An exhaust bottom mold and a bottle blowing mold

Abstract

The utility model relates to blow molding technical field especially, relates to an exhaust bottom die and blow mould. Exhaust bottom die includes upper die assembly, lower die assembly and fastener, upper die assembly includes top frame, a plurality of second profiles and a plurality of second positioning parts, all second positioning parts are arranged on the top frame bottom surface, second profile is arranged on the inboard wall of second positioning part, and the second positioning part between adjacent forms has the clamping groove, lower die assembly includes base, first profile and a plurality of first positioning parts, and first profile and first positioning part are arranged on the base, and first positioning part is inserted in the clamping groove, and first profile and second profile mutually cooperate and form the bottom cavity for blow molding, and first positioning part and the clamping groove form first exhaust gap, and first exhaust gap is communicated bottom cavity and external space. Through first exhaust gap, the gas in cavity can be discharged quickly, makes bottle bottom forming fullness, and the smooth exhaust makes the bottle blank can be more quickly attached to the mould, and improves cooling efficiency.

Description

Technical Field

[0001] This utility model relates to the field of blow molding technology, and in particular to an exhaust bottom mold and a blow molding die. Background Technology

[0002] In the blow molding process of plastic bottles, the preform is inflated and molded to fit the inner wall of the mold under high temperature and pressure. Traditional blow molding molds often suffer from poor venting in the bottle bottom area, leading to gas stagnation, which affects the quality of the bottle molding, resulting in defects such as bottle bottom depressions, deformation, and air bubbles, thus reducing the product yield. Simultaneously, air in the bottle bottom area cannot be expelled in time and is compressed between the preform and the mold cavity, occupying space and preventing the preform from fully fitting the mold. This reduces heat transfer efficiency, requires a longer cooling time for solidification, increases energy consumption, and is detrimental to efficient and energy-saving production. Utility Model Content

[0003] The technical problem to be solved by this utility model is to solve at least one of the technical problems mentioned above.

[0004] The solution to the technical problem of this utility model is: a venting bottom mold, which includes an upper mold assembly, a lower mold assembly, and fasteners. The upper mold assembly includes a top frame, a plurality of second surfaces, and a plurality of second positioning parts. All the second positioning parts are arranged circumferentially around the center of the top frame on the bottom surface of the top frame. The second surfaces are correspondingly arranged on the sidewalls of the second positioning parts facing the center of the top frame. A slot is formed between adjacent second positioning parts. The lower mold assembly includes a base, a first surface, and a plurality of first positioning parts. The first surface is located at the center of the top surface of the base. All the first positioning parts are arranged circumferentially around the center of the first surface on the base and correspond to the slots. The first positioning parts extend into the slots. The first surface and the second surface cooperate to form a bottom cavity for blow molding. A first venting gap is formed between the outer sidewall of the first positioning part and the inner sidewall of the slot. The first venting gap connects the bottom cavity with the external space. The fasteners are used to detachably connect the upper mold assembly and the lower mold assembly.

[0005] As a further improvement to the above technical solution, the lower mold assembly also includes an exhaust groove. The exhaust groove is arranged around the bottom edge of the second positioning part and extends through to the outer peripheral surface of the top frame. The exhaust groove and the top surface of the first positioning part enclose each other to form a second exhaust gap. The second exhaust gap is connected to the first exhaust gap.

[0006] As a further improvement to the above technical solution, the end of the first positioning part away from the base is provided with a guide arc surface.

[0007] As a further improvement to the above technical solution, the fastener is a bolt, the second positioning part is provided with a threaded hole, the base is provided with a through hole that matches the threaded hole, and the bolt passes through the through hole and is threadedly connected to the threaded hole.

[0008] As a further improvement to the above technical solution, the through hole is a countersunk hole, which includes a large-diameter section and a small-diameter section connected together. The large-diameter section is used to accommodate the head of the bolt, and the small-diameter section is used to accommodate the shank of the bolt.

[0009] As a further improvement to the above technical solution, the lower mold assembly also includes a cooling assembly, which includes a central cooling channel and an outer cooling channel. The central cooling channel is a cylindrical cavity opened inside the base and located directly below the first profile. The outer cooling channel is arranged around the central cooling channel on the bottom surface of the base. The central cooling channel is connected to an external cooling circuit through the outer cooling channel.

