Curing system for contact lens production
By using a segmented curing system, combined with UV curing and a thermal reaction chamber, the problems of internal stress concentration and high energy consumption in contact lens production have been solved, achieving high-quality and high-efficiency contact lens production.
Patent Information
- Application Number
- CN202511282300.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-09
- Publication Date
- 2025-12-05
AI Technical Summary
In current contact lens production, the single UV curing process leads to stress concentration within the lens, poor biocompatibility, and high energy consumption, making it difficult to meet the requirements for lens quality and production efficiency.
The system employs a segmented curing system, combining a UV curing chamber and a thermal reaction chamber. The UV curing chamber rapidly constructs the lens frame, while the thermal reaction chamber performs deep curing and stress relief. Combined with an efficient handling device, the product is automatically transferred between the two.
It improves the toughness and biocompatibility of lenses, reduces energy consumption, and increases production efficiency. The lens elongation at break and light transmittance reach higher standards, and production efficiency is increased by more than 25%.
Smart Images
Figure CN121062093A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of contact lens processing technology, in particular to a curing system for contact lens production. BACKGROUND
[0002] In the field of contact lens processing, especially in the industrialized production of soft contact lenses, the curing link plays a crucial role in product quality and production efficiency. The mainstream contact lens curing process currently uses a single UV light curing process, which roughly includes the following steps: first, inject liquid prepolymer containing photosensitive monomers into the cavity composed of upper and lower molds, then fill nitrogen into the cavity to replace oxygen to avoid oxygen inhibition effect, then place the mold under a UV light source with a wavelength of 300-400 nm for continuous irradiation for 15-30 minutes to initiate monomer crosslinking polymerization to form a solid lens, and finally peel off the cured lens and soak it in physiological saline to swell to the final size.
[0003] However, this single UV light curing process has obvious structural defects, which brings many problems to contact lens production. From the material performance point of view, long-term high-energy UV irradiation will cause uneven distribution of crosslinking density of the polymer network, usually showing high surface crosslinking degree and low internal crosslinking degree, which causes stress concentration in the lens. Actual measurement data shows that the elongation at break of the lens produced by the traditional process is only 80%-120%, which is prone to brittle fracture during wearing, and it is difficult to meet the demand of the human cornea for lens modulus. In terms of biocompatibility, if the UV curing time is insufficient, the residual amount of monomers in the lens will exceed 500 ppm, which is much higher than the ISO standard requirement of below 100 ppm; but prolonging the curing time will aggravate the yellowing phenomenon, which is caused by the side reaction of phenyl ketone photoinitiator, thereby causing the lens transmittance to decrease by 3%-5%, affecting the use effect. From the energy consumption and efficiency point of view, 15 minutes of high-power UV irradiation accounts for 65% of the total energy consumption of the production line, and because of the long curing time, the demand for flow line curing cabin is large, which increases the equipment cost of unit capacity by 40%, which is not conducive to the enterprise to control the production cost and improve the market competitiveness. SUMMARY
[0004] In view of the above technical deficiencies, the purpose of the present application is to provide a curing system for contact lens production to improve product quality and production efficiency.
[0005] To achieve the above purpose, the technical scheme adopted by the present application is as follows:
[0006] A curing system for contact lens production, comprising:
[0007] a UV light curing box for light curing of the product;
[0008] a thermal reaction box for heat treatment of the product;
[0009] The carrying device is used for carrying products into a UV light curing box and carrying products out of the UV light curing box into a thermal reaction box.
[0010] Preferably, the carrying device comprises a gantry, a cross beam, a longitudinal moving mechanism, a transverse moving mechanism, a moving platform and a carrying mechanism; the longitudinal moving mechanism comprises a first motor, a first shaft, a first toothed belt wheel, a second toothed belt wheel, a first synchronous belt and two transmission assemblies; the first motor is fixed on the upper part of the gantry; the first shaft is installed on the gantry through a bearing seat; the first toothed belt wheel is installed on the first motor; the second toothed belt wheel is installed on the first shaft; the first toothed belt wheel and the second toothed belt wheel are transmissionally connected through the first synchronous belt; the two transmission assemblies are symmetrically arranged at the two ends of the first shaft; each transmission assembly comprises a third toothed belt wheel, a fourth toothed belt wheel and a second synchronous belt; the third toothed belt wheel is installed on the first shaft; the fourth toothed belt wheel is rotatably installed on the lower part of the gantry; the third toothed belt wheel and the fourth toothed belt wheel are transmissionally connected through the second synchronous belt; the two ends of the cross beam are fixed on the two second synchronous belts; the transverse moving mechanism comprises a first guide rail, a first sliding block, a second motor, a fifth toothed belt wheel, a sixth toothed belt wheel and a third synchronous belt; the first guide rail is fixed on the cross beam; the first sliding block is slidably installed on the first guide rail; the second motor is fixed on one end of the cross beam, and the sixth toothed belt wheel is rotatably installed on the other end of the cross beam; the fifth toothed belt wheel is installed on the second motor; the fifth toothed belt wheel and the sixth toothed belt wheel are transmissionally connected through the third synchronous belt; one side of the first sliding block is fixed on the third synchronous belt; the moving platform is fixed on the first sliding block, and the carrying mechanism is installed on the moving platform.
