Line-following processing method for contact lens production

Abstract

The invention provides a line-following processing method for contact lens production. Multiple procedures of a female mold shell and a male mold shell are integrated on an automatic production line. Respectively preparing a female mold shell and a male mold shell through an injection molding process, and directly conveying the female mold shell and the male mold shell to subsequent procedures; after the inner surface of the female mold shell is subjected to transfer printing treatment, a mirror making material is injected; then, the female mold shell and the male mold shell are aligned and assembled, and the contact lenses are formed through a thermocuring or photocuring process; and after curing is completed, mold shell removing operation is carried out, and the stripped lens is hydrated and then loaded into a packaging container to be packaged. According to the invention, the production efficiency and the product consistency are improved; an accurate alignment and liquid injection control technology is adopted, so that the stable quality of the lens is ensured; the optimized hydration and packaging process shortens the production period; and meanwhile, part of mold materials can be recycled, so that resource waste and production cost are reduced. The method is suitable for industrial production of large-scale contact lenses.

Description

Technical Field

[0001] The invention relates to the technical field of contact lens production, in particular to an on-line processing method for contact lens production. Background Art

[0002] As an important vision correction and beauty product, the production process of contact lenses has a significant impact on product quality, production efficiency and cost control. At present, the production of contact lenses mainly adopts mold forming technology, the core of which includes the production of female mold shells and male mold shells, the injection of lens materials, curing and forming, and subsequent hydration treatment and packaging. However, the existing contact lens production process has the following problems and challenges:

[0003] In the prior art, the production of the female mold shell and the male mold shell and their subsequent processes are often carried out separately, and there is a lack of effective connection between mold forming and liquid injection, curing and other links, resulting in a large number of manual intervention steps in the production line. This segmented production method not only reduces production efficiency, but also increases production costs.

[0004] In the traditional contact lens production process, the alignment accuracy of the female mold shell and the male mold shell depends on manual or semi-automatic equipment, which can easily lead to problems such as uneven lens thickness and substandard optical performance due to alignment errors. At the same time, there is a lack of high-precision monitoring methods for the control of the injection volume, which further affects the consistency and quality stability of the lenses.

[0005] The processes of hydration, cleaning, testing and packaging of contact lenses after molding often require multiple independent devices to complete. The material transfer between processes is complicated and prone to contamination. In addition, the traditional hydration process takes a long time, which prolongs the production cycle and is not conducive to mass production.

[0006] In the existing process, the materials of the female mold shell and the male mold shell are mostly disposable and cannot be effectively recycled, resulting in resource waste and environmental burden. With the increasing environmental protection requirements, how to optimize the use and recycling of mold materials has become an urgent problem to be solved.

[0007] Based on the above problems, the industry is in urgent need of a contact lens production process that is efficient, highly automated, and has good product consistency. Summary of the invention

[0008] In view of the above-mentioned technical deficiencies, the purpose of the present invention is to provide an on-line processing method for contact lens production, so as to realize on-line processing of female mold shells and male mold shells, reduce manual intervention, and optimize process connection.

[0009] To achieve the above object, the present invention adopts the following technical solutions:

[0010] An in-line processing method for contact lens production comprises the following steps:

[0011] S1. Injection molding of a mother mold shell: preparing a mother mold shell by an injection molding process, and directly transferring the molded mother mold shell to a subsequent process;

[0012] S2. Pad printing of the mother mold shell: adding patterns, logos or texts on the inner surface of the mother mold shell by pad printing process;

[0013] S3, injection of the master mold shell: injecting the mirror-making material into the master mold shell after pad printing;

[0014] S4, injection molding of the male mold shell: preparing the male mold shell by an injection molding process, and directly transferring the molded male mold shell to a subsequent process;

[0015] S5. Clamping and curing the female mold shell and the male mold shell: accurately aligning and pressing the female mold shell and the male mold shell after injection, and forming the contact lens through a thermal curing or light curing process;

[0016] S6, removing the mold shell: peeling the cured female mold shell and the male mold shell from the contact lens;

[0017] S7, hydration treatment of the lens: hydrating the peeled contact lens;

[0018] S8. Lens packaging: Put the hydrated contact lenses into the PP cup, and complete the packaging, sterilization and packaging.

