UV-Cured Elastomer Injection Molding for Medical Valves

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Solution Overview

Problem

The existing production methods for multi-component injection-molded parts with hard and soft components are costly and inefficient due to the need for high-quality, expensive thermoplastics with high melting temperatures to prevent the thermoplastic component from solidifying before the elastomer hardens, and this results in material waste and assembly challenges.

Innovation Solution

A plastic injection molding tool equipped with a UV light source that cures elastomeric materials within the tool mold, allowing for the use of a wide range of thermoplastics and minimizing heat exposure, enabling the production of a single-piece multi-component valve component with a thermoplastic housing and UV-curing elastomer valve membrane, eliminating the need for additional assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high melting temperature thermoplastics are used to prevent remelting during elastomer curing, then the thermoplastic component maintains its structural integrity, but production costs increase significantly

Engineering Contradiction:

Improvestructural integrity of thermoplastic componentVSAvoidproduction cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces thermal curing with UV light curing for the elastomer component. This substitution eliminates the need for high-temperature processing, allowing standard thermoplastics to be used without remelting risks, thereby reducing material costs while maintaining structural integrity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the curing parameter from thermal energy to UV light energy. By using UV-curing elastomer material instead of thermally cured material, the process temperature is dramatically reduced, enabling the use of cost-effective standard thermoplastics that would otherwise remelt at high curing temperatures.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If high melting temperature thermoplastics are used, then the thermoplastic component does not remelt during elastomer curing, but material selection is limited

Engineering Contradiction:

Improvestructural integrity of thermoplastic componentVSAvoidthermoplastic material selection

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent replaces thermal curing with UV light curing, which eliminates the temperature constraint on thermoplastic selection. This allows virtually all standard thermoplastics to be used since they are not exposed to high curing temperatures, dramatically expanding material versatility while maintaining structural integrity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If thermal curing is used for elastomer component, then the elastomer hardens properly, but heat generation causes thermoplastic remelting

Engineering Contradiction:

Improvecuring of elastomer componentVSAvoidheat generation during curing

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The patent substitutes thermal curing with UV light curing for the elastomer component. This replacement eliminates significant heat generation during the curing process, preventing thermoplastic remelting while ensuring proper hardening of the elastomer through photopolymerization.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Productivity

If multi-component injection molding is performed without UV curing, then both components can be molded, but additional assembly steps are required

Engineering Contradiction:

Improveproduction efficiencyVSAvoidassembly process

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent combines the molding and bonding processes into a single integrated operation. The UV light source is integrated into the injection molding tool, allowing simultaneous molding of thermoplastic and elastomer components with immediate bonding, eliminating separate assembly steps and significantly improving production efficiency.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent uses UV light as an intermediary to enable immediate bonding of the elastomer component to the thermoplastic component during the molding process. This intermediary mechanism allows the two components to be permanently bonded in-situ without requiring subsequent assembly operations.

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 approach reduces production costs, minimizes material usage, and enhances the functionality of the valve component by allowing the use of standard thermoplastics and nearly all types of thermoplastics, while ensuring tightness and pressure performance, and allows for cost-effective, high-volume production of medical infusion system components.

Implementation Method 1

after the UV-curing elastomer material has been introduced into the remaining cavities

Methodology Applied

Scientific EffectUV curing: Photopolymerisation

Data Source

PatentEP3009250B1Plastic injection moulding tool for manufacturing a multi-component injection moulding part

Publication Date: 2020.04.08 B BRAUN MELSUNGEN AG

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AI summary

A multi-component injection-molded part is known, comprising a hard component made of a thermoplastic material and a soft component made of an elastomer. According to the invention, the soft component is made of a UV-curing elastomer material and is bonded to the hard component made of thermoplastic material. Applications include valve components in medical infusion systems.