Multilayered Fire-Resistant PVC Pipe with Heat-Expandable Graphite

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Solution Overview

Problem

Current fire-resistant pipes, whether metal or synthetic resin, face challenges in fire resistance and workability, with metal pipes being heavy and difficult to handle and synthetic resin pipes lacking mechanical strength and heat resistance, and existing fire-protection measures using sheet-like covering materials being complex and time-consuming.

Innovation Solution

A multilayered fire-resistant pipe is developed, comprising a tubular fire-resistant expandable layer made of a heat-expandable resin composition with heat-expandable graphite and a covering layer of polyvinyl chloride-based resin, providing heat stability and mechanical strength while allowing for easy installation and high workability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If metal piping is used, then heat resistance and fire resistance are improved, but weight increases and workability deteriorates

Engineering Contradiction:
Improvefire resistanceVSAvoidweight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent uses a composite structure combining synthetic resin base material with heat-expandable graphite particles and fire-resistant additives. This composite material achieves fire resistance comparable to metal while maintaining the lightweight advantage of synthetic resin, resolving the contradiction between fire resistance and weight.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent modifies the physical and chemical parameters of the synthetic resin by incorporating heat-expandable graphite and fire-resistant additives, changing its thermal properties to achieve fire resistance without adopting metal material, thus maintaining lightweight characteristics while improving fire resistance.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If synthetic resin piping is used, then weight decreases and workability improves, but heat resistance and fire resistance deteriorate

Engineering Contradiction:
ImproveworkabilityVSAvoidfire resistance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent creates a composite synthetic resin material incorporating heat-expandable graphite and fire-resistant additives, maintaining the ease of installation and workability of synthetic resin while endowing it with fire resistance properties, thus resolving the contradiction between workability and fire resistance.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the thermal and fire-resistant parameters of synthetic resin through material composition modification, enabling the piping to maintain both good workability and fire resistance simultaneously.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If sheet-like covering material is used for fire protection, then fire resistance is improved, but device complexity and installation time increase

Engineering Contradiction:
Improvefire resistanceVSAvoidcomplexity of fire-protection measures
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the fire protection function directly into the piping material itself by incorporating heat-expandable graphite and fire-resistant additives in the resin composition, eliminating the need for separate covering materials and simplifying the overall structure, thus resolving the contradiction between fire resistance and device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The piping material possesses inherent fire resistance through its composition, enabling it to protect itself without requiring additional external fire protection measures, thus reducing device complexity and installation steps.

Inventive Principle:
Principle #25Self-service

4Reliability

If sheet-like covering material is used for fire protection, then fire resistance is improved, but installation time increases

Engineering Contradiction:
Improvefire resistanceVSAvoidinstallation time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent combines the fire protection function with the piping material itself, eliminating the need for separate installation steps of covering materials, thus reducing installation time while maintaining fire resistance.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The piping material provides self-protection against fire through its inherent composition, eliminating the need for additional time-consuming fire protection installation steps.

Inventive Principle:
Principle #25Self-service

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 multilayered pipe effectively maintains fire resistance, ensures mechanical strength, and simplifies installation by integrating heat-expandable graphite within the polyvinyl chloride-based resin composition, achieving a balance between fire resistance and workability.

Implementation Method 1

a fire-resistant expandable layer made of a heat-expandable resin composition with heat-expandable graphite

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

heat-expandable resin composition with heat-expandable graphite having a pH of 1.5 to 4.0 in an amount of 1 to 15 parts by weight based on 100 parts by weight of a polyvinyl chloride-based resin

Methodology Applied
Scientific EffectPhase change: Phase Change

Data Source

PatentEP2184320B1Fire-resistant piping material
Publication Date: 2017.04.26 SEKISUI CHEMICAL CO LTD
  • EP2184320B1 patent drawingFigure 1~3
  • EP2184320B1 patent drawingFigure 4~5
  • EP2184320B1 patent drawingFigure 6~8

AI summary

It is an object to provide a fire-resistant piping material that can be fire-protection measures by itself and is excellent in construction workability. A single-layered fire-resistant piping material according to the present invention is constituted of a fire-resistant resin composition containing heat-expandable graphite in an amount of 1 to 10 parts by weight based on 100 parts by weight of a polyvinyl chloride-based resin. A multilayered fire-resistant piping material according to the present invention includes a tubular fire-resistant expandable layer made of a heat-expandable fire-resistant resin composition and a covering layer covering at least one of the outer surface and the inner surface of the fire-resistant expandable layer, and the fire-resistant expandable layer is formed of a fire-resistant resin composition containing heat-expandable graphite in an amount of 1 to 15 parts by weight based on 100 parts by weight of a polyvinyl chloride-based resin, and the covering layer is formed of a polyvinyl chloride-based resin composition not containing heat-expandable fire-resistant materials.