Dry Spot Tool Vacuum Layout for Controlled Composite Dry Zones

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The formation of unintended dry spots due to macroscopic gas entrapments during the manufacturing of geometrically complex composite parts, such as wind turbine rotor blades, leads to scrap parts and requires better control and understanding of dry spot formation.

Innovation Solution

A dry spot tool with a tool body having an opening and flow passages connected to a vacuum system, allowing controlled creation of dry spots by vacuum assisted resin transfer molding, using a seal cover and controlled leak system to prevent matrix material infusion into the dry spot area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If vacuum assisted resin transfer molding is used to manufacture composite parts, then the composite part can be formed with fiber reinforcement and liquid matrix material, but unintended dry spots may form due to macroscopic gas entrapments leading to scrap parts

Engineering Contradiction:
Improvecomposite part qualityVSAvoidunintended dry spots
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The dry spot tool is positioned and sealed on the mold surface before the resin infusion process begins. The vacuum system is activated in advance to create negative pressure within the tool's enclosure, establishing a controlled dry spot region before resin flow occurs. This preliminary setup prevents unintended gas entrapments by controlling the infusion process in the predetermined dry spot area.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The dry spot tool acts as an intermediary device between the vacuum system and the composite part. It mediates the resin infusion process by selectively allowing resin to flow into the mold while maintaining a controlled dry region. The tool's enclosure and sealing mechanism serve as an intermediary structure that isolates the dry spot area from the incoming resin, preventing harmful gas entrapments.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If the dry spot tool encloses a region on the mold, then a dry spot can be created in the composite part, but the tool body requires flow passages and vacuum connection to control the dry spot formation

Engineering Contradiction:
Improvedry spot location and size controlVSAvoidtool structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The dry spot tool body is segmented into functional regions: an enclosure structure that defines the dry spot area, flow passages that control resin movement, and vacuum connection interfaces. This segmentation allows each component to perform its specific function efficiently, achieving precise dry spot control while maintaining manageable structural complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The tool body serves multiple functions simultaneously: it encloses the dry spot region, provides flow passages for vacuum evacuation and resin control, and interfaces with the vacuum system. This multi-functionality reduces the need for separate components, thereby controlling device complexity while achieving precise manufacturing precision for dry spot creation.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If a seal cover is used to seal the dry spot tool and reinforcement material, then the dry spot area is isolated from matrix material infusion, but the seal cover must be removed after curing to access the dry spot

Engineering Contradiction:
Improvedry spot isolationVSAvoidpost-processing accessibility
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The seal cover is designed as a temporary, disposable component used only during the resin infusion process. It provides reliable isolation of the dry spot area from matrix material infusion but is discarded after curing, eliminating the need for complex removal mechanisms and improving post-processing accessibility.

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

Solution Approach 2:

The seal cover is installed and positioned before the resin infusion begins, establishing the isolated dry spot region in advance. After curing is complete, the seal cover is removed to provide access to the dry spot area for subsequent hole cutting or other post-processing operations, ensuring both reliable isolation during manufacturing and ease of access afterward.

Inventive Principle:
Principle #10Preliminary action

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

Enables precise and cost-effective creation of dry spots at desired locations and sizes, facilitating easier hole cutting and enhancing functional integration in composite parts like wind turbine blades.

Implementation Method 1

vacuum may be supplied to the dry spot tool by means of the vacuum system. This vacuum provides for firm attachment of the dry spot tool to the reinforcement material

Methodology Applied
Scientific EffectVacuum: Vacuum

Implementation Method 2

a vacuum is created inside of the flow passage connected via the outlets to the inlets connected to the vacuum system

Methodology Applied
Scientific EffectPressure difference: Pressure Gradient

Data Source

PatentEP4091802B1Dry spot tool for creating a dry spot in a composite part
Publication Date: 2026.01.28 SIEMENS GAMESA RENEWABLE ENERGY AS
  • EP4091802B1 patent drawingFigure 1~2
  • EP4091802B1 patent drawingFigure 3~4
  • EP4091802B1 patent drawingFigure 5

AI summary

The invention relates to a dry spot tool (1) for creating a dry spot (21) in a composite part (20) of a wind turbine during vacuum assisted resin transfer molding, whereby the dry spot tool (1) has a tool body (2) comprising: - a perimeter (P), the tool body (2) extending along the perimeter (2) and having an opening (6) in the center of the perimeter (2) for creating the dry spot (21); - a top side (3) and a bottom side (4), the top side (3) being opposite of the bottom side (4) and the bottom side (4) having at least one bottom surface (5); - outlets (7), the outlets (7) being fluidically connected to inlets (10) of the dry spot tool (1), the inlets (10) being configured for connecting hoses (11) of a vacuum system (30) thereto; and - a flow passage (8), the flow passage (8) fluidically connecting the outlets (7) with one another, extending at least for a partial length (L) thereof along the perimeter (P) of the tool body (2) and extending at least for a partial length (L) thereof in width from the outlets (7) to the bottom side (4).