Glass Container Interior Surface Etching for Delamination Control

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Solution Overview

Problem

Conventional glass containers used for pharmaceutical packaging, particularly those made from Type IA and Type IB glass compositions, suffer from delamination issues due to the high silica content and compositional heterogeneities caused by the evaporation and re-deposition of volatile borate species during the forming process, leading to the release of silica-rich flakes into the solution.

Innovation Solution

A method of forming glass containers involves removing a thin layer of the interior surface layer, typically 100 nm to 1.0 µm thick, using an aqueous treating medium with 0.001 weight percent to 0.15 weight percent fluoride ions to reduce delamination and enhance chemical durability, thereby minimizing the release of silica-rich flakes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional Type IA and Type IB glass compositions are used for pharmaceutical packaging, then chemical durability is maintained, but delamination and silica flake release occur due to compositional heterogeneities from volatile borate evaporation and re-deposition

Engineering Contradiction:
Improvechemical durabilityVSAvoiddelamination and silica flake release
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The glass container is subjected to acid treatment before use, which removes the heterogenous surface layer formed during manufacturing. This preliminary action eliminates the source of delamination and silica flake release while preserving the chemically durable bulk glass properties

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The acid treatment process changes the chemical composition and structure of the glass surface layer by removing volatile borate species and silica-rich deposits. This parameter change transforms the surface from a delamination-prone state to a stable, homogeneous state that maintains chemical durability

Inventive Principle:
Principle #35Parameter changes

2Object-generated harmful factors

If the glass container undergoes acid treatment to remove the interior surface layer, then delamination factor is reduced to ≤10, but additional processing steps are required

Engineering Contradiction:
Improvedelamination factorVSAvoidprocessing steps
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

By optimizing the acid treatment parameters (concentration, temperature, time), the process achieves effective delamination reduction in a single treatment step, minimizing the need for multiple processing steps while maintaining delamination factor ≤10

Inventive Principle:
Principle #35Parameter changes

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

The method significantly reduces the delamination factor of glass containers to less than or equal to 10, improving their resistance to chemical degradation and mechanical strength, while maintaining chemical durability and thermal stability.

Implementation Method 1

contacting the glass container with an aqueous treating medium to remove a thin layer of the interior surface layer

Methodology Applied
Scientific EffectChemical etching: Ablation

Implementation Method 2

the aqueous treating medium comprises 0.001 weight percent to 0.15 weight percent fluoride ions

Methodology Applied
Scientific EffectFluoride ion reaction: Chemical Bonding

Data Source

PatentEP3206998B1Methods for producing strengthened and durable glass containers
Publication Date: 2021.09.08 CORNING INC
  • EP3206998B1 patent drawingFigure 1
  • EP3206998B1 patent drawingFigure 2

AI summary

A method of forming a glass container including forming a glass container having a sidewall at least partially enclosing an interior volume, at least a portion of an interior surface of the sidewall having an interior surface layer; and contacting the glass container with a substantially fluoride-free aqueous treating medium to remove a thin layer of the interior surface layer having a thickness of from about 100 nm to about 1.0 μιη from the interior surface of the sidewall. The interior surface is resistant to delamination. Before contacting the glass container with the substantially fluoride-free aqueous treating medium, the exterior surface of the sidewall comprises strength-limiting surface flaws having a first shape, and after the contacting the exterior surface of the sidewall with the substantially fluoride-free aqueous treating medium, the strength-limiting surface flaws have a second shape.