Radiator Inner Surface Coating via Inversion

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current anti-corrosion methods for heating radiator elements, such as electrophoresis, fail to completely protect the inner chambers of die-cast aluminum radiators due to the Faraday cage effect and air pocket formation, leading to incomplete paint penetration and lack of corrosion protection on internal surfaces.

Innovation Solution

An electrochemical deposition process using electrophoresis or cataphoresis painting with a polymeric coating, where the radiator elements are positioned vertically with the bottom facing upwards to prevent air pocket formation, ensuring complete coverage of the inner surfaces with a protective coating made of epoxy, acrylic, or fluorinated resins, and subsequent baking for drying and polymerization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electrophoresis painting is used to protect radiator elements, then external surfaces are coated, but internal chamber surfaces remain unprotected due to incomplete paint penetration

Engineering Contradiction:
Improvecorrosion protectionVSAvoidpaint penetration completeness
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The invention divides the painting process into two distinct stages: first painting the external surfaces, then flipping the element to paint the internal chamber surfaces. This segmentation allows each surface to be treated separately with optimal paint application, ensuring complete coverage of both external and internal surfaces without the limitations of single-pass electrophoresis.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention applies the element in reversed orientation during the painting process. After painting the external surfaces, the element is flipped upside down so that the internal chamber surfaces face upward, allowing paint to properly penetrate and coat these previously inaccessible areas, thereby solving the Faraday cage effect and air pocket formation problems.

Inventive Principle:
Principle #13The other way round (Inversion)

2Ease of manufacture

If elements are immersed in painting bath with bottom up position, then external surfaces can be painted, but air pockets form in the bottom preventing paint access

Engineering Contradiction:
Improvepainting processVSAvoidcorrosion protection
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The invention systematically applies inversion by flipping the radiator element between painting stages. The element is first painted externally in the conventional position, then inverted so the internal chamber surfaces face upward for painting. This inversion eliminates air pocket formation and ensures complete paint penetration to all internal surfaces, achieving both manufacturing ease and reliable corrosion protection.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The invention performs preliminary painting of external surfaces before inverting the element for internal surface painting. This preliminary action allows the painting process to be staged appropriately, ensuring that each surface receives adequate paint application without interference from air pockets or the Faraday cage effect, thereby achieving complete coverage.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If bi-metal radiators are used with iron or brass core, then internal corrosion protection is achieved, but thermal efficiency is reduced

Engineering Contradiction:
Improvecorrosion protectionVSAvoidthermal efficiency
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The invention changes the protective parameter from material composition (bi-metal construction) to surface treatment (electrophoresis painting). Instead of using iron or brass cores for corrosion resistance, the invention applies a protective paint coating to the aluminum surfaces, thereby maintaining the superior thermal conductivity of aluminum while achieving the required corrosion protection.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite structure by combining aluminum base material with a protective paint coating. This composite approach provides corrosion protection similar to bi-metal radiators but without the thermal efficiency penalty, as the thin paint layer does not significantly impede heat transfer while the aluminum core maintains its excellent thermal conductivity.

Inventive Principle:
Principle #40Composite materials

4Reliability

If bi-metal radiators are used, then internal corrosion protection is provided, but weight of each element increases significantly

Engineering Contradiction:
Improvecorrosion protectionVSAvoidelement weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The invention changes the protection approach from using heavy ferrous materials (iron or brass) to applying a lightweight protective paint coating. This parameter change maintains corrosion protection while avoiding the significant weight increase associated with bi-metal construction, as the paint layer adds minimal weight compared to replacing aluminum with iron or brass.

Inventive Principle:
Principle #35Parameter changes

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 method provides complete corrosion protection to all inner surfaces of the radiator elements, ensuring long-term functionality even with aggressive water, while being simple, cost-effective, and efficient, with the electrochemical deposition process ensuring thorough coverage and avoiding air pockets during treatment.

Implementation Method 1

electrochemical deposition process using electrophoresis or cataphoresis painting

Methodology Applied
Scientific EffectElectrophoresis: Electrophoresis

Implementation Method 2

electrochemical deposition process using electrophoresis or cataphoresis painting with a polymeric coating

Methodology Applied
Scientific EffectElectrochemical deposition: Electrodeposition

Implementation Method 3

subsequent baking for drying and polymerization

Methodology Applied
Scientific EffectPolymerization: Photopolymerisation

Implementation Method 4

subsequent baking for drying and polymerization

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP2318573B1Anti-corrosion treatment method
Publication Date: 2017.04.26 FONDITAL SPA
  • EP2318573B1 patent drawingFigure 1
  • EP2318573B1 patent drawingFigure 2~4
  • EP2318573B1 patent drawingFigure 3

AI summary

A heating radiator element (1) having a body (2) made of die -cast aluminium and provided with an inner chamber (5) for passing the water, delimited by inner surfaces (6) of the aluminium body (2), is provided with a protective coating (51) made of an anti- corrosion polymeric coating material applied to every inner surface (6) of the aluminium body (2) so as to completely coat the chamber (5), for protecting in use the inner surfaces (6) of the aluminium body (2) against the contact with water. The application of the protective coating (51) is carried out by filling the chamber (5) with a treatment composition containing the polymeric coating material, and then draining the chamber (5) once the coating material has adhered to the inner surfaces (6) of the chamber (5).