Selective-Coated Mill Bit to Prevent Resin Clogging

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Solution Overview

Problem

Conventional finishing mill bits used in wind turbine blade manufacturing experience excessive wear and clogging due to reactivation of resin particles, leading to frequent replacements and increased manufacturing costs.

Innovation Solution

A mill bit design featuring helical flutes without abrasive coating, selective abrasive coating on cutting edges, and porting bores to enhance airflow and reduce temperature, allowing for extended operational life and improved material removal through cutting action rather than grinding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional finishing mill bits with complete abrasive coating are used, then material removal through grinding is achieved, but excessive heat is generated causing resin particle reactivation and clogging

Engineering Contradiction:
Improvematerial removal rateVSAvoidmill bit operating temperature
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The mill bit applies different surface treatments to different regions: the cutting edges have abrasive coating for material removal, while the flutes are left with smooth finishes without abrasive coating to facilitate chip evacuation and reduce heat generation, directly resolving the temperature and clogging issue

Inventive Principle:
Principle #3Local quality

2Productivity

If abrasive coating is applied to all surfaces of the mill bit, then material removal efficiency is improved, but resin particles reactivate and clog the flutes due to excessive heat

Engineering Contradiction:
Improvecutting efficiencyVSAvoidcontinuous operation capability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

Selective abrasive coating is applied only to the cutting edges and teeth surfaces where material removal is needed, while the flutes remain free of abrasive coating to maintain smooth surfaces that prevent resin particle adhesion and clogging, enabling continuous operation without interruptions

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent converts the previously harmful smooth flute surfaces (which were thought to reduce cutting efficiency) into a beneficial feature by demonstrating that they effectively evacuate chips and reduce heat, thereby preventing clogging and extending operational reliability

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Productivity

If mill bits operate at high temperatures, then material removal through grinding is effective, but the resin particles reactivate and stick to the mill bit surfaces

Engineering Contradiction:
Improvematerial removal effectivenessVSAvoidresin particle reactivation and adhesion
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The flutes are designed with smooth surfaces free of abrasive coating, creating low-friction zones that facilitate chip evacuation and reduce heat buildup, thereby preventing resin particle reactivation and adhesion while maintaining effective material removal at the abrasive-coated cutting edges

Inventive Principle:
Principle #3Local quality

4Productivity

If conventional mill bits with complete abrasive coating are used, then initial cutting performance is high, but frequent replacements are needed due to wear and clogging

Engineering Contradiction:
Improveinitial cutting performanceVSAvoidmill bit lifespan
Core Design Contradiction:
ProductivityVSDuration of action of moving object

Solution Approach 1:

The selective abrasive coating strategy maintains high cutting performance at the coated edges while the uncoated flutes prevent clogging and reduce overall wear, significantly extending the mill bit's operational life without sacrificing initial cutting effectiveness

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The design allows the mill bit to maintain its cutting edges through selective abrasion only where needed, preserving the overall structure and extending service life by preventing the cumulative wear and clogging that would otherwise require frequent replacement

Inventive Principle:
Principle #34Discarding and recovering

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 mill bit operates at reduced temperatures, preventing resin particle reactivation and clogging, significantly extending its lifespan and reducing manufacturing costs by maintaining efficiency and reducing the need for frequent replacements.

Implementation Method 1

the abrasive coating on the exterior and interior of the mill bit produces a fine powder of fiber and resin particles from the composite material

Methodology Applied
Scientific EffectAbrasion: Abrasion

Implementation Method 2

The interior of the mill bit is operatively coupled to a vacuum system for pulling a vacuum along the interior of the mill bit

Methodology Applied
Scientific EffectVacuum: Vacuum

Data Source

PatentEP3661683B1Mill bit for the manufacture of a wind turbine blade and method of forming same
Publication Date: 2024.10.02 VESTAS WIND SYSTEMS AS
  • EP3661683B1 patent drawingFigure 1
  • EP3661683B1 patent drawingFigure 2~3
  • EP3661683B1 patent drawingFigure 4~5

AI summary

A mill bit for the manufacture of a wind turbine blade includes an elongate based body having a proximal end, a distal end, an outer surface, and an internal bore that defines an inner surface, one or more flutes formed on the outer surface that defines one or more teeth, and an abrasive coating on at least a portion of the outer surface, wherein the one or more flutes are free of the abrasive coating. An abrasive coating may be selectively applied on the inner surface to provide flutes on the inner surface. Additionally, porting bores may be provided through the mill bit to fluidly connect the outside and inside of the mill bit. A method of making a mill bit is also described.