[0019] Preferably, the injection molding process of the female mold shell and the male mold shell in step S1 and step S4 includes the following process:

[0020] After injection molding, the female mold shell and the male mold shell directly enter the subsequent process before cooling to room temperature to avoid dimensional changes caused by standing still;

[0021] The transfer of injection molded products adopts automated unloading methods: robot clamping, suction cup adsorption or roller conveying.

[0022] Preferably, the pad printing process in step S2 includes the following process:

[0023] Adding a specific pattern, logo or text on the inner surface of the female mold shell by pad printing equipment, wherein the pattern is used to enhance the functionality or brand recognition of the contact lens;

[0024] After pad printing, the completeness and accuracy of pad printing are checked in real time by the visual inspection system. If defective products are detected, they are removed from the production line by the automatic sorting device.

[0025] During the pad printing process, an automatic cleaning device is used to clean the pad printing head to ensure the quality of pad printing.

[0026] Preferably, the mold closing and curing process of the female mold shell and the male mold shell in step S5 includes the following process:

[0027] The female mold shell and the male mold shell are accurately aligned through an automatic alignment device to ensure the thickness uniformity and optical performance of the lens;

[0028] After the mold is closed, the mirror material is quickly cured by a heat curing or light curing process, wherein: the heat curing temperature is controlled between 50°C and 150°C, and the time is 10 seconds to 120 seconds; the light curing wavelength is 365nm to 405nm, and the time is 5 seconds to 60 seconds;

[0029] The curing status of the lens is monitored in real time during the mold closing process to detect whether there are bubbles, deviations or other defects.

[0030] Preferably, the shell removal process in step S6 includes the following process:

[0031] The female mold shell and the male mold shell are peeled off from the lens by a mechanical separation device, wherein: the female mold shell is peeled off by rotational motion or airflow assistance; the male mold shell is peeled off by vacuum adsorption or mechanical clamping;

[0032] The stripped mold shell is recycled to the waste box or reprocessing system through an automatic transmission device;

[0033] A lens protection module is used during the stripping process to prevent the lens from being damaged due to mechanical force or friction.

[0034] Preferably, the hydration treatment in step S7 includes the following process:

[0035] Putting the peeled contact lens into a hydration tank for hydration treatment, wherein the water temperature in the hydration tank is controlled between 10° C. and 40° C.;

[0036] The hydration time is 30 minutes to 120 minutes to ensure that the lens reaches the predetermined water content;

[0037] During the hydration process, ultrasound or circulating water flow is used to accelerate the hydration process and improve the hydration efficiency.

[0038] Preferably, the lens packaging process in step S8 includes the following steps:

[0039] The hydrated contact lens is placed into the PP cup by an automatic assembly device, and the position of the lens is corrected during the assembly process;

[0040] The lens placed in the PP cup is sealed, wherein the sealing process includes heat sealing, laser sealing or ultraviolet curing sealing;

[0041] The sealed product is sterilized by a sterilization device, wherein the sterilization method includes high temperature steam sterilization, ultraviolet sterilization or ethylene oxide sterilization;

[0042] After packaging, the products are classified by batch, specification or model through automatic sorting device.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] By seamlessly connecting each process on an automated production line, the synchronous processing of the female mold shell and the male mold shell and the continuous operation of the subsequent processes are achieved, which significantly reduces the time waste and manual intervention caused by process separation in traditional processes, and greatly improves production efficiency. The automated process shortens the production cycle and meets the needs of large-scale industrial production of contact lenses. It reduces the multiple independent equipment and material transfer links required for segmented production in traditional processes, reducing equipment investment and maintenance costs. The optimization of the process reduces the need for manual operation and labor costs, while also reducing errors and defective rates caused by manual operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a flowchart of the present invention. DETAILED DESCRIPTION

[0046] The present invention will be further described below in conjunction with the accompanying drawings.