[0010] As a further improvement to the above technical solution, the external cooling water channel is a spiral flow channel.

[0011] A blow molding die includes a cavity structure for molding a bottle body, and also includes a venting bottom mold as described in any of the above claims, wherein the cavity structure and the venting bottom mold together enclose a complete cavity for molding a preform.

[0012] The beneficial effects of this utility model are as follows: the second surface of the upper mold assembly and the first surface of the lower mold assembly cooperate with each other to form the bottom cavity for blow molding, which determines the shape and contour of the bottle bottom; the slot between the second positioning parts is used to accommodate the first positioning part; the first venting gap is a tiny, continuous gap that surrounds the bottle bottom, naturally formed by the fit tolerance between the outer wall of the first positioning part and the inner wall of the slot, through which the gas in the cavity is smoothly discharged to the outside of the mold; the fasteners are used to detachably connect the upper mold assembly and the lower mold assembly, which facilitates the installation, disassembly, maintenance and replacement of the mold. Through the first venting gap, the gas in the cavity can be quickly discharged, effectively avoiding defects such as bottle bottom depression, air bubbles, and deformation, so that the bottle bottom is formed with a full shape and clear contour; the smooth venting allows the preform to fit the mold faster, improving the cooling efficiency, thereby shortening the molding cycle and increasing the output per unit time; decomposing the complex bottle bottom cavity into upper mold assembly and lower mold assembly reduces the processing difficulty of individual parts, and the venting channel is a naturally formed gap, which does not require complex precision drilling, and the disassembly and cleaning of the venting gap is also very convenient. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of one embodiment of the present invention; Figure 2This is one of the exploded views of one embodiment of this utility model; Figure 3 This is the second exploded view of one embodiment of this utility model.

[0014] Reference numerals in the attached drawings: 100-Upper mold assembly, 110-Top frame, 120-Second profile, 130-Second positioning part, 131-Exhaust groove, 140-Slot, 200-Lower mold assembly, 210-Base, 220-First profile, 230-First positioning part, 231-Guide arc surface, 240-Cooling assembly, 241-Central cooling channel, 242-Outer cooling channel, 300-Fastener, 310-Bolt, 320-Threaded hole, 330-Through hole, 331-Large diameter section, 332-Small diameter section, 400-First exhaust gap, 410-Second exhaust gap. Detailed Implementation

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments have been briefly explained above. Obviously, the described drawings are only a part of the embodiments of this utility model, not all of them. Those skilled in the art can obtain other design schemes and drawings based on these drawings without creative effort.

[0016] The following will clearly and completely describe the concept, specific structure, and technical effects of this utility model in conjunction with embodiments and accompanying drawings, so as to fully understand the purpose, features, and effects of this utility model. Obviously, the described embodiments are only a part of the embodiments of this utility model, not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are all within the scope of protection of this utility model. Furthermore, all connections / linkages mentioned herein do not simply refer to direct contact between components, but rather to the ability to form a better connection structure by adding or reducing connecting accessories according to specific implementation conditions. The various technical features in this utility model can be combined interactively without contradicting each other.

[0017] In the blow molding process of plastic bottles, the preform is inflated and molded to fit the inner wall of the mold under high temperature and pressure. Traditional blow molding molds often suffer from poor venting in the bottle bottom area, leading to gas stagnation, which affects the quality of the bottle molding, resulting in defects such as bottle bottom depressions, deformation, and air bubbles, thus reducing the product yield. Simultaneously, air in the bottle bottom area cannot be expelled in time and is compressed between the preform and the mold cavity, occupying space and preventing the preform from fully fitting the mold. This reduces heat transfer efficiency, requires a longer cooling time for solidification, increases energy consumption, and is detrimental to efficient and energy-saving production.

