A mold for making two-color products more closely injection bonded

Abstract

The application discloses a mold for tightly injection-molding and pasting a two-color product, which comprises a front mold and a back mold matched with each other, wherein the front mold comprises a first front mold core, a second front mold core, a first nozzle group and a second nozzle group, the back mold comprises two back mold cores which are symmetrically arranged and have the same structure, the back mold further comprises two movable floating plates, two groups of driving mechanisms and two groups of floating needles, the number of floating needles in each group is multiple, and the upper ends of the two groups of floating needles respectively penetrate into the two back mold cores, and one group of floating needles extends into a first cavity to form a glue running channel with a reverse buckle structure for a first color injection-molded part. The mold for tightly injection-molding and pasting a two-color product is characterized in that the floating plate, the floating needle and the driving mechanism are matched to form the glue running channel with the reverse buckle structure for the first color injection-molded part, so that the second color injection-molded part can form a cylindrical reverse buckle structure with the first color injection-molded part through the glue running channel, the adhesion of the two-color product with small volume and area is enhanced, and the quality of the product is improved.

Description

Technical Field

[0001] This invention relates to the field of mold technology, and in particular discloses a mold that enables two-color products to adhere more tightly during injection molding. Background Technology

[0002] Two-color injection molding refers to the molding process of injecting two different materials into the same mold, thereby creating parts formed from two materials. Sometimes the two materials are different colors, and sometimes they have different hardness, thus improving the product's aesthetics and assembly performance. Two-color injection molding technology is mainly used in the manufacturing of home appliances, daily-use plastic products, and automotive parts, and is a new type of injection molding technology that simplifies assembly processes and improves the appearance of products.

[0003] In existing two-color plastic part injection molding production, to improve efficiency and simplify production, two sets of front molds are used, one for molding the first color and the other for molding the second color. The two front molds have different cavities and structures to facilitate material embedding during two-color injection. Simultaneously, two identical rear molds are used. During injection molding, both molds operate simultaneously. After the first injection, the rear mold rotates 180 degrees and merges with the front mold of the second cavity to form a complete mold for the second injection. Because of the two-color injection, the bonding strength between the two materials is a crucial technical indicator. The shrinkage between the different materials is used to tightly bind the outer layer to the embedded primary injection part. However, fluctuations in process parameters during actual production can result in an unreliable bond, severely impacting product lifespan and even causing scrap.

[0004] The existing solution involves setting a slider in the mold to create an undercut structure in the first injection. Before the second injection, the slider retracts, and the second injection fills the undercut area, allowing the two injection parts to fit tightly together. However, this structure and method are not suitable for two-color injection molded products with small bonding areas, as it is difficult to accurately and reasonably set the slider's movable structure. Therefore, how to enhance the bonding strength of two-color injection molded products with small bonding areas has become an urgent problem to be solved. Summary of the Invention

[0005] In order to overcome the shortcomings and deficiencies of the existing technology, the purpose of this invention is to provide a mold that enables two-color products to be more tightly bonded during injection molding. By modifying the internal structure of the mold, the bonding degree of two-color injection molded products with small bonding areas is enhanced.

[0006] To achieve the above objectives, the present invention provides a mold for achieving tighter adhesion between two-color injection molded products, comprising a front mold and a rear mold that cooperate with each other. The front mold includes a first front mold core, a second front mold core, a first nozzle group, and a second nozzle group. The rear mold includes two symmetrically arranged and structurally identical rear mold cores. The first front mold core cooperates with one of the rear mold cores to form a first cavity, and the second front mold core cooperates with the other rear mold core to form a second cavity. The first nozzle group is used to inject a first-color injection molding fluid into the first cavity, and the second nozzle group is used to inject a second-color injection molding fluid into the second cavity. The rear mold also includes two floating mechanisms, which are arranged one-to-one with the two rear mold cores. The floating mechanisms are used to float when the rear mold cores are molding the first-color injection molded part so that the first injection molded part forms a flow channel.

[0007] The floating mechanism includes a movable floating plate, a set of drive mechanisms, and a set of floating pins. The floating plate is used to mount the floating pins.

[0008] Each set of drive mechanisms consists of four parts, which are respectively located at the four corners of the floating plate and are used to drive the floating plate to move.

[0009] There are multiple floating pins in each group. The upper ends of the two groups of floating pins pass through the two rear mold cores respectively. One group of floating pins extends into the first cavity to form a glue channel with an undercut structure in the first color injection molded part.

