A process and apparatus for the production of thermoplastic optical elements based on injection molding

Abstract

The application relates to a process and equipment for preparing a thermoplastic optical element based on injection molding, belonging to the technical field of injection molding, and comprising the following steps: step S10, raw material melting and injection filling; step S20, pressure maintaining and supplementing; step S30, cooling and solidification; and step S40, demolding; in the step S40, the optical element is separated from a mold by using the self-weight falling of the optical element during demolding; the application can solve the technical problem that external force is needed to push out during demolding in the prior art, mechanical stress is generated during demolding, and the yield is reduced.

Description

Technical Field

[0001] This invention belongs to the field of injection molding technology, and specifically relates to a process and equipment for preparing thermoplastic optical components based on injection molding. Background Technology

[0002] Thermoplastic optical components, especially those made of PMMA, are generally manufactured using injection molding. The quality of injection-molded optical components is affected by internal stress. Excessive internal stress can reduce light transmittance or even cause cracking.

[0003] A patent with publication number CN120190966A discloses a novel optical mold compression structure that facilitates rapid injection molding, the core of which lies in the design of a moving mold core. It includes a moving mold base plate, on which an ejector pin base plate is provided, and ejector pins are fixed on the ejector pin base plate to eject the product, completing the product demolding and resetting functions.

[0004] The existing technology has the following drawbacks:

[0005] The common practice is to use ejectors to eject products, which requires external force to be applied during demolding, generating mechanical stress during demolding and reducing the yield rate. Summary of the Invention

[0006] This invention provides a process and equipment for preparing thermoplastic optical components based on injection molding, which can solve the technical problem in the prior art that external force needs to be applied during demolding, resulting in demolding mechanical stress and reducing the yield.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0008] This application provides a process for preparing thermoplastic optical components based on injection molding, including the following steps:

[0009] Step S10: Raw material melting and injection filling;

[0010] Step S20: Pressure holding and shrinkage compensation;

[0011] Step S30: Cooling and curing;

[0012] Step S40: Demolding;

[0013] In step S40 above, the optical element is separated from the mold by its own weight during demolding.

[0014] By using the above technical solution, the optical components are separated by their own weight, eliminating the need for external force to demold, thus avoiding mechanical stress during demolding and improving the yield rate.

[0015] In this invention, step S40 specifically includes:

[0016] Step S41: The mold separates from the two optical surfaces of the optical element;

[0017] Step S42: The mold separates from the non-optical surface of the optical element, and the unsupported optical element falls under its own weight.

[0018] By using the above technical solution, the optical components are gradually de-supported by separating the cavity, and the parting surface is set to avoid the optical surface, which further improves the yield rate.

[0019] This application also provides an apparatus for manufacturing thermoplastic optical elements, which is used to perform the above-described step S40, including:

[0020] A fixed mold base has an annular support block, wherein the annular support block has an opening.

[0021] The moving mold base has two end face modules that are slidably connected. When the moving mold base is engaged with the fixed mold base, the two end face modules abut against the two end faces of the annular support block, and the end face modules and the annular support block form a cavity. The moving mold base has an injection port that abuts against the opening of the annular support block.

[0022] When the moving mold base separates from the fixed mold base, the two end face modules separate from the annular support block.

[0023] Through the above technical solution, the end face module moves away from or near the annular support block when the moving mold base and the fixed mold base separate or snap together, thereby decomposing or combining to form a cavity. This achieves the separation of optical components from the cavity without external force, reduces the generation of demolding mechanical stress, and improves the yield of optical components.

[0024] In this invention, the aforementioned annular support block includes:

[0025] Semi-ring block A is slidably connected to the fixed mold base;

[0026] Two semi-ring blocks B are rotatably connected to the fixed mold base;

[0027] Two retainers are fixedly connected to the fixed mold base;

[0028] When the moving mold base moves away from the fixed mold base, the semi-ring block A moves away from the retainer. When the semi-ring block A moves away from the retainer, the semi-ring block A presses the semi-ring block B outward. After being pressed, the semi-ring block B rotates in the direction away from the retainer.

