Pre-filled syringe injection mould

Abstract

The application provides a pre-filled syringe injection mold, which comprises a mold base and a plurality of forming molds arranged in the mold base. The mold base is provided with a main runner communicated with the plurality of forming molds. The forming mold is provided with a pre-filled syringe injection space. The forming mold comprises a barrel mold, a head mold and a core. The barrel mold is connected with the mold base and is provided with a first cavity for forming the outer wall of the barrel of the pre-filled syringe. The head mold is abutted with the end of the barrel mold and is connected with the mold base and is provided with a second cavity for forming the shoulder and the nipple outer wall of the pre-filled syringe. The core is arranged in the first cavity and the second cavity and forms the injection space of the pre-filled syringe with the first cavity and the second cavity. The end of the head mold towards the barrel mold is provided with a first runner surrounding the second cavity. The first runner is annular and communicated with the main runner. A plurality of gates are arranged between the first runner and the second cavity. The gates are communicated with the first runner and the second cavity. The direction of the gates is arranged at an angle with the radial direction of the position of the gates of the second cavity.

Description

Technical Field

[0001] This invention belongs to the field of injection mold technology, and specifically relates to a pre-filled syringe injection mold. Background Technology

[0002] Prefilled syringes are convenient to use, leave little residue, and provide precise dosage. They are widely used in veterinary drugs, pet medications, and other drugs, and are a common packaging form for liquid (including suspensions) and ointment drugs.

[0003] Pre-filled syringes are manufactured using injection molding. The injection molding equipment injects molten plasticized material into the mold runner, which then flows into the cavity. However, after injection molding, weld lines appear at the tip of the product, affecting not only its appearance but also the structural strength at the weld line location, thus impacting product quality. Under the same processing conditions, the strength of the weld line area is only 10-92% of that of the original material.

[0004] Especially during the filling process, when the hollow filling head is inserted into the pre-filled nipple, it applies downward pressure to tighten the needle. However, during this tightening process, the structural strength is weaker at the "weld line" location, which can lead to cracking at the nozzle.

[0005] "Weld line" refers to a three-dimensional region with a completely different morphology, structure, and mechanical properties that is formed when two molten materials come into contact.

[0006] Weld lines are mainly formed at the point where the melt fronts entering the cavity from different gates meet when two or more gates are used to reduce melt flow and mold filling time.

[0007] The pre-filled syringe uses three gates, such as Figure 1 As shown, the gate direction is perpendicular to the cavity radial direction. When the raw material flows into the three gates through the runner, the three gates divide the molten raw material. The divided molten raw material flows towards the nipple of the cavity at the same time. The molten leading edge meets at the nipple, and a straight weld line is formed at the meeting point. Therefore, a straight weld line is formed on the nipple of the pre-filled syringe, resulting in low structural strength of the nipple of the pre-filled syringe. Summary of the Invention

[0008] This invention provides a pre-filled syringe injection mold, which aims to solve the technical problem of forming weld lines at the needle tip of the pre-filled syringe in the production of existing pre-filled syringe injection molds.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A pre-filled syringe injection mold is provided, comprising a mold blank and a plurality of molding molds disposed within the mold blank. The mold blank has a main channel communicating with the plurality of molding molds. The molding molds have a pre-filled syringe injection space. The molding molds include:

[0010] The barrel mold, connected to the mold blank, has a first cavity for forming the outer wall of the barrel portion of the pre-filled syringe;

[0011] A head mold, abutting against the end of the barrel mold and connected to the mold blank, is provided with a second cavity for forming the shoulder and outer wall of the pre-filled syringe; and

[0012] The core is disposed in the first cavity and the second cavity, and together with the first cavity and the second cavity, forms an injection space for pre-filled syringe;

[0013] The head mold has a first flow channel surrounding the second cavity at one end facing the body mold. The first flow channel is annular and communicates with the main flow channel. Multiple gates are provided between the first flow channel and the second cavity. The gates communicate with the first flow channel and the second cavity. The direction of the gates is set at an angle to the radial direction of the gate location in the second cavity.

[0014] In one possible implementation of the pre-filled syringe injection mold provided by the present invention, the angle between the gate direction and the radial direction at the location of the gate in the second cavity is 30 degrees to 90 degrees.

