CN112440428A

CN112440428A - Injection molding method of flexible film

Info

Publication number: CN112440428A
Application number: CN201910793784.0A
Authority: CN
Inventors: 李运峰; 吴江; 王土权
Original assignee: Shenzhen Sibionics Technology Co Ltd
Current assignee: Shenzhen Sibionics Technology Co Ltd
Priority date: 2019-08-27
Filing date: 2019-08-27
Publication date: 2021-03-05

Abstract

The present disclosure relates to an injection molding method of a flexible film, which includes: a configuration step of preparing an upper die with a first groove and a lower die matched with the upper die, and configuring a flexible film in the lower die, wherein the lower die is provided with an injection port for providing injection molding raw materials; a mold closing step of closing the upper mold and the lower mold to form a mold cavity; a positioning procedure, namely injecting injection molding raw materials into the mold cavity through the injection port to enable the flexible film to float and be attached to the bottom of the first groove; and a molding step of holding the upper mold and the lower mold and curing and molding the injection molding material by heat treatment of the upper mold and the lower mold. According to the present disclosure, it is possible to provide an injection molding method that facilitates positioning of a flexible film in a mold and molding into a flexible film having a specific shape.

Description

Injection molding method of flexible film

Technical Field

The disclosure relates to the field of injection molding, and in particular relates to an injection molding method of a flexible film.

Background

In the field of medical devices, silicone injection molding of many sensing or structural components is required to meet biocompatibility. For implantable medical devices, for example, the sensing or structural components are often injection molded into a particular shape as needed for the environment of use.

In the existing injection molding of a sensing part or a structural part such as a flexible film, a previously prepared flexible film is loaded in a mold, and then a liquid silicone material is injected, and the liquid silicone is solidified in combination with the flexible film, thereby being injection molded into a product having a specific shape. In order to form the stimulation component into a particular shape, it is generally necessary to pre-bond the flexible membrane to the inner surface of the cavity and then cure it into the particular shape.

However, in the above prior art, if the flexible film is adhered to the inner surface of the mold in advance, the adhesive is applied to the surface of the flexible film, and the flexible film is separated from the mold after molding, which may easily cause damage to the parts and affect the usability thereof.

BRIEF SUMMARY OF THE PRESENT DISCLOSURE

The present disclosure has been made in view of the above-mentioned state of the art, and an object thereof is to provide an injection molding method capable of easily positioning and forming a flexible film having a specific shape.

Therefore, the present disclosure provides an injection molding method of a flexible film, which is characterized in that: the method comprises the following steps: a configuration step of preparing an upper die having a first groove and a lower die matched with the upper die, and configuring a flexible film in the lower die, wherein the lower die is provided with an injection port for providing an injection molding raw material; a mold closing step of closing the upper mold and the lower mold to form a mold cavity; a positioning step of injecting a molding material into the cavity through the injection port to float the flexible film and attach the film to the bottom of the first groove; and a molding step of holding the upper mold and the lower mold, and curing and molding the injection molding material by heat-treating the upper mold and the lower mold.

In the present disclosure, the flexible film is disposed in the cavity formed by the upper mold and the lower mold, and the injection molding raw material is injected into the cavity, in which case the flexible film may be floated by buoyancy of the injection molding raw material to be attached to the bottom of the first groove, and then the upper mold and the lower mold may be held and heat-treated. Therefore, the flexible film can be conveniently positioned, and an injection molding product with a specific shape can be formed.

In the injection molding method provided by the present disclosure, optionally, in the positioning step, the flexible thin film is closely attached to the bottom of the first groove by filling the mold cavity with the injection molding material. In this case, it is possible to make one side of the flexible film fit to the first groove without being coated with the injection molding material, and to make a predetermined portion of the flexible film, for example, the other side, be sufficiently coated with the injection molding material.

In the injection molding method provided by the present disclosure, optionally, the density of the flexible film is less than the density of the injection molding raw material. Thereby enabling the flexible film to float under the buoyancy of the injection molding raw material.

In the injection molding method provided by the present disclosure, optionally, the heat treatment is selected from one or a combination of cooling, heat preservation and heating. Therefore, injection molding raw materials with different properties can be better cured and molded.

