Insert Assembly for Intraocular Lens Injection Molding
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Solution Overview
Problem
The labor-intensive and costly process of manufacturing intraocular lenses with haptics, which typically involves forming a plastic disk into an intraocular lens through turning and milling operations, necessitates a more efficient method to reduce production costs.
Innovation Solution
An insert assembly for an injection mold that integrates a bounding structure within the first casting mold half, allowing the formation of both the lens and haptics cavities in a single casting mold, enabling the direct creation of an intraocular lens with integrally formed haptics by using monomeric material within the mold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional turning and milling operations are used to manufacture intraocular lenses with haptics, then the lens can be formed with optically accurate surfaces, but the process becomes labor intensive and costly
Solution Approach 1:
The patent combines multiple manufacturing operations (turning, milling, and haptic formation) into a single injection molding process. The insert assembly integrates the optical zone insert with bounding structures that form both the lens and haptics in one operation, eliminating the need for separate turning and milling steps while maintaining optical surface accuracy through the precision of the insert assembly.
Solution Approach 2:
The insert assembly is pre-configured with bounding structures that define the haptics cavity before the injection molding process begins. This preliminary arrangement of the mold components enables the formation of complex haptic geometries during the injection process itself, rather than requiring post-molding machining operations.
2Shape
If traditional multi-step manufacturing is used, then detailed haptic structures can be formed, but extensive material removal and post-treatment are required
Solution Approach 1:
The patent replaces mechanical subtractive processes (milling and cutting) with an additive injection molding process. Monomeric material is injected into the haptics cavity defined by the bounding structures of the insert assembly, building up the haptic structures directly in the desired shape without material removal. This eliminates flash generation and the need for post-treatment while maintaining complex haptic geometries.
Solution Approach 2:
The invention changes the manufacturing approach from subtractive (removing material) to additive (injecting and curing monomeric material). By controlling the injection parameters and using the bounding structures to define the cavity, complex haptic shapes are formed directly with minimal material waste and no flash removal required.
3Productivity
If injection molding is used to form the lens, then productivity increases, but integrating haptics cavities into the mold adds complexity
Solution Approach 1:
The insert assembly is divided into functional segments: the outer part assembly providing structural support and the inner part containing the optically accurate insert and bounding structures. This segmentation allows the complex haptics-forming features to be integrated into a modular component that can be manufactured and assembled systematically, managing overall mold complexity while enabling high-speed injection molding production.
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 method eliminates the need for extensive labor and material loss by forming intraocular lenses with haptics directly in the mold, resulting in a product that is ready for use after hydration, without requiring post-treatment for flash removal.
Implementation Method 1
an inner part (20) which has an optically accurately defined end surface (22)
Implementation Method 2
after curing of monomeric material deposited in the casting mold, an ophthalmic device in the implementation of an intraocular lens is formed
Data Source
AI summary
An insert assembly for the purpose of an injection mold for manufacturing a first casting mold half of a casting mold for manufacture of an ophthalmic device, wherein the insert assembly is receivable in an injection mold half of the injection mold and wherein the insert assembly includes an insert assembly end surface which bounds an injection mold cavity of the injection mold for forming a first casting mold half. The insert end surface is provided with at least one notch which forms a bounding structure cavity for forming a bounding structure which is an integral part of the first casting mold half to be formed with the injection mold and which, after placement of a second casting mold half on the first casting mold half, bounds at least one haptics cavity which links up with a lens cavity, wherein the haptics cavity is so configured that in use of the casting mold, after curing of monomeric material deposited in the casting mold, an intraocular lens is formed which comprises a lens and integrally formed-on haptics.