[0029] When the moving mold base is engaged with the fixed mold base, the semi-ring block A and the semi-ring block B are driven by the reset mechanism to fit against the retainer to form an annular support block, and the opening is provided at the end of the semi-ring block B away from the retainer.

[0030] The above technical solution uses a split-type ring support block, which separates or combines when the moving mold base and the fixed mold base are separated or snapped together. This reduces the contact area between the ring support block and the non-optical surface of the optical element during demolding, and further improves the self-weight drop efficiency of the optical element.

[0031] In this invention, the end face module is provided with a cooling pipe, the cooling pipe is connected to a cooling pipe connector, the moving mold base is provided with a through-pipe groove, and the cooling pipe connector is connected to an external coolant supply device through the through-pipe groove.

[0032] By using the above technical solution, cooling pipes are installed inside the end face module, which balances the cooling speed of the two optical surfaces, improves the uniformity of cooling and curing of optical components, further reduces the probability of internal stress generation, and improves the yield. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 An isometric view of an apparatus for preparing thermoplastic optical elements provided in an embodiment of the present invention;

[0035] Figure 2 A front view of an apparatus for manufacturing thermoplastic optical elements provided in an embodiment of the present invention;

[0036] Figure 3 for Figure 2 Sectional view at point AA;

[0037] Figure 4 for Figure 2 Sectional view at point BB in the middle;

[0038] Figure 5 This is a schematic diagram of the structure of an apparatus for manufacturing thermoplastic optical elements provided in an embodiment of the present invention after removing part of the fixed module and part of the moving module.

[0039] Icons: 1-Fixed mold base; 101-Fixed mold assembly A; 102-Fixed mold assembly B; 103-Fixed mold assembly C; 104-Fixed mold assembly D; 105-Cage; 2-Moving mold base; 201-Moving mold assembly A; 202-Moving mold assembly B; 203-Moving mold assembly C; 204-Moving mold assembly D; 205-Injection port; 206-Through-tube groove; 301-End face module; 302-Drive inclined surface; 303-Reset spring A; 304-Cooling pipe connector; 401-Half-ring block A; 402-Half-ring block B; 403-Reset spring B; 404-Wedge block; 405-Drive block; 406-Reset spring C; 407-Reset spring D; 5-Optical element. Detailed Implementation

[0040] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0041] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0042] In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0043] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to welding, bolting, or riveting; they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0044] Example:

[0045] Please refer to Figures 1 to 5 , Figures 1 to 5 The image shown is an embodiment of this application.

[0046] This embodiment provides a process for preparing thermoplastic optical components based on injection molding, including the following steps:

[0047] Step S10: Raw material melting and injection filling;

[0048] Step S20: Pressure holding and shrinkage compensation;

[0049] Step S30: Cooling and curing;

[0050] Step S40: Demolding;

[0051] In step S40 above, the optical element 5 is separated from the mold by its own weight during demolding.

[0052] It should be noted that steps S10 to S30 can be obtained by those skilled in the art from technical manuals, textbooks, technical dictionaries, etc., and they are public technical solutions. Their specific steps are not within the protection scope of this application, and therefore will not be described in detail or specifically limited here.

[0053] By using the above technical solution, the optical element 5 is separated by its own weight, eliminating the need for external force to demold, thus avoiding the generation of demolding mechanical stress and improving the yield rate.

[0054] As a preferred implementation, step S40 specifically includes:

[0055] Step S41: The mold separates from the two optical surfaces of the optical element 5;

[0056] Step S42: The mold separates from the non-optical surface of the optical element 5, and the unsupported optical element 5 falls under its own weight.

[0057] By using the above technical solution, the optical element 5 is gradually de-supported by separating the cavity, and the parting surface is set to avoid the optical surface, which further improves the yield rate.