In the injection molding method provided by the present disclosure, optionally, in the positioning process, the injection molding raw material covers an edge of the flexible film. In this case, the injection molding material can be wrapped around the edge of the flexible film, thereby enabling the flexible film to be wrapped more completely.

In the injection molding method provided by the present disclosure, optionally, the flexible film has a functional region and a non-functional region, and the functional region is not covered by the injection molding material in the positioning process. This makes it possible to leave the functional regions of the flexible film uncovered by the casting compound.

In the injection molding method provided by the present disclosure, optionally, in the molding step, the flexible film is molded into a curved surface shape having a prescribed curvature. This makes it possible to adapt the flexible film to different process requirements.

In the injection molding method provided by the present disclosure, optionally, at the lower mold, a plurality of the injection ports are provided, and the flexible film covers the plurality of the injection ports. In this case, the molding material can be introduced into the cavity from the lower mold, whereby the flexible film can be floated by the buoyancy of the molding material.

In the injection molding method provided by the present disclosure, optionally, at the lower mold, a second groove for configuring the flexible film is provided. Thereby enabling the flexible film to be disposed in the lower mold.

In the injection molding method provided by the present disclosure, optionally, the bottom of the second groove is in a protrusion shape having a prescribed curvature. In this case, the flexible film can be cured to different shapes, thereby making it possible to adapt the flexible film to different process requirements better.

According to the present disclosure, an injection molding method of a flexible film, which facilitates positioning of the flexible film in a mold and can be molded into different shapes according to process requirements, can be provided.

Drawings

Fig. 1 is a schematic flow chart illustrating an injection molding method according to an embodiment of the present disclosure.

Fig. 2 is a schematic structural view illustrating a mold according to an embodiment of the present disclosure.

Fig. 3 is a schematic structural view showing a mold in a separated state according to an embodiment of the present disclosure.

Fig. 4 is a schematic diagram illustrating placing a flexible film in a mold for injection molding according to an embodiment of the present disclosure.

Fig. 5 is a partial schematic view of the mold cavity of fig. 4.

Fig. 6 is a schematic sectional view showing the mold shown in fig. 4 after clamping and injecting the injection molding material.

Fig. 7 is a schematic cross-sectional view illustrating a mold when a flexible film according to an embodiment of the present disclosure is positioned at an upper mold.

Fig. 8 is a schematic sectional view showing another example of a mold when injecting an injection molding material according to the embodiment of the present disclosure.

Description of the symbols of the drawings:

1 … mold, 10 … upper mold, 10a … first butt surface, 11 … first groove, 11a … bottom, 20 … lower mold, 20a … second butt surface, 21 … second groove, 21a … bottom, 110 … injection molding channel, 110a1,110a2 … sub-channel, 110a … injection molding hole, 111,112 111,112 … injection port, 30 … flexible film, 30a … upper surface, 30b … lower surface, 40 … mold cavity.

Detailed Description

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description, the same components are denoted by the same reference numerals, and redundant description thereof is omitted. The drawings are schematic and the ratio of the dimensions of the components and the shapes of the components may be different from the actual ones.

In addition, the headings and the like referred to in the following description of the present disclosure are not intended to limit the content or scope of the present disclosure, but merely serve as a reminder for reading. Such a subtitle should neither be understood as a content for segmenting an article, nor should the content under the subtitle be limited to only the scope of the subtitle.

The injection molding method according to the present disclosure is an injection molding method of a flexible film (hereinafter also simply referred to as "injection molding method"). In the injection molding method according to the present disclosure, the flexible film is placed in a mold, and the injection material is injected into the mold so that the flexible film floats up in the mold due to the buoyancy of the injection material and adheres to the mold to form a shape having a predetermined curvature, and then the mold is subjected to heat treatment to perform injection molding on the flexible film. Specific embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

In the present disclosure, the flexible film may be applied in the field of medical devices, for example, the flexible film may be applied to a retinal electrical stimulator, which may include an implanted portion and an extracorporeal portion. The flexible membrane may be applied to an implanted portion of a retinal electrical stimulator. It is therefore desirable to injection mold flexible films to meet biocompatibility. The flexible film may be formed into a particular shape.

