A mold structure to prevent plastic sealant overflow

Abstract

This utility model relates to the field of plastic sealing process, and relates to a mold structure for preventing plastic sealing overflow. The utility model includes: a base, a lower template, a middle template, and an upper template. A heating plate is provided on the upper surface of the base. The lower template, middle template, and upper template are arranged sequentially upwards in a stepped shape. A high-temperature resistant sealing strip is provided around the bottom of each of the lower template, middle template, and upper template. A temperature controller is connected to the heating plate via a wire. A temperature sensor is connected to one side of the temperature controller via a wire. The temperature sensor is located on both sides of the base and close to the upper template. An annular groove is provided on the outer side of the middle part of the upper template. A T-shaped adhesive suction tube is connected inside the annular groove. A conduit is connected to the lower end of the T-shaped adhesive suction tube. The conduit passes sequentially through the upper template, middle template, lower template, heating plate, and base to the outside and is connected to a vacuum pump. A glue storage tank is connected to one side of the vacuum pump.

Description

Technical Field

[0001] The utility model relates to the field of plastic encapsulation technology, and relates to a mold structure for preventing plastic encapsulation overflow glue. Background Art

[0002] In the current Molding plastic encapsulation process, overflow glue is a key defect affecting product quality and production efficiency. The specific manifestations are as follows: during high-pressure injection of plastic encapsulation material, it is easy to overflow from the mold parting surface, resulting in product size deviation. Additional post-processing procedures such as manual glue repair are required, which not only reduces production efficiency but may also damage the product surface due to glue repair. Traditional solutions rely on increasing the clamping force, which will exacerbate mold wear, shorten the mold life, and have limited anti-overflow effect on high-viscosity plastic encapsulation materials. In addition, the existing mold structure has insufficient adaptability to the viscosity change of plastic encapsulation materials and the injection pressure fluctuation, and it is difficult to meet the requirements of different product sizes and material characteristics. Summary of the Utility Model

[0003] The utility model provides a mold structure for preventing plastic encapsulation overflow glue to solve the problems of the prior art.

[0004] The purpose of the utility model can be achieved by the following technical solutions: a mold structure for preventing plastic encapsulation overflow glue includes: a base, a lower template, a middle template, and an upper template. A heating bottom plate is provided on the upper end surface of the base. The lower template, the middle template, and the upper template are arranged upward in sequence and are in a stepped shape. High-temperature resistant sealing rubber strips are annularly arranged at the bottoms of the lower template, the middle template, and the upper template. The heating bottom plate is connected to a temperature controller through a wire. One side of the temperature controller is connected to a temperature sensor through a wire. The temperature sensor is arranged on both sides of the base and is close to the upper template. An annular groove is provided on the outer side of the middle part of the upper template. A T-shaped glue suction pipe is connected inside the annular groove. The lower end of the T-shaped glue suction pipe is connected to a conduit. The conduit passes through the upper template, the middle template, the lower template, the heating plate, and the base to the outside and is connected to a vacuum pump. A glue storage tank is connected to one side of the vacuum pump.

[0005] For further improvement, slot holes one with non-through bottoms are spacedly provided at the upper end of the lower template, slot holes two that are through are spacedly provided in the middle template, and slot holes three with non-through tops are spacedly provided at the lower end of the upper template. The slot holes one, the slot holes two, and the slot holes three are sequentially connected and provided with hydraulic buffer plungers inside. The bottom of the hydraulic buffer plunger is connected to the lower template and the top is connected to the upper template.

[0006] For further improvement, the high-temperature resistant sealing rubber strip includes rubber strip one, rubber strip two, and rubber strip three. The cross-sections of the rubber strip one, the rubber strip two, and the rubber strip three are all in the shape of a "mountain".

[0007] In a further improvement, the first ring of the adhesive strip is fixed to the lower end of the lower template and the lower end face of the adhesive strip is attached to the upper end face of the heating base plate; the second ring of the adhesive strip is fixed to the lower end of the middle template and the lower end face of the second adhesive strip is attached to the upper end face of the lower template; and the third ring of the adhesive strip is fixed to the lower end of the upper template and the lower end face of the third adhesive strip is attached to the upper end face of the middle template.

[0008] Compared with existing technologies, the beneficial effects of this utility model's mold structure for preventing plastic sealant overflow are as follows:

[0009] The mold employs a stepped labyrinth structure design with lower, middle, and upper mold plates, creating a multi-level turning path to increase resistance to molded material overflow and achieve a primary seal, blocking most of the excess material. Each mold plate has a high-temperature resistant silicone sealing strip embedded at its bottom in a "mountain" shaped cross-section. Under pressure, this strip expands laterally to fill gaps, forming a secondary seal with an elastic buffer layer. This adapts to mold wear or temperature fluctuations, enhancing sealing reliability. An annular groove on the outer side of the upper mold plate connects to a vacuum adsorption system. A vacuum pump generates negative pressure to promptly remove any trace amounts of molded material that may overflow, preventing overflow accumulation from affecting mold closing accuracy and keeping the mold clean. Temperature sensors at the mold edge, working in conjunction with a temperature controller, regulate the temperature of the heating base plate, precisely adjusting the viscosity of the molded material to improve flowability and accommodate different material processing requirements. A hydraulic buffer plunger forms a pressure compensation mechanism that automatically adjusts the sealing pressure based on the injection pressure, reducing the required mold closing force, preventing mold deformation, and extending mold life. Attached Figure Description

[0010] Figure 1 This is a structural schematic diagram of the present invention.

