Rock Screen Particle Trap for Solid Ink Print Head
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Solution Overview
Problem
Current solid ink print heads with rock screens struggle to prevent high aspect ratio particles from passing through, leading to print quality defects due to particles re-orienting and being redeposited during flow cycles, which increases the likelihood of contamination reaching the jet.
Innovation Solution
Incorporating particle traps with 'dead zones' adjacent to the rock screen perimeter to collect debris that sloughs off, minimizing interactions and preventing re-entrainment into the main flow, thereby reducing the chance of particles passing through the screen.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a rock screen is used to protect jets from contamination, then particles with smallest dimension exceeding pore size are stopped, but high aspect ratio particles can pass through and re-orient to block downstream apertures causing print quality defects
Solution Approach 1:
A particle trap is introduced as an intermediary component between the rock screen and the jet apertures. This trap captures particles that pass through the rock screen, preventing them from reaching and blocking the downstream apertures. The particle trap acts as a mediator that removes the harmful particles without interfering with the normal ink flow to the jets.
2Object-affected harmful factors
If debris is stopped by the rock screen, then particle accumulation occurs on the screen, but during subsequent flow cycles particles slough off and are delivered to the rock screen in a new orientation increasing the opportunity to pass through
Solution Approach 1:
The particle trap is positioned to intercept particles before they can slough off from the rock screen during flow cycles. By establishing this preliminary collection zone, particles are captured in a controlled environment where they cannot re-orient and pass through the rock screen again, preventing the cyclic contamination problem.
Solution Approach 2:
The particle trap extracts particles from the flow path adjacent to the rock screen. By removing particles from the vicinity of the rock screen perimeter, the system prevents particles from accumulating, sloughing off, and being redeposited in new orientations that would allow them to pass through the screen.
3Difficulty of detecting and measuring
If the rock screen perimeter is monitored for sloughing particles, then particle release can be detected, but continuous monitoring increases system complexity
Solution Approach 1:
The particle trap is designed to passively capture particles through the natural flow dynamics of the ink system. The trap utilizes the existing flow patterns and pressure differentials to draw particles into the trap zone without requiring active monitoring or control systems. The system essentially monitors and captures particles through its passive geometric design rather than through complex detection mechanisms.
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
This approach significantly enhances the quality of printed images by reducing the occurrence of contamination and improving the reliability of ink delivery, ensuring that narrow, high aspect ratio particles are effectively trapped and do not interfere with the printing process.
Implementation Method 1
The 'dead zones' are sufficiently deep to prevent particles from experiencing flow velocities that would subsequently re-entrain the particles into the main flow and back to the rock screen
Data Source
AI summary
The possibility that narrow, high aspect ratio particles will pass through a rock screen of a print head is reduced by minimizing the number of times the particles interact with the rock screen. Each interaction is an opportunity for the particle to be positioned in an orientation such that it may pass through the rock screen. The reduction in particles passing through the rock screen is achieved by positioning a particle trap adjacent to the rock screen perimeter to collect debris that sloughs off the rock screen.