Injection molding apparatus and method for forming a toothbrush handle

Abstract

The application relates to the technical field of injection molding, in particular to a toothbrush handle forming equipment and method based on secondary injection molding, wherein the secondary forming mold comprises a main mold, a top mold, a neck mold, an injection core and a fracture shaper; the injection core, the main mold and the fracture shaper are arranged on the secondary forming mold; the thickness of the neck is adjusted to shape the neck of the handle according to the combination temperature and the raw material supply of each part, so that the neck can be bent at the neck after a certain length of use, the user is prompted to replace, and the problem that the user's oral cavity is polluted after the toothbrush is used for more than the set length or times is effectively avoided.

Description

Technical Field

[0001] This invention relates to the field of injection molding technology, and in particular to a toothbrush handle molding equipment and method based on secondary injection molding. Background Technology

[0002] Toothbrushes, as hygiene products, are often used beyond their expiration date in daily life. Existing reminders often use color changes in the toothbrush bristles to indicate when to replace them; however, this method is ineffective and fails to ensure proper toothbrush replacement.

[0003] Currently, commonly used toothbrush molding equipment includes a secondary molding toothbrush injection molding machine disclosed in Chinese Patent Publication No. CN220517465U. This machine includes an injection molding machine with a fixed plate fixed to its side, a support plate fixed to the top of the fixed plate, an mounting plate slidably connected to the outer wall of the support plate, a connecting plate fixed to the top of the mounting plate, a guide rod fixed to the side wall of the support plate, the guide rod penetrating the mounting plate and slidably connected thereto, a second hydraulic rod fixed to the top of the support plate, the output end of the second hydraulic rod being connected and fixed to the connecting plate, the second hydraulic rod being used to push the mounting plate horizontally, a third hydraulic rod fixed to the top of the mounting plate, and a top plate fixed to the top of the third hydraulic rod. This invention improves toothbrush processing efficiency by setting a conveyor below an electric suction cup. When the electric suction cup releases the toothbrush, it falls onto the top of the conveyor, which then transports the toothbrush to the next processing step.

[0004] A Chinese patent publication (CN110682497B) discloses a fully automatic integrated secondary coating machine for toothbrushes. The coating machine consists of an automatic material sorting system and a vertical injection molding system. The automatic material sorting system comprises a material feeding mechanism, a material transfer mechanism, a moving tray mechanism, and a material transfer robot mechanism. The material feeding mechanism consists of a material dropper assembly, a chute lifting assembly, and a material discharge positioning assembly. The material transfer mechanism consists of a transverse module I and a material pickup unit. The moving tray mechanism consists of a transverse module II and a positioning mold. The material transfer robot mechanism includes an X-axis transverse module, a Z-axis lifting module, and a pickup clamping assembly. The vertical injection molding system consists of a vertical injection molding machine, an injection mold, and a side-loading robot assembly. The side-loading robot assembly consists of a motion module and a gripping module.

[0005] However, the above method has the following problems: except for using special color-developing materials, it cannot produce toothbrushes that can effectively indicate when to replace them. At the same time, the above equipment cannot produce toothbrush handles made of at least two materials, which leads to inaccurate molding of various parts of the toothbrush handle. Summary of the Invention

[0006] To address this issue, the present invention provides a toothbrush handle molding device and an automated blow molding method based on secondary injection molding, which overcomes the problem in the prior art that the toothbrush cannot effectively remind the user when it reaches its expiration date, thus leading to the toothbrush being used beyond its expiration date.

[0007] On one hand, the present invention provides a toothbrush handle molding device based on secondary injection molding, which is used for toothbrush handle molding and consists of a primary molding mold and a secondary molding mold, wherein the secondary molding mold includes:

[0008] Master mold;

[0009] The top mold is located on the side of the main mold near the toothbrush head, and there is a gap of a preset height between it and the main mold;

[0010] A neck mold, which is interconnected with the top mold and the main mold, and is capable of sliding within the gap;

[0011] The neck mold is equipped with a fracture shaping device, including:

[0012] A sensor, which is located inside the main mold, is used to measure the molding temperature and thickness of the rubber;

[0013] A controller, connected to the sensor and the neck mold, is used to determine the corresponding fracture molding position based on the molding temperature and the brush handle thickness.

[0014] The location of the fracture and shaping is related to the size of the brush head;

[0015] The neck bending force is positively correlated with the neck thickness;

[0016] The neck mold adjusts the corresponding fracture molding position according to the molding temperature.