In some examples, the flexible membrane may be a flexible membrane having stimulation electrodes. In other words, the flexible membrane is a stimulation component having stimulation electrodes, for example, which may be used as a sensing component for neurostimulation of an implantable medical device. In this case, the region of the flexible film having the stimulation electrodes (stimulation electrode region) may be exposed without being covered by the injection molding material (e.g., liquid silicone).

The injection molding method according to the present disclosure is particularly suitable for injection molded objects having flexibility such as flexible films. The injection object is placed in a mold, and an injection material is injected into the mold so that the injection object floats up in the mold due to the buoyancy of the injection material and adheres to the mold to form a shape having a predetermined curvature, and then the mold is heat-treated to perform injection molding on the injection object.

In the present embodiment, as shown in fig. 1, the injection molding method may include the steps of: a placement step of preparing an upper mold 10 having a first recess 11 and a lower mold 20 fitted to the upper mold 10, and placing a flexible film 30 in the lower mold 20, wherein the lower mold 20 is provided with an injection port for supplying an injection molding material (step S10); a mold clamping step of clamping the upper mold 10 and the lower mold 20 to form the cavity 40 (step S20); a positioning step of injecting a molding material into the cavity through the injection port to float the flexible film 30 and attach the same to the bottom 11a of the first groove 11 (step S30); and a molding step of holding the upper mold 10 and the lower mold 20 and curing and molding the injection material by heat-treating the upper mold 10 and the lower mold 20 (step S40).

In step S10, as described above, the upper mold 10 having the first groove 11 and the lower mold 20 mated with the upper mold 10 are prepared, and the flexible film 30 is arranged in the lower mold 20, wherein the lower mold 20 is provided with the injection ports (the

injection ports

111 and 112 in the present embodiment, see fig. 6) that provide the injection molding raw material.

Fig. 2 is a schematic structural view showing the mold 1 according to the embodiment of the present disclosure. Fig. 3 is a schematic structural view showing the mold 1 according to the embodiment of the present disclosure.

In some examples, as shown in fig. 2, the upper mold 10 and the lower mold 20 may be assembled to form the mold 1, that is, in step S10, the mold 1 including the upper mold 10 and the lower mold 20 may be used. In some examples, the upper mold 10 may be mated with the lower mold 20, e.g., secured together by bolting.

In the present embodiment, the outer shape of the mold 1 is not particularly limited, and may be, for example, a rectangular parallelepiped, a cylindrical body, a square body, or an irregular three-dimensional structure.

In some examples, the upper mold 10 has a first butting surface 10a, and the lower mold 20 has a second butting surface 20a that butts against the first butting surface 10 a. In other words, the first butting surface 10a of the upper die 10 and the second butting surface 20a of the lower die 20 can be butted to assemble the die 1.

In some examples, as shown in fig. 3, at the first abutting surface 10a, a first groove 11 may be formed. In some examples, the shape of the bottom 11a of the first groove 11 is not particularly limited. For example, the bottom 11a of the first groove 11 may have a flat shape, an arc shape, or the like.

In some examples, the flexible film 30 may have an upper surface 30a and a lower surface 30 b. Wherein the upper surface 30a of the flexible film 30 may face the upper mold 10, and the lower surface 30b may face the lower mold 20. In some examples, on the upper surface 30a of the flexible membrane 30, stimulation electrode areas as described above may be formed. In this case, the stimulation electrode region may be attached to the bottom 11a of the first groove 11 without being injection-molded by the injection molding material.

In some examples, the first groove 11 may have a bottom 11 a. In some examples, the first groove 11 may have a bottom 11a with a prescribed curvature. In some examples, in the above-described positioning process, the flexible film 30 may be attached to the bottom 11a of the first groove 11, thereby enabling the side of the flexible film 30 attached to the bottom 11a of the first groove 11 to be formed into a curved surface having the same curvature as the bottom 11a of the first groove 11.

