utility model, such as Figure 1As shown, along the width direction of the body portion 1, the size of the gate portion 2 is 'a', and the size of one end of the center of the body portion 1 is 'b', where a = 1 / 2b. It can be understood that when the melt enters the gate of the mold 200 from the runner, the melt is compressed. When it reaches the part cavity 5 from the gate, the pressure is released, and volume expansion occurs immediately, resulting in a tiger-skin pattern on the injection molded part. Therefore, by limiting the size of one end of the body portion 1 to twice the size of the gate portion 2 along the width direction of the body portion 1, the long-distance flow process of the melt on the mold 200 is better simulated, improving the accuracy of the test results using the test strip 100 of this application. Optionally, the size of the gate portion 2 along the width direction of the body portion 1 is 6.7 mm.

[0052] In some embodiments of this invention, the size of the gate portion 2 is c along the thickness direction of the body portion 1, and the size of the body portion 1 is d, where c = 2 / 3d. It is understood that when the melt enters the gate of the mold 200 from the runner, the melt is compressed. When it reaches the part cavity 5 from the gate, the pressure is released, and volume expansion occurs immediately, resulting in a tiger-skin pattern on the injection molded part. Therefore, by limiting the sizes of the body portion 1 and the gate portion 2 along the thickness direction of the body portion 1, the long-distance flow process of the melt on the mold 200 is better simulated, improving the accuracy of the test results obtained using the test strip 100 of this application. Optionally, the size of the gate portion 2 along the thickness direction of the body portion 1 is 1.6 mm.

[0053] The following is for reference. Figure 1 and Figure 2 The test strip 100 of a specific embodiment of the present utility model is described in detail below. It should be understood that the following description is merely illustrative and should not be construed as a limitation of the utility model.

[0054] The test specimen 100 is an injection molded part and includes a body part 1. On the cross section perpendicular to the thickness direction of the test specimen 100, the body part 1 is helical. The outer surface of the body part 1 has a plurality of cleavage points 111. The plurality of cleavage points 111 are evenly spaced along the length direction of the body part 1. The cleavage points 111 are located on one of the two surfaces opposite each other in the thickness direction of the body part 1. The distance between any two adjacent helical rings of the body part 1 is the same.

[0055] Therefore, by using a spiral shape for the body part 1, the melt flow on the test specimen 100 more closely resembles the flow pattern of the portion of the injection molded part far from the gate. This more realistically simulates the long-distance flow process of the melt on the mold 200, thereby improving the accuracy of the test results and better quantifying the location of the tiger-stripe pattern. The risk of tiger-stripe defects can be assessed early in product development. Simultaneously, using the mark 111 as a reference point allows for faster measurement of the distance where the tiger-stripe pattern appears, while ensuring the accuracy and repeatability of the measurement results.

[0056] The detection device according to an embodiment of the present invention is described below.

[0057] The detection device according to an embodiment of the present invention is used to test the test strip 100. The detection device includes a test chamber and a xenon lamp. The test strip 100 is located inside the test chamber, and the xenon lamp is located inside the test chamber and connected to the top or side wall of the test chamber.

[0058] Understandably, the test chamber provides a closed and controllable environment for the test specimen 100 to isolate external interference factors and ensure the accuracy of test results. At the same time, the parameters such as temperature, humidity and pressure inside the test chamber can be adjusted and controlled according to test requirements, so that the injection-molded test specimen can be tested through artificial accelerated aging experiments to simulate the risk of tiger stripe pattern appearing on the test specimen 100.

[0059] Meanwhile, the spiral design of the body 1 on the cross-section perpendicular to the thickness direction of the test specimen 100 increases the complexity and directional variation of the melt flow, making the melt flow on the test specimen 100 closer to the flow situation far from the gate in an actual injection molded part. This more realistically simulates the long-distance flow process of the melt on the mold 200, thereby improving the accuracy of the test results. In addition, this setting allows for the simulation of longer injection channels without increasing the size of the test chamber, effectively reducing testing costs.

