Magnetic Fluid Mold for Custom Polymeric Articles

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Solution Overview

Problem

The production of customized polymeric articles, such as lenses, through digital surfacing is wasteful and inefficient, resulting in significant material waste, and traditional methods of creating molds for customization are expensive and not reusable.

Innovation Solution

A method involving the use of magnetic fluids in a polymeric article casting process, where two mold half-sections are assembled with magnetic fluids applied to the inner surfaces, a magnetic field is applied to create a customized surface topography, and a fluid polymeric material is inserted and polymerized within the mold, allowing for the production of highly customized articles with reusable molds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If digital surfacing is used to customize lenses, then customization capability is improved, but material waste increases significantly

Engineering Contradiction:
Improvecustomization capabilityVSAvoidmaterial waste
Core Design Contradiction:
Adaptability or versatilityVSLoss of substance

Solution Approach 1:

The patent changes the fundamental manufacturing parameter from subtractive (cutting away material) to additive (building up material layer by layer). By using 3D printing to deposit photopolymer resin only where needed, the process achieves full customization while eliminating the 50% or more material waste inherent in digital surfacing methods.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The 3D printing process applies material locally only where required by the specific lens prescription and design parameters. Instead of starting with a complete lens blank and removing material, the system builds the lens precisely where needed, optimizing material usage while maintaining full customization capability.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If traditional molding methods are used for customization, then manufacturing precision can be maintained, but mold cost increases and reusability decreases

Engineering Contradiction:
Improveoptical surface qualityVSAvoidmold cost and reusability
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent creates a digital copy of the lens design from the prescription parameters and uses this digital model to guide the 3D printing process. This eliminates the need for physical custom molds while maintaining manufacturing precision, as the digital model can be reused indefinitely without additional cost or wear.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent replaces the mechanical mold system with a digital modeling and additive manufacturing system. Instead of requiring precision-machined physical molds for each customization, the system uses software-based lens design and automated 3D printing, eliminating mold costs while maintaining optical surface quality through precise digital control.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Loss of substance

If 3D printing is used to produce customized lenses, then material waste is reduced, but selection of polymeric materials is limited

Engineering Contradiction:
Improvematerial waste reductionVSAvoidpolymer material selection
Core Design Contradiction:
Loss of substanceVSAdaptability or versatility

Solution Approach 1:

The patent employs composite photopolymer materials that combine base resin with various functional additives and modifiers. This allows the system to achieve diverse optical properties (refractive index, Abbe number, UV blocking, etc.) using a single material platform, effectively expanding material selection while maintaining the waste-reduction benefits of additive manufacturing.

Inventive Principle:
Principle #40Composite materials

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 enables the production of customized polymeric articles with high optical surface quality while reducing waste and allowing for the reuse of molds, addressing the inefficiencies and costs associated with traditional methods.

Implementation Method 1

controllably applying a magnetic field to the one or more magnetic fluids to form a customized reversible surface in accordance with a predetermined specific surface topography

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

subjecting the mold assembly containing the fluid polymeric material to conditions sufficient to effect at least partial polymerization or hardening of the fluid polymeric material

Methodology Applied
Scientific EffectPolymerization: Photopolymerisation

Data Source

PatentUS9610741B2Methods for preparing customized polymeric articles
Publication Date: 2017.04.04 PPG INDUSTRIES OHIO INC

AI summary

The present invention provides a method for preparing a customized polymeric article including: providing two mold half-sections, each half-section having an outer surface and an inner surface; assembling the two mold half-sections to form a mold assembly such that the inner surfaces define a cavity there between; applying one or more magnetic fluids to the inner surface of a mold half-section; inserting a fluid polymeric material into the cavity; controllably applying a magnetic field to the magnetic fluids to form a customized reversible surface in accordance with a predetermined specific surface topography; subjecting the mold assembly to conditions sufficient to effect polymerization or hardening of the fluid polymeric material; and separating the two mold half-sections. Articles prepared by the method also are provided.