A plastic box and bag suction molding equipment with uniform wall thickness

Abstract

This utility model discloses a thermoforming device for plastic bags with uniform wall thickness, including a machine body. The upper part of the machine body has a closed plate with a sandwich panel. A hole corresponding to a mold core is located in the center of the closed plate. A mold core is vertically connected to the lower part of the machine body. Multiple first air-blowing holes are evenly spaced on the top of the closed plate around the hole. Two second air-blowing holes are symmetrically arranged on the mold core, located at the front and rear ends of the top of the mold core. Multiple suction holes are also evenly spaced on the top and sides of the mold core. A movable frame is sealed to the machine body above the closed plate. A thermoplastic sheet is placed on the movable frame. A bracket is fixed to the machine body above the movable frame, and multiple air-blowing guns are mounted on the bracket. The air-blowing direction of each air-blowing gun is directed towards the bends of the raised mold core. This utility model can effectively maintain the uniform wall thickness of the thermoplastic sheet during the thermoforming process of bags.

Description

Technical Field

[0001] This utility model relates to a plastic bag forming equipment with uniform wall thickness. Background Technology

[0002] Uneven wall thickness is a common problem during the thermoforming process of plastic bags. Analysis shows that the main reasons are as follows: The air inlet of the equipment is located below the movable frame. When the thermoplastic sheet is compressed and expanded, uneven force often results in inconsistent thickness. In particular, the middle part often becomes uneven in thickness due to lack of support during the switching between air inflation and suction forming, and may even produce local wrinkles. On the other hand, the mold core has many bends on its surface. These bends also cause differences in forming speed due to uneven force, and thus become thinner due to the tensile force of the surrounding thermoplastic sheet during the forming process. Utility Model Content

[0003] The purpose of this utility model is to overcome the shortcomings of the prior art and provide a plastic bag blister forming device with uniform wall thickness.

[0004] The technical solution of this utility model is: a plastic bag forming device with uniform wall thickness, including a machine body, a closed plate with a sandwich layer is provided at the upper end of the machine body, a hole corresponding to the mold core is provided in the middle of the closed plate, the mold core is lifted and connected to the lower end of the machine body, a plurality of first air blowing holes are provided at equal intervals on the top of the closed plate around the hole, two second air blowing holes are symmetrically provided on the mold core, the two second air blowing holes are respectively provided at the front and rear ends of the top of the mold core, and a plurality of suction holes are also provided at equal intervals on the top and all sides of the mold core;

[0005] A hot air blower is connected to the interlayer of the sealed plate and the two second air blowing holes through air ducts, and a vacuum pump is connected to each air suction hole on the mold core through connecting pipes.

[0006] A movable frame is also sealed and connected to the body above the closed plate. A thermoplastic sheet is provided on the movable frame. A bracket is also fixed on the body above the movable frame. Multiple air guns are provided on the bracket. The air jet direction of each air gun is set towards each bend of the mold core after it is raised.

[0007] Furthermore, the bottom of the mold core is provided with a base, and the top of the base is provided with a seal. When the mold core rises from the hole to the top of the sealing plate, the seal abuts against the bottom of the sealing plate to seal the connection between the mold core and the sealing plate.

[0008] Specifically, the mold core is a hollow mold core, the mold core is sealed to the base, and the vacuum pump is connected to the bottom of the mold core through a connecting pipe.

[0009] Furthermore, a baffle is provided on the mold core inside each of the air intake holes.

[0010] Specifically, there are two vacuum pumps, which are connected to both sides of the bottom of the mold core through connecting pipes.

[0011] Furthermore, each of the two second air inlets is individually connected to a hot air blower via a connecting branch pipe.

[0012] Furthermore, the bottom of the machine body is equipped with a cylinder for driving the mold core to rise and fall, and the piston rod of the cylinder is connected to the bottom center of the base.

[0013] Furthermore, multiple guide rods are provided between the sealing plate and the bottom of the machine body, and the base is provided with guide holes corresponding to each guide rod, with each guide rod passing through the corresponding guide hole.