[0011] Figure 2 This is a schematic diagram of the upper template and adhesive strip three in this utility model.

[0012] In the diagram, 1-base, 11-heating base plate, 12-temperature controller, 13-temperature sensor, 2-lower template, 21-slot one, 3-middle template, 31-slot two, 4-upper template, 41-annular groove, 42-T-shaped adhesive suction tube, 43-conduit tube, 44-slot three, 5-high temperature resistant sealing strip, 51-strip one, 52-strip two, 53-strip three, 6-adhesive storage tank, 7-hydraulic buffer plunger, 8-vacuum pump. Detailed Implementation

[0013] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing 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; unless otherwise expressly specified and limited, the terms "installed," "connected," and "joined" should be interpreted broadly, for example, they can refer to fixed connections or detachable connections, etc. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0014] The following is a description of the embodiments and appendices. Figures 1-2 The technical solution of this utility model will be further described below.

[0015] Example 1

[0016] A mold structure for preventing plastic sealant overflow includes: a base 1, a lower template 2, a middle template 3, and an upper template 4. The upper surface of the base 1 is provided with a heating plate 11. The lower template 2, the middle template 3, and the upper template 4 are arranged sequentially upwards in a stepped manner. The bottom of the lower template 2, the middle template 3, and the upper template 4 are all surrounded by high-temperature resistant sealing strips 5. The heating plate 11 is connected to a temperature controller 12 via wires. One side of the temperature controller 12 is connected to a temperature sensor 13 via wires. The temperature sensor 13 is located on both sides of the base 1 and close to the upper template 4. The outer side of the middle part of the upper template 4 is provided with an annular groove 41. A T-shaped adhesive suction tube 42 is connected inside the annular groove 41. The lower end of the T-shaped adhesive suction tube 42 is connected to a conduit 43. The conduit 43 passes through the upper template 4, the middle template 3, the lower template 2, the heating plate 11, and the base 1 to the outside and is connected to a vacuum pump 8. One side of the vacuum pump 8 is connected to an adhesive storage tank 6.

[0017] like Figures 1-2 As shown, the mold structure of this utility model consists of a base, a lower template, a middle template, and an upper template stacked in a stepped manner. Each template has a "mountain"-shaped high-temperature resistant sealing strip around its bottom. The heating base plate controls the edge temperature through a temperature controller and a temperature sensor. The outer annular groove of the upper template is connected to a vacuum adsorption system (T-shaped adhesive suction tube, conduit, vacuum pump, and adhesive storage tank).

[0018] Stepped labyrinth seal (one-time seal): The stepped design of the lower mold, middle mold, and upper mold forms a multi-level parting surface. When the molding compound overflows from the cavity to the outside, it has to go through multiple turning paths (similar to a labyrinth), which significantly increases the flow resistance and makes it difficult for the molding compound to directly break through the sealing interface under high pressure.

[0019] Dynamic sealing with elastic rubber strips (secondary sealing): The high-temperature resistant rubber strips (strip one, strip two, and strip three) with a "mountain" shaped cross-section expand laterally under pressure during mold closing, filling the tiny gaps between the mold plates. The elastic deformation capacity of the rubber strips allows them to adapt to dimensional fluctuations caused by slight mold wear or temperature changes, forming a dynamic sealing barrier to prevent the molding compound from overflowing from the mold plate contact surface.

[0020] Vacuum adsorption anti-overflow (active recovery): After the vacuum pump is started, a negative pressure of -0.05 to -0.08 MPa is formed in the annular groove. If the molding compound breaks through the first two sealing barriers, a small amount of overflow will be sucked into the storage tank in time by the T-shaped suction tube, avoiding the accumulation of overflow on the parting surface and affecting the subsequent mold closing accuracy, while keeping the mold clean.

[0021] Edge temperature control adjusts viscosity: A temperature sensor monitors the mold edge temperature in real time, and the temperature controller automatically adjusts the heating plate power to keep the temperature within ±2℃ of the set value. This allows for adjusting the viscosity of the molding compound by either increasing the temperature (to facilitate filling) or decreasing the temperature (to suppress overflow), thus matching the process requirements of different materials.

[0022] The stepped seal combined with the elastic sealant strip can block more than 99% of excess adhesive, significantly reducing the product dimensional deviation rate. Through the synergistic effect of the temperature control system and vacuum adsorption, it is compatible with low viscosity (such as epoxy resin with good flowability) and high viscosity molding compound, without the need for frequent adjustment of mold parameters. It reduces the post-processing and repair process, shortening the single mold production cycle by 10%-15%. At the same time, the vacuum system automatically recovers excess material, reducing material waste.

