Polyethylene Resin Pipe Composition for Ultrapure Water Purity

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional pipeline materials for ultrapure water, such as fluorine resins, face challenges in workability and cost, and polyethylene-based resins used in general-purpose pipelines elute calcium into the water, failing to meet stringent quality requirements due to chlorine-containing catalysts and neutralizing agents like calcium stearate.

Innovation Solution

A polyethylene-based resin pipeline member with a controlled calcium concentration between 10 ppm and 60 ppm, combined with a phenol antioxidant, is developed to reduce calcium elution and enhance mechanical properties, ensuring the pipeline meets the required water quality standards for ultrapure water applications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If fluorine resin is used as pipeline material for ultrapure water, then water quality purity is improved, but workability and cost deteriorate

Engineering Contradiction:

Improvewater quality purityVSAvoidworkability

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The invention changes the chemical composition parameters of the polyethylene resin by controlling catalyst residue content to 50 ppm or less and calcium stearate content to 300 ppm or less, enabling polyethylene to achieve ultrapure water quality standards while maintaining its superior workability and cost advantages over fluorine resins

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention replaces expensive fluorine resin with cost-effective polyethylene resin, achieving the same water quality protection function at lower material cost, making pipeline systems more economically viable

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Ease of manufacture

If polyethylene-based resin with chlorine-containing catalyst is used, then workability and cost are improved, but calcium elution into water increases

Engineering Contradiction:

ImproveworkabilityVSAvoidcalcium elution

Core Design Contradiction:

Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The invention strictly controls the calcium stearate content parameter to 300 ppm or less and catalyst residue to 50 ppm or less, fundamentally reducing the source of calcium elution while maintaining polyethylene's manufacturing advantages

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention takes preliminary action during resin manufacturing by controlling catalyst neutralization and additive content, preventing excessive calcium elution before the pipeline is installed and used

Inventive Principle:

Principle #9Preliminary anti-action

3Reliability

If calcium stearate is added as neutralizing agent, then catalyst neutralization is improved, but calcium elution into water worsens

Engineering Contradiction:

Improvecatalyst neutralizationVSAvoidcalcium elution

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The invention optimizes the calcium stearate content parameter to 300 ppm or less, achieving sufficient catalyst neutralization while minimizing calcium elution into ultrapure water

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention implements feedback control by measuring and adjusting calcium stearate content during manufacturing to achieve the optimal balance between catalyst neutralization and calcium elution control

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS20230151223A1Pipeline member for ultrapure water and polyethylene-based resin composition for pipeline member for ultrapure water

Publication Date: 2023.05.18 SEKISUI CHEMICAL CO LTD

AI summary

A pipe (10) includes a polyethylene-based resin layer (21) containing a polyethylene-based resin composition as a major component. The polyethylene-based resin layer (21) forms a pipeline member inner surface (10a). The polyethylene-based resin composition has a calcium concentration of 10 ppm or more and 60 ppm or less.