[0015] In one possible implementation of the pre-filled syringe injection mold provided by the present invention, the angle between the gate direction and the radial direction at the location of the gate in the second cavity is 70 degrees.

[0016] In one possible implementation of the pre-filled syringe injection mold provided by the present invention, the head mold is provided with three gates, and the three gates are arranged in a circular array around the second cavity.

[0017] In one possible implementation of the pre-filled syringe injection mold provided by the present invention, the core includes an inner cylinder, an inner shoulder, and an inner nipple connected in sequence, wherein the inner cylinder, inner shoulder, and inner nipple are respectively used to form the inner wall of the cylinder, shoulder, and nipple of the pre-filled syringe.

[0018] In one possible implementation of the pre-filled syringe injection mold provided by the present invention, a first annular protrusion is provided on the inner shoulder of the core.

[0019] The beneficial effects of the pre-filled syringe injection mold provided by the present invention are as follows: Compared with the prior art, the pre-filled syringe injection mold provided by the present invention has the gate direction set at an angle to the radial direction of the gate location of the second cavity, so that the direction of the multiple melt streams entering the cavity has a certain angle with the radial direction. In this way, the multiple melt raw materials entering the cavity will form a spiral injection, producing a spiral stirring effect, so that the multiple melt raw materials are mixed while spirally entering the cavity, greatly reducing weld lines and avoiding the disadvantage of insufficient local strength at the gate. Attached Figure Description

[0020] Figure 1 A three-dimensional structural diagram of the head mold in an existing pre-filled syringe injection mold;

[0021] Figure 2 This is a partial exploded structural diagram of a pre-filled syringe injection mold provided in an embodiment of the present invention;

[0022] Figure 3 This is a three-dimensional structural diagram of the molding die in the pre-filled syringe injection mold provided in an embodiment of the present invention;

[0023] Figure 4 This is a three-dimensional structural diagram of the head mold in the pre-filled syringe injection mold provided in an embodiment of the present invention;

[0024] Figure 5 This is a three-dimensional structural diagram of the core in the pre-filled syringe injection mold provided in an embodiment of the present invention;

[0025] Explanation of reference numerals in the attached figures:

[0026] 10. Mold blank; 20. Forming mold; 21. Body mold; 22. Head mold;

[0027] 221. First runner; 222. Gate; 223. Second cavity; 23. Core;

[0028] 231. Inner tube portion; 232. Inner shoulder portion; 233. Inner nipple; 234. First annular protrusion. Detailed Implementation

[0029] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. The following description of at least one exemplary embodiment is actually illustrative only and is in no way intended to limit this application or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0031] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0032] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0033] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms 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, and therefore should not be construed as a limitation on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0034] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways, and the spatial relative descriptions used herein will be interpreted accordingly.

[0035] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this application.

[0036] Please refer to the following: Figures 2 to 5 The pre-filled syringe injection mold provided by the present invention will now be described. The pre-filled syringe injection mold includes a mold blank 10 and a plurality of molding molds 20 disposed within the mold blank 10. The mold blank 10 has a main channel communicating with the plurality of molding molds 20. The molding molds 20 have a pre-filled syringe injection space. The molding molds 20 include a body mold 21, a head mold 22 and a core 23. The body mold 21 is connected to the mold blank 10 and has a first cavity for forming the outer wall of the pre-filled syringe. The head mold 22 abuts against the end of the body mold 21 and is connected to the mold blank 10, and has a second cavity 223 for forming the shoulder and nipple outer wall of the pre-filled syringe. The core 23 is disposed within the first cavity and the second cavity 223, and together with the first cavity and the second cavity 223, forms the injection space for forming the pre-filled syringe.

[0037] The head mold 22 has a first runner 221 surrounding the second cavity 223 at one end facing the body mold 21. The first runner 221 is annular and communicates with the main runner. Multiple gates 222 are provided between the first runner 221 and the second cavity 223. The gates 222 communicate with the first runner 221 and the second cavity 223. The direction of the gates 222 is set at an angle to the radial direction of the location of the gates 222 in the second cavity 223.

[0038] It should be noted that the pre-filled syringe injection mold provided by the present invention uses the existing mold blank 10, and only the internal molding mold 20 is improved.

