Mold Marking Process Using Temporary Elevation Materials

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Solution Overview

Problem

Existing processes for marking contact lenses with symbols on molds result in permanent indentations or elevations, limiting mold versatility and leading to issues with debris accumulation and symbol visibility, necessitating a more flexible and effective method for applying and removing markings.

Innovation Solution

A process involving applying a liquid material with a higher temperature than the mold, which solidifies upon cooling to create a temporary elevation on the mold surface, allowing for the reproduction of symbols as indentations on the contact lenses without being permanent, thus enabling mold re-use and avoiding debris-related issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If a permanent indentation or elevation is created on the mold surface to mark contact lenses, then the symbol visibility and lens identification are improved, but the mold versatility and reusability are reduced

Engineering Contradiction:
Improvesymbol visibilityVSAvoidmold versatility
Core Design Contradiction:
Loss of informationVSAdaptability or versatility

Solution Approach 1:

The mold surface is made dynamically changeable by applying temporary elevation materials (such as UV-curable resins or temperature-sensitive materials) that can be added or removed. This allows the mold to switch between marked and unmarked states, enabling versatility while maintaining symbol visibility during production cycles.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The physical state of the mold surface is changed by using materials that transition between solid and liquid states (e.g., through temperature changes or UV curing). This allows the elevation to be applied when needed for marking and removed when mold reusability is required, resolving the contradiction between permanent marking and mold versatility.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If a permanent elevation is applied to the mold surface for symbol transfer, then the symbol accuracy and consistency are improved, but debris accumulation and cleaning difficulties increase

Engineering Contradiction:
Improvesymbol accuracyVSAvoiddebris accumulation
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

Instead of creating permanent elevations on the mold, disposable or temporarily applicable elevation materials are used. These materials can be easily removed after use, preventing debris accumulation and maintaining mold cleanliness while still providing accurate symbol transfer during the molding process.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The elevation material is applied temporarily for the marking process and then discarded or recovered (removed) after use. This prevents permanent debris accumulation on the mold surface while maintaining symbol accuracy during production, as the mold can be easily cleaned and reused.

Inventive Principle:
Principle #34Discarding and recovering

3Adaptability or versatility

If multiple molds are used to provide different symbol markings, then the variety of parameters and customization options are improved, but the device complexity and cost increase

Engineering Contradiction:
Improvecustomization optionsVSAvoidmold quantity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

A single mold is made multi-functional by enabling the application of different elevation materials or patterns on its surface. This allows one mold to produce multiple types of symbols and markings by changing the temporary elevation configuration, eliminating the need for multiple dedicated molds and reducing overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The mold configuration is made dynamic and adjustable, allowing different symbol patterns to be applied to the same mold surface as needed. This flexibility enables one mold to replace multiple static molds, reducing device complexity while maintaining full customization capabilities.

Inventive Principle:
Principle #15Dynamics

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 customizable and reusable molds with improved cleanliness and visibility of symbols, reducing the need for multiple molds and minimizing debris-related problems, while ensuring the symbols remain intact on the contact lenses.

Implementation Method 1

depositing, onto the molding surface having a first temperature, a liquid material having a second temperature higher than the first temperature, and solidifying the liquid material on the molding surface upon cooling toward to the first temperature

Methodology Applied
Scientific EffectPhase change (solidification): Phase Change

Implementation Method 2

solidifying the liquid material on the molding surface upon cooling toward to the first temperature

Methodology Applied
Scientific EffectCooling: Cooling

Data Source

PatentEP3077184B1Novel process for making molded devices
Publication Date: 2021.04.14 ALCON INC
  • EP3077184B1 patent drawingFigure 1~2

AI summary

This invention is directed to a process for applying a symbol (102, 202) to a molded device (101, 201) which symbol on the molded device is visible as an indentation in the surface of the device. The process involves the step of applying the symbol as an elevation to the mold before using the mold for making the molded device. The process of the invention comprises that the elevation on the mold is produced by applying a material to the mold surface which material is liquid when being applied and which material is applied at a temperature higher than the temperature which is at or preferably below the melting point of the material, and which material solidifies at the temperature of the mold. The material applied to the mold and solidified on the mold surface as an elevation needs to remain solid during the process of using the mold for making the molded device. During the molding process the elevation of the symbol on the mold is transferred as an indentation of the symbol to the surface of the molded device. After the molding process is complete and the molded device has been separated from the mold the elevation on the mold surface can be removed and the mold can be re-used without an elevation or with another elevation being applied to make another molded device.