Thermoplastic Inner Lining for Drinking Water Pipes

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Solution Overview

Problem

The high costs associated with surface preparation methods for metal drinking water transport pipes, such as shot blasting, and the need for primers to ensure coating adhesion, make existing manufacturing processes expensive and inefficient.

Innovation Solution

A pipe with an inner coating made of thermoplastic materials based on polyolefins or polyamides, where the surface is prepared by partial reaming and hammering to remove asperities and oxide layers, followed by the application of solid coating particles at a melting temperature without the use of a primer, using a specialized surface treatment tool.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If shot blasting is used to prepare the inner surface, then coating adhesion is improved, but manufacturing cost increases due to time and cost associated with recycling the shot

Engineering Contradiction:
Improvecoating adhesionVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention extracts and eliminates the shot blasting step from the surface preparation process. Instead of using shot blasting followed by expensive recycling operations, the patent applies coating particles directly to the as-bored surface, removing the need for shot recycling infrastructure and associated costs while maintaining adequate adhesion through proper surface profiling during boring.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the expensive, reusable shot media with inexpensive coating particles that are applied once and remain on the surface as part of the final coating system. The coating particles serve dual purposes: they provide the protective coating and simultaneously act as the surface preparation medium, eliminating the need for separate shot blasting and recycling operations.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Reliability

If grinding or combination of boring and shot blasting is used to prepare the inner surface, then coating adhesion is improved, but manufacturing cost increases

Engineering Contradiction:
Improvecoating adhesionVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention merges the surface preparation function with the coating application function. The boring operation profiles the surface to accept coating, and the coating particles are applied in the same operational sequence, eliminating the need for separate grinding or shot blasting steps. This consolidation reduces manufacturing cost while achieving adequate adhesion through the combined surface profiling and coating deposition.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If a primer is applied to ensure coating adhesion, then coating adhesion is improved, but manufacturing complexity and cost increase

Engineering Contradiction:
Improvecoating adhesionVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the primer application step from the manufacturing process. By optimizing the boring surface profile and applying coating particles directly to the prepared surface, the patent achieves sufficient adhesion without requiring a separate primer layer, thereby reducing process complexity and eliminating an additional manufacturing step.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The coating particles themselves perform the adhesion function that would otherwise require a primer. The particles are applied directly to the bored surface and bond adequately without needing a separate priming layer, allowing the coating system to be self-sufficient and eliminating the primer application step.

Inventive Principle:
Principle #25Self-service

4Reliability

If shot blasting is used for surface preparation, then coating adhesion is improved, but surface treatment time increases

Engineering Contradiction:
Improvecoating adhesionVSAvoidsurface treatment time
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The invention extracts the shot blasting step from the process sequence, eliminating the time required for shot blasting operations and subsequent shot recycling preparation. The surface is prepared during the boring operation itself, and coating particles are applied directly, significantly reducing total surface treatment time while maintaining adequate adhesion.

Inventive Principle:
Principle #2Taking out (Extraction)

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

This method reduces manufacturing costs, shortens surface treatment time, eliminates the need for primers, and ensures strong adhesion and wear resistance of the coating, while maintaining compliance with health approvals for drinking water transport.

Implementation Method 1

application of solid particles of coating on the surface of the base body; before the coating application step, the base body is heated to a melting temperature of the coating particles

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP1916055B1Pipe and method of manufacturing
Publication Date: 2012.10.03 SAINT GOBAIN PAM SA
  • EP1916055B1 patent drawingFigure 1
  • EP1916055B1 patent drawingFigure 2
  • EP1916055B1 patent drawingFigure 3

AI summary

This pipe comprises: - a metal base body (8), defining an outer surface (10) and an inner surface (12) of the base body, and - an inner lining (14) applied to the inner surface (12) of the base body. The inner lining (14) comprises a thermoplastic material or a polyamide. Application: potable water transport pipes.