[0039] The beneficial effects of the pre-filled syringe injection mold provided by the present invention are as follows: Compared with the prior art, the pre-filled syringe injection mold provided by the present invention has the gate 222 direction set at an angle to the radial direction of the gate 222 of the second cavity 223, so that the direction of the multiple melt streams entering the cavity has a certain angle with the radial direction. In this way, the multiple melt raw materials entering the cavity will form a spiral injection, producing a spiral stirring effect, so that the multiple melt raw materials are mixed while spirally entering the cavity, greatly reducing weld lines and avoiding the disadvantage of insufficient local strength at the gate.

[0040] like Figure 3 and Figure 4 As shown, in a specific embodiment of the pre-filled syringe injection mold provided in this invention, the angle between the direction of the gate 222 and the radial direction at the location of the gate 222 of the second cavity 223 is 30 degrees to 90 degrees, so as to ensure the spiral flow angle of each melt.

[0041] Specifically, such as Figure 4 As shown, in a specific embodiment of the pre-filled syringe injection mold provided in this invention, the angle between the direction of the gate 222 and the radial direction at the location of the gate 222 of the second cavity 223 is 70 degrees.

[0042] Specifically, such as Figure 4 As shown, in a specific embodiment of the pre-filled syringe injection mold provided in this invention, the head mold 22 is provided with three gates 222, which are arranged in a circular array around the second cavity 223, effectively reducing the melt flow and filling time.

[0043] like Figure 5 As shown, in a specific embodiment of the pre-filled syringe injection mold provided in this invention, the core 23 includes an inner cylinder portion 231, an inner shoulder portion 232, and an inner nipple portion 233 connected in sequence. The inner cylinder portion 231, the inner shoulder portion 232, and the inner nipple portion 233 are respectively used to form the inner wall of the cylinder portion, the shoulder portion, and the nipple portion of the pre-filled syringe.

[0044] Furthermore, the inner cylinder 231, the inner shoulder 232, and the inner nipple 233 are integrally molded structures.

[0045] like Figure 5 As shown, in a specific embodiment of the pre-filled syringe injection mold provided in this invention, the inner shoulder 232 of the core 23 is provided with a first annular protrusion 234.

[0046] It should be noted that the first annular protrusion 234 on the inner shoulder 232 effectively reduces the flow area at this location. Consequently, after the molten material flows through the three gates 222, it flows into the cavity and converges at the first annular protrusion 234. In this way, the molten material first fuses and gathers together at this location, which is equivalent to forming a uniform annular inlet, before continuing to flow into the nipple cavity. This can further effectively reduce weld lines and improve structural strength.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A pre-filled syringe injection mold, comprising a mold blank and a plurality of molding molds disposed within the mold blank, wherein the mold blank has a main channel communicating with the plurality of molding molds, and the molding molds have a pre-filled syringe injection space, characterized in that, The molding die includes: The barrel mold, connected to the mold blank, has a first cavity for forming the outer wall of the barrel portion of the pre-filled syringe; The head mold abuts against the end of the barrel mold and is connected to the mold blank, and is provided with a second cavity for forming the shoulder of the pre-filled syringe and the outer wall of the nipple; The core is disposed in the first cavity and the second cavity, and together with the first cavity and the second cavity, forms an injection space for pre-filled syringe; The head mold has a first flow channel surrounding the second cavity at one end facing the body mold. The first flow channel is annular and communicates with the main flow channel. Three gates are provided between the first flow channel and the second cavity. The gates communicate with the first flow channel and the second cavity. The three gates are arranged in a circular array around the second cavity. The direction of the gates is set at an angle of 30 degrees to 90 degrees to the radial direction of the gate location in the second cavity. The core includes an inner cylinder, an inner shoulder, and an inner nipple connected in sequence. The inner cylinder, inner shoulder, and inner nipple are used to form the inner walls of the cylinder, shoulder, and nipple of the pre-filled syringe, respectively. The inner shoulder of the core is provided with a first annular protrusion.

2. The pre-filled syringe injection mold as described in claim 1, characterized in that, The angle between the gate direction and the radial direction at the location of the gate in the second cavity is 70 degrees.

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