Plastic bottle blank injection mold with split type mold core structure

Abstract

The utility model belongs to the technical field of molds, and particularly relates to a plastic bottle blank injection mold with a split type mold core structure. The plastic bottle blank fixing device comprises a plastic bottle blank fixing upper die and a plastic bottle blank fixing lower die. In the injection molding process, the plastic bottle blank fixing upper mold and the plastic bottle blank fixing lower mold are close to each other, at the moment, the split type mold core structure composed of the upper mold core barrel, the sealing barrel and the main body forming barrel is attached, the sealing barrel plays a role in sealing, a cavity is formed between the bottle blank forming inner barrel and the upper mold core barrel, and the plastic bottle blank forming inner barrel and the main body forming barrel are matched with each other. A plurality of plastic bottle blank plastic parts can be formed at a time, a split type mold core structure is adopted, on one hand, a large-size mold core can be conveniently formed, on the other hand, the whole mold core is disassembled into parts, follow-up maintenance and replacement of corresponding parts are facilitated, cost is reduced, and practicability is high.

Description

Technical Field

[0001] The utility model belongs to the technical field of molds, and relates to an injection mold for plastic preforms with a split core structure. Background Art

[0002] Plastic bottles are mainly made of materials such as polyethylene or polypropylene and added with a variety of organic solvents. Plastic bottles are widely made of polyester (PET), polyethylene (PE), and polypropylene (PP) as raw materials. After adding the corresponding organic solvents and being heated at high temperature, they are plastic containers formed by blow molding, extrusion blow molding, or injection molding through plastic molds. They are mainly used for disposable plastic packaging containers for liquids or solids such as beverages, foods, pickles, honey, dried fruits, edible oils, agricultural and veterinary drugs, etc. Plastic bottles have the characteristics of being not easily broken, low cost, high transparency, and food-grade raw materials. In the production process of plastic bottles, an injection molding mold is required to produce the preforms. When the existing injection mold for plastic preforms injects a large-sized core, due to the large volume of the forming structural parts, once damaged, the overall forming structural parts need to be replaced, resulting in high maintenance costs and production costs, and the practicability is relatively general. Therefore, there is an urgent need to design an injection mold for plastic preforms with a split core structure that can overcome the above defects.

[0003] In order to overcome the deficiencies of the prior art, people have continuously explored and proposed various solutions. For example, a Chinese patent discloses an injection mold for plastic preforms [Application No.: 202322735800.5], which includes a fixed template, a cavity plate connected to the fixed template, a movable template, and a core plate connected to the movable template. Two rows of first inserts for forming the bottle body are installed on the cavity plate, and two rows of second inserts for forming the bottle body are installed on the movable template. The two rows of the first inserts and the two rows of the second inserts correspond one by one. One end of the two rows of the first inserts extends out of the core plate. A top plate and a ejector rod for driving the displacement of the top plate are provided on the core plate. One end of the ejector rod is fixedly connected to the top plate, and the other end penetrates the core plate and the movable template. A driving part for driving the second insert to slide is also provided on the core plate. Summary of the Utility Model

[0004] The purpose of the utility model is to provide an injection mold for plastic preforms with a split core structure for the above problems.

[0005] To achieve the above purpose, the utility model adopts the following technical solutions:

[0006] An injection mold for plastic preforms with a split core structure, comprising an upper mold for fixing plastic preforms and a lower mold for fixing plastic preforms. A fixed base plate is provided below the lower mold for fixing plastic preforms. A split core structure is provided between the upper mold for fixing plastic preforms and the lower mold for fixing plastic preforms. The split core structure includes several groups of upper core cylinders, sealing cylinders and main body forming cylinders. The main body forming cylinder passes through the sealing cylinder. One end of the sealing cylinder abuts against the upper core cylinder, and the other end abuts against the main body forming cylinder. A preform forming inner cylinder part is provided at the top of the main body forming cylinder. A cavity is formed between the preform forming inner cylinder part and the upper core cylinder.

