A vacuum forming cavity for a foam packaging box

Abstract

The utility model relates to the field of foam box mould, specifically relates to a kind of foam packaging box vacuum forming cavity, comprising: forming mould and be equipped with several forming chambers on the forming mould, and the inner wall of each forming chamber is opened several mounting holes;Detachable installation is arranged on the exhaust joint of the mounting hole, and it is opened exhaust hole near forming chamber one end.This utility model is by spring, limiting piece, hinged rod and plugging block inside the exhaust joint setting automatic plugging mechanism, realized the automatic opening of exhaust hole when steam injection and automatic closing when stopping steam supply.The mechanism can cut off the connection of mould cavity and exhaust passage in the moment when steam stops conveying, fundamentally avoid the residual pressure in mould cavity to melt material of EPS bead reverse " flush " and " extrusion " into the inside of exhaust hole, solve the exhaust hole blockage problem caused by melt material solidification accumulation.

Description

Technical Field

[0001] This utility model relates to the field of foam box molds, and in particular to a vacuum forming cavity for foam packaging boxes. Background Technology

[0002] Foam packaging boxes, especially those made of expandable polystyrene (EPS), are widely used in logistics and transportation in industries such as food, pharmaceuticals, and electronics due to their excellent cushioning, insulation, and lightweight properties. The mainstream production process is steam heating molding, which involves filling pre-expanded EPS beads into a mold with a specific cavity using a vacuum forming chamber. Steam heating further expands and fuses the beads, which are then cooled and solidified. During this molding process, numerous micro-venting holes (or "steam holes") need to be created on the walls of the molding cavity of the mold. The main function of these venting holes is to act as steam channels, allowing steam to penetrate the entire mold cavity evenly and rapidly, ensuring that the EPS beads are fully heated and melted. However, the existing venting method presents a significant technical challenge. During the steam injection stage, high-pressure steam carries the molten material from the EPS beads through these tiny vent holes. When the steam supply suddenly stops, the residual pressure within the mold cavity and the expansion force of the beads themselves cause the incompletely solidified molten material to be "flushed" and "squeezed" back into the vent holes. These residues solidify after cooling within the channels, forming solid blockages. With repeated molding cycles, this blockage accumulates and worsens, eventually completely clogging the vent holes. This affects the uniformity of steam penetration in subsequent production processes, leading to quality defects such as localized defects in the product. Furthermore, the blockage reduces production efficiency and mold lifespan. Utility Model Content

[0003] In view of this, the purpose of this utility model is to propose a vacuum forming cavity for foam packaging boxes to solve the technical problems in the prior art.

[0004] To achieve the above objectives, this utility model provides a vacuum forming cavity for a foam packaging box, comprising: The molding die and several molding cavities provided on the molding die, each molding cavity having several mounting holes on its inner wall; A vent connector that can be detachably installed on the mounting hole has a vent hole at the end near the molding chamber; A connecting ring is fixed to the inner wall of the exhaust connector and is located on the side of the exhaust connector away from the exhaust hole; A positioning member fixed to the inner wall of the exhaust connector has a through hole in its middle. The middle part of the positioning member moves through the through hole to pass through a limiting member, and one end of the positioning member rests on the inner ring of the connecting ring. A spring fitted onto the limiting member, with its two ends respectively fixed to one end surface of the limiting member and one side of the positioning member; At least one hinge rod is hinged to the other end of the limiting member, and a sealing block is hinged to one end of the hinge rod. The sealing block is slidably installed on one side of the inner wall of the exhaust connector near the exhaust hole to block the exhaust hole.

[0005] Preferably, the inner wall of the mounting hole is provided with an internal thread, and the surface of one end of the exhaust connector is provided with an external thread that mates with the internal thread. The exhaust connector is detachably installed on the mounting hole by means of a threaded connection.

[0006] Preferably, a hexagonal fastening ring is fixed to the outer peripheral wall of the exhaust connector at the end away from the exhaust hole, and a sealing ring is fitted on the outer peripheral wall of the exhaust connector, with one side of the sealing ring overlapping one side of the hexagonal fastening ring.

[0007] Preferably, the limiting member includes a tapered portion and a movable rod fixedly connected to one side of the tapered portion. The tapered portion overlaps the inner ring of the connecting ring. The movable rod passes through a through hole in the middle of the positioning member. A limiting ring is fixedly connected to one end of the movable rod away from the tapered portion. The end of the hinged rod is hinged to the limiting ring. The spring is sleeved on the outer peripheral wall of the movable rod, and one end of the spring is fixedly connected to the surface of the tapered portion.