[0011] Preferably, the carrying mechanism comprises a third motor, a seventh toothed belt wheel, an eighth toothed belt wheel, a fourth synchronous belt, a second guide rail, a second sliding block and a lifting module; the third motor and the second guide rail are fixed on the moving platform; the seventh toothed belt wheel is installed on the third motor; the eighth toothed belt wheel is rotatably installed on the moving platform; the seventh toothed belt wheel and the eighth toothed belt wheel are transmissionally connected through the fourth synchronous belt; the second sliding block is slidably installed on the second guide rail; one side of the second sliding block is fixedly connected with the fourth synchronous belt; the lifting module comprises a lifting electric cylinder and a carrying plate; the lifting electric cylinder is fixed on the second sliding block; the carrying plate is fixed on the piston rod of the lifting electric cylinder; a guide column is fixedly arranged on the carrying plate.
[0012] Preferably, the hot reaction box comprises a box body, a pushing mechanism and a carrying mechanism; the inside of the box body is provided with a heating cavity, and the top is provided with an air inlet; the top end of the box body is fixedly provided with a hot air blower, and the air outlet of the hot air blower is connected with the air inlet; the carrying mechanism is configured with two, and the two carrying mechanisms are symmetrically arranged in the heating cavity and fixed on the box body; the pushing mechanism is arranged between the two carrying mechanisms, and the pushing mechanism is located below the carrying mechanism and is fixed on the box body; one side of the upper part of the box body is provided with a feeding port, and one side of the lower part is provided with a discharging port matched with the carrying mechanism.
[0013] Preferably, the pushing mechanism comprises a pushing support, a fourth motor, a ninth toothed belt wheel, a tenth toothed belt wheel, a fifth synchronous belt, a third guide rail, a third sliding block, a bearing plate, a fifth motor, an eleventh toothed belt wheel, a twelfth toothed belt wheel, a sixth synchronous belt, a fourth guide rail, a fourth sliding block and a pushing plate; the pushing support is fixed on the box body; the third guide rail and the fourth motor are fixed on the pushing support; the third sliding block is slidably mounted on the third guide rail; the ninth toothed belt wheel is mounted on the fourth motor; the tenth toothed belt wheel is rotatably mounted on the pushing support; the ninth toothed belt wheel and the tenth toothed belt wheel are drivingly connected through the fifth synchronous belt; one side of the third sliding block is fixed on the fifth synchronous belt; the bearing plate is fixed on the upper part of the third sliding block; the fifth motor and the fourth guide rail are fixed on the bearing plate; the eleventh toothed belt wheel is mounted on the fifth motor; the twelfth toothed belt wheel is rotatably mounted on the bearing plate; the eleventh toothed belt wheel and the twelfth toothed belt wheel are drivingly connected through the sixth synchronous belt; the fourth sliding block is slidably mounted on the fourth guide rail; one side of the sixth synchronous belt is fixed on the sixth synchronous belt; the pushing plate is fixed on the upper part of the fourth sliding block.
[0014] Preferably, the carrying mechanism comprises a second shaft, a third shaft, a sixth motor, a thirteenth toothed belt wheel, a fourteenth toothed belt wheel, a seventh synchronous belt and a cross bar; the sixth motor is fixed on the box body; the second shaft and the third shaft are rotatably mounted on the box body; the second shaft and the third shaft are arranged in parallel and spaced apart in an up-down manner; the second shaft is located on the upper side of the inside of the box body, and the third shaft is located on the lower side of the inside of the box body; the second shaft is drivingly connected with the output shaft of the sixth motor through a shaft coupling; the thirteenth toothed belt wheel is configured with two and symmetrically mounted on the two ends of the second shaft; the fourteenth toothed belt wheel is configured with two and symmetrically mounted on the two ends of the third shaft; the seventh synchronous belt is configured with two; the thirteenth toothed belt wheel and the fourteenth toothed belt wheel are drivingly connected through the seventh synchronous belt; the two ends of the cross bar are respectively fixed on the two seventh synchronous belts; the axis of the cross bar and the second shaft are arranged in parallel; the cross bar is configured with multiple; the multiple cross bars are arranged in an equidistant array along the outer side of the seventh synchronous belt.
[0015] Preferably, the cross bar is provided with a plurality of rollers; the plurality of rollers are arranged in an equidistant array along the length direction of the cross bar.
[0016] Compared with the prior art, the present application has the following advantages:
[0017] The UV light curing box can quickly cure the product, preliminarily build the solid skeleton of the lens, avoid the uneven crosslinking problem caused by traditional single long-time UV curing, the heating cavity in the heat reaction box cooperates with the air blower to provide a uniform and stable heating environment, and the two sets of load carrying mechanisms can drive the product to slowly move downward, so that the product is fully heated to complete deep curing, and at the same time, the internal stress generated in the UV curing stage is eliminated, the lens brittle fracture problem is effectively improved, the lens toughness and biocompatibility are improved, the monomer residue and yellowing phenomenon are reduced, and the lens transmittance is ensured.