[0058] This embodiment also provides an apparatus for manufacturing thermoplastic optical elements, which is used to implement the above-described step S40, such as... Figures 1 to 3 As shown, it includes:

[0059] The fixed mold base 1 has an annular support block, and the annular support block has an opening;

[0060] The moving mold base 2 has two end face modules 301 slidably connected. When the moving mold base 2 is engaged with the fixed mold base 1, the two end face modules 301 abut against the two end faces of the annular support block respectively. The end face modules 301 and the annular support block form a cavity. The moving mold base 2 has an injection port 205, which abuts against the opening of the annular support block.

[0061] When the moving mold base 2 separates from the fixed mold base 1, the two end face modules 301 separate from the annular support block.

[0062] To facilitate the installation of the internal structure, such as Figure 1 and Figure 4As shown, the fixed mold base 1 is divided into fixed mold group A101, fixed mold group B102, fixed mold group C103 and fixed mold group D104, and tightened by screws and nuts. The moving mold base 2 is divided into moving mold group A201, moving mold group B202, moving mold group C203 and moving mold group D204, and tightened by screws and nuts. The separate processing and assembly method reduces the processing difficulty of the internal cavity.

[0063] When working, refer to Figure 3 As shown, the end face module 301 is connected to a driving inclined surface 302. A return spring A303 abuts against the lower part of the driving inclined surface 302. In its natural state, under the pressure of the return spring A303, the driving inclined surface 302 extends beyond the inclined surface of the moving mold base 2. When the moving mold base 2 approaches the fixed mold base 1, the inclined surface of the fixed mold base 1 presses against the driving inclined surface 302 and pushes down the return spring A303. At this time, the end face module 301 moves towards the injection port 205 and finally abuts against the two end faces of the annular support block. Figure 3 The two end face modules 301 are based on the same principle, but the spring force of the two return springs A303 needs to be set in consideration of the weight difference of the end face module 301.

[0064] Through the above technical solution, the end face module 301 moves away from or near the annular support block when the moving mold base 2 and the fixed mold base 1 are separated or snapped together, thereby decomposing or combining to form a cavity. This achieves the separation of the optical element 5 from the cavity without external force, reduces the generation of demolding mechanical stress, and improves the yield of the optical element 5.

[0065] As a preferred implementation method, such as Figure 4 As shown, the aforementioned annular support block includes:

[0066] Semi-ring block A401 is slidably connected to fixed mold base 1;

[0067] Two semi-ring blocks B402 are rotatably connected to the fixed mold base 1;

[0068] Two retainers 105 are fixedly connected to the fixed mold base 1;

[0069] When the moving mold base 2 moves away from the fixed mold base 1, the drive block 405 loses pressure and pops out under the drive of the return spring C406. The wedge block 404 loses the blocking of the drive block 405 and loses the downward pressure. The semi-ring block A401 moves away from the retainer 105 under the drive of the return spring B403. When the semi-ring block A401 moves away from the retainer 105, the inclined surfaces at both ends of the semi-ring block A401 press outward against the semi-ring block B402. After being pressed, the semi-ring block B402 rotates away from the retainer 105.

[0070] When the moving mold base 2 is engaged with the fixed mold base 1, the semi-ring blocks A401 and B402, driven by the reset mechanism, fit against the retainer 105 to form an annular support block. The opening is located at the end of the semi-ring block B402 away from the retainer 105. Specifically, the driving block 405 is pressed down by the moving mold base 2 to press the wedge block 404, and the wedge block 404 pushes the semi-ring block A401 forward. The semi-ring blocks B402 on both sides rotate towards the middle under the drive of the reset spring D407.

[0071] It should be noted that in this embodiment, all the reset springs are adjustable pre-charged air springs, and the spring force can be changed by adjusting the internal air pressure.