[0047] like Figure 1 As shown, an in-line processing method for contact lens production comprises the following steps:

[0048] S1. Injection molding of a mother mold shell: preparing a mother mold shell by an injection molding process, and directly transferring the molded mother mold shell to a subsequent process;

[0049] S2. Pad printing of the mother mold shell: adding patterns, logos or texts on the inner surface of the mother mold shell by pad printing process;

[0050] S3, injection of the master mold shell: injecting the mirror-making material into the master mold shell after pad printing;

[0051] S4, injection molding of the male mold shell: preparing the male mold shell by an injection molding process, and directly transferring the molded male mold shell to a subsequent process;

[0052] S5. Clamping and curing the female mold shell and the male mold shell: accurately aligning and pressing the female mold shell and the male mold shell after injection, and forming the contact lens through a thermal curing or light curing process;

[0053] S6, removing the mold shell: peeling the cured female mold shell and the male mold shell from the contact lens;

[0054] S7, hydration treatment of the lens: hydrating the peeled contact lens;

[0055] S8. Lens packaging: Put the hydrated contact lenses into the PP cup, and complete the packaging, sterilization and packaging.

[0056] Example 1: In-line contact lens processing method based on thermal curing process

[0057] This embodiment adopts a thermal curing process to produce contact lenses, which specifically includes the following steps:

[0058] Injection molding of the mother mold

[0059] Use an injection molding machine to inject polypropylene (PP) material into the master mold for injection molding, the injection temperature is 180°C, the injection pressure is 80MPa, and the cooling time is 5 seconds;

[0060] The molded mother mold shell is taken out by a robot and directly transferred to the pad printing station to avoid dimensional changes due to excessive cooling.

[0061] Pad printing of the master mold

[0062] Printing the brand logo and positioning pattern on the inner surface of the mother mold shell by pad printing equipment;

[0063] The pad printing ink is UV curing ink, which is cured for 3 seconds by ultraviolet lamp (wavelength 365nm, power 100W) after pad printing;

[0064] After pad printing is completed, the pattern integrity is checked by visual inspection equipment, and defective products are sorted and removed from the production line by robotic arms.

[0065] Injection of the master mold

[0066] Inject the contact lens material (e.g. HEMA monomer solution) into the mother mold shell through the injection device, with an injection volume of 50 μL;

[0067] During the injection process, the injection volume is monitored in real time to ensure uniform distribution of the material.

[0068] Injection molding of male mold shell

[0069] The polycarbonate (PC) material is injected into the male mold by using an injection molding machine for injection molding, the injection temperature is 200°C, the injection pressure is 90MPa, and the cooling time is 6 seconds;

[0070] The molded male mold shell is taken out by the robot and directly transferred to the mold closing station.

[0071] Clamping and curing of female and male mold shells

[0072] At the mold closing station, the automatic alignment device is used to accurately align and press the female mold shell and the male mold shell after injection;

[0073] After the mold is closed, the mold is sent to a heat curing device and cured at a temperature of 60°C for 120 seconds to completely cure the mirror-making material.

[0074] De-molding

[0075] The cured female mold shell and male mold shell are peeled off by a mechanical separation device, and the peeling is carried out by a combination of rotational motion and vacuum adsorption to avoid damage to the contact lens;

[0076] The stripped mold shell is recycled to the waste box through a conveyor belt.

[0077] Hydration of lenses

[0078] Place the peeled contact lens into a hydration tank, control the water temperature at 25°C, and hydrate for 60 minutes;

[0079] During the hydration process, ultrasonic vibration (frequency 40kHz) is used to accelerate the hydration process to ensure that the lens reaches the predetermined water content (38%).

[0080] Lens packaging

[0081] The hydrated lenses are placed into PP cups by an automatic assembly device, and physiological saline is added as a preservation solution;

[0082] After the PP cup is sealed by heat sealing, it is sent to the high-temperature steam sterilization device and sterilized at 121°C for 15 minutes;

[0083] The sterilized products are classified and packaged through automatic sorting devices to form the final products.

[0084] Embodiment 2: Contact lens on-line processing method based on light curing process

[0085] This embodiment adopts a light curing process to produce contact lenses, which specifically includes the following steps:

[0086] Injection molding of the mother mold

[0087] Use an injection molding machine to inject polypropylene (PP) material into the master mold for injection molding, the injection temperature is 185°C, the injection pressure is 85MPa, and the cooling time is 4 seconds;

[0088] The molded mother mold shell is taken out by a robot and directly transferred to the pad printing station.