[0018] The longitudinal moving mechanism in the conveying device can drive the cross beam to stably move longitudinally through the cooperation of the motor, the toothed belt wheel and the synchronous belt; the transverse moving mechanism can drive the moving platform to adjust the position transversely; the lifting module and the guide column structure of the conveying mechanism can realize the precise lifting and positioning of the product, avoid the error and inefficiency of manual conveying, ensure the efficient transmission of the product between the UV light curing box and the heat reaction box, and improve the overall production efficiency.
[0019] The pushing mechanism realizes double-stroke movement through the combination of multiple motors, toothed belt wheels, synchronous belts and sliding block guides, can accurately push the product completed curing in the heat reaction box out of the discharge port, avoid the unloading jam, further ensure the smoothness of the production process, reduce the risk of equipment failure, reduce the production interruption time, and help the enterprise to steadily improve the production capacity. BRIEF DESCRIPTION OF DRAWINGS
[0020] Figure 1 is a structural schematic view of the present application;
[0021] Figure 2 is a structural schematic view of the conveying device in the present application;
[0022] Figure 3 is Figure 2 is a local enlarged view of A in the present application;
[0023] Figure 4 is a structural schematic view of the heat reaction box in the present application;
[0024] Figure 5 is Figure 4 is a local enlarged view of B in the present application;
[0025] Figure 6 is a structural schematic view of the pushing mechanism in the present application.
[0026] Among them:
[0027] 1, handling device; 11, gantry; 12, fourth toothed pulley; 13, second synchronous belt; 14, first synchronous belt; 15, second toothed pulley; 16, first motor; 17, first shaft; 18, third toothed pulley; 19, cross beam; 110, first guide rail; 111, first sliding block; 112, moving platform; 113, third motor; 114, second guide rail; 115, object plate; 116, guide column; 117, third synchronous belt; 118, second motor; 2, heat reaction box; 21, box body; 22, pushing mechanism; 221, pushing support; 222, fifth synchronous belt; 223, fourth motor; 224, ninth toothed pulley; 225, twelfth toothed pulley; 226, sixth synchronous belt; 227, fourth sliding block; 228, fourth guide rail; 229, pushing plate; 2210, bearing plate; 2211, third guide rail; 2212, tenth toothed pulley; 23, loading mechanism; 24, hot air machine; 25, seventh synchronous belt; 26, roller; 27, third shaft; 28, fourteenth toothed pulley; 29, cross rod; 3, UV light curing box. DETAILED DESCRIPTION
[0028] The application will be further described below with reference to the drawings.
[0029] As Figures 1 to 6 shown, a curing system for contact lens production includes:
[0030] a UV light curing box 3 for light curing of the product;
[0031] a heat reaction box 2 for heat treatment of the product;
[0032] The carrying device 1 is used for carrying products into the UV light curing box 3 and carrying products from the UV light curing box 3 to the heat reaction box 2; the carrying device 1 comprises a portal frame 11, a cross beam 19, a longitudinal moving mechanism, a transverse moving mechanism, a moving platform 112 and a carrying mechanism; the longitudinal moving mechanism comprises a first motor 16, a first shaft 17, a first toothed belt wheel, a second toothed belt wheel 15, a first synchronous belt 14 and two transmission assemblies; the first motor 16 is fixed on the upper part of the portal frame 11; the first shaft 17 is installed on the portal frame 11 through a bearing seat; the first toothed belt wheel is installed on the first motor 16; the second toothed belt wheel 15 is installed on the first shaft 17; the first toothed belt wheel and the second toothed belt wheel 15 are drivingly connected through the first synchronous belt 14; the two transmission assemblies are symmetrically arranged at the two ends of the first shaft 17; the transmission assembly comprises a third toothed belt wheel 18, a fourth toothed belt wheel 12 and a second synchronous belt 13; the third toothed belt wheel 18 is installed on the first shaft 17; the fourth toothed belt wheel 12 is rotatably installed on the lower part of the portal frame 11; the third toothed belt wheel 18 and the fourth toothed belt wheel 12 are drivingly connected through the second synchronous belt 13; the two ends of the cross beam 19 are fixed on the two second synchronous belts 13; the transverse moving mechanism comprises a first guide rail 110, a first sliding block 111, a second motor 118, a fifth toothed belt wheel, a sixth toothed belt wheel and a third synchronous belt 117; the first guide rail 110 is fixed on the cross beam 19; the first sliding block 111 is slidably installed on the first guide rail 110; the second motor 118 is fixed on one end of the cross beam 19, the sixth toothed belt wheel is rotatably installed on the other end of the cross beam 19, and the fifth toothed belt wheel is installed on the second motor 118; the fifth toothed belt wheel and the sixth toothed belt wheel are drivingly connected through the third synchronous belt 117; one side of the first sliding block 111 is fixed on the third synchronous belt 117; the moving platform 112 is fixed on the first sliding block 111, and the carrying mechanism is installed on the moving platform 112.