[0010] Specifically, the front mold includes a front template, a sprue seat, and a front mold base connected in sequence. There are two sprue seats, which are used to fix the first nozzle group and the second nozzle group respectively. The front mold base is used to fix the first front mold core and the second front mold core.

[0011] Specifically, the front mold also includes a front mold insert and a plurality of core pins. The front mold insert is disposed on the first front mold core and forms the first cavity with one of the rear mold cores. The plurality of core pins are installed on the first front mold core and pass through the front mold insert. The number of core pins is less than or equal to the number of a set of floating pins. Each core pin is correspondingly disposed to a floating pin and has the same axis. The core pins are used to form a flow channel for the first color injection molded part to be injected with the fluid for the second color injection molding.

[0012] Specifically, the front mold also includes two positioning rods. One end of the two positioning rods is installed on the front mold base, and the other end of the two positioning rods is inserted into the rear mold. Both positioning rods are located on the side of the first front mold core close to the second front mold core. The rear mold is provided with positioning holes for accommodating the positioning rods. The positioning rods are used for mold closing and positioning after the rear mold rotates.

[0013] Specifically, the rear mold also includes a base plate, mold feet, a rear template, and a rear mold base connected in sequence. There are three mold feet, which are spaced apart to form two movable spaces between the base plate and the rear template. The rear mold base is used to fix and install two rear mold cores. The bottom of the rear mold base is provided with clearance space for accommodating the movement of the floating plate. The floating plate is movably connected to the rear mold base via a guide.

[0014] Specifically, the drive mechanism includes a push rod, a lever, and a hinge. The push rod is movably inserted into the rear mold base, and the lever is hinged to the rear mold plate via the hinge. One end of the lever abuts against the bottom end of the push rod, and the other end of the lever abuts against the bottom of the floating plate.

[0015] Specifically, the bottom of the front mold base is provided with four clearance holes and four pads. The four clearance holes are arranged around the second front mold core and are used to accommodate the top of the ejector pin; the four pads are arranged around the first front mold core and are used to abut the top of the ejector pin.

[0016] Specifically, the rear mold also includes two ejection mechanisms, which are movably arranged in two different activity spaces, and both ejection mechanisms are used to eject the product.

[0017] Specifically, it also includes the following processes:

[0018] A. Drive the front mold and rear mold to close, so that a first cavity and a second cavity are formed between the front mold and the rear mold; B. Drive the floating pin to rise through the drive mechanism;

[0019] C. Inject the first color injection molding fluid into the first cavity to form the first color injection molded part;

[0020] D. The floating pin is reset by controlling the drive mechanism to form a flow channel in the first-color injection molded part for the flow of the second-color injection fluid, and then the front mold and rear mold are driven to open.

[0021] E. Control the rear mold to rotate 180° before driving the front and rear molds to close;

[0022] F. Inject the second color injection fluid into the first cavity to form the second color injection molded part, while simultaneously performing step B in the second cavity, and then inject the first color injection fluid into the second cavity to form the first color injection molded part; G. Open the mold and remove the second color injection molded part.

[0023] The beneficial effects of this invention: The mold for achieving tighter adhesion in two-color injection molding of products, as described in this invention, includes a front mold and a rear mold that cooperate with each other. The front mold includes a first front mold core, a second front mold core, a first nozzle group, and a second nozzle group. The rear mold includes two symmetrically arranged rear mold cores with identical structures. The rear mold also includes two movable floating plates, two sets of drive mechanisms, and two sets of floating pins. In actual production, when the front mold and rear mold are closed, the floating plate corresponding to the first cavity is driven upward by the drive mechanism, causing the corresponding set of floating pins to extend into the first cavity. The first nozzle group injects the first color injection molding fluid into the first cavity. The floating plate and floating pins corresponding to the second cavity do not move, and the second nozzle group does not work. The floating pins cause the first color injection molded part to form a glue-flowing channel with an undercut structure. After the first color injection molded part cools and solidifies, the front mold and rear mold are opened. The rear mold rotates 180 degrees and recloses with the front mold. At this time, the empty second cavity becomes the first cavity, and the corresponding... The floating plate is driven upward by the drive mechanism, causing a corresponding set of floating needles to extend into the first cavity. The first nozzle group injects the first color injection molding fluid into the first cavity. The cavity containing the first injection molded part is the second cavity, and its corresponding floating plate is no longer driven by the drive mechanism and returns to its original position. The floating needles retract from the first color injection molded part, and the second nozzle group injects the second color injection molding fluid into the second cavity. The second color injection molding fluid flows into the glue channel filling the first color injection molded part and cools and solidifies, thereby making the first color injection molded part and the second color injection molded part tightly bonded to form an inseparable integral product. At this time, the mold for tightly bonded two-color products is designed by using a floating plate, floating needles, and drive mechanism to form a glue channel with an undercut structure in the first color injection molded part. In this way, the second color injection molded part can form a cylindrical undercut structure with the first color injection molded part through the glue channel, enhancing the bonding of small-area two-color products and improving the quality of such products. Attached Figure Description