[0089] Pad printing of the master mold

[0090] Printing positioning patterns and anti-counterfeiting marks on the inner surface of the mother mold shell by pad printing equipment;

[0091] The pad printing ink is a high temperature resistant ink, which is dried for 5 seconds by a hot air device (temperature 70°C) after pad printing;

[0092] After pad printing is completed, the pattern quality is inspected by visual inspection equipment, and defective products are sorted and removed from the production line by robotic arms.

[0093] Injection of the master mold

[0094] Inject the contact lens material (e.g., silicone hydrogel monomer solution) into the mother mold shell through an injection device, with an injection volume of 45 μL;

[0095] During the injection process, the flow control system monitors the injection accuracy in real time to ensure consistency.

[0096] Injection molding of male mold shell

[0097] Use an injection molding machine to inject polycarbonate (PC) material into a male mold for injection molding, the injection temperature is 195°C, the injection pressure is 92MPa, and the cooling time is 5 seconds;

[0098] The molded male mold shell is taken out by the robot and directly transferred to the mold closing station.

[0099] Clamping and curing of female and male mold shells

[0100] At the mold closing station, the automatic alignment device is used to accurately align and press the female mold shell and the male mold shell after injection;

[0101] After the mold is closed, the mold is sent to a light curing device and irradiated with a 365nm wavelength ultraviolet light source for 60 seconds to completely cure the mirror-making material.

[0102] De-molding

[0103] The cured female mold shell and male mold shell are peeled off by a mechanical separation device, and the peeling is carried out by a combination of airflow assistance and mechanical clamping;

[0104] The stripped mold shell is recycled to the recycling system via a conveyor belt.

[0105] Hydration of lenses

[0106] Place the peeled contact lens into a hydration tank, control the water temperature at 30°C, and hydrate for 90 minutes;

[0107] During the hydration process, a circulating water flow is used to ensure that the lens is evenly hydrated, and the final water content reaches 45%.

[0108] Lens packaging

[0109] The hydrated lenses are loaded into PP cups by an automatic assembly device, and buffer is added as a preservation solution;

[0110] After the PP cup is sealed by laser packaging, it is sent to the ethylene oxide sterilization device for sterilization for 12 hours;

[0111] The sterilized products are packaged in batches through automatic sorting devices to form the final products.

[0112] illustrate:

[0113] The differences between Example 1 and Example 2 are as follows:

[0114] Embodiment 1 is based on a thermal curing process and is suitable for the production of conventional contact lenses; Embodiment 2 is based on a photocuring process and is suitable for the production of silicone hydrogel contact lenses that are material-sensitive and require rapid curing.

[0115] Specific process parameters: The key parameters of each step (such as temperature, pressure, time, injection volume, etc.) are clearly defined to facilitate practical application and technical protection.

[0116] Strong operability: The two embodiments cover different production needs, reflecting the flexibility and adaptability of the process method, while ensuring the wide applicability and innovation of the patent.

Claims

1. An in-line processing method for contact lens production, characterized in that: The following steps are involved: S1, injection molding of mother mold shell; S2, mother shell mold pretreatment; S3, injection molding of male mold shell; S4. Clamping and curing of female mold shell and male mold shell: S5, removing the mold shell: peeling the cured female mold shell and the male mold shell from the contact lens; S6, hydration treatment of the lens: hydrating the peeled contact lens; S7, lens packaging: put the hydrated contact lenses into PP cups, and complete the packaging, sterilization and packaging; The female shell mold in S1, the male shell mold in S2, and the PP cup in S7 are injection molded, and the injection molding equipment is correspondingly combined in the contact lens production line.

