Thin-wall in-mold label pasting and plastic forming mold with flip cover and forming method of thin-wall in-mold label pasting and plastic forming mold

Abstract

The invention relates to a thin-wall in-mold labeling plastic forming mold with a flip cover and a forming method. The mold comprises a fixed mold body, a movable mold body is arranged on one side of the fixed mold body, and a self-adaptive labeling mechanism is arranged on the inner side of the movable mold body; the self-adaptive labeling device has the beneficial effects that through the self-adaptive labeling mechanism, precise labeling of a labeling body in the injection molding process is achieved, firstly, the labeling body is placed on the surface of an electrostatic plate in advance through a mechanical arm and is preliminarily adsorbed and fixed through tiny adsorption holes of a re-adsorption plate at the negative pressure ranging from-0.03 MPa to-0.05 MPa, then four laser points are started, and the labeling body can be accurately attached to the surface of the electrostatic plate through the mechanical arm; the laser beams correspond to the four positioning points respectively, the positioning points receive feedback signals and then transmit the feedback signals to the central control switch, and if any positioning point does not receive the laser signals, the central control switch automatically triggers the alarm and locks the mold closing action of the mold, so that the mark punching risk caused by deviation of the film pasting position is prevented.

Description

Technical Field

[0001] The invention relates to the technical field of injection molding, in particular to a thin-wall in-mold labeling injection molding die with a flip cover and a molding method. Background Art

[0002] As product packaging and appearance design continue to demand both functionality and aesthetics, in-mold labeling technology is increasingly used in plastic product processing. This technology effectively improves the appearance consistency, wear resistance, and anti-counterfeiting performance of the product by integrating prefabricated labels or decorative films with the plastic melt during the injection molding process. It is widely used in food containers, daily chemical packaging, electronic housings and other fields.

[0003] In the actual implementation process, there are still some problems:

[0004] There are still many technical difficulties in in-mold labeling of thin-walled plastic parts with flip-top structures, such as seasoning boxes, milk powder boxes, and wet wipes lids. On the one hand, thin-walled products require high positioning accuracy of the labeling film, and the film is prone to problems such as shifting, wrinkling, and falling off, especially in the structural area where the flip-top component opens and closes frequently. On the other hand, existing in-mold labeling equipment mostly adopts a fixed labeling structure, lacking the ability to dynamically adjust the film position, making it difficult to adapt to the correction needs of different products or film deviations, resulting in a high rate of defective products such as punched labels and misaligned labels. In addition, most existing labeling methods rely on static adsorption or mechanical positioning, lacking effective real-time feedback and alarm mechanisms, and cannot promptly terminate mold closing and injection molding operations when labeling anomalies occur, thus burying quality risks. Summary of the Invention

[0005] (1) Technical issues to be resolved

[0006] In order to solve the above problems in the prior art, the present invention provides a thin-walled in-mold labeling plastic molding die with a flip cover and a molding method to solve the problems of easy displacement and wrinkling of the film and lack of dynamic adjustment ability of the film position.

[0007] (2) Technical solution

[0008] In order to achieve the above object, the main technical solutions adopted by the present invention are:

[0009] A thin-wall in-mold labeling plastic molding die with a flip cover, comprising a fixed mold body, a movable mold body provided on one side of the fixed mold body, and an adaptive labeling mechanism provided on the inner side of the movable mold body;

[0010] The adaptive labeling mechanism includes an electrostatic plate, a re-absorption plate and a central control switch.

[0011] The adaptive labeling mechanism also includes an alarm, a positioning point, a mounting plate, a laser point, a guide rail 1, a driving slider 1, a connecting plate and a guide rail 2. The backs of the two guide rails 1 are fixedly connected to the mounting plate, and the mounting plate is fixedly connected to the inner wall of the movable mold body.

[0012] 3. A thin-walled in-mold labeling plastic molding mold with a flip-up cover according to claim 1, characterized in that: the front faces of the two guide rails 1 are vertically slidably connected to two driving sliders 1, the front faces of the two driving sliders 1 are fixedly connected to connecting plates, and the inner side of the fixed mold body is provided with a workpiece body with a flip-up cover.