[0024] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0025] Figure 2 For the present invention Figure 1 A schematic diagram of the cross-sectional structure of AA;

[0026] Figure 3 For the present invention Figure 1 Schematic diagram of the cross-sectional structure of BB;

[0027] Figure 4 For the present invention Figure 2 A schematic diagram of the local structure of C;

[0028] Figure 5 For the present invention Figure 2 A schematic diagram of the local structure of D;

[0029] Figure 6For the present invention Figure 3 A schematic diagram of the partial structure of E in the middle;

[0030] Figure 7 For the present invention Figure 6 A schematic diagram of the local structure of F;

[0031] Figure 8 This is a three-dimensional structural diagram of the floating mechanism of the present invention.

[0032] The reference numerals in the figures include:

[0033] 1—Front mold; 10—First front mold core; 11—Second front mold core

[0034] 12—First Nozzle Group 13—Second Nozzle Group 14—Front Template

[0035] 15—Gateway seat; 16—Front mold seat; 161—Relief hole

[0036] 162—Padded block; 17—Front mold insert; 18—Core pin

[0037] 19—Positioning rod

[0038] 2—Rear mold 20—Rear mold core 201—Positioning hole

[0039] 21—Floating plate 22—Drive mechanism 221—Push rod

[0040] 222—Lever 223—Hinge 23—Floating Pin

[0041] 24—Base plate 25—Mold foot 26—Rear template

[0042] 27—Rear mold base 28—Ejection mechanism

[0043] 3—Two-color product; 31—First color injection molded part; 32—Second color injection molded part. Detailed Implementation

[0044] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention.

[0045] Please see Figures 1 to 8As shown, the present invention provides a mold for achieving tighter adhesion between two-color injection molded products. It includes a front mold 1 and a rear mold 2 that cooperate with each other. The front mold 1 includes a first front mold core 10, a second front mold core 11, a first nozzle assembly 12, and a second nozzle assembly 13. The shapes of the first front mold core 10 and the second front mold core 11 differ. The first front mold core 10 requires a columnar structure to form a hole structure in the first-color injection molded part 31. The rear mold 2 includes two symmetrically arranged and structurally identical rear mold cores 20. The first front mold core 10 cooperates with one of the rear mold cores 20 to form a first cavity, and the second front mold core 11 cooperates with the other rear mold core 20 to form a second cavity. The first nozzle assembly 12 is used to inject the first-color injection molding fluid into the first cavity, and the second nozzle assembly 13 is used to inject the second-color injection molding fluid into the second cavity. The first nozzle assembly 12 and the second nozzle assembly 13 are respectively connected to different single-color injection molding machines. In this embodiment, both the first nozzle assembly 12 and the second nozzle assembly 13 include two nozzles. One rear mold core 20 has two structurally identical cavities, allowing for the production of two products at a time.

[0046] In actual production, the first front mold core 10 and a rear mold core 20 form a first cavity. The first nozzle group 12 injects the first color injection molding fluid into the first cavity. The second front mold core 11 and another rear mold core 20 form a second cavity. The second nozzle group 13 does not inject the second color injection molding fluid into the second cavity for the time being. After the injection molding fluid in the first cavity cools and solidifies into the first color injection molded part 31, the front mold 1 and the rear mold 2 open. The rear mold 2 rotates 180° and re-closes with the front mold 1. At this time, the first front mold core 10 and the rear mold core 2 without the injection molded part are... A new first cavity is formed. The second front mold core 11 and the rear mold core 20, which houses the first-color injection molded part 31, form a new second cavity. The first nozzle group 12 injects the first-color injection molding fluid into the new first cavity, while the second nozzle group 13 injects the second-color injection molding fluid into the new second cavity. After the injection molding fluids in the first cavity and the second cavity have cooled and solidified, the front mold 1 and the rear mold 2 are opened again to demold the two-color injection molded product in the second cavity. The rear mold 2 is then rotated 180° again, and the above steps are repeated for cyclic production.

