A blow molding mold

Abstract

The application discloses a blow molding mold, which comprises an inner wall for defining a container body, and an inner molding surface and an outer molding surface for defining a container bottom, wherein the outer molding surface comprises a bottom molding surface for defining a part of the container bottom, a bottom foot forming position for defining a container bottom foot, and a bottom edge molding surface for defining a bottom edge portion; an annular groove is arranged between the inner molding surface and the outer molding surface, an exhaust groove is arranged at a radial far end of the outer molding surface, and an exhaust structure for directly or indirectly connecting a cavity space to the outside is arranged in the annular groove and / or the exhaust groove. The annular groove, the exhaust groove and the communication groove for connecting the annular groove and the exhaust groove are arranged at the bottom of the blow molding mold, and the exhaust structure for directly or indirectly connecting the cavity space to the outside is arranged in the annular groove and / or the exhaust groove, so that air at corresponding positions of the container bottom can be quickly exhausted, air resistance during expansion molding of the container bottom is reduced, and the container bottom is beneficial to be molded when a bottle is blown under low pressure.

Description

Technical Field

[0001] This invention relates to the field of blow molding technology, and more specifically to a blow molding mold. Background Technology

[0002] In existing technology, containers are formed by blowing a container preform into a blow molding die. The blow molding die structure generally includes a left half-die, a right half-die that fits the left half-die, and a bottom die that fits the bottom of both the left and right half-dies. A cavity is formed between the left half-die, right half-die, and bottom die. The container preform expands within the cavity until it conforms to the inner wall of the cavity, thus forming a container. For a specific structure, please refer to Chinese utility model patent document with patent application number 202122664676.9, entitled "A Bottom Die Cooling Channel Structure, Bottom Die, and Blow Molding Die."

[0003] Reference Figure 1 As shown, some existing containers include a container body 01, a container bottom surface 02, and a container foot 03 disposed between the container body 01 and the container bottom surface 02. The container bottom surface 02 has a bottom recess in the middle, and the part connecting the container bottom surface 02 and the container foot 03 serves as the bottom edge. If the existing mold cavity structure is used to blow-dry the container preform, since the mold cavity structure does not have corresponding venting structures for the bottom foot forming position, the bottom molding surface defining the bottom surface, and the bottom recess forming surface defining the bottom recess, a higher blowing pressure is required to ensure that all parts of the container bottom are fully formed. This results in a large consumption of high-pressure gas. Once the blowing pressure drops, some parts of the container bottom will not be fully formed, affecting the quality of the finished product and hindering enterprises from improving product quality, saving energy and reducing emissions, and achieving efficient production. Summary of the Invention

[0004] To overcome the shortcomings of existing technology, a blow molding mold is provided that can quickly expel gas from the bottom of the mold cavity, making it easier to shape the bottom of the container.

[0005] The technical solution adopted by this invention to solve its technical problem is: A blow molding mold includes an inner wall defining a container body, and an inner molding surface and an outer molding surface defining the bottom of the container. The outer molding surface includes a bottom molding surface that defines a portion of the container bottom surface, a bottom foot forming position that defines the container bottom foot, and a bottom edge molding surface that defines the bottom edge portion, which are connected in sequence. An annular groove is provided between the inner molding surface and the outer molding surface, and an exhaust groove is provided at the radially distal end of the outer molding surface. At least one communicating groove is provided between the annular groove and the exhaust groove. An exhaust structure is provided in the annular groove and / or the exhaust groove to directly or indirectly connect the cavity space to the outside.

[0006] In this invention, the venting groove is located between the bottom forming position and / or the bottom molding surface and the bottom forming position.

[0007] In this invention, the exhaust structure includes a second exhaust port disposed within the exhaust groove and connected to the outside.

[0008] In this invention, the connecting grooves are provided in multiple places and spaced around the periphery of the inner molding surface.

[0009] In this invention, the inner molded surface includes a peripheral surface and protrusions and recesses located on the peripheral surface. At least some of the protrusions and / or recesses are provided with air guide grooves in contact with the peripheral surface. The air guide grooves are directly or indirectly connected to the exhaust structure via an air collection groove.