[0072] like Figure 3 As shown, the specific demolding process is as follows: When the moving mold base 2 moves away from the fixed mold base 1, the two end face modules 301 move upward and downward. The combined movement direction of the end face modules 301 is the upper left (lower left) in the figure. At this time, due to the fact that the ring support block is not completely separated, the optical element 5 cannot move with the end face module 301. At the same time, under the obstruction of the retainer 105, the semi-ring block A401 and the semi-ring block B402 can also separate from the optical element 5. At this time, the optical element 5 is only supported by two points on the side, so it cannot maintain balance and falls due to its own weight.

[0073] By adopting the above technical solution, a split ring-shaped support block is used, which separates or combines when the moving mold base 2 and the fixed mold base 1 are separated or snapped together. This reduces the contact area between the ring-shaped support block and the non-optical surface of the optical element 5 during demolding, and further improves the self-weight drop efficiency of the optical element 5.

[0074] In a preferred embodiment, the end face module 301 is provided with a cooling pipe, the cooling pipe is connected to a cooling pipe connector 304, the moving mold base 2 is provided with a through-pipe groove 206, and the cooling pipe connector 304 is connected to an external coolant supply device through the through-pipe groove 206.

[0075] It should be noted that the external cooling circuit is not within the scope of protection of this application. This application only protects the specific location of the cooling pipe joint 304. Therefore, it will not be described in detail or specifically limited here. Those skilled in the art can purchase a suitable cooling circuit through public channels.

[0076] By using the above technical solution, a cooling pipe is installed in the end face module 301, which balances the cooling speed of the two optical surfaces, improves the uniformity of cooling and curing of the optical element 5, further reduces the probability of internal stress generation, and improves the yield.

[0077] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope described in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An apparatus for preparing thermoplastic optical elements, characterized in that, include: A fixed mold base (1) has an annular support block, the annular support block having an opening, the annular support block comprising: The semi-ring block A (401) is slidably connected to the fixed mold base (1); Two semi-ring blocks B (402) are rotatably connected to the fixed mold base (1); Two retainers (105) are fixedly connected to the fixed mold base (1); The moving mold base (2) has two end face modules (301) slidably connected. When the moving mold base (2) is engaged with the fixed mold base (1), the two end face modules (301) abut against the two end faces of the annular support block respectively. The end face modules (301) and the annular support block form a cavity. The moving mold base (2) has an injection port (205) which abuts against the opening of the annular support block. When the moving mold base (2) is engaged with the fixed mold base (1), the semi-ring block A (401) and the semi-ring block B (402) are engaged with the retainer (105) under the drive of the reset mechanism to form a ring-shaped support block; When the moving mold base (2) separates from the fixed mold base (1), the two end face modules (301) separate from the annular support block, and the semi-annular block A (401) moves away from the retainer (105). When the semi-annular block A (401) moves away from the retainer (105), the semi-annular block A (401) presses the semi-annular block B (402) outward. After being pressed, the semi-annular block B (402) rotates away from the retainer (105), thereby realizing the separation of the annular support block from the non-optical surface of the optical element.

2. The apparatus for preparing thermoplastic optical elements according to claim 1, characterized in that, The end face module (301) is provided with a cooling pipe, which is connected to a cooling pipe connector (304). The moving mold base (2) has a through-pipe groove (206), and the cooling pipe connector (304) is connected to an external coolant supply device through the through-pipe groove (206).

3. A process for preparing thermoplastic optical components based on injection molding, comprising the following steps: Step S10: Raw material melting and injection filling; Step S20: Pressure holding and shrinkage compensation; Step S30: Cooling and curing; Step S40: Demolding; The feature is that the apparatus for preparing thermoplastic optical elements as described in claim 2 is used, and in step S40, the optical element is separated from the mold by its own weight during demolding.

4. The process for preparing thermoplastic optical elements based on injection molding according to claim 3, characterized in that, Step S40 specifically includes: Step S41: The mold separates from the two optical surfaces of the optical element; Step S42: The mold separates from the non-optical surface of the optical element, and the unsupported optical element falls under its own weight.

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