[0014] The beneficial effects of this utility model are as follows: The utility model provides a first air-blowing hole and a second air-blowing hole on the sealing plate and the mold core, respectively. The thermoplastic sheet expands uniformly upwards under the combined action of the first and second air-blowing holes. Before vacuum forming, the thermoplastic sheet is always supported by hot air, which can prevent uneven thickness of the thermoplastic sheet during expansion. During the vacuum forming process of the thermoplastic sheet, each air gun blows air onto each bend of the mold core. On the one hand, this applies a certain pressure to the thermoplastic sheet at that location, providing external force to assist in the forming of the thermoplastic sheet at that position, which can prevent uneven thickness of the plastic sheet at that position. On the other hand, it can accelerate the cooling of the thermoplastic sheet, allowing it to quickly set. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model;

[0016] Figure 2 yes Figure 1 Enlarged view of part A in the middle.

[0017] In the diagram: 1. Body; 2. Enclosure plate; 3. Interlayer; 4. Mold core; 5. First air blowing hole; 6. Second air blowing hole; 7. Suction hole; 8. Air duct; 9. Connecting pipe; 10. Movable frame; 11. Bracket; 12. Air blowing gun; 13. Base; 14. Seal; 15. Baffle plate; 16. Connecting branch pipe; 17. Cylinder; 18. Guide rod. Detailed Implementation

[0018] The technical solution of this utility model will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0019] Combination Figure 1 and Figure 2As shown, a plastic bag forming device with uniform wall thickness includes a machine body 1. The upper part of the machine body 1 is provided with a closed plate 2 with a sandwich layer 3. The middle part of the closed plate 2 is provided with a hole corresponding to the mold core 4. The lower part of the machine body 1 is connected to the mold core 4 in a lifting manner. Multiple first air blowing holes 5 are provided at equal intervals on the top of the closed plate 2 around the hole. Two second air blowing holes 6 are symmetrically provided on the mold core 4. The two second air blowing holes 6 are respectively provided at the front and rear ends of the top of the mold core 4. Multiple suction holes 7 are also provided at equal intervals on the top and around the mold core 4.

[0020] A hot air blower is connected to the interlayer 3 of the sealing plate 2 and the two second air blowing holes 6 through the air pipe 8, and a vacuum pump is connected to each air suction hole 7 on the mold core 4 through the connecting pipe 9.

[0021] A movable frame 10 is also sealed and connected to the body 1 above the closed plate 2. The movable frame 10 is provided with a thermoplastic sheet. A bracket 11 is also fixed on the body 1 above the movable frame 10. The bracket 11 is provided with multiple air guns 12. The air jet direction of each air gun 12 is set towards each bend of the raised mold core 4.

[0022] The working principle and beneficial effects of the above structure are as follows: The heated thermoplastic sheet is fixed on the movable frame 10. Since the movable frame 10 is sealed to the machine body 1, and the sealing plate 2 seals the upper part of the machine body 1, the thermoplastic sheet is placed in a relatively enclosed space. At this time, hot air is blown upward from each of the first air holes 5, and hot air is blown out from the two second air holes 6 while the mold core 4 rises. The thermoplastic sheet expands upward evenly under the combined action of the first air holes 5 and the second air holes 6, which can avoid uneven thickness of the thermoplastic sheet during the expansion process. When the mold core 4 is completely raised to the top of the sealing plate 2, the thermoplastic sheet and the sealing plate 2 form a complete gap. In a sealed environment, the first air blowing hole 5 and the second air blowing hole 6 stop blowing air and pass through the one-way valve to prevent backflow. Each suction hole 7 draws air in, and the thermoplastic sheet is quickly thermoformed. During the thermoplastic sheet forming process, each air gun 12 blows air into each bend of the mold core 4. On the one hand, it applies a certain pressure to the thermoplastic sheet at that part, so that the thermoplastic sheet is assisted by external force in the forming of the thermoplastic sheet at that position, which can avoid uneven thickness of the plastic sheet at that position. On the other hand, it can accelerate the cooling of the thermoplastic sheet and make it quickly set. After the thermoforming is completed, the mold core 4 is lowered. At this time, the formed bag is removed from the movable frame 10 and cut to obtain the finished product.

[0023] In another embodiment, such as Figure 1 As shown, the bottom of the mold core 4 is provided with a base 13, and the top of the base 13 is provided with a seal 14. When the mold core 4 rises from the hole to the top of the sealing plate 2, the seal 14 abuts against the bottom of the sealing plate 2 to seal the connection between the mold core 4 and the sealing plate 2, so as to prevent air from seeping in from the connection between the mold core 4 and the sealing plate 2 during the vacuum forming of the bag.

[0024] In another embodiment, such as Figure 1 As shown, the mold core 4 is a hollow mold core 4, the mold core 4 is sealed to the base 13, and the vacuum pump is connected to the bottom of the mold core 4 through the connecting pipe 9.