[0007] In the above injection mold for plastic preforms with a split core structure, the preform forming inner cylinder part includes a preform forming inner conical cylinder. A conical cylinder cavity is provided in the upper core cylinder. The preform forming inner conical cylinder is adapted to the shape of the conical cylinder cavity.

[0008] In the above injection mold for plastic preforms with a split core structure, the preform forming inner conical cylinder is integrally formed with the main body forming cylinder. A thread forming protrusion is provided at the junction of the preform forming inner conical cylinder and the main body forming cylinder. A thread forming recess is provided at the bottom of the conical cylinder cavity. The thread forming protrusion is adapted to the shape of the thread forming recess.

[0009] In the above injection mold for plastic preforms with a split core structure, an injection hole communicating with the conical cylinder cavity is provided at the top of the upper core cylinder.

[0010] In the above injection mold for plastic preforms with a split core structure, a plug-in part is provided in the middle of the main body forming cylinder. The diameter of the plug-in part gradually decreases from bottom to top.

[0011] In the above injection mold for plastic preforms with a split core structure, the plug-in part is in fit with the inner wall of the sealing cylinder.

[0012] In the above injection mold for plastic preforms with a split core structure, an embedded sealing ring is provided at the top of the sealing cylinder. An embedded ring groove is provided in the upper core cylinder. The embedded sealing ring is in snap-fit with the embedded ring groove.

[0013] In the above injection mold for plastic preforms with a split core structure, an outer ring is provided in the middle of the sealing cylinder. The outer ring is in fit with the upper core cylinder.

[0014] In the above injection mold for plastic preforms with a split core structure, several positioning holes are provided in the fixed base plate. A positioning bottom shaft is provided at the bottom of the main body forming cylinder. The positioning bottom shaft is in snap-fit with the positioning holes.

[0015] In the above-mentioned plastic preform injection mold with a split core structure, a spiral cooling groove is provided on the outer circumference of the upper core cylinder.

[0016] Compared with the existing technology, the advantages of the present utility model are as follows:

[0017] 1. During the injection molding process of the present utility model, the plastic preform fixing upper mold and the plastic preform fixing lower mold approach each other. At this time, the split core structure composed of the upper core cylinder, the sealing cylinder, and the main body forming cylinder fits together. The sealing cylinder plays a sealing role, and a cavity is formed between the inner cylinder part of the preform and the upper core cylinder. The molten material is injected from the upper core cylinder into the cavity for injection molding. Multiple plastic preform plastic parts can be formed at one time. By adopting the split core structure, on the one hand, it is convenient to form a large-size core, and on the other hand, it is disassembled into parts, which is convenient for subsequent maintenance and replacement of corresponding parts, reducing costs and having strong practicability.

[0018] 2. The inner conical cylinder of the preform forming in the present utility model is integrally formed with the main body forming cylinder, avoiding the appearance of seams or gaps. The thread forming protrusion and the thread forming recess cooperate to form the thread part of the plastic preform plastic part, eliminating the need for secondary finishing and shortening the process.

[0019] Other advantages, objectives, and features of the present utility model will be partially reflected by the following description and partially understood by those skilled in the art through the research and practice of the present utility model. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a structural schematic diagram of the present utility model.

[0021] Figure 2 is a partial structural schematic diagram of the present utility model.

[0022] Figure 3 is a structural schematic diagram of the upper core cylinder.

[0023] Figure 4 is a structural schematic diagram of the fixed substrate.

[0024] Figure 5 is a structural schematic diagram of the main body forming cylinder.

