Conical Sleeve Drop Dispenser for Uniform Viscous Liquid Droplets
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Solution Overview
Problem
Conventional drop dispensers fail to deliver uniform-sized droplets of viscous liquids, often incorporating air bubbles and resulting in inconsistent delivery volumes due to surface tension and viscoelastic properties, making them unsuitable for precise medicament dosages.
Innovation Solution
A drop dispenser featuring a conical sleeve member with a centrally located aperture and raised ridge forming a nozzle, which is in liquid communication with a conical chamber, minimizing air bubble inclusion and ensuring uniform droplet formation, suitable for viscous liquids up to 15 Pa*s, and compatible with squeezable containers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a narrow passage is used between the liquid reservoir and the aperture, then the droplet size can be controlled, but air bubbles are entrapped in the liquid stream particularly when the liquid is viscous
Solution Approach 1:
The passage is divided into two distinct sections: a wider reservoir passage and a narrower aperture. This segmentation allows the liquid to flow smoothly through the wider passage without turbulence that would trap air bubbles, while still achieving controlled droplet formation at the narrower aperture.
Solution Approach 2:
A conical transition zone is introduced as an intermediary between the reservoir passage and the aperture. This conical section acts as a mediator that gradually reduces the passage width, preventing sudden pressure changes and air bubble entrapment while maintaining the ability to form uniform droplets at the aperture.
2Device complexity
If conventional nozzle designs are used, then the structure is simple, but droplets of viscous liquids are not of uniform size or are too large in volume
Solution Approach 1:
The nozzle design features different geometries at different locations: a wider reservoir passage for bulk liquid flow and a precisely dimensioned aperture for droplet formation. This local differentiation of geometric properties allows the nozzle to maintain simplicity overall while achieving precise droplet size control at the critical aperture region.
Solution Approach 2:
The aperture dimensions are specifically optimized for viscous liquids, with the inner diameter and raised ridge geometry tailored to the viscosity range (up to 15 Pa·s). By changing the geometric parameters of the aperture compared to conventional nozzles, uniform droplet formation is achieved for viscous formulations.
3Ease of operation
If ordinary dispensers are used for viscous materials, then surface tension and viscoelastic properties cause 'ribboning' behavior, but the delivery volumes become inconsistent
Solution Approach 1:
The raised ridge at the aperture creates a pre-defined separation point for the liquid stream before it exits. This preliminary structural feature counteracts the viscoelastic tendency of viscous liquids to form ribbons by forcing the liquid to break into discrete droplets at the ridge location, preventing ribboning behavior.
Solution Approach 2:
The conical chamber and aperture geometry create curved flow paths that promote spherical droplet formation. The curvature of the conical surface and the circular aperture work together to shape the viscous liquid into uniform spherical droplets, counteracting the ribboning effect caused by viscoelastic properties.
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 the accurate, reproducible, and consistent delivery of small, uniform droplets of viscous liquids, avoiding 'ribboning' and air bubbles, particularly beneficial for medicament formulations like eye drops.
Implementation Method 1
surface tension and viscoelastic properties of the liquid to be dispensed
Implementation Method 2
The interior space of the substantially conical sleeve member forms a substantially conical chamber between the upper end and the lower end
Data Source
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AI summary
A drop dispenser has a substantially conical sleeve member with a narrow upper end and a wide lower end. Centrally located at the apex of the upper end of the sleeve member is an aperture which has an inner diameter and is circumscribed by a raised ridge. The aperture and the ridge form a nozzle. The interior space of the substantially conical sleeve member forms a substantially conical chamber between the narrow upper end and wide lower end of the sleeve member. The nozzle is in liquid communication with the chamber through the aperture. The drop dispenser may have external threads at the lower end of the sleeve member for engaging a cap having a protuberance centrally located at its internal top end for hermetically engaging the aperture of the nozzle when the cap fully engages the sleeve member.