In some examples, as shown in fig. 3, at the second abutting surface 20a, a second groove 21 may be formed. In some examples, the shape of the bottom 21a of the second groove 21 is not particularly limited. For example, the bottom 21a of the second groove 21 may have a flat shape, an arc shape, or the like.

In some examples, the bottom 21a of the second groove 21 may have a protrusion shape having a predetermined curvature, and in this case, a side of the flexible film 30 facing the bottom 21a of the second groove 21 may be coated with the injection molding material in the molding process, thereby being molded into a curved surface shape having the same curvature as the bottom 21a of the second groove 21. In some examples, the predetermined curvature may match the curvature of the bottom 11a of the first groove 11, thereby enabling the flexible film 30 to be formed into a curved shape in which the curvature of the injection-molded product covering the upper surface 30a is the same as the curvature of the injection-molded product covering the lower surface 30 b. In some examples, in the molding process (step S40, described later), the flexible film 30 may be molded into a curved shape having a prescribed curvature. This enables the flexible film 30 to be molded into a molded article having a specific shape.

Fig. 4 is a schematic diagram illustrating placing a flexible film in a mold for injection molding according to an embodiment of the present disclosure. Fig. 5 is a partial schematic view of the mold cavity of fig. 4. Fig. 6 is a schematic sectional view showing the mold shown in fig. 4 after clamping and injecting the injection molding material.

In some examples, the second groove 21 may be used to configure the flexible film 30, for example, as shown in fig. 4, the flexible film 30 may be configured in the second groove 21 of the lower mold 20 along the direction of arrow a in fig. 4. Thereby enabling the flexible film 30 to be disposed in the lower mold 20. In some examples, the flexible film 30 may be disposed in the lower mold 20 in a direction parallel to the abutment surface 20 a.

In some examples, as shown in fig. 4, the flexible film 30 may be sheet-like. In some examples, the flexible membrane 30 may be other regular blocks, spheres, or irregular random shapes. In some examples, the size of the flexible film 30 may match the size of the second recess 21. For example, the size of the flexible film 30 may be smaller than the size of the second recess 21. Thereby enabling the flexible film 30 to be conveniently disposed in the second recess 21.

In some examples, the material of the flexible film 30 may be selected to be flexible. Thereby facilitating the flexible film 30 to be fitted to the mold 1 and formed into various shapes (described later). In some examples, the flexible film 30 may be composed of a flexible insulating material. In this case, the electrical interference of the flexible film with other devices can be effectively reduced. In some examples, the flexible film 30 may be composed of at least one selected from polyimide, polydimethylsiloxane, and poly-p-xylylene chloride. Thus, the flexible film 30 having excellent biocompatibility can be obtained, and is preferably used in the field of medical devices.

In some examples, the lower mold 20 may be provided with an injection port. In some examples, the injection molding material may be injected into the lower mold 20 (e.g., the second groove 21) through an injection port. For example, as shown in fig. 6, injection ports (e.g., injection port 111 and injection port 112) may be provided at the bottom 21a of the second groove 21.

In step S20, as described above, the upper mold 10 and the lower mold 20 may be clamped to form the cavity 40.

In some examples, as shown in fig. 4 to 6, in step S20, the flexible film 30 may be disposed in the lower mold 20, the upper mold 10 and the lower mold 20 may be clamped in the direction indicated by the arrow a in fig. 4, and the mold cavity 40 may be formed. In some instances, the mold cavity 40 is sealed except in connection with the injection port, in which case the molding material injected into the mold cavity 40 does not flow out of the mold cavity 40.

As described above, after the upper mold 10 and the lower mold 20 can be assembled to form the mold 1, the first recess 11 and the second recess 21 can be combined to form the mold cavity 40. In some examples, the shape and size of mold cavity 40 may be determined by the shape and size of first recess 11 and second recess 21. In some examples, the injection molding compound may cover the edges of the flexible film 30. For example, the edges of the flexible film 30 may have a gap with the mold cavity 40. In this case, during the injection of the injection molding material to the flexible film 30, the injection molding material covers the edge of the upper surface 30a in addition to the lower surface 30b of the flexible film 30, whereby the edge of the flexible film 30 is covered with the injection molding material.

