Hollow Glass Micro-Venting for Particle-Free Pressure Equalization
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Solution Overview
Problem
Conventional methods for producing hollow glass body products, such as glass tubes, result in the generation of glass splinters or particles that can contaminate the interior, and the introduction of vent holes for pressure equalization risks introducing impurities or failing to prevent negative pressure, which is detrimental for pharmaceutical packaging.
Innovation Solution
A method involving laser-based irradiation to create micrometer-sized filamentary defects on the outer surface of hollow glass bodies, forming open passages for pressure equalization without allowing particles larger than 50 micrometers to enter the interior, combined with a thermal separation process to seal both ends, ensuring a particle-free and pressure-equalized environment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional brittle fracturing is used to separate glass tubes, then separation is achieved, but glass splinters or particles are generated that contaminate the interior
Solution Approach 1:
The patent changes the physical state parameter of the glass from brittle (room temperature) to ductile (elevated temperature above transformation temperature). This allows the glass to be separated by drawing and stretching without brittle fracturing, thereby eliminating glass splinter generation while maintaining ease of separation
Solution Approach 2:
The patent applies preliminary heating to soften the glass at the separation point before separation occurs. This preliminary action of thermal softening enables the subsequent separation process to proceed without generating particles, as the glass becomes pliable and can be pulled apart cleanly
2Stress or pressure
If a vent hole is introduced using laser or burner, then pressure equalization is achieved, but particles are generated inside the tube or impurities are introduced
Solution Approach 1:
The patent creates multiple localized micro-vent channels distributed across the glass wall rather than a single large vent hole. Each micro-channel is locally formed by laser irradiation, providing sufficient pressure equalization while the distributed arrangement minimizes particle generation and impurity introduction compared to conventional single-hole methods
Solution Approach 2:
The patent replaces the conventional mechanical/burner-based vent hole creation with laser-based irradiation. This substitution allows for precise, controlled formation of micro-channels that equalize pressure without the mechanical contact and particle generation associated with burner or mechanical drilling methods
3Stress or pressure
If conventional vent holes with diameter of 1-3 mm are used, then pressure equalization is achieved, but particles can enter through the vent opening during transport
Solution Approach 1:
The patent segments a single large vent hole into multiple micro-vent channels with diameters less than 50 micrometers. This segmentation maintains the total venting area for pressure equalization while creating individual channels too small for particles to penetrate, thus preventing particle ingress during transport and handling
Solution Approach 2:
The patent creates a porous-like structure in the glass wall with multiple micro-channels distributed across the surface. This porous arrangement provides effective pressure equalization while the small pore sizes (micro-channel diameters) act as a physical barrier to particle ingress, similar to how porous filters work
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 produces hollow glass bodies with effective pressure equalization and a robust particle barrier, preventing contamination and ensuring the integrity of the interior space, particularly suitable for pharmaceutical packaging.
Implementation Method 1
a laser-based irradiation device (8) including an ultrashort pulsed laser (30) for producing focused laser radiation (10)
Implementation Method 2
a thermal sealing device (5) for hot forming the hollow glass body (6) so as to produce a hollow glass body product (1) that has two closed ends
Data Source
AI summary
A method for producing a hollow glass body product includes: providing a hollow glass body having an outer surface; forming the hollow glass body product so as to have a first end portion and a second end portion, the first end portion being sealed by a first bottom and the second end portion being sealed by a second bottom; and laser-based irradiating of the hollow glass body with focused laser radiation to produce a plurality of spaced apart filamentary defects in a predetermined arrangement pattern in the outer surface of at least the first end portion, thereby generating a plurality of open passages connecting an interior of the hollow glass body to the outer surface thereof by at least part of the filamentary defects. A diameter of the passages is sized to be less than 50 micrometers and a plurality of the open passages provide gaseous communication to the interior.