[0010] In this invention, the blow molding mold includes a mold cavity structure and a bottom mold. The mold cavity structure includes two mold cavity halves, each mold cavity halves having a half mold cavity and a half mold mounting position. The bottom mold includes a mold bottom and a bottom mold forming part disposed on the mold bottom. The two half mold cavities and the bottom mold are configured to form a cavity. The inner wall, the inner mold forming surface, and the outer mold forming surface together define the forming surface of the cavity.

[0011] In this invention, the inner wall and the outer molding surface are located on the half mold cavity of the mold cavity half mold. A semi-circular hole is provided between the half mold mounting position and the outer molding surface. The semi-circular hole has a hole wall. The inner molding surface is located on the bottom mold forming part. A peripheral surface is provided between the mold bottom and the inner molding surface. The venting structure includes a fitting gap between the hole wall and the peripheral surface. The annular groove is provided by the fitting gap or the annular groove is arranged around the edge of the outer molding surface and communicates with the fitting gap.

[0012] In this invention, the venting structure further includes a mold cavity venting groove located on the hole wall, which extends from the annular groove to the half-mold mounting position.

[0013] In this invention, the inner wall is located in the semi-mold cavity, the inner mold surface and the outer mold surface are located in the bottom mold forming part, and the annular groove is provided with a first vent hole that communicates with the outside.

[0014] In this invention, the exhaust structure further includes a first exhaust port disposed within the annular groove and connected to the outside.

[0015] The beneficial effects of the present invention are as follows: The present invention provides an annular groove, an exhaust groove, and a connecting groove connecting the annular groove and the exhaust groove at the bottom of the blow molding mold, and provides an exhaust structure in the annular groove and / or the exhaust groove to directly or indirectly connect the cavity space to the outside, which can quickly exhaust the air at the corresponding position of the bottom of the container, reduce the air resistance when the bottom of the container expands and is formed, which is beneficial to the forming of the bottom of the container during low-pressure blow molding, and makes the bottom of the container more full.

[0016] Furthermore, by connecting the annular groove and the venting groove through the connecting groove, an interlaced venting path is formed at the bottom of the mold cavity structure, which enhances the ability to vent quickly and achieves an effect close to "no air resistance". This is more conducive to the forming of the container bottom during low-pressure blow molding, and at the same time, it can be formed by using a thinner material to cover the container bottom, which is beneficial to the lightweighting of the container bottom. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the container's structure; Figure 2 This is a schematic diagram of the structure of Embodiment 1; Figure 3 for Figure 2 Enlarged view of part A; Figure 4 This is a schematic diagram of the bottom mold structure of Example 1; Figure 5 This is a schematic diagram of the structure of Example 2; Figure 6 for Figure 5 Enlarged view of part B; Figure 7 This is a schematic diagram of the structure of Example 3; Figure 8 This is a schematic diagram of the bottom mold structure in Example 3; Figure 9 for Figure 8 Enlarged view of part C. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "left," "right," "top / bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for 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. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] Example 1: like Figures 2 to 4 As shown, this embodiment discloses a blow molding mold, including a mold cavity structure 10 and a bottom mold 20. The mold cavity structure 10 includes two mold cavity half molds 11, each mold cavity half mold 11 having a half mold cavity 12 and a half mold mounting position 13. The bottom mold 20 includes a mold bottom 21 and a bottom mold forming part disposed on the mold bottom 21. The two half mold cavities 12 and the bottom mold 20 are configured to form a cavity. The cavity includes an inner wall 121 defining the container body 01, an inner molded surface 22 defining the bottom, and an outer molded surface 24. The inner wall 121, the outer molded surface 24, and the inner molded surface 22 together define the forming surface of the cavity and together define the shape of the container. The outer molding surface 24 includes a bottom molding surface 241 for defining a portion of the container bottom surface 02, a bottom foot forming position 242 for defining the container bottom foot 03, and a bottom edge molding surface 243 for defining the bottom edge portion, which are connected in sequence. The container bottom surface 02 is jointly defined by the bottom molding surface 241 and the inner molding surface 22. In this embodiment, the bottom molding surface 241 is approximately parallel to the placement surface, or it can be a plane or curved / arc surface that is inclined towards or away from the placement surface. The above structure is basically the same as the patent technology solution of the applicant's earlier application, and will not be described in detail here. An annular groove 25 is provided between the inner molding surface 22 and the outer molding surface 24, and an exhaust groove 26 is provided at the radially distal end of the outer molding surface 24. A plurality of connecting grooves 27 are provided between the annular groove 25 and the exhaust groove 26, and the plurality of connecting grooves 27 are spaced around the periphery of the inner molding surface 22. The number of the connecting grooves 27 is preferably 2, 3, 5, 7 or a multiple thereof, and the connecting grooves 27 are preferably distributed at equal angles, that is, the included angle between adjacent connecting grooves 27 is equal. The annular groove 25 and / or the venting groove 26 are provided with venting structures that directly or indirectly connect the cavity space to the outside.

