Multi-Layer Polymer Bonding for PVC and Non-PVC CAPD Components
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Solution Overview
Problem
Total PVC container-closure systems for continuous ambulatory peritoneal dialysis (CAPD) face public and regulatory concerns due to plasticizers, while total non-PVC systems are more expensive. A cost-effective hybrid system combining non-PVC and PVC components is needed.
Innovation Solution
A multi-layer article with a polymer blend comprising propylene and α-olefin copolymer and carbon monoxide-containing polyolefin-based copolymer is used to bond non-PVC and PVC components, allowing autoclave and solvent bonding, ensuring adhesion without bisphenol A release.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If total non-PVC materials are used for all components, then health safety concerns are resolved, but system cost increases
Solution Approach 1:
The patent applies local quality by differentiating material selection based on functional requirements: non-PVC materials are used specifically for components contacting dialysis solution during sterilization (injection molded parts, tubing interior), while PVC is used for non-contact components. This localized application resolves health concerns for critical components while maintaining cost-effectiveness for other parts.
Solution Approach 2:
The system is segmented into distinct material zones: non-PVC segments for solution-contact components and PVC segments for non-contact components. This segmentation allows each segment to be optimized independently for its specific function, enabling the hybrid approach that balances safety and cost.
2Adaptability or versatility
If non-PVC injection molded parts are bonded to PVC tubing, then hybrid system is formed, but adhesion strength is insufficient
Solution Approach 1:
The patent introduces an intermediary bonding approach using solvent bonding with cyclohexanone that temporarily dissolves both non-PVC and PVC materials at the interface, creating a molecular-level bond. This intermediary chemical process enables strong adhesion between incompatible materials that cannot be bonded by conventional mechanical or thermal methods alone.
Solution Approach 2:
The bonding process utilizes parameter changes by controlling solvent concentration, temperature, and exposure time to achieve optimal bond strength. The solvent bonding parameters are carefully adjusted to dissolve sufficient material for bonding while maintaining structural integrity of both non-PVC and PVC components.
3Object-affected harmful factors
If non-PVC components are used, then autoclave bonding is required, but bonding reliability during steam sterilization is compromised
Solution Approach 1:
The patent applies preliminary action by pre-forming strong solvent bonds between non-PVC and PVC components before sterilization. This preliminary bonding creates a robust connection that can withstand the thermal and mechanical stresses of autoclave sterilization, ensuring bond reliability is established before the sterilization process begins.
Solution Approach 2:
The solvent bonding process provides beforehand cushioning by creating a chemical bond that acts as a buffer against the stresses of subsequent sterilization. This pre-established bond strength compensates for the potential weakening effects of heat and moisture during autoclave processing.
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 hybrid system provides a cost-effective solution with improved adhesion strength between non-PVC and PVC components, maintaining performance during steam sterilization and avoiding health risks from bisphenol A.
Implementation Method 1
PVC-based injection molded parts are frequently connected with PVC tubing by solvent bonding or radio frequency energy
Implementation Method 2
Non-PVC injection molded parts can be connected with non-PVC tubing by autoclave heat bonding during steam sterilization
Implementation Method 3
maintaining performance during steam sterilization
Data Source
Figure 1
AI summary
The present disclosure provides multi-layer articles that comprise a polyolefin component and a polymer blend attached to the polyolefin component, wherein the polymer blend includes (1) a propylene and α-olefin copolymer in an amount from about 15% to about 70% by weight of the polymer blend, and (2) a carbon monoxide-containing polyolefin-based copolymer in an amount from about 25% to about 85% by weight of the polymer blend. The polymer blend has an extractables fraction with pH higher than 5. Also provided are methods of bonding a first layer comprising polyvinyl chloride to a second layer comprising the disclosed polymer blend.