[0018] Therefore, this utility model proposes an exhaust bottom mold, referring to... Figures 1-3 It includes an upper mold assembly 100, a lower mold assembly 200, and fasteners 300. The upper mold assembly 100 includes a top frame 110, a plurality of second profiles 120, and a plurality of second positioning parts 130. All the second positioning parts 130 are arranged circumferentially around the center of the top frame 110 on the bottom surface of the top frame 110. The second profiles 120 are correspondingly disposed on the sidewalls of the second positioning parts 130 facing the center of the top frame 110. A slot 140 is formed between adjacent second positioning parts 130. The lower mold assembly 200 includes a base 210, a first profile 220, and a plurality of first positioning parts 230. The first profile 220 is disposed on the bottom frame 110. At the center of the top surface of the base 210, all the first positioning parts 230 are arranged circumferentially around the center of the first profile 220 and correspond one-to-one with the slot 140. The first positioning parts 230 extend into the slot 140 one-to-one. The first profile 220 and the second profile 120 cooperate to form a bottom cavity for blow molding. A first venting gap 400 is formed between the outer side wall of the first positioning part 230 and the inner side wall of the slot 140. The first venting gap 400 connects the bottom cavity with the external space. The fastener 300 is used to detachably connect the upper mold assembly 100 and the lower mold assembly 200.

[0019] The second surface 120 of the upper mold assembly 100 and the first surface 220 of the lower mold assembly 200 cooperate with each other to form a bottom cavity for blow molding, which determines the shape and outline of the bottle bottom; the slot 140 between the second positioning parts 130 is used to accommodate the first positioning part 230; the first venting gap 400 is a small, continuous gap that surrounds the bottle bottom, naturally formed by the fit tolerance between the outer side wall of the first positioning part 230 and the inner side wall of the slot 140, through which the gas in the cavity is smoothly discharged to the outside of the mold; the fastener 300 is used to detachably connect the upper mold assembly 100 and the lower mold assembly 200, which facilitates the installation, disassembly, maintenance and replacement of the mold. The first venting gap 400 allows for rapid exhaust of gas from the cavity, effectively preventing defects such as bottle bottom depressions, bubbles, and deformation, resulting in a full and clear bottle bottom. Smooth venting allows the preform to fit the mold more quickly, improving cooling efficiency and thus shortening the molding cycle and increasing output per unit time. Decomposing the complex bottle bottom cavity into an upper mold assembly 100 and a lower mold assembly 200 reduces the processing difficulty of individual parts. The venting channel is a naturally formed gap, eliminating the need for complex precision drilling, and disassembling and cleaning the venting gap is also very convenient.

[0020] During the blow molding process of plastic bottles, the upper mold assembly 100 and the lower mold assembly 200 are locked together by fasteners 300. The first positioning part 230 is inserted into the slot 140. The first molded surface 220 and all the second molded surfaces 120 are assembled together to form a complete and smooth bottom cavity. High-pressure gas is injected into the preform, causing it to expand and fit into the cavity. The air in the bottom area of ​​the bottle is quickly pushed to the edge of the cavity by the plastic. The compressed air enters the first venting gap 400 formed by the first positioning part 230 and the slot 140 through the junction of the first molded surface 220 and the second molded surface 120. This gap acts as an efficient venting channel, continuously guiding the gas to the outside of the mold. After the gas is exhausted, the plastic completely adheres to the cold cavity surface, cools and solidifies rapidly, forming a precisely shaped bottle bottom. After cooling, the fasteners 300 are loosened, the mold is opened, and the molded bottle is removed. Specifically, the width of the first venting gap 400 is 0.1mm to 0.5mm.

[0021] The low-lying area between the bottom of the second positioning part 130 and the top surface of the first positioning part 230 may form a dead zone for venting, and the trapped gas will form tiny bubbles at the corresponding position at the bottom of the bottle. Therefore, in one embodiment, the lower mold assembly 200 further includes a venting groove 131, which is disposed around the bottom edge of the second positioning part 130 and extends through to the outer peripheral surface of the top frame 110. The venting groove 131 and the top surface of the first positioning part 230 enclose a second venting gap 410, and the second venting gap 410 is connected to the first venting gap 400. The second venting gap 410 covers the venting dead angle between the bottom of the second positioning part 130 and the top surface of the first positioning part 230, and can discharge the stagnant gas that cannot be reached by the single first venting gap 400, completely solving hidden quality problems such as fine air bubbles at the bottom of the bottle, local deformation, and uneven wall thickness, and further improving the product qualification rate; the dual venting channels increase the total venting cross-sectional area, and the gas can be discharged simultaneously through the first gap and the second gap, avoiding the accumulation of gas in the cavity, allowing the preform to fit the inner wall of the mold more quickly and shortening the molding cycle.