[0017] Furthermore, it also includes:

[0018] Injection head;

[0019] The injection core is disposed at the neck mold and is provided with a sealing element that cooperates with the main mold and the top mold to seal the gaps at the neck mold and the main mold, and to seal the gaps at the top mold and the neck mold.

[0020] The main mold is connected to the injection head and the injection core, and has grooves corresponding to the injection head and the injection core for shaping the raw material and forming a brush handle;

[0021] The fracture shaping device is located at one end of the neck mold near the brush head and is connected to the neck mold to form a corresponding fracture shaping position on the brush handle.

[0022] Furthermore, the injection core surrounds the tail of the brush head and is positioned at a corresponding location on the neck mold to prevent raw materials from entering the corresponding location of the brush head during a single injection molding process.

[0023] The brush head is connected to the brush handle during the secondary injection molding process;

[0024] The injection-molded core is located on the extension line of the tail of the brush head.

[0025] Furthermore, the neck mold is located in the free area between the main mold and the top mold, and is provided with a limiter that can be fitted onto the injection core;

[0026] The limiter includes a pair of limit slots, and each limit slot can slide separately within the free area.

[0027] Furthermore, the controller determines the corresponding neck thickness and the corresponding neck bending force based on the thickness of the brush handle;

[0028] Wherein, the neck bending force is greater than the brush head bending force but less than the bending force threshold;

[0029] The bending force of the brush head is the minimum bending force that breaks the brush head;

[0030] The bending force threshold is proportional to the neck thickness, and a maximum threshold is provided.

[0031] Furthermore, when controlling the neck mold, the controller determines the position of the neck mold based on the neck bending force in order to reduce the neck thickness;

[0032] The thickness of the neck is inversely proportional to the bending force of the neck and directly proportional to the forming temperature.

[0033] Furthermore, the fracture shaping position is set according to the length of the neck and the length of the main mold. The controller has a preset ratio, wherein when the ratio of the length of the neck to the length of the main mold reaches the preset ratio, the fracture shaping position is set on the side closer to the main mold.

[0034] On the other hand, the present invention provides a method for molding a toothbrush handle based on secondary injection molding, comprising:

[0035] Step S1: Heat the raw material to the injection molding state;

[0036] Step S2: Place the injection core into the corresponding position of the primary molding mold and the neck mold, and close the mold;

[0037] Step S3: Inject raw material into the neck mold to complete one injection molding;

[0038] Step S4: Horizontally flip and open the one-time forming mold;

[0039] Step S5: Position the main mold, neck mold, and top mold and close the mold.

[0040] Step S6: Inject raw materials into the self-made mold to complete the secondary injection molding;

[0041] Step S7: Let it stand and reach the cooling temperature, then open the top mold, neck mold and main mold in sequence to form the finished brush handle;

[0042] Step S8: Remove the injection-molded core from the finished toothbrush.

[0043] Furthermore, step S5 also includes:

[0044] Step S501: Measure the temperature of the main mold at the junction of the main mold and the injection head where the raw material is located;

[0045] Step S502: Adjust the bending position of the neck mold according to the temperature of the main mold;

[0046] Step S503: Close the top mold and the neck mold in sequence;

[0047] The bending position refers to the position of the neck mold in the horizontal direction.

[0048] Furthermore, step S5 also includes:

[0049] Step S504: When the main mold is closed, the injection core is moved downwards and blocks the main mold;

[0050] Step S505: Adjust the position of the injection core so that it is close to the top mold to reach the preset position;

[0051] The preset position is the position where, during secondary injection molding, the neck mold can press onto the injection core at the corresponding position when the mold is closed, and the top mold can fit into the injection core.

[0052] Compared with the prior art, the beneficial effect of the present invention is that by setting the injection core, the main mold and the fracture molder on the secondary molding mold, the neck of the brush handle is shaped by adjusting the thickness of the neck according to the bonding temperature of each part and the supply of raw materials. This allows the neck to bend irreversibly after a certain period of use, thus prompting the user to replace the toothbrush. This effectively avoids the problem of oral contamination caused by the toothbrush being used beyond the set time or number of times.

[0053] Furthermore, by setting an injection core and a fracture molder at the neck mold, the raw material is sealed in the secondary molding mold, which effectively avoids the molding failure problem caused by raw material leakage. At the same time, by setting an injection core and cooperating with the primary molding mold, toothbrush handles of different shapes can be produced on the same production line, thereby effectively improving the yield of toothbrush handles while ensuring product hygiene.