[0025] In the figure: plastic preform fixing upper mold 1, plastic preform fixing lower mold 2, fixed substrate 3, split core structure 4, upper core cylinder 5, sealing cylinder 6, main body forming cylinder 7, inner cylinder part of the preform 8, inner conical cylinder of the preform 9, conical cylinder cavity 10, thread forming protrusion 11, thread forming recess 12, injection hole 13, insertion part 14, embedded sealing ring 15, embedded ring groove 16, outer ring 17, positioning hole 18, positioning bottom shaft 19, spiral cooling groove 20. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The present utility model will be further described below with reference to the accompanying drawings.

[0027] As Figures 1-5 shown, an injection mold for plastic preforms with a split mold core structure includes a plastic preform fixing upper mold 1 and a plastic preform fixing lower mold 2. A fixed substrate 3 is provided below the plastic preform fixing lower mold 2. A split mold core structure 4 is provided between the plastic preform fixing upper mold 1 and the plastic preform fixing lower mold 2. The split mold core structure 4 includes a plurality of groups of upper mold core cylinders 5, sealing cylinders 6, and main body forming cylinders 7. The main body forming cylinder 7 passes through the sealing cylinder 6. One end of the sealing cylinder 6 abuts against the upper mold core cylinder 5, and the other end abuts against the main body forming cylinder 7. A preform forming inner cylinder part 8 is provided at the top of the main body forming cylinder 7. A cavity is formed between the preform forming inner cylinder part 8 and the upper mold core cylinder 5.

[0028] In this embodiment, during the injection molding process, the plastic preform fixing upper mold 1 and the plastic preform fixing lower mold 2 approach each other. At this time, the split mold core structure 4 composed of the upper mold core cylinder 5, the sealing cylinder 6, and the main body forming cylinder 7 fits together. The sealing cylinder 6 plays a sealing role. A cavity is formed between the preform forming inner cylinder part 8 and the upper mold core cylinder 5. The molten material is injected into the cavity from the upper mold core cylinder 5 for injection molding. Multiple plastic preform plastic parts can be formed at one time. By adopting the split mold core structure, on the one hand, it is convenient to form a large-size mold core, and on the other hand, it is disassembled into parts, which is convenient for subsequent maintenance and replacement of corresponding parts, reduces costs, and has strong practicability.

[0029] Combined with Figures 1-5 shown, the preform forming inner cylinder part 8 includes a preform forming inner conical cylinder 9. A conical cylinder cavity 10 is provided inside the upper mold core cylinder 5. The shape of the preform forming inner conical cylinder 9 is adapted to the conical cylinder cavity 10.

[0030] Specifically, during the injection molding process, the preform forming inner conical cylinder 9 and the conical cylinder cavity 10 cooperate to form the main body of the plastic part.

[0031] The preform forming inner conical cylinder 9 and the main body forming cylinder 7 are integrally formed. A thread forming protrusion 11 is provided at the junction of the preform forming inner conical cylinder 9 and the main body forming cylinder 7. A thread forming recess 12 is provided at the bottom of the conical cylinder cavity 10. The shape of the thread forming protrusion 11 is adapted to the thread forming recess 12.

[0032] In this embodiment, the preform forming inner conical cylinder 9 and the main body forming cylinder 7 are integrally formed to avoid seams or voids. The thread forming protrusion 11 and the thread forming recess 12 cooperate to form the thread part of the plastic preform plastic part, eliminating the need for secondary finishing and shortening the process.

[0033] Combined withFigure 3 As shown, an injection hole 13 communicating with the conical barrel cavity 10 is provided at the top of the upper die core barrel 5.

[0034] In this embodiment, the molten material is injected into the cavity through the injection hole 13.

[0035] The middle part of the main body forming barrel 7 has a plug-in part 14, the diameter of the plug-in part 14 gradually decreases from bottom to top, and the plug-in part 14 fits against the inner wall of the sealing barrel 6.

[0036] In this embodiment, before injection molding, the plug-in part 14 fits against the inner wall of the sealing barrel 6, and the diameter of the plug-in part 14 gradually decreases from bottom to top, which is convenient for mold closing and opening, and improves the smoothness.