[0013] A second guide rail is fixedly connected between the two connecting plates, and a second driving slider is slidably connected to the inner side of the second guide rail.

[0014] The outer side of the driving slider 1 is fixedly connected to a base, and the middle part of the base is connected to a central control switch.

[0015] The inner side of the base is fixedly connected with a reabsorption plate, the outer side of the reabsorption plate is connected with an electrostatic plate, and the outer side of the electrostatic plate adsorbs the labeling body.

[0016] Four laser points are fixedly connected to the inner side of the base, and four positioning points are connected to the inner side of the fixed mold body. The four positioning points are electrically connected to the central control switch, and the central control switch is electrically connected to the alarm.

[0017] A method for forming a thin-walled in-mold label with a flip cover, applied to the forming mold according to any one of claims 1 to 9, comprising the following steps:

[0018] S1: Pre-positioning, the robot places the labeling body on the surface of the electrostatic plate, starts the microporous adsorption of the re-absorption plate 302, and the adsorption pressure is -0.03 to -0.05 MPa;

[0019] S2: Position calibration, activate the laser point to emit the laser beam. When the positioning point 305 does not receive all the laser signals, the central control switch triggers the alarm and locks the mold closing action;

[0020] S3: Position compensation, which involves adjusting the three-dimensional position of the drive slider 1 and the drive slider 2 until the positioning point feedback signal meets the standard;

[0021] S4: Electrostatic adsorption, applying 10-12kV voltage to make the labeling body 4 close to the mold cavity, holding time 0.5-1s;

[0022] S5: Injection molding, injecting molten plastic at an injection pressure of 60-80MPa, and controlling the melt temperature at 230±5℃;

[0023] S6: Open the mold and take out the part. After a cooling time of 15-20s, the mold is opened and the hinge area is ejected after a delay of 0.3-0.5s.

[0024] In S2, the tolerance thresholds for alignment calibration are: X / Y axis offset ≤ 0.1 mm, angular deviation ≤ 0.5. When the thresholds are exceeded, the central control switch automatically generates a compensation amount and drives sliders 1 and 2 to perform closed-loop adjustment.

[0025] The electrostatic adsorption adopts pulse voltage, and its parameters are:

[0026] Rise time: 100μs, pulse frequency: 50Hz, duty cycle: 30%-70% adjustable

[0027] In S5, the injection speed is controlled in three stages:

[0028] First stage, 0-30% stroke: 40mm / s;

[0029] Second stage, 30-80% stroke: 120 mm / s;

[0030] Stage 3, 80-100% stroke: 60 mm / s.

[0031] (3) Beneficial effects

[0032] The beneficial effect of the present invention is that through the adaptive labeling mechanism, precise attachment of the labeling body during the injection molding process is achieved. First, the labeling body is pre-placed on the surface of the electrostatic plate by a robot, and is initially adsorbed and fixed with a negative pressure of -0.03 to -0.05 MPa through the tiny adsorption holes of the re-absorption plate. Subsequently, four laser points are started, and the laser beams correspond to four positioning points respectively. The positioning points receive feedback signals and transmit them to the central control switch. If any positioning point does not receive a laser signal, the central control switch will automatically trigger the alarm and lock the mold closing action of the mold, thereby preventing the risk of labeling caused by film position offset. Under the alarm prompt, the operator can adjust the driving slider 1 and the driving slider 2 to achieve three-dimensional compensation of the film position along the X direction or Z direction. The adjustment process is closed-loop control. When the positioning point signal meets the set X / Y axis offset ≤0.1mm and angle deviation ≤0.5° accuracy threshold, the central control switch releases the alarm and allows entry to the next process. , After the positioning is completed, the control system applies a 10-12kV high-voltage pulse voltage to the electrostatic plate, with a rising edge time of 100μs, a pulse frequency of 50Hz, and an adjustable duty cycle of 30%-70%, so that the label body fits tightly into the designated position of the mold cavity and is held for 0.5-1s. Then the injection molding process is started, and the molten plastic is injected into the cavity at an injection pressure of 60-80MPa and a temperature of 230±5℃. The three-stage injection speed control 0-30% stroke: 40mm / s, 30-80% stroke: 120mm / s, 80-100% stroke: 60mm / s is adopted to ensure the filling uniformity of the film area and the structural integrity of the product. After the injection molding is completed, the mold is opened after 15-20s of cooling. In particular, in order to ensure the structural integrity of the lid with a flip cover, the hinge area adopts a delayed ejection strategy of 0.3-0.5s to effectively avoid deformation or demolding and tearing problems, ensuring that the final finished product is accurately and firmly filmed and the flip cover functions normally. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the structure of the present invention;