[0033] Further, the carrying mechanism comprises a third motor 113, a seventh toothed belt wheel, an eighth toothed belt wheel, a fourth synchronous belt, a second guide rail 114, a second sliding block and a lifting module; the third motor 113 and the second guide rail 114 are fixed on the moving platform 112; the seventh toothed belt wheel is installed on the third motor 113; the eighth toothed belt wheel is rotatably installed on the moving platform 112; the seventh toothed belt wheel and the eighth toothed belt wheel are drivingly connected through the fourth synchronous belt; the second sliding block is slidably installed on the second guide rail 114; one side of the second sliding block is fixedly connected with the fourth synchronous belt; the lifting module comprises a lifting electric cylinder and a carrying plate 115; the lifting electric cylinder is fixed on the second sliding block; the carrying plate 115 is fixed on the piston rod of the lifting electric cylinder; the carrying plate 115 is fixedly provided with a guide column 116.
[0034] Further, the hot reaction box 2 comprises a box body 21, a pushing mechanism 22 and a carrying mechanism 23; the inside of the box body 21 is provided with a heating cavity, and the top is provided with an air inlet; the top end of the box body 21 is fixedly provided with a hot air fan 24, and the air outlet of the hot air fan 24 is connected with the air inlet; the carrying mechanism 23 is configured with two, and the two carrying mechanisms 23 are symmetrically arranged in the heating cavity and fixed on the box body 21; the pushing mechanism 22 is arranged between the two carrying mechanisms 23, and the pushing mechanism 22 is arranged below the carrying mechanism 23 and fixed on the box body 21; one side of the upper part of the box body 21 is provided with a feeding port, and one side of the lower part is provided with a discharging port matched with the carrying mechanism 23.
[0035] Further, the pushing mechanism 22 has a double structure, and specifically comprises a pushing support 221, a fourth motor 223, a ninth toothed belt wheel 224, a tenth toothed belt wheel 2212, a fifth synchronous belt 222, a third guide rail 2211, a third sliding block, a bearing plate 2210, a fifth motor, an eleventh toothed belt wheel, a twelfth toothed belt wheel 225, a sixth synchronous belt 226, a fourth guide rail 228, a fourth sliding block 227 and a pushing plate 229; the pushing support 221 is fixed on the box body 21; the third guide rail 2211 and the fourth motor 223 are fixed on the pushing support 221; the third sliding block is slidably mounted on the third guide rail 2211; the ninth toothed belt wheel 224 is mounted on the fourth motor 223; the tenth toothed belt wheel 2212 is rotatably mounted on the pushing support 221; the ninth toothed belt wheel 224 and the tenth toothed belt wheel 2212 are drivingly connected through the fifth synchronous belt 222; one side of the third sliding block is fixed on the fifth synchronous belt 222; the bearing plate 2210 is fixed on the upper part of the third sliding block; the fifth motor and the fourth guide rail 228 are fixed on the bearing plate 2210; the eleventh toothed belt wheel is mounted on the fifth motor; the twelfth toothed belt wheel 225 is rotatably mounted on the bearing plate 2210; the eleventh toothed belt wheel and the twelfth toothed belt wheel 225 are drivingly connected through the sixth synchronous belt 226; the fourth sliding block 227 is slidably mounted on the fourth guide rail 228; one side of the sixth synchronous belt 226 is fixed on the sixth synchronous belt 226; and the pushing plate 229 is fixed on the upper part of the fourth sliding block 227. The third sliding block and the fourth sliding block 227 are driven to move by the fourth motor 223 and the fifth motor, so as to realize the movement of the pushing plate 229, and the material at the lowermost part in the box body 21 is pushed out from the discharging port by the pushing plate 229, so as to realize the discharging.
[0036] Further, the material carrying mechanism 23 comprises a second shaft, a third shaft 27, a sixth motor, a thirteenth toothed pulley, a fourteenth toothed pulley 28, a seventh synchronous belt 25 and a cross rod 29; the sixth motor is fixed on the box body 21; the second shaft and the third shaft 27 are rotatably installed on the box body 21; the second shaft and the third shaft 27 are arranged in parallel and spaced apart in an up-down direction; the second shaft is located on the upper side of the inside of the box body 21, and the third shaft 27 is located on the lower side of the inside of the box body 21; the second shaft is in transmission connection with the output shaft of the sixth motor through a shaft coupling; the thirteenth toothed pulley is provided with two toothed pulleys and is symmetrically installed at the two ends of the second shaft; the fourteenth toothed pulley 28 is provided with two toothed pulleys and is symmetrically installed at the two ends of the third shaft 27; the seventh synchronous belt 25 is provided with two synchronous belts; the thirteenth toothed pulley and the fourteenth toothed pulley 28 are in transmission connection through the seventh synchronous belt 25; the cross rod 29 is fixed at the two ends of the two seventh synchronous belts 25 respectively; the cross rod 29 and the second shaft are arranged in parallel; the cross rod 29 is provided with a plurality of cross rods; the plurality of cross rods 29 are arranged in an equidistant array along the outer side of the seventh synchronous belt 25. The carrying mechanism puts the material into the heating cavity from the feeding port on the upper part of the box body 21, places the material on the corresponding cross rods 29 of the two material carrying mechanisms 23 on both sides of the material, holds the material through the cross rods 29, heats the material through the air heater 24, and when the sixth motor starts to transport the material to the lower part of the box body 21 to the discharging port through the seventh synchronous belt 25, the carrying mechanism takes out the material from the discharging port.