[0008] Preferably, the tapered portion is made of high-temperature resistant rubber.

[0009] Preferably, the inner ring of the connecting ring has a tapered through groove, the taper of the tapered through groove matches the taper of the tapered part, and the outer peripheral wall of the tapered part overlaps the inner wall of the tapered through groove.

[0010] Preferably, the positioning element includes a collar sleeved around the outer periphery of the movable rod and positioning rods symmetrically fixed to the outer wall of the collar, with the end of each positioning rod away from the collar fixedly connected to the inner wall of the exhaust connector.

[0011] Preferably, there are two hinge rods, which are symmetrically hinged to the limiting ring at one end of the movable rod, and each of the two hinge rods is connected to a sealing block.

[0012] Preferably, a slider is fixedly connected to the side of the sealing block away from the hinge rod, and a groove is provided on the inner wall of the exhaust connector near the exhaust hole, and the slider is slidably installed in the groove.

[0013] The beneficial effects of this utility model are as follows: The vacuum forming cavity for a foam packaging box, as described in this utility model, utilizes an automatic sealing mechanism consisting of a spring, a limiting component, a hinged rod, and a sealing block inside the exhaust connector. This mechanism enables the exhaust port to automatically open during steam injection and automatically close when steam supply stops. This mechanism can quickly disconnect the mold cavity from the exhaust channel the instant steam supply stops, fundamentally preventing residual pressure in the mold cavity from "flushing" and "squeezing" the molten EPS beads back into the exhaust port. This solves the problem of exhaust port blockage caused by the accumulation of solidified molten material, thereby reducing downtime caused by cleaning clogged vents and improving production efficiency and mold lifespan. The vent connector is detachably installed on the molding die via a threaded connection. When cleaning or maintenance is required, the entire vent connector can be easily unscrewed from the die for centralized processing or replacement. The operation is simple, time-saving, and labor-saving, facilitating daily maintenance of the equipment and reducing long-term maintenance and labor costs. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a perspective view of the present invention; Figure 2 This is a partial cross-sectional view of the mounting hole structure of this utility model; Figure 3 This is a partial structural cross-sectional view of the exhaust connector, connecting ring, and sealing block of this utility model; Figure 4 This is a front view of the present invention.

[0016] The diagram is marked as follows: 1. Molding mold; 2. Mounting hole; 3. Venting connector; 301. Venting hole; 4. Connecting ring; 5. Positioning component; 6. Limiting component; 7. Spring; 8. Hinge rod; 9. Sealing block; 10. Sealing ring. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments.

[0018] It should be noted that, unless otherwise defined, the technical or scientific terms used in this utility model should have the ordinary meaning understood by one of ordinary skill in the art to which this utility model pertains. The terms "first," "second," and similar terms used in this utility model do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0019] The first aspect of this utility model proposes a vacuum forming cavity for a foam packaging box, such as... Figure 1-4 As shown, it includes: The molding die 1 and several molding cavities provided on the molding die 1, each molding cavity having several mounting holes 2 on its inner wall; The exhaust connector 3 is detachably installed on the mounting hole 2, and has an exhaust hole 301 at the end near the molding chamber. It should be added that the exhaust hole 301 is connected to the molding chamber. The exhaust connector 3 has a chamber for gas to pass through, and the chamber is connected to the exhaust hole 301. During the molding process of the foam packaging box, steam enters the molding chamber through the exhaust holes 301 of the male mold and the female mold respectively, causing the EPS beads to expand and form in the mold. The connecting ring 4 is fixed to the inner wall of the exhaust connector 3 and is located on the side of the exhaust connector 3 away from the exhaust hole 301; The positioning part 5 is fixed to the inner wall of the exhaust connector 3, with a through hole in its middle. The positioning part 5 moves through the limiting part 6 through the through hole, and one end of it is placed on the inner ring of the connecting ring 4. A spring 7 is fitted onto the limiting member 6, with its two ends fixed to one end surface of the limiting member 6 and one side of the positioning member 5, respectively. At least one hinge rod 8 is hinged to the other end of the limiting member 6, and a sealing block 9 is hinged to one end of the hinge rod 8. The sealing block 9 is slidably installed on one side of the inner wall of the exhaust connector 3 near the exhaust hole 301 to block the exhaust hole 301.