[0054] Furthermore, by using a sliding limiter, the thickness and temperature of the brush handle neck are monitored and the breakage position of the brush handle neck is set. This not only prevents the toothbrush from causing oral contamination after being used for a set time or number of times, but also effectively improves the consistency and yield of individual batches of toothbrush handles.

[0055] Furthermore, by setting a bending force threshold and monitoring the toothbrush handle forming process, the breakage threshold of the toothbrush handle can be determined. At the same time, by adjusting the breakage position, the neck breakage behavior of the toothbrush handle can be controlled. This allows for the effective setting of reminders for users to replace their toothbrushes and avoids unnecessary breakage during normal use, thereby effectively improving the yield of toothbrush handles.

[0056] Furthermore, by controlling the secondary molding process, the neck mold, in conjunction with the fracture molding device, shapes the neck of the toothbrush handle. This effectively improves production efficiency and enhances the mechanical properties of the secondary injection molded toothbrush. Additionally, the neck is designed to automatically bend after a certain period of use, thus preventing the toothbrush from being used beyond its intended lifespan. Attached Figure Description

[0057] Figure 1 This is a schematic diagram of the toothbrush handle molding equipment based on secondary injection molding according to the present invention;

[0058] Figure 2 This is a schematic diagram of the toothbrush handle molding equipment based on secondary injection molding according to an embodiment of the present invention;

[0059] Figure 3 This is a schematic diagram showing the operation of the primary molding equipment and the secondary molding equipment according to an embodiment of the present invention;

[0060] Figure 4 This is a flowchart of a toothbrush handle forming method according to an embodiment of the present invention;

[0061] The components are: 1. Top mold; 2. Neck mold; 3. Main mold; 4. Fracture molder; 5. Brush handle; 6. Brush head; 7. One-time molding mold; 8. Injection core. Detailed Implementation

[0062] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0063] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0064] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0065] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0066] To better understand this plan, the relevant content is explained below:

[0067] Two-shot molding (or overmolding) is a technique that involves injecting two different materials or colors of plastic into a single part in two separate injection molding processes within a single production cycle.

[0068] For toothbrushes, the core purpose is to wrap a soft elastomer (such as rubber) around a hard plastic (such as PP or ABS) to provide a comfortable grip and anti-slip function.

[0069] The standard toothbrush handle forming process includes the following steps:

[0070] Step 1: Design the brush handle. The main body in the middle is made of rigid polypropylene (PP), while the area for the thumb and forefinger to hold it is covered with a layer of rubber.

[0071] Step Two:

[0072] Material selection:

[0073] For the first injection molding (rigid plastic): choose polypropylene (PP), which is low in cost, rigid, lightweight and waterproof.

[0074] Second injection molding (soft rubber): Select rubber that is soft, elastic, non-slip, comfortable to the touch, and has excellent surface adhesion to PP.

[0075] Step 3:

[0076] Mold making:

[0077] The core part of the mold can rotate. First, the hard plastic part is injected. After molding, the mold is rotated at a certain angle (such as 180°) to bring the hard plastic part to the second mold cavity, and then soft plastic is injected to wrap it.

[0078] Step 4: Injection Molding

[0079] A. First injection molding:

[0080] Injection molding: Molten PP material is injected into the first mold cavity.

[0081] Cooling and pressure holding: Allow it to cool and solidify fully, forming a complete hard brush handle skeleton.

[0082] Transfer: After the mold is opened, the hard plastic part is not ejected and detached. Instead, it is transferred to the second injection station along with the core part of the mold through the rotation or translation mechanism of the mold.

[0083] B. Second injection molding:

[0084] Preparation: At this point, the cured PP brush handle skeleton remains in the second mold cavity as an "insert".

[0085] Mold closing: The second mold cavity is closed, and the area of ​​the PP skeleton to be coated is precisely exposed in the new mold cavity space.

[0086] Secondary injection: Molten rubber material is injected into a second mold cavity, and the rubber flows through and wraps around the designated area of ​​the PP skeleton.

[0087] Bonding principle: Because PP and rubber have good compatibility at the molecular level, the high temperature of rubber will slightly melt the surface of PP. The two penetrate and intertwine at the contact interface, and after cooling, they form a strong chemical and mechanical bond, rather than a simple physical bond.

