Gravure Roll Non-Contact Fluid Ejection for Adhesive Application
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Solution Overview
Problem
Current machinery for applying adhesives onto absorbent articles is inflexible and inaccurate, leading to uneven distribution and high energy consumption, with issues like foam formation and stringing, making it inefficient for high-speed production.
Innovation Solution
A non-contact application process using a gravure roll with a hollow rotating shell and a stationary cylindrical core, where positive pressure is used to eject fluid from cavities onto the article, minimizing cohesive forces and improving uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a gravure roll is continuously supplied with adhesive from a bath, then the roll can be coated with adhesive for pattern application, but a large amount of energy is expended to maintain the bath and adhesive at required temperature
Solution Approach 1:
The invention extracts the adhesive supply method from a continuous bath system and replaces it with an intermittent dosing system. Adhesive is supplied only when cavities need refilling, rather than continuously maintaining a large adhesive bath. This eliminates the energy waste of heating and maintaining a large volume of adhesive at process temperature.
Solution Approach 2:
The invention implements periodic adhesive supply through a dosing mechanism that refills cavities at specific intervals during roll rotation. Instead of continuous supply from a bath, adhesive is dosed periodically only when cavities require refilling, significantly reducing the time and energy adhesive spends at elevated temperatures.
2Ease of operation
If a gravure roll rotates through an adhesive bath, then the roll becomes coated with adhesive, but air bubbles form within the adhesive bath resulting in foam formation
Solution Approach 1:
The invention removes the adhesive bath entirely from the system and replaces it with direct adhesive delivery to cavities. This eliminates the interface between rotating roll and bath that causes air bubble entrapment and foam formation, while still achieving complete cavity coating.
Solution Approach 2:
The invention introduces a dosing mechanism as an intermediary between adhesive supply and cavity filling. This mediator delivers adhesive directly to cavities without requiring a bath, preventing air bubble incorporation while ensuring complete cavity coverage for pattern transfer.
3Productivity
If adhesive is applied using spray guns or slot coaters for high-speed production, then placement speed increases, but the equipment is inflexible and inaccurate regarding fluid deposition pattern
Solution Approach 1:
The invention segments the adhesive application function into individual cavities distributed around the roll perimeter. Each cavity acts as an independent dosing unit that can be precisely controlled, enabling both high-speed operation and accurate pattern deposition. The segmented cavity structure replaces the continuous application of spray guns with discrete, controllable adhesive delivery points.
Solution Approach 2:
The invention applies adhesive with different properties at different locations around the roll. Each cavity receives a controlled amount of adhesive tailored to its specific position and function in the pattern, rather than uniform application. This local control of adhesive quantity and timing enables precise pattern accuracy at high speeds.
4Manufacturing precision
If a gravure roll uses large excess adhesive to ensure full coverage, then even pattern application is achieved, but the process becomes highly inefficient with difficult-to-control fluid distribution
Solution Approach 1:
The invention applies adhesive in precisely controlled partial amounts to each cavity, rather than using excessive adhesive to ensure coverage. The dosing mechanism delivers only the required volume to each cavity, eliminating waste while ensuring complete coverage. This partial action approach achieves even patterns without the inefficiency of excess material.
Solution Approach 2:
The invention implements a feedback-controlled dosing system that monitors cavity fill status and adhesive consumption. The system adjusts adhesive delivery to each cavity based on actual needs, preventing both over-application and under-application. This closed-loop control ensures efficient adhesive use while maintaining even pattern coverage.
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 process enables precise and uniform application of adhesives at high speeds, reducing stringing and contamination, and maintaining adhesive performance until disposal of the absorbent article.
Implementation Method 1
positive pressure is used to eject fluid from cavities onto the article
Data Source
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AI summary
An apparatus (200) for providing non-contact application of fluids (110) onto web materials (500) and articles is disclosed. The apparatus comprises a gravure roll (200) having a hollow rotating shell (250) having a plurality of cavities (210) disposed within the outer surface thereof and a stationary cylindrical core (260) having a central bore (290) and a channel (270) disposed therein. A fluid disposed within a respective cavity of the plurality of cavities disposed within the outer surface of the hollow rotating shell is removed from the respective cavity by the positive pressure when the positive pressure is fluidly communicated from the central bore through the channel and into the cavity from the surface of the stationary cylindrical core.