[0034] Figure 2 This is a structural diagram of the fixed mold body of the present invention;

[0035] Figure 3 For the present invention Figure 2 Middle A shows the enlarged picture;

[0036] Figure 4 It is a structural schematic diagram of the mounting plate portion of the present invention;

[0037] Figure 5 For the present invention Figure 4 Enlarged view of point B in the middle;

[0038] Figure 6 A schematic structural diagram of a portion of the guide rail of the present invention;

[0039] Figure 7 It is a schematic flow chart of the molding method of the present invention.

[0040] [Description of Reference Numerals]

[0041] 1. Fixed mold body; 2. Moving mold body; 3. Adaptive labeling mechanism; 301. Alarm; 302. Positioning point; 303. Mounting plate; 304. Laser point; 305. Guide rail 1; 306. Drive slider 1; 307. Connecting plate; 308. Guide rail 2; 309. Drive slider 2; 310. Base; 311. Electrostatic plate; 312. Re-absorption plate; 313. Central control switch; 4. Workpiece body with flip cover; 5. Labeling body. DETAILED DESCRIPTION

[0042] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation methods in conjunction with the accompanying drawings.

[0043] Please refer to Figures 1 to 7 As shown, a thin-walled in-mold labeling plastic molding die with a flip cover and a molding method of the present invention include a fixed mold body 1, a movable mold body 2 is provided on one side of the fixed mold body 1, and an adaptive labeling mechanism 3 is provided on the inner side of the movable mold body 2;

[0044] The adaptive labeling mechanism 3 includes an electrostatic plate 311 , a reabsorption plate 312 and a central control switch 313 . In the actual implementation process, the labeling body 5 is accurately attached during the injection molding process. First, the labeling body 5 is pre-placed on the surface of the electrostatic plate 311 by the robot, and is initially adsorbed and fixed with a negative pressure of -0.03 to -0.05 MPa through the tiny adsorption holes of the re-absorption plate 312. Subsequently, the four laser points 304 are started, and the laser beams correspond to the four positioning points 302 respectively. The positioning points 302 receive feedback signals and transmit them to the central control switch 313. If any positioning point 302 does not receive the laser signal, the central control switch 313 will automatically trigger the alarm 301 and lock the mold closing action, thereby preventing the risk of labeling caused by the offset of the film position. Under the alarm prompt, the operator can adjust the driving slider 1 306 and the driving slider 2 309 to achieve three-dimensional compensation of the film position along the X direction or Z direction. The adjustment process is closed-loop control. When the positioning point 302 signal meets the set accuracy threshold of X / Y axis offset ≤0.1mm and angle deviation ≤0.5°, the central control switch 313 The alarm is released and the next process is allowed. After positioning is completed, the control system applies a 10-12kV high-voltage pulse voltage to the electrostatic plate 311, with a rising edge time of 100μs, a pulse frequency of 50Hz, and an adjustable duty cycle of 30%-70%, so that the labeling body 5 fits tightly in the designated position of the mold cavity. The holding time is 0.5-1s, and then the injection molding process is started. The molten plastic is injected into the cavity at an injection pressure of 60-80MPa and a temperature of 230±5℃, and a three-stage injection speed control is adopted. -30% stroke: 40mm / s, 30-80% stroke: 120mm / s, 80-100% stroke: 60mm / s to ensure filling uniformity and product structural integrity in the film area. After injection molding is completed, the mold is opened after 15-20 seconds of cooling. In particular, to ensure the structural integrity of the lid with a flip cover, the hinge area adopts a delayed ejection strategy of 0.3-0.5s to effectively avoid deformation or tearing during demolding, ensuring that the film of the final product is accurately and firmly applied and the flip cover functions properly.

