PPS Powder Coating for Thick Smooth Crack-Free Films

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods struggle to form a film with a thickness of 500 μm or more using polyphenylene sulfide powder coating materials without cracking, while maintaining high hardness and excellent heat and chemical resistance.

Innovation Solution

A film forming method using a polyphenylene sulfide resin powder coating material, heated above its melting point within a range of 250 to 400°C, forms a film with a thickness of 500 μm or more and a surface roughness of 0.30 μm or less, utilizing a polyphenylene sulfide resin with an MFR of 10 to 100 g/10 min and an average particle size of 20 to 500 μm, without inorganic fillers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a thick film is formed by single coating, then the film thickness requirement is met, but the surface smoothness deteriorates

Engineering Contradiction:
Improvefilm thicknessVSAvoidsurface smoothness
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by optimizing the melt flow rate (MFR) of the polyphenylene sulfide resin to a specific range of 10-100 g/10min. This parameter control enables the resin to flow and level out during curing, producing a smooth surface even on thick films (500 μm or more) formed by single coating, thus resolving the contradiction between film thickness and surface smoothness.

Inventive Principle:
Principle #35Parameter changes

2Volume of moving object

If the heating temperature is increased to form a thick film, then the film thickness increases, but cracking occurs on the coating film

Engineering Contradiction:
Improvefilm thicknessVSAvoidcrack-free coating
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The patent applies parameter changes by controlling the heating temperature within a specific range of 250-400°C. This temperature optimization ensures sufficient melting and flow of the polyphenylene sulfide resin to form thick films without causing excessive thermal stress that would lead to cracking, thus resolving the contradiction between film thickness and crack-free coating.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent utilizes phase transitions by heating the polyphenylene sulfide resin above its melting point to enable complete melting and uniform flow. This phase change from solid to liquid state allows the resin to fill the coating area uniformly and then solidify into a crack-free thick film, resolving the contradiction between achieving sufficient thickness and preventing cracking.

Inventive Principle:
Principle #36Phase transitions

3Strength

If polyphenylene sulfide powder coating material is used, then high hardness and chemical resistance are achieved, but forming a thick smooth film by single coating is difficult

Engineering Contradiction:
ImprovehardnessVSAvoidsurface roughness
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by optimizing the melt flow rate of the polyphenylene sulfide resin to 10-100 g/10min and controlling the heating temperature to 250-400°C. These parameter optimizations enable the resin to achieve complete melting and uniform flow, resulting in a smooth surface (Ra of 0.30 μm or less) on thick films while preserving the inherent high hardness and chemical resistance of polyphenylene sulfide.

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 achieves a smooth, crack-free film with high hardness and excellent heat and chemical resistance, suitable for applications like heat exchangers and excavating members.

Implementation Method 1

heating the powder coating material at a temperature equal to or higher than a melting point of the polyphenylene sulfide resin and within a range of 250 to 400° C.

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentUS12528969B2Film forming method, polyphenylene sulfide powder coating material, coating film, and coated article
Publication Date: 2026.01.20 DAIKIN INDUSTRIES LTD

AI summary

Provided is a film forming method that can form a film having a thickness of 500 μm or more with a single coating of a substrate.The present disclosure is a film forming method using a powder coating material containing a polyphenylene sulfide resin, the method including heating the powder coating material at a temperature equal to or higher than a melting point of the polyphenylene sulfide resin and within a range of 250 to 400° C., in which a single coating of a substrate forms a film having a thickness of 500 μm or more; and the obtained film has a surface roughness, Ra, of 0.30 μm or less.