[0022] In this embodiment, the inner wall 121 and the outer molded surface 24 are located on the semi-mold cavity 12. A semi-circular hole 16 is provided between the semi-mold mounting position 13 and the outer molded surface 24. The semi-circular hole 16 has a hole wall 161. The inner molded surface 22 is located on the bottom mold forming part. A peripheral surface 211 is provided between the mold bottom 21 and the inner molded surface 22. The venting structure includes a fitting gap 3 between the hole wall 161 and the peripheral surface 211. The fitting gap 3 comes from the gap between the bottom mold 20 and the mold cavity structure 10. The width of the fitting gap is 0.2-0.7mm. In order to improve the venting efficiency of the fitting gap, an annular groove 25 is also provided. The annular groove 25 surrounds the edge of the outer molded surface 24. The annular groove 25 is a notch located between the hole wall 161 and the bottom molded surface 241. The recess depth of the notch is 0.5-1mm and the width is 0.1-1.2mm. Excessive depth and excessive width are avoided as much as possible to reduce the impact on the forming of the container body. In implementation, the depth and width of the cavity venting groove 17 are the same as the width of the notch. Since the cavity venting groove 17 is located at the bottom of the annular groove 25, the width of the cavity venting groove 17 can be appropriately increased, preferably less than 6 times the width of the notch. Simultaneously, multiple cavity venting grooves 17 are spaced apart on the hole wall 161. The cavity venting grooves 17 extend from the outer mold surface 24 to the half-mold mounting position 13 and also connect to the annular groove 25. Venting channels are formed between the cavity venting grooves 17 and the peripheral surface 211, and the gas entering the annular groove 25 is discharged through the venting channels. The annular groove 25 is preferably located at the lowest point within the cavity, enabling rapid discharge of air entering the bottom area of ​​the cavity, achieving a better venting effect.

[0023] In this embodiment, the cavity venting groove 17 and the annular groove 25 are both located on one side of the semi-circular hole 16. In practice, the cavity venting groove 17 and the annular groove 25 can also be located on the circumferential surface 211. In practice, a gap is provided between the mold bottom 11 and the half-mold mounting position 13. The fitting gap 3 and the cavity venting groove 17 communicate directly or indirectly with the outside through this gap, and the gas discharged through the fitting gap 3 and the cavity venting groove 17 is discharged through this gap. This embodiment achieves optimized venting function with only minor modifications to the overall mold, facilitating upgrades to older molds and promoting widespread adoption.

[0024] In a preferred embodiment, the inner molded surface 22 includes a peripheral surface 221 and protrusions and recesses located on the peripheral surface 221. The protrusions and recesses define the recessed area forming the bottom of the container. The protrusions include domes, reinforcing ribs, etc., and the recesses are not shown in the accompanying drawings. Air guide grooves 23 are provided at the contact points between some or all of the protrusions and / or recesses and the peripheral surface 221. The air guide grooves 23 surround the outer periphery of the protrusions and / or recesses and connect to the annular groove 25 via an air collection groove 231. The width of the air guide groove 23 is less than or equal to the width of the air collection groove 231, and the depth of the air guide groove 23 is the same as the depth of the air collection groove 231. Preferably, the width of the air guide groove 23 is 0.25-0.75 times the width of the air collection groove 231, or the area of ​​the exhaust surface of the air guide groove 23 is 0.25-0.75 times the area of ​​the exhaust surface of the air collection groove 231. The air guide groove 23 can accelerate the air discharge speed at the corresponding position of the bottom depression, making the bottom depression more full.