[0037] Further, the cross rod 29 is provided with a plurality of rollers 26; the plurality of rollers 26 are arranged in an equidistant array along the length direction of the cross rod 29. The arrangement of the rollers 26 facilitates the taking and placing of the material.
[0038] Working principle
[0039] Based on the segmented curing technology logic of "UV curing pre-mature + thermal curing post-mature", through the cooperative work of the three core components of the UV light curing box 3, the thermal reaction box 2 and the carrying device 1, the material stress accumulation, the biocompatibility risk and the energy consumption efficiency bottleneck problem of the traditional single UV curing process are solved, and the efficient and high-quality production of the contact lenses is realized. The overall working mechanism can be divided into the following three parts:
[0040] 1. Overall cooperative process
[0041] During production, first, the contact lenses mold containing liquid prepolymer (such as HEMA, SiMA, etc.) is replaced by nitrogen (to avoid oxygen inhibition), and then the mold tray is accurately transported to the UV light curing box 3 by the conveying device 1 for "pre-curing"; after completion, the conveying device 1 acts again to transfer the preliminarily cured mold to the thermal reaction box 2 for "post-curing"; finally, the pushing mechanism 22 of the thermal reaction box 2 pushes out the cured mold, which enters the subsequent demolding and hydration processing link, forming a closed-loop production process of "pre-processing → UV pre-mature → thermal post-mature → subsequent processing".
[0042] 2. Core component working mechanism
[0043] (1) UV light curing box 3: quickly build the skeleton and inhibit oxygen inhibition
[0044] Functional positioning: assume the role of "pre-curing", quickly initiate the crosslinking of the prepolymer through short-time UV irradiation to form the preliminary solid skeleton of the lens, avoiding the uneven crosslinking caused by long-time UV in traditional process.
[0045] Key parameters: the UV light source with a wavelength of 300-400 nm (commonly 365-380 nm) is used by default;
[0046] Irradiation intensity 5-20 mW / cm 2 , curing time 5-6 min (much shorter than the traditional 15-30 min).
[0047] Technical logic: short-time UV irradiation can quickly activate the surface layer photoinitiator to form a continuous polymer network "skeleton" in the mold, and because the irradiation time is short, it avoids too large difference in crosslinking density between the surface layer and the interior, laying a foundation for subsequent thermal curing "completing" polymerization.
[0048] (2) Thermal reaction box 2: deep curing + stress relief, improve material performance
[0049] Functional positioning: assume the role of "post-curing", activate the deep layer of unreacted initiators through gentle heating to complete the remaining polymerization reaction, and eliminate the frozen stress in the UV curing stage through chain relaxation.
[0050] Key structure and action:
[0051] Heating system: the hot air fan 24 at the top of the box 21 sends 42-45℃ hot air into the heating cavity through the air inlet, and the hot air flows from top to bottom to ensure uniform temperature in the cavity (temperature difference ≤ ±1℃);
[0052] Loading mechanism 23: two sets of symmetrical loading components (including second shaft, third shaft 27, seventh synchronous belt 25, cross bar 29 and roller 26) lift the mold tray, the sixth motor drives the synchronous belt to slowly move the cross bar 29 downward (speed 5mm / min), ensuring that the mold is evenly heated in the heating cavity for 10-11min;
[0053] Unloading mechanism: adopts "double stroke pushing mechanism 22" (fourth motor 223 drives third slider to move longitudinally, and fifth motor drives fourth slider 227 to move transversely), which can accurately push the mold tray at the bottom out of the discharge port, avoiding unloading jam.
[0054] Technical logic: moderate temperature of 42-45℃ can activate UV-cured unreacted deep initiator, promote "diffusion-controlled polymerization" (instead of traditional UV "chain growth dominant"), increase polymerization degree from 70% to more than 98%; at the same time, the polymer chain can relax and reorganize in a hot environment, eliminating the internal stress of traditional process and improving the toughness of the lens.
[0055] (3) Handling device 1: accurate and efficient cross-device transmission
[0056] Functional positioning: connect UV photocuring box 3 and thermal reaction box 2 to realize automatic and high-precision transfer of mold tray, avoid positioning errors and low efficiency of manual handling.
[0057] Key structure and action:
[0058] Longitudinal movement: the first motor 16 drives the first shaft 17 to rotate through the first synchronous belt 14, and then drives the two end transmission components (third / fourth toothed belt pulley 12, second synchronous belt 13), so that the cross beam 19 moves longitudinally along the gantry 11 (speed 40-50mm / s);
[0059] Transverse movement: the second motor 118 drives the first slider 111 to slide transversely along the first guide rail 110 on the cross beam 19 through the third synchronous belt 117 (speed 30-40mm / s), and drives the moving platform 112 to adjust the transverse position;
[0060] Lifting and carrying: the third motor 113 of the handling mechanism drives the second slider to move along the second guide rail 114 through the fourth synchronous belt, and the lifting cylinder drives the loading plate 115 to lift (stroke 200mm), the guide column 116 (2-4) on the loading plate 115 ensures that the positioning error of the mold tray is ≤±0.5mm, avoiding the displacement of the mold during transfer.
