Tungsten-Free Ceramic Tip for Glass Syringe Cone Forming

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Solution Overview

Problem

Existing methods for forming the cone to house a needle in glass syringes face challenges such as contamination from tungsten compounds, limited temperature resistance of alternative materials like silicon nitride, and the need for costly controlled atmospheres to prevent tungsten oxide formation, which affects the precision, speed, and reliability of the process.

Innovation Solution

A forming apparatus with a tungsten-free ceramic tip doped with yttrium compounds, featuring a specialized geometry that allows effective lubrication and cooling, reducing tungsten contamination and enabling high-temperature resistance without the need for controlled atmospheres, while maintaining the precision and speed of tungsten tips.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If tungsten tips are used for forming the cone, then forming speed and temperature resistance are improved, but tungsten contamination of the glass syringe body occurs

Engineering Contradiction:
Improveforming speedVSAvoidtungsten contamination
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The invention extracts and removes the tungsten tip from the forming system entirely, replacing it with a tungsten-free ceramic tip made of silicon nitride. This eliminates the source of tungsten contamination while maintaining the cone forming function, directly resolving the contradiction between productivity and contamination.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs disposable forming cones made of plastic material that are discarded after a single use. This eliminates the need for durable tungsten tips that cause contamination, as the disposable cones leave no harmful residues on the glass syringe body while maintaining forming speed and temperature resistance capabilities.

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

2Object-generated harmful factors

If silicon nitride tips are used instead of tungsten, then tungsten contamination is prevented, but temperature resistance and forming speed are reduced

Engineering Contradiction:
Improvetungsten contaminationVSAvoidtemperature resistance
Core Design Contradiction:
Object-generated harmful factorsVSTemperature

Solution Approach 1:

The patent uses disposable plastic forming cones that are discarded after one use. These cones are designed to withstand the high temperatures and mechanical stresses of the forming process for the duration of a single operation, then are discarded rather than reused. This approach prevents tungsten contamination while achieving the necessary temperature resistance through the temporary nature of the tool.

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

Solution Approach 2:

The invention uses composite material solutions including plastic forming cones that combine thermal resistance properties with mechanical forming capabilities. The plastic material is specifically selected to withstand the high temperatures of glass forming while maintaining structural integrity during the forming process, thereby achieving temperature resistance without tungsten contamination.

Inventive Principle:
Principle #40Composite materials

3Productivity

If forming speed is increased to process large batches, then productivity is improved, but the risk of defects and cracks increases

Engineering Contradiction:
Improvebatch processing speedVSAvoiddefect-free forming
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The disposable plastic forming cones are designed to be used once and discarded, ensuring that each forming operation uses a fresh, uncontaminated tool. This eliminates wear-related defects and contamination that would accumulate with reusable tips, maintaining high reliability even at increased forming speeds for large batch processing.

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

Solution Approach 2:

The invention changes the material parameters of the forming tool from metal (tungsten) to plastic, fundamentally altering the interaction between the tool and glass. The plastic material provides different thermal and mechanical properties that reduce stress concentrations and prevent cracks during high-speed forming, thereby maintaining reliability while increasing productivity.

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 solution achieves precise and rapid forming of syringe needles with minimal tungsten contamination, extending tool life and ensuring the syringe is free of tungsten compounds, optimizing production efficiency and compatibility with sensitive medicinal substances.

Implementation Method 1

a flow of lubricant-coolant liquid is properly dosed at the contact between the glass and the forming tip, in order to lower its working temperature

Methodology Applied
Scientific EffectLubrication: Lubrication

Implementation Method 2

a flow of lubricant-coolant liquid is properly dosed at the contact between the glass and the forming tip, in order to lower its working temperature

Methodology Applied
Scientific EffectCooling: Cooling

Data Source

PatentEP3929165B1Apparatus for forming a cone for housing a needle in a syringe, method for making a cone for housing a needle in a syringe, and the syringe thereof.
Publication Date: 2024.04.17 STEVANATO GRP SPA
  • EP3929165B1 patent drawingFigure 1a~1b
  • EP3929165B1 patent drawingFigure 2a~5c
  • EP3929165B1 patent drawingFigure 6a~9c

AI summary

An apparatus for forming (4) a housing cone (8) of a needle in a syringe body (12) of a glass syringe, comprising a forming tool (16) shaped to make a hole (20) for the creation of the housing cone (8), a lubricant-coolant liquid dispensing device (24), wherein the forming tool (16) comprises a grip portion (28), a tip (32), a tip body (36), interposed between the tip (32) and the grip portion (28), suitable for making said hole (20). The grip portion (28), tip body (36), and tip (32) are in one piece and aligned along a prevailing extension axis (X-X). The tip body (36), with respect to a cross-sectional plane perpendicular to the prevailing extension axis (X-X), has a non-circular cross section, inscribed within the maximum circle (40) having as its radius the maximum distance between a point (P) of the cross section and the prevailing extension axis (X-X), measured on the cross-sectional plane.