Multilayer Fluoropolymer Films for High-Purity Contact

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Solution Overview

Problem

Current high-purity polymer bags used in biological and biochemical applications lack chemical resistance, are not easily sterilizable by steam autoclave, and require additional steps for heat-sealability, limiting their usability in high-purity contact applications.

Innovation Solution

A multi-layer film with at least one melt-processable fluoropolymer layer, preferably polyvinylidene fluoride (PVDF) or its copolymers, that can be steam or gamma sterilized and is heat-sealable without additional layers, providing a high-purity contact surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If current high-purity polymer bags are used, then they provide a clean contact surface, but they lack chemical resistance and cannot be steam sterilized

Engineering Contradiction:
Improvechemical resistanceVSAvoidsterilizability
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the chemical composition parameters of the polymer material from conventional polymers (EVA, LLDPE, PCTFE) to fluoropolymers (PVDF, PTFE, ECTFE, ETFE). This parameter change enables the material to simultaneously achieve high chemical resistance, steam sterilizability, and heat-sealability that the conventional polymers lack.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite multi-layer film structures where fluoropolymer layers are combined with other functional layers. The fluoropolymer provides chemical resistance and sterilizability, while other layers contribute properties like heat sealability or barrier functions, creating a composite material that satisfies multiple contradictory requirements.

Inventive Principle:
Principle #40Composite materials

2Reliability

If fluoropolymer films are used for high-purity contact, then chemical resistance is improved, but heat-sealability is lost requiring additional polyolefin layers

Engineering Contradiction:
Improvechemical resistanceVSAvoidlayer structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent selects specific fluoropolymer types (PVDF, PTFE, ECTFE, ETFE) and adjusts their molecular weight, crystallinity, and composition parameters to achieve both chemical resistance and inherent heat-sealability. This parameter optimization allows single-layer or simplified multi-layer structures without requiring additional polyolefin heat-seal layers.

Inventive Principle:
Principle #35Parameter changes

3Strength

If multi-layer structures with nylon and EVOH are used, then strength and barrier properties are improved, but sterilization complexity increases

Engineering Contradiction:
Improvemechanical strengthVSAvoidsterilization process
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent changes the material composition to fluoropolymers with inherently high mechanical strength and barrier properties, eliminating the need for nylon reinforcement layers and EVOH barrier layers. This parameter change simplifies the sterilization process since fluoropolymers can be steam sterilized without the complexity associated with sterilizing multi-material structures containing nylon and EVOH.

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 film offers high chemical resistance, steam and gamma sterilizability, and heat-sealability, enabling on-site assembly and sterilization, reducing lead times and increasing flexibility in high-purity contact applications.

Implementation Method 1

Fluoropolymers, and especially polyvinylidene fluoride (PVDF), are known to be highly chemical resistant

Methodology Applied
Scientific EffectChemical resistance:

Implementation Method 2

current bags cannot be sterilized in a steam autoclave, as they will melt together and become useless

Methodology Applied
Scientific EffectSteam sterilization:

Implementation Method 3

They are also not easily heat-sealable, or require an extra step to provide heat-sealability

Methodology Applied
Scientific EffectHeat sealing:

Data Source

PatentUS9044923B2Multilayer fluoropolymer films
Publication Date: 2015.06.02 ARKEMA INC

AI summary

The invention relates to a multi-layer film having at least one fluoropolymer layer, useful for high-purity contact applications. Preferably the fluoropolymer layer(s) are polyvinylidene fluoride polymers and copolymers.