[0088] Cooling and holding pressure: Cool again to ensure that the soft rubber part is fully cured and tightly bonded to the hard rubber.

[0089] The present invention aims to utilize the characteristics of the toothbrush handle and the brush head to prepare a toothbrush handle that can alert the user through breakage. The appearance of the toothbrush handle is not limited, and the toothbrush head can be prepared in advance or simultaneously with the first or second injection molding.

[0090] It should be noted that if toothbrush heads are manufactured using secondary injection molding, the brush handle will provide better feedback, but the brush head will have lower hardness.

[0091] If toothbrush heads are manufactured using a single injection molding process, the brush handle will have a poorer feedback effect and will be prone to brittle fracture, but the brush head itself will have higher hardness.

[0092] Please see Figure 1 As shown, this is a schematic diagram of the toothbrush handle 5 molding device based on secondary injection molding according to the present invention. In the diagram, the mold of the molding device consists of a primary molding mold 7 and a secondary molding mold. Please refer to [link / reference needed]. Figure 2 As shown, this is a schematic diagram of the toothbrush handle 5 molding equipment based on secondary injection molding according to the present invention. In the figure, the secondary molding mold includes:

[0093] Main mold 3;

[0094] The top mold 1 is located on the side of the main mold 3 near the toothbrush head 6, and is separated from the main mold 3 by a gap of a preset height.

[0095] The neck mold 2 is connected to the top mold 1 and the main mold 3, and can slide within the gap;

[0096] Specifically, the neck mold 2 is provided with a fracture molder 4, including:

[0097] The sensor, which is installed inside the main mold 3, is used to measure the molding temperature and thickness of the rubber;

[0098] The controller, which is connected to the sensor and the neck mold 2, is used to determine the corresponding fracture molding position based on the molding temperature and the thickness of the brush handle 5.

[0099] The location of the fracture and shaping is related to the size of the brush head 6;

[0100] Neck bending force is positively correlated with neck thickness;

[0101] The neck mold 2 adjusts the corresponding fracture molding position according to the molding temperature.

[0102] By using an injection core 8, a main mold 3, and a fracture molder 4 on a secondary molding die, the neck of the brush handle 5 is shaped by adjusting the thickness of the neck according to the bonding temperature of each part and the supply of raw materials. This allows the neck to bend irreversibly after a certain period of use, thus reminding the user to replace the toothbrush. This effectively prevents the toothbrush from causing oral contamination after being used for more than the set time or number of times.

[0103] Please cooperate. Figure 2 See Figure 3As shown, this is a schematic diagram of the operation of the primary molding equipment and the secondary molding equipment according to an embodiment of the present invention. The diagram also includes:

[0104] An injection head is used to inject raw materials into a mold;

[0105] Injection core 8 is provided at the neck mold 2 and is provided to cooperate with the main mold 3 and the top mold 1 to seal the gaps at the neck mold 2 and the main mold 3, and to seal the gaps at the top mold 1 and the neck mold 2.

[0106] The main mold 3 is connected to the injection head and the injection core 8, and has grooves corresponding to the injection head and the injection core 8 for shaping the raw material and forming the finished brush handle 5.

[0107] The fracture shaping device 4 is located at one end of the neck mold 2 near the brush head 6 and is connected to the neck mold 2 to form a corresponding fracture shaping position on the brush handle 5.

[0108] Specifically, the injection core 8 surrounds the tail of the brush head 6 and is positioned at a corresponding location on the neck mold 2 to prevent raw materials from entering the corresponding location of the brush head 6 during a single injection molding process.

[0109] During the secondary injection molding process, the brush head 6 is connected to the brush handle 5;

[0110] The injection core 8 is located on the extension line at the tail of the brush head 6.

[0111] By using an injection core 8 and a fracture molding device 4 at the neck mold 2, the raw material is sealed in the secondary molding mold, which effectively avoids molding failure caused by raw material leakage. At the same time, by using the injection core 8 and cooperating with the primary molding mold, toothbrush handles 5 of different shapes can be produced on the same production line, thereby effectively improving the yield of toothbrush handles 5 while ensuring product hygiene.

[0112] Specifically, the neck mold 2 is located in the free area between the main mold 3 and the top mold 1, and is equipped with a limiter that can be fitted onto the injection core 8;

[0113] The limiter includes a pair of limit slots, and each limit slot can slide independently within the free area.