[0020] When steam enters the molding chamber through the exhaust connector 3, the steam entering the exhaust connector 3 is squeezed at one end of the limiting member 6, causing the limiting member 6 to move toward the exhaust hole 301. At the same time, the spring 7 is compressed by the gas, so that the limiting member 6 and the connecting ring 4 are in an open state, releasing the blockage. Simultaneously, the other end of the limiting member 6 pushes the hinged sealing block 9 to move away from the exhaust hole 301, so that the sealing block 9 releases the blockage of the exhaust hole 301. At this time, the steam smoothly enters the molding chamber through the exhaust hole 301. When steam heating stops, spring 7 returns to its elastic state after being stressed, pushing one end of the limiting member 6 to seal the inner ring of the connecting ring 4 again. At the same time, the other end of the limiting member 6 pulls the hinged sealing block 9 to slide closer to the vent hole 301, sealing the vent hole 301. This can quickly cut off the connection between the mold cavity and the vent channel the moment the steam stops supplying steam, preventing the molten material on the surface of the EPS beads from being "washed" and "squeezed" into the hole when the steam stops supplying steam. After cooling and solidification, the molten material will accumulate repeatedly and eventually completely block the vent hole, affecting the subsequent processing quality. The automatic sealing mechanism effectively avoids the blockage of the vent hole 301, ensuring the stability of the molding quality and the long-term use of the mold. In addition, it should be noted that the cooling and demolding stages are carried out by setting separate cooling vents in the molding mold to demold the molded product. This is existing technology and will not be elaborated on further.

[0021] In this embodiment: the inner wall of the mounting hole 2 is provided with an internal thread, and one end of the exhaust connector 3 is provided with an external thread that mates with the internal thread. The exhaust connector 3 is detachably installed on the mounting hole 2 via a threaded connection. The threaded connection between the exhaust connector 3 and the mounting hole 2 facilitates regular cleaning or replacement of the exhaust connector 3, making maintenance convenient.

[0022] In this embodiment, a hexagonal fastening ring is fixed to the outer peripheral wall of the exhaust connector 3 at the end furthest from the exhaust hole 301. A sealing ring 10 is fitted onto the outer peripheral wall of the exhaust connector 3, with one side of the sealing ring 10 overlapping one side of the hexagonal fastening ring. After the exhaust connector 3 is installed in place, the sealing ring 10 fits tightly against the back of the molding mold 1, enhancing the sealing performance.

[0023] In this embodiment: the limiting member 6 includes a tapered portion and a movable rod fixedly connected to one side of the tapered portion. The tapered portion overlaps the inner ring of the connecting ring 4. The movable rod passes through the through hole in the middle of the positioning member 5. The end of the movable rod away from the tapered portion is fixedly connected to the limiting ring. The end of the hinge rod 8 is hinged to the limiting ring. The spring 7 is sleeved on the outer peripheral wall of the movable rod, and one end of the spring 7 is fixedly connected to the surface of the tapered portion. It should be noted that one side of the limiting ring overlaps the side of the positioning member 5, and the hinge rod 8 is inclined so that the distance from the end of the hinge rod 8 near the limiting ring to the inner wall of the exhaust connector 3 is greater than the distance from the end of the hinge rod 8 near the sealing block 9 to the inner wall of the exhaust connector 3. When the movable rod drives the limiting ring to move, the hinge rod 8 can smoothly drive the hinged sealing block 9 to move.

[0024] In this embodiment, the tapered portion is made of high-temperature resistant rubber. This high-temperature resistant rubber material can withstand the high-temperature environment during the molding process, preventing deformation and failure.

[0025] In this embodiment, the inner ring of the connecting ring 4 has a tapered through groove, the taper of which matches the taper of the tapered portion, and the outer peripheral wall of the tapered portion overlaps the inner wall of the tapered through groove. By setting the tapered portion at one end of the limiting member 6 with the tapered through groove of the inner ring of the connecting ring 4, the contact area between the tapered portion and the inner wall of the connecting ring 4 can be increased, thereby improving the sealing effect.

[0026] In this embodiment, the positioning component 5 includes a collar sleeved around the outer periphery of the movable rod and positioning rods symmetrically fixed to the outer wall of the collar. The end of each positioning rod away from the collar is fixedly connected to the inner wall of the exhaust connector 3. The fixed connection of the end of each positioning rod away from the collar to the inner wall of the exhaust connector 3 ensures the stable fixation of the positioning component 5.