[0060] Understandably, the xenon lamp accelerated aging method is based on the principle of photochemical reaction. It accelerates the aging process of test specimen 100 by simulating the spectral components of sunlight, such as ultraviolet, visible, and infrared light, and by controlling environmental parameters such as temperature and humidity. This method can simulate the aging process experienced by test specimen 100 under prolonged exposure in a natural environment in a short time, thereby rapidly assessing its performance changes. Therefore, by simulating the lighting conditions in a natural environment using a xenon lamp located inside the test chamber, the aging process of test specimen 100 is accelerated to assess the risk of tiger-skin pattern formation and improve the accuracy of test results.

[0061] Specifically, this application can test the interior and exterior parts of a vehicle. The test conditions for the irradiation test of the interior parts are shown in Table 1, and the test conditions for the irradiation test of the interior and exterior parts are shown in Table 2. The cumulative irradiance of the interior materials is 1250 KJ / ㎡, and the cumulative irradiance of the exterior materials is 2900 KJ / ㎡.

[0062] Table 1 Irradiation Tests of Interior Materials

[0063]

[0064] Table 2 Irradiation Tests of Exterior Materials

[0065]

[0066] It should be noted that the testing device and operation according to the embodiments of this utility model are known to those skilled in the art, and will not be described in detail here.

[0067] According to an embodiment of this utility model, the testing device is used to test the test sample 100. The testing device includes a test chamber, inside which the test sample 100 is located. The test chamber provides a closed and controllable environment for the test sample 100, isolating external interference factors and ensuring the accuracy of the test results. Simultaneously, the spiral design of the body part 1 on the cross-section perpendicular to the thickness direction of the test sample 100 increases the complexity and direction change of the melt flow, making the melt flow on the test sample 100 more closely resemble the flow situation far from the gate in actual injection molded parts. This more realistically simulates the long-distance flow process of the melt on the mold 200, thereby improving the accuracy of the test results. Furthermore, this setup allows for the simulation of a longer injection runner without increasing the size of the test chamber, effectively reducing testing costs. A xenon lamp located inside the test chamber and connected to the top or side wall of the test chamber simulates the lighting conditions in the natural environment, thereby accelerating the aging process of the test sample 100 to assess the risk of tiger-skin pattern formation and improve the accuracy of the test results.

[0068] The mold 200 of this utility model embodiment is described below.

[0069] According to the mold 200 of this utility model embodiment, such as Figures 1-4 As shown, the injection molding test specimen 100 is used. The mold 200 includes an upper mold 3 and a lower mold 4, with a cavity 5 between the lower mold 4 and the upper mold 3. The cavity 5 is spiral-shaped. Thus, through the spiral cavity 5 between the lower mold 4 and the upper mold 3, the melt fills the cavity 5 to form a spiral body part 1. Simultaneously, the spiral cavity 5 makes the melt flow more closely resemble the flow pattern far from the gate in actual injection molded parts, thereby more realistically simulating the long-distance flow process of the melt on the mold 200, improving the accuracy of the test results of the test specimen 100, and better quantifying the location of the tiger-stripe pattern.

[0070] According to the embodiment of this utility model, the mold 200 is used for injection molding test strip 100. The mold 200 includes an upper mold 3 and a lower mold 4. A cavity 5 is provided between the lower mold 4 and the upper mold 3. The cavity 5 is spiral-shaped, thereby forming a spiral body part 1. At the same time, the spiral cavity 5 makes the melt flow closer to the flow situation far away from the gate in the actual injection molded part, thereby more realistically simulating the long-distance flow process of the melt on the mold 200, and thus improving the accuracy of the test results of the test strip 100.

[0071] In some embodiments of this invention, at least one of the upper mold 3 and the lower mold 4 has a plurality of protrusions protruding toward each other or a plurality of recesses recessed toward the opposite direction. Thus, by having at least one of the upper mold 3 and the lower mold 4 with a plurality of protrusions protruding toward each other, a recessed portion corresponding to the protrusion is formed on the outer surface of the body part 1, thereby forming a clef 111 on the outer surface of the body part 1. Alternatively, by having at least one of the upper mold 3 and the lower mold 4 with a plurality of recessed portions recessed toward the opposite direction, a protrusion corresponding to the recess is formed on the outer surface of the body part 1, thereby forming a clef 111 on the outer surface of the body part 1. Furthermore, using the clef 111 as a reference, the distance at which the tiger stripe pattern appears can be measured more quickly.