[0037] An embedded sealing ring 15 is provided at the top of the sealing barrel 6, an embedded ring groove 16 is provided inside the upper die core barrel 5, and the embedded sealing ring 15 is in snap-fit with the embedded ring groove 16.

[0038] In this embodiment, during injection molding, the embedded sealing ring 15 is in snap-fit with the embedded ring groove 16 to effectively seal the bottom of the cavity and prevent the molten material from leaking from the bottom of the cavity.

[0039] Combined with Figures 1-2 As shown, an outer ring 17 is provided in the middle of the sealing barrel 6, and the outer ring 17 fits against the upper die core barrel 5.

[0040] In this embodiment, the outer ring 17 fits against the upper die core barrel 5 to avoid gaps.

[0041] Combined with Figures 2-5 As shown, a number of positioning holes 18 are provided inside the fixed base plate 3, a positioning bottom shaft 19 is provided at the bottom of the main body forming barrel 7, and the positioning bottom shaft 19 is in snap-fit with the positioning holes 18.

[0042] In this embodiment, during mold closing, the positioning bottom shaft 19 is in snap-fit with the positioning holes 18 to achieve snap-fit and position the main body forming barrel 7 to prevent the main body forming barrel 7 from shaking during injection molding.

[0043] Combined with Figures 1-2 As shown, a spiral cooling groove 20 is provided on the outer circle of the upper die core barrel 5.

[0044] In this embodiment, after injection molding is completed, cooling water is passed to the spiral cooling groove 20 for spiral cooling to increase the cooling area.

[0045] The working principle of the present utility model is:

[0046] During the injection molding process, the plastic preform fixing upper mold 1 and the plastic preform fixing lower mold 2 approach each other. At this time, the split mold core structure 4 composed of the upper mold core cylinder 5, the sealing cylinder 6, and the main body forming cylinder 7 fits together. The sealing cylinder 6 plays a sealing role. A cavity is formed between the preform forming inner cylinder part 8 and the upper mold core cylinder 5. The molten material is injected into the cavity through the injection hole 13 of the upper mold core cylinder 5 for injection molding. Multiple plastic preform plastic parts can be formed at one time. The split mold core structure is adopted. On the one hand, it is convenient to form large-size mold cores. On the other hand, it is disassembled into parts, which is convenient for subsequent maintenance and replacement of corresponding parts, reduces costs, and has strong practicability.

[0047] During the injection molding process, the preform forming inner conical cylinder 9 cooperates with the conical cylinder cavity 10 to form the main body of the plastic part. The preform forming inner conical cylinder 9 is integrally formed with the main body forming cylinder 7 to avoid seams or gaps. The thread forming protrusion 11 cooperates with the thread forming recess 12 to form the thread part of the plastic preform plastic part, eliminating the need for secondary precision machining and shortening the process.

[0048] Before injection molding, the insertion part 14 fits against the inner wall of the sealing cylinder 6. The diameter of the insertion part 14 gradually decreases from bottom to top, facilitating mold closing and opening and improving smoothness.

[0049] During injection molding, the embedded sealing ring 15 is snap-fitted with the embedded ring groove 16 to effectively seal the bottom of the cavity and prevent the molten material from leaking from the bottom of the cavity. The outer ring 17 fits against the upper mold core cylinder 5 to avoid gaps.

[0050] When closing the mold, the positioning bottom shaft 19 is snap-fitted with the positioning hole 18 to achieve snap-fitting and position the main body forming cylinder 7 to prevent the main body forming cylinder 7 from shaking during injection molding.

[0051] After injection molding is completed, cooling water is introduced into the spiral cooling groove 20 for spiral cooling to increase the cooling area.

[0052] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Those skilled in the art of the present invention can make various modifications or supplements to the described specific embodiments or use similar methods for substitution, but will not deviate from the spirit of the present invention.