2. An in-line processing method for contact lens production, characterized in that: The following steps are involved: S1. Injection molding of a mother mold shell: preparing a mother mold shell by an injection molding process, and directly transferring the molded mother mold shell to a subsequent process; S2. Pad printing of the mother mold shell: adding patterns, logos or texts on the inner surface of the mother mold shell by pad printing process; S3, injection of the master mold shell: injecting the mirror-making material into the master mold shell after pad printing; S4, injection molding of the male mold shell: preparing the male mold shell by an injection molding process, and directly transferring the molded male mold shell to a subsequent process; S5. Clamping and curing the female mold shell and the male mold shell: accurately aligning and pressing the female mold shell and the male mold shell after injection, and forming the contact lens through a thermal curing or light curing process; S6, removing the mold shell: peeling the cured female mold shell and the male mold shell from the contact lens; S7, hydration treatment of the lens: hydrating the peeled contact lens; S8, lens packaging: put the hydrated contact lenses into PP cups, and complete the packaging, sterilization and packaging; The female shell mold in S1, the male shell mold in S4, and the PP cup in S8 are injection molded, and the injection molding equipment is correspondingly combined in the contact lens production line.

3. The in-line processing method for contact lens production according to claim 1, characterized in that: The injection molding process of the female mold shell and the male mold shell in step S1 and step S4 includes the following processes: After injection molding, the female mold shell and the male mold shell directly enter the subsequent process before cooling to room temperature to avoid dimensional changes caused by standing still; The transfer of injection molded products adopts automated unloading methods: robot clamping, suction cup adsorption or roller conveying.

4. The in-line processing method for contact lens production according to claim 1, characterized in that: The pad printing process in step S2 includes the following process: Adding a specific pattern, logo or text on the inner surface of the female mold shell by pad printing equipment, wherein the pattern is used to enhance the functionality or brand recognition of the contact lens; After pad printing, the completeness and accuracy of pad printing are checked in real time by the visual inspection system. If defective products are detected, they are removed from the production line by the automatic sorting device. During the pad printing process, an automatic cleaning device is used to clean the pad printing head to ensure the quality of pad printing.

5. The in-line processing method for contact lens production according to claim 1, characterized in that: The mold closing and curing process of the female mold shell and the male mold shell in step S5 includes the following processes: The female mold shell and the male mold shell are accurately aligned through an automatic alignment device to ensure the thickness uniformity and optical performance of the lens; After the mold is closed, the mirror material is quickly cured by a heat curing or light curing process, wherein: the heat curing temperature is controlled between 50°C and 150°C, and the time is 10 seconds to 120 seconds; the light curing wavelength is 365nm to 405nm, and the time is 5 seconds to 60 seconds; The curing status of the lens is monitored in real time during the mold closing process to detect whether there are bubbles, deviations or other defects.

6. The in-line processing method for contact lens production according to claim 1, characterized in that: The shell removal process in step S6 includes the following steps: The female mold shell and the male mold shell are peeled off from the lens by a mechanical separation device, wherein: the female mold shell is peeled off by rotational motion or airflow assistance; the male mold shell is peeled off by vacuum adsorption or mechanical clamping; The stripped mold shell is recycled to the waste box or reprocessing system through an automatic transmission device; A lens protection module is used during the stripping process to prevent the lens from being damaged due to mechanical force or friction.

7. The in-line processing method for contact lens production according to claim 1, characterized in that: The hydration treatment in step S7 includes the following process: Putting the peeled contact lens into a hydration tank for hydration treatment, wherein the water temperature in the hydration tank is controlled between 10° C. and 40° C.; The hydration time is 30 minutes to 120 minutes to ensure that the lens reaches the predetermined water content; During the hydration process, ultrasound or circulating water flow is used to accelerate the hydration process and improve the hydration efficiency.

8. The in-line processing method for contact lens production according to claim 1, characterized in that: The lens packaging process in step S8 includes the following steps: The hydrated contact lens is placed into the PP cup by an automatic assembly device, and the position of the lens is corrected during the assembly process; The lens placed in the PP cup is sealed, wherein the sealing process includes heat sealing, laser sealing or ultraviolet curing sealing; The sealed product is sterilized by a sterilization device, wherein the sterilization method includes high temperature steam sterilization, ultraviolet sterilization or ethylene oxide sterilization; After packaging, the products are classified by batch, specification or model through automatic sorting device.

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