Print Head Nozzle Selection for Coating Bead Uniformity

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Solution Overview

Problem

Existing methods for applying a bead of coating product to complex or awkward surfaces are inefficient, often resulting in excess consumption of coating material and difficulty in achieving uniform thickness and geometry, due to the need for complex robot configurations and excessive nozzle arrangements.

Innovation Solution

A method using a print head with multiple nozzles centered on a central axis, where the nozzles are selectively activated based on the trajectory and direction of movement relative to the surface, allowing for dynamic adaptation of nozzle selection and activation to optimize coating application along a fixed curved path without rotating the print head.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the print head is rotated or the robot configuration is adjusted to change bead width or follow surface geometry, then the coating can be adapted to complex surfaces, but the device complexity and cost increase

Engineering Contradiction:
Improveadaptability to surface geometryVSAvoidrobot configuration complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent divides the nozzle array into multiple independently controllable groups or zones. By selectively activating specific nozzle groups based on the surface geometry and desired bead shape, the system achieves adaptability without requiring mechanical rotation or complex reconfiguration of the entire print head assembly.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic control of nozzle activation states, where nozzles are selectively turned on or off in real-time based on the trajectory and surface characteristics. This dynamic nozzle selection allows the system to adapt to complex surfaces while maintaining a simple, fixed mechanical configuration.

Inventive Principle:
Principle #15Dynamics

2Reliability

If multiple nozzles are activated to cover complex geometries, then complete coverage is achieved, but coating material consumption increases

Engineering Contradiction:
Improvecoating coverage completenessVSAvoidcoating material consumption
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent applies local quality by assigning different activation states to different nozzle groups based on their position relative to the desired bead geometry. Nozzles are selectively activated only where coating is needed, with activation duration and intensity adjusted locally to achieve uniform coverage while minimizing material usage in areas where nozzles are farther from the target surface.

Inventive Principle:
Principle #3Local quality

3Device complexity

If the print head moves along a curved path without rotation, then device complexity is reduced, but achieving uniform bead thickness on complex surfaces becomes difficult

Engineering Contradiction:
Improveprint head configurationVSAvoidbead thickness uniformity
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent incorporates feedback control where the activation state of each nozzle group is determined based on real-time information about the print head position, trajectory, and desired bead geometry. This feedback mechanism allows the system to maintain uniform bead thickness by dynamically adjusting which nozzles are active, compensating for variations in distance to the surface without requiring mechanical adjustments.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3995315B1Method and installation for applying a coating product on a surface
Publication Date: 2024.06.26 EXEL INDUSTRIES
  • EP3995315B1 patent drawingFigure 1
  • EP3995315B1 patent drawingFigure 2
  • EP3995315B1 patent drawingFigure 3

AI summary

In this method of applying a bead (C) of coating product onto a surface to be coated (S), by means of a print head (10) equipped with several nozzles (12) each centered on a central axis (A12), the application of coating product takes place by moving the print head and the surface to be coated relative to each other, by moving the print head along a fixed path (T) relative to the surface to be coated, without rotating the print head around an axis (A10) parallel to the central axes (A12) of the nozzles. This process includes a step of selecting some of the nozzles (12A) for a point (P) of the trajectory (T), according to the direction (F1) of the trajectory at that point and/or according to a previous point (P') of the trajectory already reached by the print head and the direction (F1') of the trajectory at that previous point, and a step of activating the selected nozzles at that point (P).The selected nozzles (12A) are arranged on a line (L12), or are part of a group of nozzles delimited by a line (L12), whose regression line (D12) coincides with a line (D) perpendicular to the direction of the trajectory (T) or as close as possible to a line perpendicular to the direction of the trajectory among the lines that can be defined with the nozzles (12) of the print head (10).