[0023] As a further preferred embodiment, the lower template 2 is provided with a slot 21 at the upper end that is not through at the bottom, the middle template 3 is provided with a slot 31 that is through at the bottom, and the upper template 4 is provided with a slot 44 at the lower end that is not through at the top. The slots 21, 31 and 44 are connected in sequence and are provided with a hydraulic buffer plunger 7 inside. The bottom of the hydraulic buffer plunger 7 is connected to the lower template 2 and the top is connected to the upper template 4.

[0024] During mold closing, the upper mold plate presses down, causing the plunger to compress the hydraulic oil in the slot, creating an elastic support force. During injection, when the molding compound is pushed against the upper mold plate under high pressure, the plunger automatically adjusts the sealing pressure through the buffering effect of the hydraulic oil (the pressure range is adjustable according to the viscosity of the hydraulic oil and the cross-sectional area of ​​the plunger), offsetting part of the injection pressure and preventing mold deformation or excessive wear of the molding strip due to excessive mold closing force. This reduces the fixed mold closing force required to resist injection pressure in traditional processes, reduces wear on key mold components (such as parting surfaces and guide pillars), and extends their lifespan by more than 30%. The sealing force can be adjusted in real time according to the injection pressure, making it particularly suitable for high-pressure, rapid injection processes and preventing overflow caused by pressure fluctuations.

[0025] As a further preferred embodiment, the high-temperature resistant sealing strip 5 includes strip 1 51, strip 2 52, and strip 3 53, all of which have a "mountain" shaped cross-section. Strip 1 51 is circumferentially fixed to the lower end of the lower template 2, with its lower end face adhering to the upper end face of the heating base plate 11. Strip 2 52 is circumferentially fixed to the lower end of the middle template 3, with its lower end face adhering to the upper end face of the lower template 2. Strip 3 53 is circumferentially fixed to the lower end of the upper template 4, with its lower end face adhering to the upper end face of the middle template 3.

[0026] When subjected to pressure, the "mountain" shaped structure expands horizontally on both sides, forming multiple sealing lips (similar to the multi-lip structure of a mechanical seal). Compared to traditional rectangular rubber strips, it has a larger contact area and a longer sealing path. The rubber strip is made of high-temperature resistant silicone material (temperature resistance up to 180-220℃), which maintains elasticity during the curing process of the molding compound, preventing loss of sealing effect due to high-temperature hardening.

[0027] Multiple expansion lips can effectively prevent the molding compound from seeping through the mold gaps, especially for low-viscosity molding compounds (such as those with high fluidity at the initial injection stage) to prevent overflow; the "mountain" shaped rubber strip has a large amount of compression deformation, which can compensate for the mold processing accuracy error (such as flatness deviation ≤0.05mm) and reduce the difficulty of mold assembly.

[0028] The preferred embodiments of this utility model have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of this utility model without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of this utility model through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A mold structure for preventing plastic sealant overflow, characterized in that, include: The system comprises a base, a lower template, a middle template, and an upper template. The upper surface of the base is equipped with a heating plate. The lower, middle, and upper templates are arranged sequentially upwards in a stepped manner. The bottom of each of the lower, middle, and upper templates is surrounded by a high-temperature resistant sealing strip. The heating plate is connected to a thermostat via wires. A temperature sensor is connected to one side of the thermostat via wires. The temperature sensor is located on both sides of the base, close to the upper template. An annular groove is provided on the outer side of the middle of the upper template. A T-shaped adhesive suction tube is connected inside the annular groove. The lower end of the T-shaped adhesive suction tube is connected to a conduit. The conduit passes sequentially through the upper template, middle template, lower template, heating plate, and base to the outside and is connected to a vacuum pump. A glue storage tank is connected to one side of the vacuum pump.

2. The mold structure for preventing plastic sealant overflow according to claim 1, characterized in that, The lower template has a slot 1 that is not through at the bottom, spaced at the upper end; the middle template has a slot 2 that is through at the bottom, spaced at the bottom; and the upper template has a slot 3 that is not through at the top, spaced at the lower end. The slots 1, 2, and 3 are connected in sequence and have a hydraulic buffer plunger inside. The bottom of the hydraulic buffer plunger is connected to the lower template and the top is connected to the upper template.

3. The mold structure for preventing plastic sealant overflow according to claim 1, characterized in that, The high-temperature resistant sealing strip includes strip one, strip two, and strip three, and the cross-sections of strip one, strip two, and strip three are all "mountain" shaped.

4. The mold structure for preventing plastic sealant overflow according to claim 3, characterized in that, The first ring of the adhesive strip is fixed to the lower end of the lower template, and the lower end face of the adhesive strip is attached to the upper end face of the heating base plate. The second ring of the adhesive strip is fixed to the lower end of the middle template, and the lower end face of the second adhesive strip is attached to the upper end face of the lower template. The third ring of the adhesive strip is fixed to the lower end of the upper template, and the lower end face of the third adhesive strip is attached to the upper end face of the middle template.

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