Flexible Cable PVC Layers from Heat-Treated Rigid Recycled PVC
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rigid polyvinyl chloride (PVC) recycled from materials like plumbing and carpentry is not suitable for electrical cables due to its rigidity and difficulty in plasticization, limiting the spectrum of recycled PVCs usable for flexible layers in cables.
Innovation Solution
Subjecting rigid PVC to a heat treatment followed by mixing with a plasticizer to create a plasticized PVC composition, which is then used to form flexible layers in electrical cables, overcoming the challenge of incorporating plasticizers in rigid PVC.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If rigid PVC is used directly in cable layers, then the structural integrity and rigidity are improved, but the flexibility and processability deteriorate
Solution Approach 1:
The patent applies parameter changes by modifying the physical state of rigid PVC through heat treatment. The rigid PVC is heated to temperatures above its glass transition temperature (Tg > 40°C), transforming it from a rigid state to a more plasticized state that can be mixed with plasticizers. This parameter change enables the material to transition from unsuitable for flexible cable layers to suitable for such applications.
Solution Approach 2:
The patent employs preliminary action by subjecting rigid PVC to heat treatment before mixing with plasticizers. This pre-treatment step modifies the morphology and crystallinity of the rigid PVC, making it more receptive to plasticizer incorporation. The heat treatment is performed at temperatures sufficient to melt or soften the rigid PVC structure, enabling subsequent plasticization that would otherwise be difficult or impossible.
2Ease of operation
If rigid PVC is mixed with plasticizer without heat treatment, then the flexibility is improved, but the mixing efficiency and plasticizer incorporation deteriorate
Solution Approach 1:
The patent applies preliminary action by heating the rigid PVC before mixing with plasticizers. This pre-heating step softens or melts the rigid PVC structure, creating a more receptive matrix for plasticizer incorporation. The heat treatment modifies the morphology and crystallinity of the PVC, enabling efficient mixing and homogeneous distribution of plasticizers that would otherwise be difficult to achieve.
Solution Approach 2:
The patent changes the temperature parameter of the rigid PVC to above its glass transition temperature before mixing. This parameter change transforms the material from a rigid, difficult-to-mix state to a softer, more processable state. The elevated temperature facilitates plasticizer penetration and distribution, resulting in efficient mixing and homogeneous plasticized PVC suitable for flexible cable layers.
3Adaptability or versatility
If the spectrum of recycled PVC is expanded to include rigid PVC, then the environmental and economic benefits of recycling are improved, but the difficulty of plasticization and processing increases
Solution Approach 1:
The patent applies preliminary action by implementing a heat treatment step before plasticizer mixing. This pre-treatment enables rigid PVC, which would otherwise be difficult or impossible to plasticize, to be successfully transformed into flexible PVC. The heat treatment modifies the rigid PVC structure, making it receptive to plasticizer incorporation and enabling its use in flexible cable applications.
Solution Approach 2:
The patent changes the temperature parameter of rigid PVC to above its glass transition temperature, fundamentally altering its properties. This parameter change enables the rigid PVC to accept plasticizers and be processed into flexible formulations. The method successfully expands the range of recyclable PVC materials by transforming rigid recycled PVC into suitable flexible cable layer material.
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 resulting plasticized PVC exhibits suitable properties for insulating and protective layers in electrical cables, enhancing the environmental and economic benefits of recycling while ensuring flexibility and performance.
Implementation Method 1
the rigid PVC having been subjected to a heat treatment prior to mixing with the plasticizer, this heat treatment having induced within the PVC a modification of its morphology and/or its crystallinity due to a melting of the PVC
Implementation Method 2
mixing a plasticizer with a rigid PVC having been subjected to a heat treatment prior to mixing with the plasticizer
Data Source
AI summary
The present invention relates to an electrical cable comprising at least one polyvinyl chloride (PVC) based layer surrounding at least one elongated conductive element, wherein said layer comprises a plasticized PVC obtained by mixing a plasticizer with a rigid PVC subjected to heat treatment (for example, hot forming of the extrusion type) prior to mixing with the plasticizer, typically a recycled rigid PVC.