[0053] Although this text uses terms such as plastic preform fixing upper die 1, plastic preform fixing lower die 2, fixing substrate 3, split die core structure 4, upper die core cylinder 5, sealing cylinder 6, main body forming cylinder 7, preform forming inner cylinder part 8, preform forming inner cone cylinder 9, cone cylinder cavity 10, thread forming protrusion 11, thread forming recess 12, injection hole 13, insertion part 14, embedded sealing ring 15, embedded ring groove 16, outer ring 17, positioning hole 18, positioning bottom shaft 19, spiral cooling groove 20 more frequently, it does not exclude the possibility of using other terms. The use of these terms is only to more conveniently describe and explain the essence of the present utility model, and interpreting them as any kind of additional restriction is contrary to the spirit of the present utility model.

Claims

1. An injection mold for plastic preforms with a split core structure, comprising a plastic preform fixing upper mold (1) and a plastic preform fixing lower mold (2), characterized in that, A fixed base plate (3) is provided below the plastic preform fixing lower die (2). A split die core structure (4) is provided between the plastic preform fixing upper die (1) and the plastic preform fixing lower die (2). The split die core structure (4) includes several groups of upper die core cylinders (5), sealing cylinders (6), and main body forming cylinders (7). The main body forming cylinder (7) passes through the sealing cylinder (6). One end of the sealing cylinder (6) abuts against the upper die core cylinder (5), and the other end abuts against the main body forming cylinder (7). A preform forming inner cylinder part (8) is provided at the top of the main body forming cylinder (7). A cavity is formed between the preform forming inner cylinder part (8) and the upper die core cylinder (5).

2. The plastic preform injection mold with a split mold core structure according to claim 1, characterized in that, The preform forming inner cylinder part (8) includes a preform forming inner conical cylinder (9). A conical cylinder cavity (10) is provided in the upper die core cylinder (5). The shape of the preform forming inner conical cylinder (9) is adapted to the shape of the conical cylinder cavity (10).

3. The plastic preform injection mold with a split core structure according to claim 2, characterized in that, The preform forming inner conical cylinder (9) is integrally formed with the main body forming cylinder (7). A thread forming protrusion (11) is provided at the junction of the preform forming inner conical cylinder (9) and the main body forming cylinder (7). A thread forming recess (12) is provided at the bottom of the conical cylinder cavity (10). The shape of the thread forming protrusion (11) is adapted to the shape of the thread forming recess (12).

4. The plastic preform injection mold with a split core structure according to claim 3, characterized in that, An injection hole (13) communicating with the conical cylinder cavity (10) is provided at the top of the upper die core cylinder (5).

5. The plastic preform injection mold with a split core structure according to claim 4, characterized in that, The middle part of the main body forming cylinder (7) has a plug-in part (14), and the diameter of the plug-in part (14) gradually decreases from bottom to top.

6. The plastic preform injection mold with a split mold core structure according to claim 5, characterized in that, The plug-in part (14) is in fit with the inner wall of the sealing cylinder (6).

7. The plastic preform injection mold with a split core structure according to claim 6, characterized in that, An embedded sealing ring (15) is provided at the top of the sealing cylinder (6). An embedded ring groove (16) is provided in the upper die core cylinder (5). The embedded sealing ring (15) is in snap-fit with the embedded ring groove (16).

8. The plastic preform injection mold with a split mold core structure according to claim 7, characterized in that, An outer ring (17) is provided in the middle of the sealing cylinder (6). The outer ring (17) is in fit with the upper die core cylinder (5).

9. The plastic preform injection mold with a split core structure according to claim 8, characterized in that, Several positioning holes (18) are provided in the fixed base plate (3). A positioning bottom shaft (19) is provided at the bottom of the main body forming cylinder (7). The positioning bottom shaft (19) is in snap-fit with the positioning holes (18).

10. The plastic preform injection mold with a split mold core structure according to claim 9, characterized in that, A spiral cooling groove (20) is provided on the outer circle of the upper die core cylinder (5).

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