[0027] In this embodiment, two hinge rods 8 are provided, and the two hinge rods 8 are symmetrically hinged to the limiting ring at one end of the movable rod, and each of the two hinge rods 8 is connected to a sealing block 9. The symmetrical structure makes the movement of the sealing block 9 more stable and the sealing of the exhaust hole 301 more reliable.

[0028] In this embodiment, a slider is fixedly connected to the side of the sealing block 9 away from the hinge rod 8. A groove is formed on the inner wall of the exhaust connector 3 near the exhaust hole 301, and the slider is slidably installed in the groove. The cooperation between the slider and the groove ensures that the sealing block 9 will not shift during movement, thus improving the sealing accuracy.

[0029] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the present invention includes the claims being limited to these examples; within the framework of the present invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in the details for the sake of brevity.

[0030] This utility model is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A vacuum forming cavity for a foam packaging box, characterized in that, include: A molding die (1) and a plurality of molding chambers provided on the molding die (1), each molding chamber having a plurality of mounting holes (2) on its inner wall. A vent connector (3) is detachably installed on the mounting hole (2), and a vent hole (301) is opened at one end near the molding chamber. A connecting ring (4) is fixed to the inner wall of the exhaust connector (3) and is located on the side of the exhaust connector (3) away from the exhaust hole (301); The positioning member (5) is fixed to the inner wall of the exhaust connector (3), with a through hole in its middle. The positioning member (5) passes through the limiting member (6) through the through hole, and one end of it is placed on the inner ring of the connecting ring (4). A spring (7) is fitted onto the limiting member (6), and the two ends of the spring (7) are respectively fixed to one end surface of the limiting member (6) and one side of the positioning member (5); At least one hinge rod (8) is hinged to the other end of the limiting member (6), and a sealing block (9) is hinged to one end of the hinge rod (8). The sealing block (9) is slidably installed on one side of the inner wall of the exhaust connector (3) near the exhaust hole (301) to block the exhaust hole (301).

2. The vacuum forming cavity for a foam packaging box according to claim 1, characterized in that, The inner wall of the mounting hole (2) is provided with an internal thread, and the surface of one end of the exhaust connector (3) is provided with an external thread that matches the internal thread. The exhaust connector (3) is detachably installed on the mounting hole (2) by means of a threaded connection.

3. A vacuum forming cavity for a foam packaging box according to claim 1 or 2, characterized in that, A hexagonal fastening ring is fixed to the outer peripheral wall of the exhaust connector (3) at the end away from the exhaust hole (301). A sealing ring (10) is fitted on the outer peripheral wall of the exhaust connector (3), and one side of the sealing ring (10) overlaps one side of the hexagonal fastening ring.

4. The vacuum forming cavity for a foam packaging box according to claim 3, characterized in that, The limiting member (6) includes a tapered part and a movable rod fixedly connected to one side of the tapered part. The tapered part overlaps the inner ring of the connecting ring (4). The movable rod passes through the through hole in the middle of the positioning member (5). The end of the movable rod away from the tapered part is fixedly connected to the limiting ring. The end of the hinge rod (8) is hinged to the limiting ring. The spring (7) is sleeved on the outer peripheral wall of the movable rod, and one end of the spring (7) is fixedly connected to the surface of the tapered part.

5. The vacuum forming cavity for a foam packaging box according to claim 4, characterized in that, The tapered part is made of high-temperature resistant rubber.

6. The vacuum forming cavity for a foam packaging box according to claim 4, characterized in that, The inner ring of the connecting ring (4) is provided with a tapered through groove, the taper of the tapered through groove matches the taper of the tapered part, and the outer peripheral wall of the tapered part overlaps the inner wall of the tapered through groove.

7. The vacuum forming cavity for a foam packaging box according to claim 4, characterized in that, The positioning component (5) includes a collar sleeved around the outer periphery of the movable rod and positioning rods symmetrically fixed to the outer wall of the collar. The end of each positioning rod away from the collar is fixedly connected to the inner wall of the exhaust connector (3).

8. The vacuum forming cavity for a foam packaging box according to claim 4, characterized in that, There are two hinge rods (8), which are symmetrically hinged to the limiting ring at one end of the movable rod, and the two hinge rods (8) are respectively connected to a sealing block (9).

9. The vacuum forming cavity for a foam packaging box according to claim 7, characterized in that, The sealing block (9) is fixedly connected to a slider on the side away from the hinge rod (8). The inner wall of the exhaust connector (3) near the exhaust hole (301) is provided with a sliding groove, and the slider is slidably installed in the sliding groove.

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