[0114] By using a sliding limiter, the thickness and temperature of the brush handle 5 neck are monitored and the breakage position of the brush handle 5 neck is adjusted and set. This not only prevents the toothbrush from causing oral contamination after being used for a set time or number of times, but also effectively improves the consistency and yield of individual batches of toothbrush handle 5.

[0115] Specifically, the controller determines the corresponding neck thickness and the corresponding neck bending force based on the thickness of the brush handle 5.

[0116] Among them, the neck bending force is greater than the brush head bending force 6 and less than the bending force threshold.

[0117] The bending force of brush head 6 is the minimum bending force that breaks brush head 6;

[0118] The bending force threshold is proportional to the neck thickness, and a maximum threshold is set.

[0119] Specifically, when controlling the neck mold 2, the controller determines the position of the neck mold 2 based on the neck bending force in order to reduce the neck thickness;

[0120] Among them, the thickness of the neck is inversely proportional to the neck bending force and directly proportional to the forming temperature.

[0121] In practice, the neck mold is installed in the free area between the main mold and the top mold.

[0122] The limiter (not shown in the figure) includes two symmetrical guide sliders fixed to the bottom of the neck mold, which can control the position of the neck mold.

[0123] Specifically, the fracture shaping position is set according to the length of the neck and the length of the main mold 3. The controller has a preset ratio. When the ratio of the length of the neck to the length of the main mold 3 reaches the preset ratio, the fracture shaping position is set on the side closer to the main mold 3.

[0124] In practice, the neck bending force can be set between 15N and 25N.

[0125] The brush head bending force (i.e. the minimum bending force required to break the brush head) can be set by controlling the length and thickness of the neck, and is generally set to 10N. The neck bending force must be greater than 10N to avoid accidental breakage during normal use.

[0126] Understandably, the brush head bending force can be set according to the brush handle length and by utilizing the thinnest point of the brush handle constructed using the fracture shaping device set in this scheme. During manufacturing, it can be selected according to Table 1 below. Table 1 is the brush head bending force selection table:

[0127] Table 1 Selection Table for Brush Head Bending Force

[0128]

[0129] It should be noted that the bending force of the brush head should generally not exceed the safety threshold of 30N to ensure that users (especially children) can break the brush head with reasonable force or during daily use, thus avoiding injury to the user.

[0130] By setting a bending force threshold and monitoring the forming process of the toothbrush handle 5, the breakage threshold of the toothbrush handle 5 is determined. At the same time, by adjusting the breakage position, the neck breakage behavior of the toothbrush handle 5 is made controllable. This allows for the effective setting of reminders for users to replace their toothbrushes and avoids unnecessary breakage during normal use, thereby effectively improving the yield of the toothbrush handle 5.

[0131] Please see Figure 4 As shown, it is a flowchart of a toothbrush handle forming method according to an embodiment of the present invention, including:

[0132] Step S1: Heat the raw material to the injection molding state;

[0133] Step S2: Place the injection core 8 into the corresponding position of the primary molding mold 7 and the neck mold 2, and close the mold;

[0134] Step S3: Inject raw material into the neck mold 2 to complete one injection molding;

[0135] Step S4: Horizontally flip and open the one-time forming mold 7;

[0136] Step S5: Position the main mold 3, neck mold 2, and top mold 1 and close the molds;

[0137] Step S6: Inject raw materials into three locations of the self-made mold to complete the secondary injection molding;

[0138] In addition, the mold-making process also includes:

[0139] Step S7: Let it stand and reach the cooling temperature, then open the top mold 1, neck mold 2 and main mold 3 in sequence to form the finished brush handle 5.

[0140] Step S8: Remove the injection-molded core 8 from the finished toothbrush.

[0141] Specifically, step S5 also includes:

[0142] Step S501: Measure the temperature of the main mold 3 at the junction of the main mold 3 and the injection head;

[0143] Step S502: Adjust the bending position of the neck mold 2 according to the temperature of the main mold 3;

[0144] Step S503: Close the top mold 1 and the neck mold 2 in sequence;

[0145] The bending position is the position of the neck mold 2 in the horizontal direction.

[0146] Specifically, step S5 also includes:

[0147] In step S504, when the main mold 3 is closed, the injection core 8 is moved downwards and blocks the main mold 3.

[0148] Step S505: Adjust the position of the injection core 8 so that it is close to the top mold 1 to reach the preset position;

[0149] The preset position is the position where the neck mold 2 can be pressed onto the injection core 8 when the mold is closed during the secondary injection molding process, and the top mold 1 can fit into the injection core 8.