[0025] In another embodiment, combined Figure 1 and Figure 2 As shown, a baffle plate 15 is also provided on the mold core 4 inside each of the air suction holes 7 to prevent the negative pressure in the middle of the air suction hole 7 from being too large, which would cause serious deformation of the thermoplastic sheet in that part during vacuum forming.

[0026] In another embodiment, there are two vacuum pumps, which are connected to both sides of the bottom of the mold core 4 through connecting pipe 9 to ensure the efficiency of vacuum forming and uniform air intake of each suction hole 7.

[0027] In another embodiment, combined Figure 1 and Figure 2 As shown, each of the two second air holes 6 is individually connected to a hot air blower via a connecting branch pipe 16 to ensure the air volume when the two second air holes 6 are working.

[0028] In another embodiment, such as Figure 1 As shown, the bottom of the machine body 1 is provided with a cylinder 17 that drives the mold core 4 to rise and fall, and the piston rod of the cylinder 17 is connected to the bottom center of the base 13.

[0029] In another embodiment, such as Figure 1 As shown, multiple guide rods 18 are provided between the bottom of the sealing plate 2 and the body 1. The base 13 is provided with guide holes corresponding to each guide rod 18. Each guide rod 18 passes through the corresponding guide hole to ensure the stability of the base 13 when it is raised or lowered.

Claims

1. A thermoforming device for plastic bags with uniform wall thickness, comprising a machine body (1), characterized in that, The upper part of the machine body (1) is provided with a closed plate (2) with a sandwich layer (3). The middle part of the closed plate (2) is provided with a hole corresponding to the mold core (4). The lower part of the machine body (1) is connected to the mold core (4) in a lifting manner. The top of the closed plate (2) around the hole is provided with a plurality of first air blowing holes (5) at equal distances. The mold core (4) is provided with two second air blowing holes (6) symmetrically arranged. The two second air blowing holes (6) are respectively located at the front and rear ends of the top of the mold core (4). The top and surrounding area of ​​the mold core (4) are also provided with a plurality of suction holes (7) at equal distances. A hot air blower is connected to the interlayer (3) of the closed plate (2) and the two second air blowing holes (6) through the air pipe (8), and a vacuum pump is connected to each air suction hole (7) on the mold core (4) through the connecting pipe (9); A movable frame (10) is also sealed and connected to the body (1) above the closed plate (2). A thermoplastic sheet is provided on the movable frame (10). A bracket (11) is also fixed on the body (1) above the movable frame (10). Multiple air guns (12) are provided on the bracket (11). The air jet direction of each air gun (12) is set towards each bend of the mold core (4) after it is raised.

2. The plastic bag thermoforming equipment with uniform wall thickness as described in claim 1, characterized in that, The bottom of the mold core (4) is provided with a base (13), and the top of the base (13) is provided with a seal (14). When the mold core (4) rises from the hole to the top of the sealing plate (2), the seal (14) abuts against the bottom of the sealing plate (2) to seal the connection between the mold core (4) and the sealing plate (2).

3. The plastic bag thermoforming equipment with uniform wall thickness as described in claim 2, characterized in that, The mold core (4) is a hollow mold core (4), and the mold core (4) is sealed to the base (13). The vacuum pump is connected to the bottom of the mold core (4) through the connecting pipe (9).

4. The plastic bag thermoforming equipment with uniform wall thickness as described in claim 3, characterized in that, Each of the air intake holes (7) has a baffle plate (15) on the mold core (4) inside.

5. The plastic bag thermoforming equipment with uniform wall thickness as described in claim 4, characterized in that, There are two vacuum pumps, which are connected to the two sides of the bottom of the mold core (4) through connecting pipes (9).

6. The plastic bag thermoforming equipment with uniform wall thickness as described in claim 5, characterized in that, The two second air holes (6) are each connected to a hot air blower separately through a connecting branch pipe (16).

7. The plastic bag thermoforming equipment with uniform wall thickness as described in claim 6, characterized in that, The bottom of the machine body (1) is provided with a cylinder (17) for driving the mold core (4) to rise and fall. The piston rod of the cylinder (17) is connected to the bottom center of the base (13).

8. The thermoforming equipment for plastic bags with uniform wall thickness as described in claim 7, characterized in that, Multiple guide rods (18) are provided between the bottom of the sealing plate (2) and the body (1). The base (13) is provided with guide holes corresponding to each guide rod (18), and each guide rod (18) passes through the corresponding guide hole.

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