[0047] The rear mold 2 also includes two floating mechanisms, each corresponding to one of the two rear mold cores 20. These floating mechanisms are used to float the rear mold core 20 when molding the first color injection molded part, allowing the first injection molded part to form a flow channel. Figure 8As shown, the floating mechanism includes a movable floating plate 21, a set of drive mechanisms 22, and a set of floating pins 23. The floating plate 21 is used to mount the floating pins 23. When the front mold 1 and the rear mold 2 are closed, the front mold 1 will trigger the set of drive mechanisms 22 corresponding to the first front mold core 10, causing the drive mechanisms 22 to drive the corresponding floating plate 21 to move closer to the front mold 1, thereby causing the set of floating pins 23 on the floating plate 21 to insert into the first cavity. The set of drive mechanisms 22 corresponding to the second front mold core 11 will not be triggered, so the floating plate 21 corresponding to it will not move, and the set of floating pins 23 on the floating plate 21 will not insert into the second cavity, but will only remain in the rear mold core 20.

[0048] Each group of drive mechanisms 22 consists of four parts. The four drive mechanisms 22 are respectively set at the four corners of the floating plate 21 and are used to drive the floating plate 21 to move. Each floating plate 21 is provided with four drive mechanisms 22, and the four drive mechanisms 22 are set at the four corners. The four drive mechanisms 22 drive the floating plate 21 to move at the same time, so that the movement of the floating plate 21 is more stable, thereby making the group of floating needles 23 move stably and helping to protect the floating needles 23 from damage.

[0049] There are multiple floating pins 23 in each group. The upper ends of the two groups of floating pins 23 pass through the two rear mold cores 20 respectively. One group of floating pins 23 extends into the first cavity to form a flow channel with an undercut structure in the first color injection molded part 31. A group of floating pins 23 corresponding to the first front mold core 10 extends into the first cavity and cooperates with the columnar structure of the first front mold core 10. After the first color injection fluid fills the first cavity, the first color injection molded part 31, after cooling and forming, has a flow channel with an undercut structure. When the mold is opened, the rear mold 2 rotates 180 degrees and then closes, the group of floating pins 23 that have entered the hole of the first color injection molded part 31 exits the first color injection molded part 31, allowing the second color injection fluid to enter the flow channel. Then, it cools and forms a columnar undercut structure, so that the first color injection molded part 31 and the second color injection molded part 32 are tightly bonded to form a two-color product 3.

[0050] In actual production, the front mold 1 and the rear mold 2 are closed. At this time, the floating plate 21 corresponding to the first cavity is driven upward by the driving mechanism 22, causing a set of floating needles 23 to extend into the first cavity. The first nozzle group 12 injects the first color injection molding fluid into the first cavity. The floating plate 21 and floating needles 23 corresponding to the second cavity do not move, and the second nozzle group 13 does not work. The floating needles 23 will cause the first color injection molded part 31 to form a hole with an undercut structure. After the first color injection molded part 31 cools and solidifies, the front mold 1 and the rear mold 2 are opened. The rear mold 2 rotates 180 degrees and recloses with the front mold 1. At this time, the empty second cavity becomes the first cavity, and the corresponding floating... The moving plate 21 is driven upward by the driving mechanism 22, causing a corresponding set of floating needles 23 to extend into the first cavity. The first nozzle group 12 injects the first color injection molding fluid into the first cavity. The cavity with the first injection molded part is the second cavity. The corresponding floating plate 21 is no longer driven by the driving mechanism 22 and returns to its original position. The set of floating needles 23 exits the first color injection molded part 31. The second nozzle group 13 injects the second color injection molding fluid into the second cavity. The second color injection molding fluid flows into the glue channel filling the first color injection molded part 31 and cools and forms, thereby making the first color injection molded part 31 and the second color injection molded part 32 tightly bonded to form an inseparable whole product.