[0150] By controlling the secondary molding process, the neck mold 2, together with the fracture molding device 4, shapes the neck of the toothbrush handle 5. This effectively improves production efficiency and enhances the mechanical properties of the secondary injection molded toothbrush. In addition, the neck is designed to automatically bend after a certain period of use, thus avoiding the problem of toothbrushes being used beyond their service life.

[0151] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

[0152] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A toothbrush handle molding equipment based on secondary injection molding, used for toothbrush handle molding, characterized in that, The toothbrush handle forming equipment consists of a primary forming mold and a secondary forming mold, wherein the secondary forming mold includes: Master mold; The top mold is located on the side of the main mold near the toothbrush head, and there is a gap of a preset height between it and the main mold; A neck mold, which is interconnected with the top mold and the main mold, and is capable of sliding within the gap; Injection head; The injection core is disposed at the neck mold and is used to seal the gap between the neck mold and the main mold, and to seal the gap between the top mold and the neck mold; A fracture shaping device is located at one end of the neck mold near the brush head and is connected to the neck mold to form corresponding fracture shaping positions on the brush handle. The main mold is connected to the injection head and the injection core, and is provided with grooves corresponding to the injection head and the injection core for shaping the raw material and forming a brush handle; The fracture shaping device includes: A sensor, which is located inside the main mold, is used to measure the molding temperature and thickness of the rubber; A controller, connected to the sensor and the neck mold, is used to determine the corresponding fracture molding position based on the molding temperature and the brush handle thickness. The location of the fracture and shaping is related to the size of the brush head; Neck bending force is positively correlated with neck thickness; The neck mold adjusts the corresponding fracture molding position according to the molding temperature; The injection core surrounds the tail of the brush head and is positioned at a corresponding location on the neck mold to prevent raw materials from entering the corresponding location of the brush head during a single injection molding process. The brush head is connected to the brush handle during the secondary injection molding process; The injection-molded core is disposed on the extension line of the tail of the brush head; The neck mold is located in the free area between the main mold and the top mold, and is provided with a limiter that can be fitted onto the injection core. The limiter includes a pair of limit slots, and each limit slot can slide within the free area. The controller determines the corresponding neck thickness and the corresponding neck bending force based on the thickness of the brush handle. The neck bending force is greater than the brush head bending force but less than the bending force threshold. The bending force of the brush head is the minimum bending force that breaks the brush head; The bending force threshold is proportional to the neck thickness, and a maximum threshold is provided.

2. The toothbrush handle molding equipment based on secondary injection molding according to claim 1, characterized in that, The fracture shaping position is set according to the length of the neck and the length of the main mold. The controller has a preset ratio. When the ratio of the length of the neck to the length of the main mold reaches the preset ratio, the fracture shaping position is set on the side closer to the main mold.

3. A method for forming a toothbrush handle based on secondary injection molding, wherein the equipment described in any one of claims 1-2 is characterized in that, include: Step S1: Heat the raw material to the injection molding state; Step S2: Place the injection core into the corresponding position of the primary molding mold and the neck mold, and close the mold; Step S3: Inject raw material into the neck mold to complete one injection molding; Step S4: Horizontally flip and open the one-time forming mold; Step S5: Position the main mold, neck mold, and top mold and close the mold. Step S6: Inject raw materials into the self-made mold to complete the secondary injection molding; Step S7: Let it stand and reach the cooling temperature, then open the top mold, neck mold and main mold in sequence to form the finished brush handle; Step S8: Remove the injection-molded core from the finished toothbrush.

4. The toothbrush handle forming method according to claim 3, characterized in that, Step S5 further includes: Step S501: Measure the temperature of the main mold at the junction of the main mold and the injection head where the raw material is located; Step S502: Adjust the bending position of the neck mold according to the temperature of the main mold; Step S503: Close the top mold and the neck mold in sequence; The bending position is the horizontal position of the neck mold.

5. The toothbrush handle forming method according to claim 4, characterized in that, Step S5 further includes: Step S504: When the main mold is closed, the injection core is moved downwards and blocks the main mold; Step S505: Adjust the position of the injection core so that it is close to the top mold to reach the preset position; The preset position is the position where, during secondary injection molding, the neck mold can press onto the injection core at the corresponding position when the mold is closed, and the top mold can fit against the injection core.

Images