Colored Glass Transmittance Control via Fe2O3-TiO2 Product
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Solution Overview
Problem
It is challenging to finely control the transmittance of colored glass for pharmaceutical containers to meet the varying standards specified in the Japanese Pharmacopoeia, particularly when the thickness of the container changes, as the transmittance is not solely determined by the contents of Fe2O3 and TiO2, and existing methods struggle to maintain productivity while achieving the required light-shading properties.
Innovation Solution
A method involving blending a glass batch with specific compositions, including 65% to 75% SiO2, 0% to 20% B2O3, 1% to 10% Al2O3, and 0.01% to 5% Fe2O3 and TiO2, with a product of Fe2O3 and TiO2 content within a certain range (1.00≤[Fe2O3]×[TiO2]<6.00), and using a reducing agent like metal aluminum or sulfur to control the redox state and melting temperature, ensuring the glass meets the Japanese Pharmacopoeia standards without reducing productivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the contents of Fe2O3 and TiO2 are adjusted to control transmittance, then the light-shading property is improved, but the manufacturing precision deteriorates because it is difficult to finely control the transmittance when thickness changes
Solution Approach 1:
The invention changes the parameter control approach from individual component contents to a product relationship parameter. By controlling the product of Fe2O3 content and TiO2 content to fall within a specific range (0.003 to 0.03 when expressed as percentages), the patent achieves precise transmittance control that adapts to varying glass thicknesses. This parameter transformation allows the system to maintain manufacturing precision across different thickness specifications.
Solution Approach 2:
The invention utilizes the composite interaction between Fe2O3 and TiO2 components in the glass material. Rather than controlling each component independently, the patent exploits their combined effect on transmittance by maintaining their product within a specific range. This composite approach allows the glass composition to adapt to thickness variations while maintaining consistent optical properties.
2Manufacturing precision
If the melting temperature is increased to control redox state and transmittance, then the light-shading property is improved, but the productivity deteriorates due to increased viscosity and reduced forming efficiency
Solution Approach 1:
The invention changes the control parameter from melting temperature to the product of Fe2O3 and TiO2 contents. This parameter substitution allows transmittance control to be achieved through compositional adjustment rather than thermal process modification, thereby maintaining productivity while achieving the desired optical properties.
Solution Approach 2:
The invention replaces the thermal control mechanism (melting temperature adjustment) with a compositional control mechanism (Fe2O3 and TiO2 content product). This substitution eliminates the need to modify melting conditions, thereby maintaining production efficiency while achieving precise transmittance control through chemical composition adjustment.
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 allows for precise control of transmittance in colored glass for pharmaceutical containers, satisfying the Japanese Pharmacopoeia standards for both short- and long-wavelength regions across different thicknesses, while maintaining productivity and fining properties, thus preventing light alteration and UV blocking.
Implementation Method 1
the transmittance of the glass is not determined unambiguously by the contents of Fe2O3 and TiO2, and relates to a redox state at the time of melting of the glass, and when a reducing agent is used, a product of the content of Fe2O3 and the content of TiO2 in a glass composition closely relates to the transmittance of the colored glass for a pharmaceutical container
Data Source
AI summary
The present invention relates to a method of producing a colored glass for a pharmaceutical container by which the transmittance of a glass to be obtained is easily controlled so as to satisfy the standards of the Japanese Pharmacopoeia.