[0051] Please see Figures 1 to 3 As shown, the front mold 1 includes a front mold plate 14, a sprue seat 15, and a front mold base 16 connected in sequence. There are two sprue seats 15, which are used to fix the first nozzle assembly 12 and the second nozzle assembly 13, respectively. The front mold base 16 is used to fix the first front mold core 10 and the second front mold core 11. The two sprue seats 15 are arranged left and right corresponding to the positions of the first front mold core 10 and the second front mold core 11, respectively. In this embodiment, the gate for connecting the first nozzle assembly 12 is located on one side of the sprue seat 15 where the first nozzle assembly 12 is installed, and the gate for connecting the second nozzle assembly 13 to the injection molding machine is located on the front mold plate 14.

[0052] Please see Figure 5As shown, in this embodiment, the front mold 1 further includes a front mold insert 17 and a plurality of core pins 18. The front mold insert 17 is disposed on the first front mold core 10 and forms the first cavity with one of the rear mold cores 20. The plurality of core pins 18 are installed on the first front mold core 10 and pass through the front mold insert 17. The number of core pins 18 is less than or equal to the number of a set of floating pins 23. Each core pin 18 is correspondingly disposed with one floating pin 23 and has the same axis. The core pins 18 are used to form a flow channel for the first color injection molded part 31 to be injected with the second color injection fluid. There are two front mold inserts 17, which correspond to the two cavities of one rear mold 2 respectively. The columnar structure that the first front mold core 10 needs to be provided is replaced in this embodiment by a plurality of core pins 18 and protrusions provided on the front mold insert 17, which facilitates the production and processing of the first front mold core 10. The diameter of the core pin 18 and the diameter of the protrusion are both smaller than the diameter of the floating pin 23. The protrusion of the core pin 18 or / and the front mold insert 17 abuts against the floating pin 23, so that the hole formed by the first color injection molded part 31 is smaller at the top and larger at the bottom. The fluid for the second color injection molding flows into the glue channel and cools to form a column with a smaller diameter at the top and larger at the bottom. The column of the second color injection molded part 32 and the hole of the first color injection molded part 31 are interlocked to make the first injection molded part and the second injection molded part fit tightly together.

[0053] Please see Figure 2 and Figure 5 As shown, the front mold 1 also includes two positioning rods 19. One end of each positioning rod 19 is mounted on the front mold base 16, and the other end is inserted into the rear mold 2. Both positioning rods 19 are located on the side of the first front mold core 10 near the second front mold core 11. The rear mold 2 is provided with positioning holes 201 for accommodating the positioning rods 19. The positioning rods 19 are used for mold closing and positioning after the rear mold 2 rotates. The rear mold 2 is provided with four positioning holes 201, which are arranged in pairs inside the two rear mold cores 20. During the injection molding process, when the mold is opened and the rear mold 2 rotates 180 degrees and then closes again, the cooperation between the two positioning rods 19 and the positioning holes 201 enables the front mold 1 and the rear mold 2 to close precisely, ensuring the accuracy and quality of the product.

[0054] Please see Figures 1 to 3As shown, the rear mold 2 also includes a base plate 24, mold feet 25, a rear template 26, and a rear mold base 27 connected in sequence. There are three mold feet 25, which are spaced apart to form two movable spaces between the base plate 24 and the rear template 26. The rear mold base 27 is used to fix and install two rear mold cores 20. The bottom of the rear mold base 27 is provided with clearance space for accommodating the movement of a floating plate 21. The floating plate 21 is movably connected to the rear mold base 27 via a guide. Positioning holes 201 pass through the rear mold cores 20, the rear mold base 27, and the rear template 26. The base plate 24 is connected to a central shaft, which passes through the middle mold feet 25 and the rear template 26 and is connected at its end to the rear mold base 27. The two rear mold cores 20 and the four positioning holes 201 are symmetrically arranged about the axis of the central shaft. The entire rear mold 2 rotates around the axis of the central shaft.

[0055] Please see Figures 6 to 8 As shown, the drive mechanism 22 includes a push rod 221, a lever 222, and a hinge 223. The push rod 221 is movably inserted into the rear mold base 27, and the lever 222 is hinged to the rear mold plate 26 via the hinge 223. One end of the lever 222 abuts against the bottom end of the push rod 221, and the other end of the lever 222 abuts against the bottom of the floating plate 21. In the drive mechanism 22 corresponding to the first front mold core 10, the push rod 221 is pressed against the front mold 1 to apply pressure to one end of the lever 222, and the other end of the lever 222 pries the floating plate 21 closer to the rear mold core 20, thereby driving the floating pin 23 to insert into the first cavity. The drive mechanism 22 corresponding to the second front mold core 11 does not contact the front mold 1, so the push rod 221 and the lever 222 are in a stationary state, and the floating plate 21 and the floating pin 23 are in the initial position.