[0025] In this embodiment, the venting structure further includes a second vent 261 located within the venting groove 26 and connected to the outside. Multiple second vents 261 are provided and evenly spaced around the cavity axis. The second vent 261 penetrates the mold cavity structure 10 and connects directly or indirectly to the outside. The preferred location of the venting groove 26 is between the bottom molding surface 241 and the bottom forming position 242; in other embodiments, it can also be located on the bottom forming position 242 and / or the bottom molding surface, all to reduce the gas pressure in the area, allowing gas from other areas to quickly enter and then exit the area. When setting the direction of the second vent 261, it can be selected to be parallel / perpendicular / at a certain angle to the cavity axis, depending on the location of the second vent 261. Air entering the concave area can be quickly guided into the annular groove 25 through the air guide groove 23, air entering the bottom surface 02 area of ​​the container can be quickly discharged through the annular groove 25, and air corresponding to the bottom foot 03 of the container can be quickly discharged through the exhaust groove 26. This achieves rapid discharge of air corresponding to the bottom of the entire container bottle, reduces air resistance during the expansion and molding of the container bottom, facilitates the molding of the container bottom during low-pressure blow molding, and makes the container bottom more full. In this embodiment, the concave depth of the air collecting groove 231 and the exhaust groove 26 is 0.5-1mm, and the width is 0.5-1.5mm. The diameter of the second exhaust hole 261 corresponds to the width of the exhaust groove 26.

[0026] Example 2: Reference Figures 5 to 6 As shown, the structure and principle of this embodiment are basically the same as those of embodiment one. The difference is that when the fit gap 3 between the bottom mold 20 and the mold cavity structure 10 is large, such as 0.5-1.5mm, the top of the fit gap 3 forms the annular groove 25, and the hole wall 161 does not need to be provided with the mold cavity venting groove 17, which can meet the venting requirements.

[0027] Example 3: Reference Figures 7 to 9 As shown, the structure and principle of this embodiment are basically the same as those of Embodiment 1, except that the container bottom surface 02 and container foot 03 are both defined and formed by related structures within the bottom mold 20. In this embodiment, the inner wall 121 is located in the semi-mold cavity 12, the inner mold surface 22 and the outer mold surface 24 are located in the bottom mold forming part, an annular groove 25 is provided between the inner mold surface 22 and the outer mold surface 24, and an exhaust groove 26 is provided at the radially distal end of the outer mold surface 24. A plurality of connecting grooves 27 are provided between the annular groove 25 and the exhaust groove 26. The exhaust structure includes a second exhaust hole 261 located within the exhaust groove 26 and connected to the outside.

[0028] During implementation, the air guide grooves 23 on the inner molded surface 22 guide the gas from the raised and / or recessed areas into the annular groove 25 via the gas collection groove 231. The gas entering the annular groove 25 then enters the exhaust groove 26 via the connecting groove 27. Simultaneously, the gas in the corresponding areas of the annular groove 25 and the exhaust groove 26 directly enters the annular groove 25 and the exhaust groove 26, respectively. Finally, the gas is discharged to the outside through the second exhaust hole 261. This exhaust method allows the gas in the middle of the inner molded surface 22 to be quickly discharged through guidance, avoiding insufficient container forming in the middle area due to poor exhaust, which would require increasing the blowing pressure. It also solves the problems of large structural differences between the inner molded surface 22 and other parts of the container bottom, complex exhaust structures, and low exhaust efficiency. Since the bottom of the container is formed by the bottom mold, it is easier to design a cooling scheme that meets the cooling needs of the entire bottom of the container, avoiding uneven cooling at the bottom.