[0061] 3. Technical advantage logic of segmented curing
[0062] Through the combination of "UV pre-ripening + thermal post-ripening", the three major problems of traditional process are solved:
[0063] Material stress: UV short time build skeleton to avoid uneven crosslinking, heat curing chain relaxation to eliminate frozen stress, so that the lens fracture elongation is increased from 80-120% to more than 150%;
[0064] Biocompatibility: heat curing completes polymerization reaction, reducing monomer residue from >500ppm to <100ppm (complying with ISO standards), and short UV irradiation reduces photo initiator side reactions, reducing light transmittance from 3-5% to <1%;
[0065] Energy efficiency: UV irradiation time is shortened by more than 60%, reducing the total energy consumption of the production line by 30%, while the automatic transmission of the conveying device 1 increases the production capacity per unit time by more than 25%.
[0066] Example 1: Production of silicone hydrogel spherical daily disposable contact lenses
[0067] 1. Product background
[0068] For the mainstream silicone hydrogel daily disposable contact lenses on the market, the product needs to balance high oxygen permeability (silicon component) and wearing comfort (hydrogel base), and traditional single UV curing is easy to cause edge brittle fracture and uneven oxygen permeability.
[0069] 2. Production parameters and process
[0070] Pre-treatment stage: inject liquid prepolymer (HEMA 60%, SiMA 25%, photo initiator 1%, other additives 14%) into spherical mold, fill nitrogen gas (flow rate 10 L / min) into mold cavity for 2 min to replace oxygen in the cavity.
[0071] UV pre-mature curing:
[0072] Conveying device action: longitudinal movement speed of gantry 50 mm / s, transverse movement speed 30 mm / s, lifting cylinder stroke 200 mm, positioning mold tray (diameter 150 mm) through 2 guide columns on the loading plate, positioning error ±0.5 mm, and feeding the tray into the UV light curing box;
[0073] UV parameters: wavelength 365 nm, irradiation intensity 15 mW / cm 2 , curing time 5 min, forming a preliminary solid skeleton (polymerization degree 70%), surface crosslinking density controlled at 1.2 mmol / cm 3 (avoiding overcrosslinking).
[0074] Heat post-curing:
[0075] Transfer: the moving platform is moved to the feeding port of the thermal reaction box by the transverse moving mechanism (800 mm from the UV light curing box, 26 s moving time), the lifting cylinder is lowered by 150 mm, and the tray is sent into the crossbar of the loading mechanism through the feeding port (crossbar spacing 20 mm, roller assisted positioning to avoid scratches on the tray);
[0076] Thermal curing parameters: hot air blower air temperature 45°C, heating chamber air speed 0.8 m / s, the sixth motor of the loading mechanism drives the crossbar to move downward at a speed of 5 mm / min, the total curing time is 10 min, and the polymerization degree is increased to 98.5% after the activation of the deep initiator;
[0077] Unloading: the fourth motor of the pushing mechanism drives the third sliding block to move longitudinally by 200 mm (speed 20 mm / s), the fifth motor drives the fourth sliding block to move transversely by 150 mm (speed 15 mm / s), and the tray is pushed out of the discharge port by the double-stroke pushing plate (discharge port diameter 160 mm, matching the size of the tray).
[0078] Subsequent processing: after demolding, the lens is soaked in physiological saline (temperature 25°C) for 4 h for expansion, and the final shaping is completed.
[0079] 3. Implementation effect
[0080] Material performance: lens elongation at break 150% (traditional process 100%), oxygen permeability coefficient DK value 28 x 10-11 (complying with the oxygen permeability requirements of daily disposable lenses), no edge brittle fracture phenomenon;
[0081] Biocompatibility: monomer residual amount 85 ppm (far lower than the ISO 100 ppm standard), light transmittance 92% (traditional process 88%), no yellowing;
[0082] Production efficiency: unit time production capacity 150 pieces / h (traditional process 120 pieces / h), total energy consumption of production line reduced by 32% (UV energy consumption ratio reduced from 65% to 38%).
[0083] Example 2: Production of hydrogel Toric astigmatism correcting contact lenses
[0084] 1. Product background
[0085] For hydrogel contact lenses for astigmatism correction, the product uses a Toric aspherical mold, and the edge thickness is 15-20% thicker than ordinary lenses. Traditional UV curing is prone to cause excessive crosslinking at the edge, insufficient toughness, and higher mold positioning requirements (astigmatism axis needs to be accurately aligned).
[0086] 2. Production parameters and process
[0087] Pre-treatment stage: inject the hydrogel pre-polymer containing special crosslinking agent (dimethyl acrylate ethylene glycol adapted to the structure of astigmatism) into the Toric mold, extend the nitrogen replacement time to 3 min (the thick edge needs more oxygen removal), and align the mold axis mark with the tray positioning hole.