[0056] Please see Figure 6 As shown, the bottom of the front mold base 16 is provided with four clearance holes 161 and four pads 162. The four clearance holes 161 are arranged around the second front mold core 11 and are used to accommodate the top end of the ejector rod 221. The four pads 162 are arranged around the first front mold core 10 and are used to abut the top end of the ejector rod 221. When the mold is closed, the four pads 162 simultaneously abut the top end of the corresponding ejector rod 221, so that the ejector rod 221 applies pressure to one end of the lever 222. The other end of the lever 222 pries the floating plate 21 closer to the rear mold core 20, thereby driving the set of floating pins 23 to insert into the first cavity. The floating plate 21 and floating pins 23 corresponding to the second front mold core 11 are in the initial position. The floating plate 21 presses against one end of the lever 222, and the other end of the lever 222 abuts against the ejector rod 221. The upper end of the ejector rod 221 extends into the clearance hole 161. When the front mold 1 and the rear mold 2 are opened and the rear mold 2 is rotated to close the mold again, the four clearance holes 161 and the four pads 162 are swapped relative to the rear mold 2, and the activity states of the two sets of drive mechanisms 22 are opposite to the above states, realizing alternating work.

[0057] Please see Figures 1 to 3As shown, the rear mold 2 also includes two ejection mechanisms 28, which are movably disposed in two separate movable spaces. Both ejection mechanisms 28 are used to eject products. Each ejection mechanism 28 includes a push plate, an ejector plate, and multiple ejector pins. The push plate is connected to the rear mold plate 26 via guide pillars, the ejector plate is mounted on the push plate, and the multiple ejector pins are mounted on the ejector plate. The two ejection mechanisms 28 do not eject products simultaneously; instead, they alternately eject the two-color products 3 formed on their corresponding rear mold cores 20. The ejection mechanism 28 corresponding to the cavity of a formed two-color product 3 will eject and demold that product. The base plate 24 is provided with through holes corresponding to the two ejection mechanisms 28. The drive ends of two cylinders pass through these through holes to drive the two ejection mechanisms 28, achieving alternating ejection actions.

[0058] Specifically, it also includes the following processes:

[0059] A. Drive the front mold and rear mold to close, so that a first cavity and a second cavity are formed between the front mold and the rear mold; B. Drive the floating pin to rise through the drive mechanism;

[0060] C. Inject the first color injection molding fluid into the first cavity to form the first color injection molded part;

[0061] D. The floating pin is reset by controlling the drive mechanism to form a flow channel in the first-color injection molded part for the flow of the second-color injection fluid, and then the front mold and rear mold are driven to open.

[0062] E. Control the rear mold to rotate 180° before driving the front and rear molds to close;

[0063] F. Inject the second color injection fluid into the first cavity to form the second color injection molded part, while simultaneously performing step B in the second cavity, and then inject the first color injection fluid into the second cavity to form the first color injection molded part; G. Open the mold and remove the second color injection molded part.

[0064] The above description is only a preferred embodiment of the present invention. For those skilled in the art, there will be changes in the specific implementation and application scope based on the ideas of the present invention. The content of this specification should not be construed as a limitation of the present invention.

Claims

1. A mold for making two-color products adhere more tightly during injection molding, comprising a front mold (1) and a rear mold (2) that cooperate with each other, the front mold (1) comprising a first front mold core (10), a second front mold core (11), a first nozzle group (12), and a second nozzle group (13), the rear mold (2) comprising two symmetrically arranged and structurally identical rear mold cores (20), the first front mold core (10) cooperating with one of the rear mold cores (20) to form a first cavity, the second front mold core (11) cooperating with the other rear mold core (20) to form a second cavity, the first nozzle group (12) being used to inject a first-color injection molding fluid into the first cavity, and the second nozzle group (13) being used to inject a second-color injection molding fluid into the second cavity; characterized in that: The rear mold (2) also includes two floating mechanisms, which are set one-to-one with the two rear mold cores (20). The floating mechanisms are used to float when the rear mold core (20) is molding the first color injection molded part so that the first injection molded part forms a glue channel. The floating mechanism includes a movable floating plate (21), a set of drive mechanisms (22), and a set of floating pins (23). The floating plate (21) is used to mount the floating pin (23); The number of each set of drive mechanisms (22) is four. The four drive mechanisms (22) are respectively set at the four corners of the floating plate (21) and are used to drive the floating plate (21) to move. There are multiple floating pins (23) in each group. The upper ends of the two groups of floating pins (23) pass through the two rear mold cores (20) respectively. One group of floating pins (23) extends into the first cavity so that the first color injection molded part (31) forms a glue channel with an undercut structure. The front mold (1) also includes a front mold insert (17) and a plurality of core pins (18). The front mold insert (17) is disposed on the first front mold core (10) and forms the first cavity with one of the rear mold cores (20). The plurality of core pins (18) are installed on the first front mold core (10) and pass through the front mold insert (17). The number of core pins (18) is less than or equal to the number of a set of floating pins (23). Each core pin (18) is disposed corresponding to a floating pin (23) and has the same axis. The core pins (18) are used to form a flow channel for the first color injection molded part (31) to be injected with the second color injection fluid.