In step S30, as described above, the injection molding material 50 is injected into the cavity through the injection port, so that the flexible film 30 floats and adheres to the bottom 11a of the first recess 11.

In some examples, in step S30, the injection molding material 50 may be injected into the mold cavity 40 through injection ports (e.g., injection port 111 and injection port 112) (see fig. 6 and 7). Specifically, in some examples, the flexible film 30 may float to fit the mold 1 (e.g., the bottom 11a of the first groove 11) under the buoyancy of the injection molding material 50 (e.g., liquid silicone rubber).

In the positioning process (step S30), the injection molding material 50 may be selected to have a density greater than that of the flexible film 30. This enables the flexible film 30 to better float under the buoyancy of the casting compound 50. In some examples, the injection molding material 50 may include plastic or liquid silicone. This enables the casting compound 50 to be better coated on the surface of the flexible film 30. In some examples, the plastic and liquid silicone gel used may be biocompatible. In some examples, the plastic may be composed of at least one selected from polylactic acid and polyurethane, thereby enabling the flexible film 30 to be better applied in the field of medical devices.

In some examples, the mold 1 may be provided with a glue injection hole 110 a. In some examples, as shown in fig. 2, the glue injection hole 110a may be provided to the upper mold 10. In this case, the molding material 50 may enter the mold cavity 40 through the injection hole 110 a.

In some examples, the mold 1 is provided with an injection channel 110 connected to the injection hole 110 a. In some examples, the injection material 50 may be injected from the injection hole 110a, and the injection material 50 may flow along the injection channel 110 after entering the injection hole 110 a.

Additionally, in some examples, injection channel 110 may communicate with mold cavity 40 to form an injection port (e.g., injection port 111 or injection port 112). In this case, the injection molding material 50 may enter the mold cavity 40 from the injection port 111 and the injection port 112 along the injection channel 110 (see fig. 6).

In the positioning process (step S30), the injection raw material 50 may be injected from the injection hole 110a into the mold cavity 40 (for example, the injection raw material may be injected toward the injection hole 110a in the gravity direction), and may flow along the injection channel 110 after the injection raw material 50 enters the injection hole 110a, and the injection channel 110 may change the flow direction of the injection raw material 50, so that the injection raw material 50 (via the sub-channel 110a1 and the sub-channel 110a2) can enter the mold cavity 40 from an injection port (for example, the injection port 111 or the injection port 112). In this case, since the injection raw material 50 entering the mold cavity 40 is subjected to gravity, the flexible film 30 disposed above the

injection port

111 or 112 after entering the mold cavity 40 is stopped to flow along the lower surface 30b of the flexible film 30 and gradually supports the entire lower surface 30b of the flexible film 30, and the flexible film 30 floats by the buoyancy of the injection raw material 50 to make the upper surface 30a of the flexible film 30 fit to the mold 1 (e.g., the bottom 11a of the first groove 11), thereby positioning the flexible film 30 in a specific shape.

In some examples, the injection port may be one or more. In the example shown in fig. 6, the bottom 21a of the second groove 21 may form an injection port 111 and an injection port 112.

In some examples, the injection channel 110 may be divided into a plurality of sub-channels in the mold 1, which may communicate with the mold cavity 40 to form a plurality of injection ports. For example, as shown in fig. 6 and 7, the injection passage 110 may be divided into two sub-passages (sub-passage 110a1 and sub-passage 110a2) in the mold 1, and the two sub-passages 110a1 and 110a2 may communicate with the mold cavity 40. In some examples, the outflow ports of the two sub-channels 110a1 and 110a2, i.e., injection port 111 and injection port 112, may be disposed at the bottom 21a of the second groove 21.

In some examples, as described above, the bottom 21a of the second groove 21 may be provided with a plurality of injection ports (e.g., injection port 111 and injection port 112). In some examples, flexible film 30 disposed in second recess 21 may cover the plurality of injection ports (e.g., injection port 111 and injection port 112). In this case, the molding material 50 can be introduced into the cavity 40 from the lower mold, and the flexible film can be floated by the buoyancy of the molding material 50 and attached to the mold 1 (for example, the bottom 11a of the first groove 11).