[0045] Optionally, the adaptive labeling mechanism 3 further includes an alarm 301, a positioning point 302, a mounting plate 303, a laser point 304, a guide rail 1 305, a driving slider 1 306, a connecting plate 307, and a guide rail 2 308. The backs of the two guide rails 1 305 are fixedly connected to the mounting plates 303, which are fixedly connected to the inner wall of the movable mold body 2. In actual implementation, during operation, the laser beams emitted by the laser point 304 are respectively irradiated to the set positioning points 302, and the mounting plates 303 are used to stabilize the position of the entire labeling structure in the mold cavity. When no corresponding laser signal is detected at any positioning point 302, the central control switch 313 will trigger the alarm 301 to issue a warning and stop the mold closing, avoiding the film from deviating and entering the injection molding stage, thereby preventing the generation of defective products. At the same time, the guide rail and slider combination provides an adjustable support structure, which is conducive to the subsequent rapid and accurate compensation of the film position.

[0046] Optionally, two driving sliders 306 are vertically slidably connected to the front surfaces of the two guide rails 305. A connecting plate 307 is fixedly connected to the front surfaces of both driving sliders 306. A workpiece body 4 with a flip-top lid is provided inside the fixed mold body 1. In actual implementation, the driving sliders 306 are adjusted up and down along the vertical direction of the guide rails 305, driving the labeling body 5 to perform fine vertical alignment adjustments. This allows for rapid precision compensation based on positioning errors, effectively improving film application accuracy and consistency while reducing the frequency of manual intervention.

[0047] Optionally, a second guide rail 308 is fixedly connected between the two connecting plates 307, and a second drive slider 309 is slidably connected to the inner side of the second guide rail 308. In actual implementation, the combination of the connecting plates 307 and the second guide rail 308 forms a transverse sliding structure, and the second drive slider 309 can be adjusted horizontally or in the front-to-back direction along the second guide rail 308, thereby achieving flexible adjustment of the labeling mechanism in multiple dimensions, ensuring that the film application position accurately coincides with the mold cavity, and improving the product yield rate.

[0048] Optionally, a base 310 is fixedly connected to the outer side of the driving slider 1 306, and a central control switch is connected to the middle of the base 310. In actual implementation, the base 310 serves as the structural support unit of the labeling mechanism, and the central control switch 313 is integrated and provides a stable fulcrum for various components. The central control switch 313 can adjust its position with the movement of the slider 1, achieving closed-loop adjustment of the film application accuracy and ensuring the linkage stability between the control system and the physical actuator.

[0049] Optionally, a reabsorption plate 312 is fixedly connected to the inner side of the base 310, and an electrostatic plate 311 is connected to the outer side of the reabsorption plate 312. The labeling body 5 is adsorbed to the outer side of the electrostatic plate 311. In actual implementation, when the labeling body 5 is placed on the electrostatic plate 311, the microporous structure in the reabsorption plate 312 can generate uniform adsorption force, preventing problems such as warping and displacement of the label. It provides a basic pre-positioning for subsequent electrostatic adsorption, ensures the initial position of the label is accurate, and improves the overall adhesion quality of the label.

[0050] Optionally, four laser points 304 are fixedly connected to the inner side of the base 310, and four positioning points 302 are connected to the inner side of the fixed mold body 1. The four positioning points 302 are electrically connected to a central control switch 313, which is in turn electrically connected to an alarm 301. In actual implementation, the four laser points 304 and the corresponding positioning points 302 together form an optical alignment system that can detect film deviation information in real time. The central control switch 313 quickly triggers the alarm 301 upon detecting an abnormal signal, effectively preventing product scrapping caused by mislabeling and improving the safety and intelligence level of the equipment.