[0088] UV pre-mature curing:
[0089] Transport device adjustment: due to the higher positioning accuracy requirement of the astigmatism mold, the longitudinal / lateral movement speed is reduced to 40 mm / s, the carrier plate is increased to 4 guide columns (diameter 8 mm, spacing 50 mm), the positioning error is controlled within ±0.3 mm, and the mold axis position is ensured without deviation;
[0090] UV parameters: wavelength 380 nm (longer wavelength can penetrate thick edge), irradiation intensity 12 mW / cm 2 (avoid excessive crosslinking of the edge), curing time 6 min, initial polymerization degree 68%, edge crosslinking density controlled at 1.0 mmol / cm 3 .
[0091] Thermal post-curing:
[0092] Thermal curing adjustment: the hydrogel material is sensitive to high temperature, the temperature of the air heater is reduced to 42℃, the air speed in the heating chamber is reduced to 0.6 m / s, and the curing time is extended to 11 min (thick edge needs longer polymerization time); the distance between the horizontal bars of the material loading mechanism is reduced to 15 mm (adapted to the aspherical profile of the Toric mold), the number of rollers is increased to 8 per horizontal bar (originally 6), and the stability of the tray is improved;
[0093] Unloading optimization: the length of the Toric mold tray is increased to 200 mm (originally 150 mm), the double stroke adjustment of the material pushing mechanism is "longitudinal 250 mm + lateral 200 mm", and the fourth motor speed is reduced to 1500 rpm (originally 1800 rpm) to avoid the deviation of the mold axis position caused by fast pushing of the material.
[0094] Subsequent processing: after demolding, gradient hydration process is adopted (the concentration of physiological saline is gradually increased from 0.9% to 1.2%), which avoids uneven swelling of the thick edge, and the swelling time is 5 h.
[0095] 3. Implementation effect
[0096] Material performance: lens elongation at break 160% (satisfies the toughness requirement of astigmatism lens for repeated wearing), edge crosslinking uniformity error ≤5% (traditional process 12%), astigmatism axis deviation ≤±1° (meets the optical correction requirement);
[0097] Biocompatibility: monomer residual amount 72 ppm, light transmittance 93% (no yellowing), and corneal adaptability score improved by 15% (traditional process is prone to foreign body sensation due to high edge hardness);
[0098] Production efficiency: 140 pieces / hour (110 pieces / hour for traditional process), total energy consumption is still 28% lower than traditional process, and mold rejection rate is reduced from 5% to 2% (positioning accuracy is improved).
Claims
1. A curing system for contact lens production, characterized by, The application relates to a UV light curing box (3) for light curing of products, a thermal reaction box (2) for thermal treatment of products, and a conveying device (1) for conveying the products into the UV light curing box (3) and into the thermal reaction box (2). The conveying device (1) comprises a portal frame (11), a cross beam (19), a longitudinal moving mechanism, a transverse moving mechanism, a moving platform (112) and a conveying mechanism; the longitudinal moving mechanism comprises a first motor (16), a first shaft (17), a first toothed belt wheel, a second toothed belt wheel (15), a first synchronous belt (14) and two transmission assemblies; the first motor (16) is fixed to the upper portion of the portal frame (11); the first shaft (17) is installed on the portal frame (11) through a bearing seat; the first toothed belt wheel is installed on the first motor (16); the second toothed belt wheel (15) is installed on the first shaft (17); the first toothed belt wheel and the second toothed belt wheel (15) are transmissionally connected through the first synchronous belt (14); the two transmission assemblies are symmetrically arranged at the two ends of the first shaft (17); the transmission assembly comprises a third toothed belt wheel (18), a fourth toothed belt wheel (12) and a second synchronous belt (13); the third toothed belt wheel (18) is installed on the first shaft (17); the fourth toothed belt wheel (12) is rotatably installed on the lower portion of the portal frame (11); the third toothed belt wheel (18) and the fourth toothed belt wheel (12) are transmissionally connected through the second synchronous belt (13); the two ends of the cross beam (19) are fixed to the two second synchronous belts (13); the transverse moving mechanism comprises a first guide rail (110), a first sliding block (111), a second motor (118), a fifth toothed belt wheel, a sixth toothed belt wheel and a third synchronous belt (117); the first guide rail (110) is fixed to the cross beam (19); the first sliding block (111) is slidably installed on the first guide rail (110); the second motor (118) is fixed to one end of the cross beam (19), the sixth toothed belt wheel is rotatably installed on the other end of the cross beam, and the fifth toothed belt wheel is installed on the second motor (118); the fifth toothed belt wheel and the sixth toothed belt wheel are transmissionally connected through the third synchronous belt (117); one side of the first sliding block (111) is fixed to the third synchronous belt (117); the moving platform (112) is fixed to the first sliding block (111), and the conveying mechanism is installed on the moving platform (112). 2. A curing system for contact lens production as claimed in claim 1, wherein, 3. A curing system for contact lens production as claimed in claim 2, wherein, The carrying mechanism comprises a third motor (113), a seventh toothed belt wheel, an eighth toothed belt wheel, a fourth synchronous belt, a second guide rail (114), a second sliding block and a lifting module; the third motor (113) and the second guide rail (114) are fixed on the moving platform (112); the seventh toothed belt wheel is installed on the third motor (113); the eighth toothed belt wheel is rotatably installed on the moving platform (112); the seventh toothed belt wheel and the eighth toothed belt wheel are drivingly connected through the fourth synchronous belt; the second sliding block is slidably installed on the second guide rail (114); one side of the second sliding block is fixedly connected with the fourth synchronous belt; the lifting module comprises a lifting electric cylinder and a carrying plate (115); the lifting electric cylinder is fixed on the second sliding block; the carrying plate (115) is fixed on a piston rod of the lifting electric cylinder; a guide column (116) is fixedly arranged on the carrying plate (115).
