Bio-Based Ophthalmic Lens Composition With Stress-Indicating UV Protection
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Solution Overview
Problem
The manufacturing process of ophthalmic lenses contributes significantly to water contamination and pollution by microplastics, posing a threat to ecosystems and human health, and the industry generates substantial waste that is difficult to recycle due to the use of conventional polymeric materials.
Innovation Solution
The use of thermoplastic aliphatic polyester (PLA) combined with metal oxide nanoparticles and naphthopyrans, along with advanced injection techniques like rapid heat cycle moulding (RHCM), to produce lenses that are environmentally sustainable, recyclable, and have improved optical and mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional polymeric materials (polycarbonate, polyureas, polyurethanes) are used for manufacturing ophthalmic lenses, then optical performance and durability are improved, but environmental pollution by microplastics and water contamination worsen
Solution Approach 1:
The patent changes the material parameter from conventional petrochemical polymers to thermoplastic aliphatic polyesters (PLA, PHA), fundamentally altering the chemical composition to enable biodegradation and eliminate persistent microplastic pollution while maintaining lens functionality
Solution Approach 2:
The patent creates composite materials by combining thermoplastic aliphatic polyester with metal oxide nanoparticles (ZrO2, ZnO, SiO2, MgO, TiO2) and organic coatings (naphthopyrans), achieving both environmental sustainability and enhanced optical-mechanical properties
2Object-generated harmful factors
If thermoplastic aliphatic polyester (PLA) is used as the polymeric component, then environmental sustainability and recyclability are improved, but mechanical strength and optical clarity may deteriorate
Solution Approach 1:
The patent incorporates metal oxide nanoparticles (ZrO2, ZnO, SiO2, MgO, TiO2) into the PLA matrix to form composite materials that enhance mechanical strength, elasticity, and hydrophobicity while preserving the biodegradable nature of PLA
Solution Approach 2:
The patent applies functional coatings with specific local properties: metal oxide nanoparticles provide UV protection and hydrophobicity at the surface, while naphthopyrans provide photochromic functionality, allowing different regions of the lens to have specialized properties without compromising the bulk material's biodegradability
3Productivity
If advanced injection techniques (rapid heat cycle moulding) are used, then production efficiency and precision are improved, but process complexity increases
Solution Approach 1:
The patent utilizes rapid phase transitions of the thermoplastic aliphatic polyester between solid and molten states through controlled heating and cooling cycles, enabling quick moulding and demoulding operations that dramatically reduce production cycle time
Solution Approach 2:
The patent dynamically changes temperature parameters during the moulding process, rapidly heating the mould to melt the polymer for injection, then quickly cooling it to solidify the lens, optimizing both production speed and dimensional precision
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 reduces environmental impact by minimizing microplastic pollution, enhances optical quality, and improves mechanical strength and UV protection while maintaining clarity, with rapid heat cycle moulding ensuring precise and efficient lens production.
Implementation Method 1
The integration of metal oxide nanoparticles significantly improves the mechanical strength, elasticity and hydrophobicity of the lenses
Implementation Method 2
the lenses of the present invention comprise organic coatings, particularly, but not exclusively, naphthopyrans
Implementation Method 3
naphthopyrans as photochemical coatings and mechanohoric materials
Implementation Method 4
advanced injection techniques such as rapid heat cycle moulding (RHCM)
Implementation Method 5
rapid heat cycle moulding (RHCM) comprising rapid heating and cooling cycles
Data Source
AI summary
The present invention relates to optical lenses, particularly ophthalmic lenses, comprising bio-based and biodegradable materials and their manufacturing process. The lenses are composed of a thermoplastic aliphatic polyester, preferably polylactic acid (PLA), or polyhydroxyalkanoates (PHA), combined with metal oxide nanoparticles (ZrO2, ZnO, SiO2, MgO, TiO2) and naphthopyrans. This composition significantly improves optical and mechanical properties while reducing environmental impact compared to conventional petroleum-based lenses. The manufacturing process employs rapid heat cycle moulding (RHCM) technology with Variotherm systems, ensuring precise temperature control and superior optical quality. The naphthopyrans function both as UV blockers (95-99% protection) and as mechanophoric materials that visibly change colour under mechanical stress, providing a visual indication of lens integrity. The invention offers exceptional optical performance with high Abbe numbers while addressing environmental concerns through biodegradability and reduced microplastic pollution.