[0051] Optionally, a method for forming a thin-walled in-mold label with a flip cover, applied to the forming mold of any one of claims 1 to 9, comprises the following steps:

[0052] S1: Pre-positioning, the robot places the labeling body 5 on the surface of the electrostatic plate 311, and starts the microporous adsorption of the re-absorption plate 312302, with an adsorption pressure of -0.03 to -0.05 MPa;

[0053] S2: alignment calibration, activate the laser point 304 to emit the laser beam. When the positioning points 302-305 do not receive all the laser signals, the central control switch 313 triggers the alarm 301 and locks the mold closing action;

[0054] S3: Position compensation, performing three-dimensional position adjustment by driving slider 1 306 and driving slider 2 309 until the feedback signal of positioning point 302 meets the standard;

[0055] S4: Electrostatic adsorption, applying a voltage of 10-12 kV to make the labeling body 54 close to the mold cavity, holding time 0.5-1 s;

[0056] S5: Injection molding, injecting molten plastic at an injection pressure of 60-80MPa, and controlling the melt temperature at 230±5℃;

[0057] S6: Open the mold and remove the part. After a cooling period of 15-20 seconds, the mold is opened, and the hinge area is ejected with a delay of 0.3-0.5 seconds. In actual implementation, this method constructs a complete in-mold labeling process through steps S1 to S6. From pre-adsorption, automatic calibration, position compensation, electrostatic adsorption, injection molding, and delayed ejection, all key processes are automatically controlled. This ensures stable film quality and structural integrity of thin-walled parts, as well as clear formation of the flap area, significantly improving the consistency of the finished product and production efficiency.

[0058] Optionally, in S2, the tolerance thresholds for alignment calibration are: X / Y axis offset ≤ 0.1mm, and angular deviation ≤ 0.5°. When these thresholds are exceeded, central control switch 313 automatically generates compensation and drives slider 1 306 and slider 2 309 to perform closed-loop adjustment. In actual implementation, the high-precision tolerances of ≤ 0.1mm for the X / Y axis and ≤ 0.5° for the angle set during alignment calibration ensure precise alignment between the film and the mold cavity. When these tolerances are exceeded, the control system automatically generates error compensation instructions to drive the sliders for adjustment, forming a closed-loop precision control circuit, effectively implementing automatic deviation correction and reducing human intervention.

[0059] Optionally, electrostatic adsorption uses a pulsed voltage with the following parameters:

[0060] Rise time: 100μs, pulse frequency: 50Hz, duty cycle: 30%-70% adjustable

[0061] In S5, the injection speed is controlled in three stages:

[0062] First stage, 0-30% stroke: 40mm / s;

[0063] Second stage, 30-80% stroke: 120 mm / s;

[0064] The third stage, 80-100% stroke: 60mm / s. In actual implementation, by controlling the rise time and pulse frequency, the electrostatic adsorption strength and uniformity can be adjusted, preventing thermal damage to the film or electrostatic burns, and improving the bonding effect. The injection speed is controlled in three stages to alleviate defects such as bubbles, warping, and loose mold release in thin-walled products during high-speed injection molding, thereby enhancing structural accuracy and film adhesion stability.

[0065] The above shows and describes the basic principles, main features and advantages of the present invention, and the standard parts used in the present invention can be purchased from the market, and special-shaped parts can be customized according to the description in the specification and the drawings. The specific connection methods of each part adopt conventional means such as mature bolts, rivets, welding, etc. in the existing technology. The machinery, parts and equipment all adopt conventional models in the existing technology, and the circuit connection adopts the conventional connection method in the existing technology, which will not be described in detail here.

[0066] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's description and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A thin-walled in-mold labeling mold with a flip cover, comprising a fixed mold body (1), characterized in that: A movable mold body (2) is provided on one side of the fixed mold body (1), and an adaptive labeling mechanism (3) is provided on the inner side of the movable mold body (2); An adaptive labeling mechanism (3) comprises an electrostatic plate (311), a reabsorption plate (312), and a central control switch (313).