In some examples, the glue injection hole 110a may be one or more. In some examples, the injection hole 110a may be provided at the upper mold 10 and/or the lower mold 20. In this case, the process requirements of different molding processes can be better adapted, thereby facilitating the subsequent injection of the molding material 50 into the mold cavity 40.

In some examples, the viscosity of the injection molding material 50 may be 10 to 100 kilo pascal seconds. Preferably, the viscosity of the injection molding material 50 may be 30 to 60 kilopascal seconds. In this case, the viscosity of the injection molding material 50 is controlled within a certain range, which not only satisfies the requirement that the injection molding material 50 has sufficient fluidity, but also effectively suppresses the occurrence of problems such as leakage, thereby optimizing the molding process and facilitating the injection molding of the flexible film 30.

In some examples, the amount of buoyancy of the injection molding material 50 may be adjusted by controlling the injection rate of the injection molding material 50. In some examples, the amount of buoyancy generated by the injection molding material 50 may be equivalent to the amount of buoyancy generated by an atmospheric pressure of 0.8 to 0.9 kPa. Thereby enabling the amount of buoyancy to be adjusted so that the flexible film 30 is better conformed to the mold 1.

In some examples, the injection amount of the injection molding material 50 may be adjusted according to the size of the mold cavity 40. Thereby enabling process requirements for the flexible film 30 to be met. In some examples, in step S30, the mold cavity 40 may be filled with the injection molding material 50.

Additionally, in some examples, the flexible film 30 may include a functional region and a non-functional region (not shown). For example, the functional region of the flexible film 30 is the stimulation electrode region described above, and the non-functional region may be other regions of the flexible film 30 that do not include the functional region.

In some examples, the functional regions of the flexible film 30 may not be covered by the injection molding compound 50 and the non-functional regions may be covered by the injection molding compound 50. In some examples, the molding material 50 may enter the mold cavity 40 through the injection gate, and the manner in which one side of the flexible film 30 having the functional region (e.g., the upper surface 30a of the flexible film) is disposed in the mold 1 may be determined by the manner in which the molding material 50 enters the mold cavity 40. For example, the molding material 50 may enter the cavity 40 from the bottom 21a of the second groove 21, and the side of the flexible film 30 having the functional region may be made to face the bottom 11a of the first groove 11. In this case, when the molding material 50 enters the cavity 40, the flexible film 30 floats and fits on the mold 1, for example, the bottom of the first groove 11, by the molding material 50. This makes it possible to keep the functional regions of the flexible film 30 free from the coating of the casting compound 50.

In some examples, as shown in fig. 8, the bottom 11a of the first recess 11 may be provided with a boss 12 that matches the functional region. In some examples, the functional area (i.e., the stimulation electrode area described above) may be covered by the projections 12 when the flexible film 30 is floated and conformed to the mold 1 by the injection molding material 50. In this case, it is possible to make the functional region of the flexible film 30 not covered by the injection molding material 50. In some examples, the functional region may completely coincide with the upper surface 12a of the boss 12, i.e., the edge of the boss 12 may conform to the surface of the flexible film 30 on the peripheral side of the functional region. In some examples, the non-functional region on the same side of the flexible film 30 as the functional region may have a gap between it and the bottom 11a of the first recess 11. In this case, the functional region of the flexible film 30 can be made not to be covered with the molding material 50, and the non-functional region can be made to be covered with the molding material 50.

In some examples, the gap between the boss 12 and the lower mold 20 may be greater than the thickness of the flexible film 30. In this case, the flexible film 30 can be better coated with the molding compound 50 in the presence of the lands 12.

In some examples, the boss 12 may have an upper surface 12a with a prescribed curvature. In some examples, the upper surface 12a of the boss 12 is concave. This enables the portion of the flexible film 30 bonded to the boss 12 to be formed into a curved surface having the same curvature as the upper surface 12a of the boss 12. In some examples, the curvature of the upper surface 12a of the boss 12 may be the same as the curvature of the bottom 11a of the first groove 11.