2. The mold for making two-color products adhere more tightly during injection molding according to claim 1, characterized in that: The front mold (1) includes a front template (14), a sprue seat (15) and a front mold base (16) connected in sequence. There are two sprue seats (15). The two sprue seats (15) are used to fix the first nozzle group (12) and the second nozzle group (13) respectively. The front mold base (16) is used to fix the first front mold core (10) and the second front mold core (11).

3. The mold for making two-color products adhere more tightly during injection molding according to claim 2, characterized in that: The front mold (1) also includes two positioning rods (19). One end of the two positioning rods (19) is installed on the front mold base (16), and the other end of the two positioning rods (19) is inserted into the rear mold (2). The two positioning rods (19) are located on the side of the first front mold core (10) close to the second front mold core (11). The rear mold (2) is provided with a positioning hole (201) for accommodating the positioning rods (19). The positioning rods (19) are used for mold closing and positioning after the rear mold (2) rotates.

4. The mold for making two-color products adhere more tightly during injection molding according to claim 1, characterized in that: The rear mold (2) also includes a base plate (24), mold feet (25), a rear template (26) and a rear mold base (27) connected in sequence. There are three mold feet (25). The three mold feet (25) are spaced apart so that two movable spaces are formed between the base plate (24) and the rear template (26). The rear mold base (27) is used to fix two rear mold cores (20). The bottom of the rear mold base (27) is provided with a clearance space for accommodating the movement of the floating plate (21). The floating plate (21) is movably connected to the rear mold base (27) via a guide.

5. The mold for making two-color products adhere more tightly during injection molding according to claim 4, characterized in that: The drive mechanism (22) includes a push rod (221), a lever (222) and a hinge (223). The push rod (221) is movably inserted into the rear mold base (27). The lever (222) is hinged to the rear template (26) via the hinge (223). One end of the lever (222) abuts against the bottom end of the push rod (221), and the other end of the lever (222) abuts against the bottom of the floating plate (21).

6. The mold for making two-color products adhere more tightly during injection molding according to claim 5, characterized in that: The bottom of the front mold base (16) is provided with four clearance holes (161) and four pads (162). The four clearance holes (161) are arranged around the second front mold core (11) and are used to accommodate the top of the ejector rod (221). The four pads (162) are arranged around the first front mold core (10) and are used to abut against the top of the ejector rod (221).

7. The mold for making two-color products adhere more tightly during injection molding according to claim 4, characterized in that: The rear mold (2) also includes two ejection mechanisms (28), which are respectively movably set in two activity spaces. Both ejection mechanisms (28) are used to eject the two-color product (3).

8. The mold for making two-color products adhere more tightly during injection molding according to claim 1, characterized in that: It also includes the following processes: A. Drive the front mold and the rear mold to close the mold, so that a first cavity and a second cavity are formed between the front mold and the rear mold; B. The floating needle is driven to rise via a drive mechanism; C. Inject the first color injection molding fluid into the first cavity to form the first color injection molded part; D. The floating pin is reset by controlling the drive mechanism to form a flow channel in the first-color injection molded part for the flow of the second-color injection fluid, and then the front mold and rear mold are driven to open. E. Control the rear mold to rotate 180° before driving the front and rear molds to close; F. Inject the second color injection molding fluid into the first cavity to form the second color injection molded part, while performing step B in the second cavity, and then inject the first color injection molding fluid into the second cavity to form the first color injection molded part; G. Open the mold and remove the second color injection molded part.

Images