2. The thin-wall in-mold labeling mold with a flip cover according to claim 1, characterized in that: The self-adaptive labeling mechanism (3) further comprises an alarm (301), a positioning point (302), a mounting plate (303), a laser point (304), a guide rail 1 (305), a driving slider 1 (306), a connecting plate (307) and a guide rail 2 (308), wherein the back surfaces of the two guide rails 1 (305) are fixedly connected to the mounting plate (303), and the mounting plate (303) is fixedly connected to the inner wall of the movable mold body (2).

3. The thin-wall in-mold labeling mold with a flip cover according to claim 2, characterized in that: The front faces of the two guide rails (305) are vertically slidably connected to two driving sliders (306), and the front faces of the two driving sliders (306) are fixedly connected to connecting plates (307). The inner side of the fixed mold body (1) is provided with a workpiece body (4) with a flip cover.

4. The thin-wall in-mold labeling mold with a flip cover according to claim 3, characterized in that: A second guide rail (308) is fixedly connected between the two connecting plates (307), and a second driving slider (309) is slidably connected to the inner side of the second guide rail (308).

5. The thin-wall in-mold labeling mold with a flip cover according to claim 4, characterized in that: The outer side of the driving slider (306) is fixedly connected to a base (310), and the middle of the base (310) is connected to a central control switch (313).

6. The thin-wall in-mold labeling mold with a flip cover according to claim 5, characterized in that: The inner side of the base (310) is fixedly connected to a reabsorption plate (312), the outer side of the reabsorption plate (312) is connected to an electrostatic plate (311), and the outer side of the electrostatic plate (311) adsorbs a labeling body (5).

7. The thin-wall in-mold labeling mold with a flip cover according to claim 6, characterized in that: Four laser points (304) are fixedly connected to the inner side of the base (310), and four positioning points (302) are connected to the inner side of the fixed mold body (1). The four positioning points (302) are electrically connected to a central control switch (313), and the central control switch (313) is electrically connected to an alarm (301).

8. A method for forming a thin-walled in-mold label with a flip cover, characterized by: The molding die according to any one of claims 1 to 7 comprises the following steps: S1: Pre-positioning, the robot places the labeling body (5) on the surface of the electrostatic plate (311), starts the microporous adsorption of the reabsorption plate (312) 302, and the adsorption pressure is -0.03 to -0.05 MPa; S2: alignment calibration, activating the laser point (304) to emit a laser beam, when the positioning point (302) 305 does not receive all the laser signals, the central control switch (313) triggers the alarm (301) and locks the mold closing action; S3: Position compensation, performing three-dimensional position adjustment by driving slider 1 (306) and driving slider 2 (309) until the feedback signal of the positioning point (302) meets the standard; S4: electrostatic adsorption, applying 10-12kV voltage to make the labeling body (5) 4 close to the mold cavity, holding time 0.5-1s; S5: Injection molding, injecting molten plastic at an injection pressure of 60-80MPa, and controlling the melt temperature at 230±5℃; S6: Open the mold and take out the part. After a cooling time of 15-20s, the mold is opened and the hinge area is ejected after a delay of 0.3-0.5s.

9. The method for forming a thin-walled in-mold label with a flip cover according to claim 8, characterized in that: In S2, the tolerance thresholds of alignment calibration are: X / Y axis offset ≤ 0.1 mm, angle deviation ≤ 0.

5. When the thresholds are exceeded, the central control switch (313) automatically generates a compensation amount and drives the slider 1 (306) and the slider 2 (309) to perform closed-loop adjustment.

10. The method for forming a thin-walled in-mold label with a flip cover according to claim 9, characterized in that: The electrostatic adsorption adopts pulse voltage, and its parameters are: rising edge time: 100μs, pulse frequency: 50Hz, duty cycle: 30%-70% adjustable. In S5, the injection speed adopts three-stage control: First stage, 0-30% stroke: 40mm / s; Second stage, 30-80% stroke: 120 mm / s; Stage 3, 80-100% stroke: 60 mm / s.

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