[0022] Alignment deviations may cause the first positioning part 230 to rigidly collide with the inlet of the slot 140, damaging the fitting accuracy of the mold and even preventing the positioning part from being inserted into the slot 140. Therefore, in one embodiment, the end of the first positioning part 230 away from the base 210 is provided with a guide arc surface 231. The guide arc surface 231, through its arc transition, can correct slight alignment deviations during mold closing, allowing the first positioning part 230 to smoothly insert into the slot 140, completely avoiding rigid collisions of the straight-edge structure, and protecting the edge integrity of the first positioning part 230 and the slot 140; there is no need for repeated manual adjustment of the mold alignment, as the guide arc surface 231 can adaptively guide the insertion, shortening the mold closing time; it avoids deformation of the positioning part or the slot 140 caused by collisions, ensuring that the smoothness of the dual venting channels is not affected after the first positioning part 230 is inserted.

[0023] In one embodiment, the fastener 300 is a bolt 310. The second positioning part 130 is provided with a threaded hole 320, and the base 210 is provided with a through hole 330 that matches the threaded hole 320. The bolt 310 passes through the through hole 330 and is threadedly connected to the threaded hole 320. The bolt 310 connection point is directly integrated with the second positioning part 130. When connected, the clamping force of the bolt 310 can be directly applied to the positioning mating surface, avoiding relative misalignment between the upper and lower molds. Multiple second positioning parts 130 are evenly distributed along the circumference of the top frame 110, and the corresponding bolts 310 are also arranged circumferentially. The clamping force can evenly cover the mating surfaces of the upper and lower molds, avoiding local gaps and ensuring stable bottle bottom forming pressure.

[0024] The protruding head of the bolt 310 will cause unevenness on the bottom surface of the base 210, preventing the mold from fully fitting against the worktable surface during installation. Therefore, in one embodiment, the through hole 330 is a countersunk hole, which includes a connected large-diameter section 331 and a small-diameter section 332. The large-diameter section 331 is used to accommodate the head of the bolt 310, and the small-diameter section 332 is used to accommodate the shank of the bolt 310. The large-diameter section 331 of the countersunk hole can completely accommodate the head of the bolt 310, keeping the head of the bolt 310 flush with the bottom surface of the base 210, avoiding scratching of equipment components such as the conveyor track and positioning blocks; the large-diameter section 331 of the bolt 310 prevents impact wear during handling and maintenance; there is no need to reserve extra space to avoid the head of the bolt 310, the overall height of the mold is reduced, making it more suitable for small blow molding equipment with limited space, and expanding the applicability of the mold.

[0025] Traditional cooling channels typically consist of a single outer ring around the edge of the base 210, far from the first surface 220. This prevents heat from being quickly dissipated from the center of the bottle bottom, leading to shrinkage, indentation, and warping after cooling. Therefore, in one embodiment, the lower mold assembly 200 further includes a cooling assembly 240. The cooling assembly 240 includes a central cooling channel 241 and an outer cooling channel 242. The central cooling channel 241 is a cylindrical cavity formed inside the base 210 and located directly below the first surface 220. The outer cooling channel 242 surrounds the central cooling channel 241 on the bottom surface of the base 210, and the central cooling channel 241 is connected to an external cooling circuit via the outer cooling channel 242. The central cooling channel 241 is directly aligned with the first molded surface 220, quickly absorbing heat from the core area; the outer cooling channel 242 surrounds and assists, shortening the molding cycle and reducing energy consumption; the base 210 has a uniform overall temperature, reducing the metal fatigue rate, reducing mold surface oxidation and molded surface wear, and lowering mold maintenance and replacement costs.

