Plastic Lens Casting Apparatus Discharge Control
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Solution Overview
Problem
High-viscosity plastic lens starting materials with rapid initial polymerization rates pose challenges in cast polymerization methods, leading to optical defects and inefficient use of starting material due to halted discharge and subsequent recommencement issues in casting processes.
Innovation Solution
A method and apparatus that continuously stir and supply the starting material liquid during discharge halts, using signal processing to control discharge based on completion signals and predetermined times to ensure efficient casting into multiple molds, reducing waste and maintaining optical quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If discharge of mixed liquid is halted after casting into mold, then polymerization can complete in mold, but mixed liquid in mixer becomes highly viscous causing optical defects
Solution Approach 1:
The system performs preliminary actions by continuously stirring the mixed liquid in the mixer before discharge is needed, and prepares the casting mold positioning in advance. The control unit predicts when discharge should occur based on predetermined timing, ensuring the mixed liquid is ready for casting before the mold arrives, thus preventing viscosity increase while maintaining optical quality.
Solution Approach 2:
The control unit uses feedback from the predetermined timing system and actual casting progress to adjust discharge control. By monitoring whether casting is complete and when the next mold will arrive, the system dynamically controls discharge timing, ensuring optimal viscosity for casting while preventing defects from excessive polymerization.
2Productivity
If discharge continues without halting, then mixed liquid maintains proper viscosity, but starting material flows out during mold conveyance reducing effective use level
Solution Approach 1:
The system dynamically adjusts discharge timing based on real-time conditions. The control unit continuously monitors casting progress and mold conveyance timing, switching discharge between halted and continuing states optimally. This dynamic control ensures material is cast efficiently during productive periods while preventing waste during mold conveyance, maintaining both productivity and optical quality.
Solution Approach 2:
The discharge operation follows periodic cycles: discharge continues during active casting, halts during mold conveyance, then resumes when next mold is positioned. This periodic on-off pattern maximizes effective material use by synchronizing discharge with productive casting periods while preventing overflow waste, thereby improving productivity without compromising lens optical characteristics.
3Reliability
If discharge is halted for high-viscosity material, then polymerization control improves, but difficulty recommencing discharge increases
Solution Approach 1:
The stirring action continues continuously even when discharge is halted, maintaining the mixed liquid in a uniform, pumpable state. This continuous stirring prevents the liquid from becoming too viscous or setting up during the halt period, making recommencement of discharge easy and reliable. The system thus maintains polymerization control during halt while ensuring smooth restart capability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables the production of plastic lenses with good optical characteristics while minimizing material waste by managing the polymerization and discharge processes effectively, even with high-viscosity materials.
Implementation Method 1
mixing and discharging part with stirring means for stirring the plastic lens starting material liquid
Implementation Method 2
polymerizable plastic lens starting material liquid is cast into a casting mold and polymerized within the casting mold
Data Source
AI summary
A method of casting a plastic lens starting material liquid using a casting apparatus comprising at least a mixing and discharging part and a casting part, and casting a plastic lens starting material liquid sequentially into multiple casting molds. Discharge of the plastic lens starting material liquid from the mixing and discharging part is halted based on a discharge halt preparation completion signal transmitted by the casting part, the discharge that has been halted is recommenced (1) at least based on a discharge recommencement preparation completion signal transmitted by the casting part or (2) by reception by the mixing and discharging part of a forced discharge start signal transmitted upon elapsing a predetermined time following halting of the discharge or following reception of the discharge halt preparation completion signal without transmission of a discharge recommencement preparation completion signal by the casting part, and the stirring in the mixing and discharging part is continued during the period when the discharge is halted.