Conductor Jacket Surface Smoothness via Polymer Blending
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ethylene-based solution resins (SR resins) used for cable jackets do not process well on extrusion equipment, resulting in unacceptable surface smoothness compared to gas phase polymerization resins (GP resins) with broader molecular weight distribution, limiting their application in cable jacket manufacturing.
Innovation Solution
A process involving blending broad molecular weight distribution ethylene-based polymers with narrow molecular weight distribution ethylene-based polymers and optional carbon black, followed by extrusion at high speeds, to produce conductor jackets with improved surface smoothness and tensile properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If narrow MWD ethylene-based polymer (SR resin) is used for cable jacket, then mechanical properties are improved, but surface smoothness deteriorates at typical extrusion line speeds
Solution Approach 1:
The patent combines narrow MWD ethylene-based polymer (SR resin) with broad MWD ethylene-based polymer (GP resin) to create a blended composition. This merging allows the compound to inherit the superior mechanical properties of narrow MWD resin while gaining the excellent surface smoothness and processability of broad MWD resin, resolving the contradiction between mechanical performance and surface quality.
Solution Approach 2:
The invention creates a composite material system by formulating a compound containing both narrow MWD and broad MWD ethylene-based polymers in specific ratios (30-70 wt% narrow MWD and 70-30 wt% broad MWD). This composite approach enables simultaneous achievement of high mechanical properties and acceptable surface smoothness that neither resin can achieve alone.
2Manufacturing precision
If broad MWD ethylene-based polymer (GP resin) is used for cable jacket, then surface smoothness is improved, but mechanical properties deteriorate
Solution Approach 1:
The patent merges broad MWD ethylene-based polymer (GP resin) with narrow MWD ethylene-based polymer (SR resin) in a controlled blend ratio. This combination allows the compound to achieve the excellent surface smoothness characteristics of broad MWD resin while compensating for its inferior mechanical properties through the contribution of narrow MWD resin.
Solution Approach 2:
The invention formulates a composite compound containing both broad MWD and narrow MWD ethylene-based polymers with broad MWD resin comprising 30-70 wt% and narrow MWD resin comprising 70-30 wt%. This composite material structure enables the cable jacket to exhibit both superior surface smoothness and enhanced mechanical properties.
3Ease of manufacture
If narrow MWD ethylene-based polymer (SR resin) is used for cable jacket, then processability is improved, but surface smoothness deteriorates at high extrusion speeds
Solution Approach 1:
The patent combines narrow MWD ethylene-based polymer (SR resin) which offers good processability with broad MWD ethylene-based polymer (GP resin) which provides excellent surface smoothness. The blended compound maintains the processability advantages of narrow MWD resin while eliminating its surface defects through the incorporation of broad MWD resin.
Solution Approach 2:
The invention creates a composite compound formulation where narrow MWD resin (30-70 wt%) provides processability and broad MWD resin (70-30 wt%) ensures surface quality. This composite approach enables high-speed extrusion with acceptable surface smoothness, resolving the contradiction between ease of manufacture and manufacturing precision.
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 process enhances the processability of SR resins, achieving surface smoothness between 30 µ-inch to 80 µ-inch and improved tensile properties, addressing the limitations of SR resins in cable jacket production.
Implementation Method 1
blending a broad molecular weight distribution (MWD) ethylene-based polymer with a narrow MWD ethylene-based polymer
Implementation Method 2
extruding the blend component over a conductor at a rate greater than 1.02 m/s
Data Source
AI summary
The present disclosure provides a process. In an embodiment, the process includes blending a broad molecular weight distribution (MWD) ethylene-based polymer having an 121/12 ratio from 55 to 85 with a narrow MWD ethylene-based polymer having an 121/12 ratio from 20 to 50. The process includes forming a blend component comprising from 20 wt% to 45 wt% of the broad MWD ethylene-based polymer, from 80 wt% to 55 wt% of the narrow MWD ethylene-based polymer, and optional carbon black. The blend component has a density from 0.925 g/cc to 0.955 g/cc and an 121/12 ratio from 30 to 55. The process includes extruding the blend component over a conductor at a rate greater than 1.02 m/s, and forming a conductor jacket having a surface smoothness from 30 μ-inch to 80 μ-inch.