[0026] The bends in the flow channel can easily create stagnant areas, causing slow flow of the cooling medium in localized areas around the edge of the base 210, preventing heat from being dissipated in time. Therefore, in one embodiment, the external cooling water channel 242 is a spiral flow channel. The spiral flow channel has no right-angle bends or stagnant areas, allowing the cooling medium to flow continuously along the spiral trajectory, completely avoiding localized overheating and ensuring the overall flatness of the first surface 220. The path length of the spiral flow channel is longer than that of an annular flow channel of the same diameter, and the contact between the flow channel and the bottom surface of the base 210 is more comprehensive, increasing the heat dissipation area, improving cooling efficiency, and further shortening the molding cycle. The bends in the spiral flow channel are smooth arc transitions, reducing water flow resistance, maintaining a stable flow rate without upgrading the water pump power, reducing cooling system energy consumption, and meeting the requirements of high-efficiency and energy-saving production.

[0027] A blow molding die includes a cavity structure for molding a bottle body, and also includes a venting bottom mold as described in any of the above claims, wherein the cavity structure and the venting bottom mold together enclose a complete cavity for molding a preform.

[0028] The bottle bottom is the area most prone to poor venting during the blow molding process. By integrating a bottom mold with high-efficiency venting, defects such as scorching, material shortage, air bubbles, and unclear bottom contours can be completely resolved. Smooth venting at the bottom means that air in the mold cavity can be discharged evenly and quickly, preventing air from being squeezed into the bottle body, thereby indirectly improving the smoothness of the bottle surface and the molding quality. It reduces scrap and defective products caused by bottom quality problems, directly lowering production costs. It also enables efficient and uniform cooling of the bottle bottom, significantly shortening the overall cooling and setting time of the bottle and increasing the output per unit time.

[0029] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A venting bottom mold, characterized in that, The assembly includes an upper mold assembly, a lower mold assembly, and fasteners. The upper mold assembly includes a top frame, multiple second surfaces, and multiple second positioning parts. All the second positioning parts are arranged circumferentially around the center of the top frame on the bottom surface of the top frame. The second surfaces are correspondingly arranged on the sidewalls of the second positioning parts facing the center of the top frame, and slots are formed between adjacent second positioning parts. The lower mold assembly includes a base, a first surface, and multiple first positioning parts. The first surface is located at the center of the top surface of the base. All the first positioning parts are arranged circumferentially around the center of the first surface on the base and correspond to the slots. The first positioning parts extend into the slots. The first surface and the second surface cooperate to form a bottom cavity for blow molding. A first venting gap is formed between the outer sidewall of the first positioning part and the inner sidewall of the slot, and the first venting gap connects the bottom cavity with the external space. The fasteners are used to detachably connect the upper mold assembly and the lower mold assembly.

2. The venting bottom mold according to claim 1, characterized in that, The lower mold assembly also includes an exhaust groove, which is disposed around the bottom edge of the second positioning part and extends through to the outer peripheral surface of the top frame. The exhaust groove and the top surface of the first positioning part enclose each other to form a second exhaust gap, and the second exhaust gap is connected to the first exhaust gap.

3. The venting bottom mold according to claim 1, characterized in that, The first positioning part has a guide arc surface at the end away from the base.

4. The venting bottom mold according to claim 1, characterized in that, The fastener is a bolt, the second positioning part is provided with a threaded hole, the base is provided with a through hole that matches the threaded hole, and the bolt passes through the through hole and is threadedly connected to the threaded hole.

5. The venting bottom mold according to claim 4, characterized in that, The through hole is a countersunk hole, which includes a large-diameter section and a small-diameter section connected together. The large-diameter section is used to accommodate the head of the bolt, and the small-diameter section is used to accommodate the shank of the bolt.

6. The venting bottom mold according to claim 1, characterized in that, The lower mold assembly also includes a cooling assembly, which includes a central cooling channel and an outer cooling channel. The central cooling channel is a cylindrical cavity formed inside the base and located directly below the first profile. The outer cooling channel surrounds the central cooling channel on the bottom surface of the base. The central cooling channel is connected to an external cooling circuit through the outer cooling channel.

7. The venting bottom mold according to claim 6, characterized in that, The external cooling water channel is a spiral flow channel.

8. A blow molding die, comprising a cavity structure for molding a bottle body, characterized in that, It also includes the venting bottom mold as described in any one of claims 1-7, wherein the mold cavity structure and the venting bottom mold together enclose a complete cavity for molding the preform.

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