[0072] In some embodiments of this utility model, such as Figures 1-4 As shown, at least one of the upper mold 3 and the lower mold 4 has a gating gate 31 that communicates with the cavity 5, and the gating gate 31 is located at one end of the center of the cavity 5. Thus, the melt enters the cavity 5 through the gating gate and flows outward from one end of the center of the cavity 5 in a spiral shape to form the spiral body part 1.

[0073] In some embodiments, such as Figure 3 and Figure 4 As shown, the mold 200 also includes a positioning ring 6, a first mounting plate 7, a second mounting plate 8, a square iron 9, an upper ejector plate 10, and a lower ejector plate 11. The upper mold 3 200 has a sprue 31 communicating with the cavity 5. The first mounting plate 7 is stacked on top of the upper mold 3 and is used to mount the mold 200 onto the injection molding machine. The second mounting plate 8 is located below the lower mold 4 and is used to mount the mold 200 onto the injection molding machine. The lower mold 4 and the second mounting plate 8 are spaced apart and connected by the square iron 9. The upper ejector plate 10 and the lower ejector plate 11 are stacked on top of the second mounting plate 8. The upper ejector pin of the upper ejector plate 10 and the lower ejector pin of the lower ejector plate 11 are used to eject the test strip 100 from the cavity 5. The positioning ring 6 is located above the first mounting plate 7 and is used for positioning with the injection molding machine.

[0074] It should be noted that other components of the mold 200 according to the present invention, such as the positioning ring 6, the first mounting plate 7, the second mounting plate 8, the square iron 9, the upper ejector plate 10, the lower ejector plate 11, etc., and their operation are known to those skilled in the art and will not be described in detail here.

[0075] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0076] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A test strip for testing the risk of tiger-stripe patterns appearing on injection-molded parts, characterized in that, The test strip is an injection-molded part and includes: The body portion is helical in cross-section perpendicular to the thickness direction of the test strip. The outer surface of the body portion has multiple cleavage points, which are evenly spaced along the length direction of the body portion. The cleavage points are located on one of the two surfaces opposite each other in the thickness direction of the body portion.

2. The test strip according to claim 1, characterized in that, The distance between two adjacent markings is 5mm-20mm.

3. The test strip according to claim 1, characterized in that, The length of the main body is 500mm-1000mm; And / or, the thickness of the body portion is 1.8mm-3mm.

4. The test strip according to claim 1, characterized in that, The radius of the body portion at the midpoint of its width direction at one end located at the center is 18mm-20mm; And / or, the width of the body portion is 15mm-20mm; And / or, the distance between any two adjacent spiral rings of the body portion is the same.

5. The test strip according to claim 1, characterized in that, Also includes: The gate is directly connected to the central end of the body. Along the width direction of the body, the size of the gate is a, and the size of the central end of the body is b, where a = 1 / 2b. And / or, along the thickness direction of the body portion, the size of the gate portion is c, and the size of the body portion is d, where c = 2 / 3d.

6. A detection device, characterized in that, The detection device is used for testing the test strip according to any one of claims 1-5, and comprises: The test chamber contains the test strip. A xenon lamp, which is located inside the test chamber and connected to the top or side wall of the test chamber.

7. A mold, characterized in that, The mold for injection molding test specimens according to any one of claims 1-5 comprises: upper mold; The lower mold has a cavity between it and the upper mold, and the cavity is spiral-shaped.

8. The mold according to claim 7, characterized in that, At least one of the upper mold and the lower mold has a plurality of protrusions that bulge toward each other or a plurality of recesses that are recessed toward each other.

9. The mold according to claim 7, characterized in that, At least one of the upper mold and the lower mold has a gating gate communicating with the cavity, the gating gate being located at one end of the center of the cavity.

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