4. The curing system for contact lens production of claim 1, wherein, The hot reaction box (2) comprises a box body (21), a pushing mechanism (22) and a carrying mechanism (23); the inside of the box body (21) is provided with a heating cavity, and the top is provided with an air inlet; a hot air fan (24) is fixedly arranged at the top end of the box body (21), and the air outlet of the hot air fan (24) is connected with the air inlet; the carrying mechanism (23) is configured with two, and the two carrying mechanisms (23) are symmetrically arranged in the heating cavity and fixed on the box body (21); the pushing mechanism (22) is arranged between the two carrying mechanisms (23), and the pushing mechanism (22) is arranged below the carrying mechanisms (23) and fixed on the box body (21); one side of the upper part of the box body (21) is provided with a feeding port, and one side of the lower part is provided with a discharging port matched with the carrying mechanism (23).
5. A curing system for contact lens production as claimed in claim 4, wherein, The pushing mechanism (22) comprises a pushing support (221), a fourth motor (223), a ninth toothed belt wheel (224), a tenth toothed belt wheel (2212), a fifth synchronous belt (222), a third guide rail (2211), a third sliding block, a carrying plate (2210), a fifth motor, an eleventh toothed belt wheel, a twelfth toothed belt wheel (225), a sixth synchronous belt (226), a fourth guide rail (228), a fourth sliding block (227) and a pushing plate (229); the pushing support (221) is fixed on the box body (21); the third guide rail (2211) and the fourth motor (223) are fixed on the pushing support (221); the third sliding block is slidably installed on the third guide rail (2211); the ninth toothed belt wheel (224) is installed on the fourth motor (223); the tenth toothed belt wheel (2212) is rotatably installed on the pushing support (221); the ninth toothed belt wheel (224) and the tenth toothed belt wheel (2212) are drivingly connected through the fifth synchronous belt (222); one side of the third sliding block is fixed on the fifth synchronous belt (222); the carrying plate (2210) is fixed on the upper part of the third sliding block; The fifth motor and the fourth guide rail (228) are fixed on the bearing plate (2210); the eleventh toothed belt wheel is installed on the fifth motor; the twelfth toothed belt wheel (225) is rotatably installed on the bearing plate (2210); the eleventh toothed belt wheel and the twelfth toothed belt wheel (225) are drivingly connected through the sixth synchronous belt (226); the fourth sliding block (227) is slidably installed on the fourth guide rail (228); one side of the sixth synchronous belt (226) is fixed on the sixth synchronous belt (226); and the material pushing plate (229) is fixed on the upper portion of the fourth sliding block (227).
6. A curing system for contact lens production as defined in claim 4, wherein, The loading mechanism (23) comprises a second shaft, a third shaft (27), a sixth motor, a thirteenth toothed belt wheel, a fourteenth toothed belt wheel (28), a seventh synchronous belt (25) and a cross bar (29); the sixth motor is fixed on the box body (21); the second shaft and the third shaft (27) are rotatably installed on the box body (21); the second shaft and the third shaft (27) are arranged in parallel and spaced apart in an up-down direction; the second shaft is located on the upper side of the interior of the box body (21), and the third shaft (27) is located on the lower side of the interior of the box body (21); the second shaft is drivingly connected with the output shaft of the sixth motor through a shaft coupling; the thirteenth toothed belt wheel is provided with two toothed belt wheels and is symmetrically installed on the two ends of the second shaft; the fourteenth toothed belt wheel (28) is provided with two toothed belt wheels and is symmetrically installed on the two ends of the third shaft (27); the seventh synchronous belt (25) is provided with two synchronous belts; the thirteenth toothed belt wheel and the fourteenth toothed belt wheel (28) are drivingly connected through the seventh synchronous belt (25); the two ends of the cross bar (29) are respectively fixed on the two seventh synchronous belts (25); the cross bar (29) and the second shaft are arranged in parallel; the cross bar (29) is provided with a plurality of cross bars; and the plurality of cross bars (29) are arranged in an equidistant array along the outer side of the seventh synchronous belt (25).
7. A curing system for contact lens production as claimed in claim 6, wherein, The cross bar (29) is provided with a plurality of rollers (26); the plurality of rollers (26) are arranged in an equidistant array along the length direction of the cross bar (29).