Glass Syringe Adhesive Curing With UV LED and Hot Air

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Solution Overview

Problem

Existing adhesive curing methods for glass syringes, such as using mercury lamps, are inefficient, costly, and prone to oxygen inhibition, leading to incomplete curing and potential contamination risks.

Innovation Solution

A method combining UV LED curing with hot air treatment is employed, where hot air is applied to accelerate and optimize the adhesive curing process, ensuring complete bonding without compromising the integrity of the glass syringe.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If UV LED line array is used for curing adhesive, then curing speed is improved, but oxygen inhibition causes incomplete curing on the outer surface

Engineering Contradiction:
Improvecuring speedVSAvoidcuring completeness
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent applies hot air heating to change the temperature parameter of the adhesive, which accelerates the curing reaction and overcomes oxygen inhibition. The heated air raises the adhesive temperature to optimize curing conditions, ensuring complete polymerization even under UV LED irradiation where oxygen presence would otherwise prevent full curing on the surface.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent combines two different curing mechanisms - UV LED radiation and hot air thermal heating - into a composite curing system. This dual-approach methodology integrates photopolymerization with thermally activated curing, where the hot air component compensates for the oxygen inhibition limitation of UV curing alone, achieving complete and reliable adhesive bonding.

Inventive Principle:
Principle #40Composite materials

2Reliability

If traditional mercury lamps are used for curing, then adhesive can be cured, but the process is inefficient and costly

Engineering Contradiction:
Improveadhesive curingVSAvoidcuring efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent replaces traditional mercury lamp UV curing with UV LED technology. This substitution eliminates the inefficiencies and high operational costs associated with mercury lamps while maintaining effective adhesive curing. UV LEDs provide more energy-efficient, longer-lasting, and cost-effective UV radiation for photopolymerization.

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

Solution Approach 2:

The patent introduces hot air heating as an additional parameter to optimize the curing process. By controlling temperature through heated air, the system accelerates curing speed and improves efficiency, replacing the slow and costly traditional mercury lamp process while ensuring complete adhesive bonding.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If UV radiation alone is used for curing, then the adhesive cures internally, but the outer surface remains partially uncured due to oxygen inhibition

Engineering Contradiction:
Improveinternal curingVSAvoidsurface curing
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies hot air heating to change the temperature parameter of the adhesive surface, which accelerates the curing reaction and overcomes oxygen inhibition. The heated air raises the adhesive temperature to optimize curing conditions, ensuring complete polymerization even under UV LED irradiation where oxygen presence would otherwise prevent full curing on the surface.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces hot air as an intermediary medium to transfer thermal energy to the adhesive surface. This thermal energy acts as a mediator that penetrates through the oxygen layer and activates the curing reaction at the surface, complementing the UV radiation that primarily cures internal areas.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 enhances bonding strength and durability, reduces defects, and ensures consistent curing of adhesives like Loctite AA 3345, improving the quality and safety of pharmaceutical glass syringes.

Implementation Method 1

curing the adhesive by means of radiation

Methodology Applied
Scientific EffectPhotopolymerisation: Photopolymerisation

Implementation Method 2

heating at least one of the glass barrel, needle and adhesive by means of hot air

Methodology Applied
Scientific EffectConvection heating: Convection

Data Source

PatentEP4656695A1Method of curing adhesive with hot air treatment
Publication Date: 2025.12.03 ATS CORPORATION
  • EP4656695A1 patent drawingFigure 1~2
  • EP4656695A1 patent drawingFigure 3~4
  • EP4656695A1 patent drawing

AI summary

A method for curing adhesive during assembly of a glass syringe comprises the following steps a.) to d.): a.) providing an adhesive, a glass barrel and a needle; b.) dispensing the adhesive onto the glass barrel and/or needle; c.) arranging the needle onto the barrel; d.) curing the adhesive by means of radiation; and the method further comprises: heating at least one of the glass barrel, needle and adhesive by means of hot air.