In some examples, flexible film 30 may float and fit on mold 1 under the action of injection molding material 50, with a gap between flexible film 30 and bottom 21a of second recess 21. In this case, the non-functional region of the flexible film 30 can be coated with the injection molding material 50.

In step S40, the upper mold 10 and the lower mold 20 may be held, and the upper mold 10 and the lower mold 20 may be heat-treated to cure and mold the injection material 50 (molding step), as described above.

In step S40, in some examples, the clamped state of the upper mold 10 and the lower mold 20 (see fig. 2) may be maintained, and the upper mold 10 and the lower mold 20 may be placed in a heat treatment apparatus (not shown) for heat treatment to cure and mold the injection molding material 50. In some examples, the heat treatment apparatus is not particularly required, and may be a conventional oven or a specially-made heat treatment apparatus. In some examples, the upper mold 10 and the lower mold 20 that are held in the clamped state may be directly heat-treated without being placed in a heat treatment apparatus, for example, by heating the mold 1 with a moving heat source. Therefore, the requirements of different heat treatments under different process conditions can be met.

In some examples, the heat treatment may be selected from one or a combination of cooling, holding, heating. In this case, the injection molding materials having different properties can be cured and molded by different heat treatment methods, and thus the injection molding materials having different properties can be cured and molded more favorably. In some examples, a thermoset injection molding material may be cured by heating. In other examples, the thermoplastic injection molding material may be solidified by cooling.

In some examples, in the molding process (step S40), the temperature for curing molding may be 110 to 150 ℃. Thereby, the optimum molding time and rate can be controlled, enabling better injection molding of the flexible film 30.

In some examples, the shape of flexible film 30 after injection molding may match the shape of mold cavity 40, e.g., flexible film 30 after injection molding may be the same as mold cavity 40. Thus, the flexible film 30 can be formed into a specific shape after the molding step. In some examples, the flexible film 30 is formed as a flexible film having a prescribed curvature, wherein a lower surface 30b of the flexible film is covered with an injection molding material such as silicone, and an upper surface 30a of the flexible film 30 is not covered with the injection molding material such as silicone.

While the present disclosure has been described in detail above with reference to the drawings and the embodiments, it should be understood that the above description does not limit the present disclosure in any way. Those skilled in the art can make modifications and variations to the present disclosure as needed without departing from the true spirit and scope of the disclosure, which fall within the scope of the disclosure.

Claims

1. An injection molding method of a flexible film is characterized in that:

the method comprises the following steps:

a configuration step of preparing an upper die having a first groove and a lower die matched with the upper die, and configuring a flexible film in the lower die, wherein the lower die is provided with an injection port for providing an injection molding raw material;

a mold closing step of closing the upper mold and the lower mold to form a mold cavity;

a positioning step of injecting a molding material into the cavity through the injection port to float the flexible film and attach the film to the bottom of the first groove; and

and a molding step of holding the upper mold and the lower mold, and heat-treating the upper mold and the lower mold to cure and mold the injection molding material.

2. The injection molding method of claim 1, wherein:

in the positioning step, the flexible film is brought into close contact with the bottom of the first groove by filling the cavity with the molding material.

3. The injection molding method of claim 1, wherein:

the density of the flexible film is less than that of the injection molding raw material.

4. The injection molding method of claim 1, wherein:

the heat treatment is selected from one or the combination of cooling, heat preservation and heating.

5. The injection molding method of claim 1, wherein:

in the positioning procedure, the injection molding raw material covers the edge of the flexible film.

6. The injection molding method of claim 1, wherein:

the flexible film has a functional region and a non-functional region, and the functional region is not covered by the injection molding material in the positioning process.

7. The injection molding method of claim 1, wherein:

in the forming step, the flexible film is formed into a curved surface having a predetermined curvature.

8. The injection molding method of claim 1, wherein:

at the lower mold, a plurality of the injection ports are provided, and the flexible film covers the plurality of injection ports.

9. The injection molding method of claim 1, wherein:

and a second groove for configuring the flexible film is arranged on the lower die.

10. The injection molding method of claim 9, wherein:

the bottom of the second groove is in a protruding shape with a specified curvature.