[0029] In implementation, the venting structure may further include a first vent 251 disposed within the annular groove 25. The first vent 251 communicates with the outside. Multiple first vents 251 are provided and evenly spaced around the cavity axis. The first vent 251 penetrates the bottom mold 20 and communicates with the outside in a manner parallel to or inclined to the cavity axis, or penetrates the bottom mold 20 and communicates with the outside via a multi-segment path at multiple angles. Gas entering the annular groove 25 is discharged through the first vent 251. During manufacturing, the bottom mold 20 can be manufactured using additive manufacturing methods such as 3D printing, or using a combination of additive and subtractive manufacturing methods.

[0030] In this embodiment, the width and depth of the annular groove 25 are preferably such that they do not affect the forming of the container, such as a recess depth of 0.5-1mm and a width of 0.5-1.5mm. The diameter of the first exhaust hole 251 corresponds to the width of the annular groove 25. The arrangement of the air guide groove 23, the air collection groove 231, the exhaust groove 26, and the second exhaust hole 261 are as described in Embodiment 1.

[0031] The above description is only a preferred embodiment of the present invention. Any technical solution that achieves the purpose of the present invention by essentially the same means is within the protection scope of the present invention.

Claims

1. A blow molding die, characterized in that: The mold includes an inner wall defining the main body of the container, and an inner molded surface and an outer molded surface defining the bottom of the container. The outer molded surface includes a bottom molded surface that defines part of the bottom surface of the container, a bottom foot forming position that defines the bottom foot of the container, and a bottom edge molded surface that defines the bottom edge. An annular groove is provided between the inner molded surface and the outer molded surface, and an exhaust groove is provided at the radially distal end of the outer molded surface. At least one connecting groove is provided between the annular groove and the exhaust groove, and the annular groove and the exhaust groove are connected through the connecting groove to form an exhaust path with intersecting annular diameters at the bottom of the mold cavity structure. An exhaust structure is provided in the annular groove and the exhaust groove to directly or indirectly connect the cavity space to the outside. The exhaust structure is located at the bottom of the cavity space.

2. The blow molding die according to claim 1, characterized in that: The venting groove is located between the bottom forming position and / or the bottom molded surface and the bottom forming position.

3. The blow molding die according to claim 1, characterized in that: The exhaust structure includes a second exhaust port located within the exhaust groove and connected to the outside.

4. A blow molding die according to claim 1, characterized in that: The connecting grooves are provided in multiple places and are spaced around the periphery of the inner molded surface.

5. A blow molding die according to claim 1, characterized in that: The inner molded surface includes a peripheral surface and raised and recessed positions located on the peripheral surface. At least some of the raised and / or recessed positions are provided with air guide grooves in contact with the peripheral surface. The air guide grooves are directly or indirectly connected to the exhaust structure via air collection grooves.

6. A blow molding die according to any one of claims 1-5, characterized in that: The blow molding mold includes a mold cavity structure and a bottom mold. The mold cavity structure includes two mold cavity halves, each mold cavity halves having a half mold cavity and a half mold mounting position. The bottom mold includes a mold bottom and a bottom mold forming part disposed on the mold bottom. The two half mold cavities and the bottom mold are configured to form a cavity. The inner wall, the inner mold forming surface, and the outer mold forming surface together define the forming surface of the cavity.

7. A blow molding die according to claim 6, characterized in that: The inner wall and outer molding surface are located on the half mold cavity of the mold cavity half mold. A semi-circular hole is provided between the half mold mounting position and the outer molding surface. The semi-circular hole has a hole wall. The inner molding surface is located on the bottom mold forming part. A peripheral surface is provided between the mold bottom and the inner molding surface. The venting structure includes a fitting gap between the hole wall and the peripheral surface. The annular groove is provided by the fitting gap or the annular groove is set around the edge of the outer molding surface and communicates with the fitting gap.

8. A blow molding die according to claim 7, characterized in that: The venting structure also includes a cavity venting groove located on the hole wall, which extends from the annular groove to the half-mold mounting position.

9. A blow molding die according to claim 6, characterized in that: The inner wall is located in the semi-mold cavity, the inner mold surface and the outer mold surface are located in the bottom mold forming part, and the annular groove is provided with a first vent hole that connects to the outside.

10. A blow molding die according to claim 9, characterized in that: The exhaust structure also includes a first exhaust port located within the annular groove and connected to the outside.

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