Digital Print Head Shielding for Curing Element Contamination

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Solution Overview

Problem

The proximity of curing elements to ejectors in digital printing leads to unwanted contamination and impaired efficacy and uniformity due to product spray, necessitating frequent cleaning shutdowns.

Innovation Solution

Incorporating shielding means, such as air pumps, electric charge generators, and barrier elements, to divert and contain the sprayed product away from curing elements, ensuring effective drying while maintaining print quality and reducing cleaning interruptions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If curing elements are arranged in proximity to ejectors, then drying efficacy is improved, but product spray contaminates the curing elements

Engineering Contradiction:

Improvedrying efficacyVSAvoidcontamination of curing elements

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A shield is introduced as an intermediary element positioned between the ejector and the curing element. The shield has a first portion that receives spray from the ejector and a second portion that allows radiation to pass through to the substrate, thereby protecting the curing element from contamination while maintaining drying efficacy.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The shield is divided into multiple portions: a first portion facing the ejector that receives and blocks spray, and a second portion that is transparent to radiation. This segmentation allows each portion to perform its specific function - blocking harmful spray while allowing beneficial radiation to pass through.

Inventive Principle:

Principle #1Segmentation

2Manufacturing precision

If curing elements are cleaned frequently to remove contamination, then print quality is maintained, but productivity decreases due to shutdowns

Engineering Contradiction:

Improveprint qualityVSAvoidprint speed

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The shield is installed in advance to prevent contamination before it occurs. By receiving spray at its first portion, the shield protects the curing element from contamination in the first place, eliminating the need for frequent cleaning shutdowns and maintaining both print quality and productivity.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The spray that would normally be harmful by contaminating the curing element is redirected by the shield to a designated first portion. This converts the harmful spray into a contained flow that does not affect the curing element or print quality, allowing continuous operation.

Inventive Principle:

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

3Object-affected harmful factors

If the shield's first portion receives spray, then curing element contamination is prevented, but spray deviation must be controlled

Engineering Contradiction:

Improvecuring element protectionVSAvoidspray trajectory control

Core Design Contradiction:

Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The shield is designed with different local properties: the first portion is positioned and shaped to receive and block spray, while the second portion is made transparent to radiation. Each portion has optimized local characteristics to perform its specific function effectively.

Inventive Principle:

Principle #3Local quality

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 solution effectively prevents product spray from reaching curing elements, maintaining print quality and speed by continuously diverting and containing the spray, thus minimizing the need for shutdowns and ensuring consistent performance.

Implementation Method 1

The shielding means may comprise an air pump for blasting air or generating an airstream, such that when the sprayed product is ejected it can be deviated with respect to the curing element

Methodology Applied

Scientific EffectAirstream generation:

Implementation Method 2

the shielding means may comprise an electric charge generator for generating a static charge such that when the sprayed product is ejected it can be deviated with respect to the curing element

Methodology Applied

Scientific EffectStatic charge generation: Electrostatics

Implementation Method 3

The drying element is a UV, UV-LED, or infrared radiation emission source

Methodology Applied

Scientific EffectUV curing: Photopolymerisation

Implementation Method 4

The drying element is a UV, UV-LED, or infrared radiation emission source

Methodology Applied

Scientific EffectInfrared drying: Infrared Radiation

Data Source

PatentUS11673411B2Head, machine, and method for digital printing on substrates

Publication Date: 2023.06.13 BARBERAN LATORRE JESUS FRANCISCO

AI summary

A digital print head, a digital printing machine having the head, and a method for digital printing on substrates using the head, the digital print head having an ejector for ejecting a product onto the substrate; a drying element for acting on the product ejected onto the substrate such that it is dried; and shielding element to prevent the ejected product from directly reaching the drying element by spray. Likewise, the drying element is located with respect to the ejector in such a way that when the product is ejected it may be subjected to the drying that may be provided by the drying element.