Water-Soluble Delayed Release Capsule with Gas-Relief Pinholes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Water-soluble capsules used for delayed release of alkaline actives in laundry face challenges such as pressure build-up due to gas generation, residue left on wash load, and incompatibility with laundry detergents, as they are either not soluble enough or dissolve prematurely.
Innovation Solution
Incorporating pinholes in the capsule shell to allow gas escape while preventing liquid entry, using a thick water-soluble polymer capsule with a uniform wall thickness to delay release and ensure complete dissolution without residue, and eliminating the need for protective coatings by providing adequate barrier properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If the capsule is made water-tight to delay release, then delayed release performance is improved, but gas pressure build-up occurs inside the capsule
Solution Approach 1:
The capsule shell incorporates pinholes that allow gas to pass through while maintaining water barrier properties. These pinholes enable gas relief to prevent pressure build-up while the thick wall structure maintains delayed release by blocking liquid water penetration.
2Speed
If the capsule wall is made thin to improve solubility, then dissolution speed is improved, but delayed release performance deteriorates
Solution Approach 1:
The capsule employs non-uniform wall thickness with thicker regions providing delayed release barrier and thinner regions enabling eventual dissolution. The pinholes are strategically positioned and sized to allow gas passage while maintaining local water barrier properties where needed.
3Duration of action of stationary object
If the capsule wall is made thick to delay release, then delayed release performance is improved, but complete dissolution without residue becomes difficult
Solution Approach 1:
The capsule utilizes controlled wall thickness parameters (thick enough to delay release but thin enough to dissolve completely). The pinhole configuration and polymer composition are adjusted to ensure the capsule dissolves fully after the delayed release period without leaving residue on laundry.
4Reliability
If protective coatings are added to prevent premature dissolution, then device complexity is improved, but manufacturing complexity increases
Solution Approach 1:
The invention eliminates the need for separate protective coatings by integrating the delayed release function directly into the capsule shell structure itself. The pinhole-equipped thick wall design provides inherent premature dissolution prevention without requiring additional coating layers.
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 prevents pressure build-up, ensures complete dissolution of the capsule without leaving residue, and maintains the effectiveness of alkaline actives by controlling the release timing and compatibility with laundry detergents.
Implementation Method 1
the capsule shell comprises a pinhole sized and shaped (A) to permit gaseous fluid communication between the interior capsule volume and an environment external to the capsule shell
Implementation Method 2
a water-soluble delayed release capsule for delivery of a water-sensitive composition, the capsule comprising: (a) a capsule shell comprising a water-soluble polymer
Implementation Method 3
the capsule shell has a wall thickness in a range of about 100 μm to about 5000 μm
Data Source
AI summary
Disclosed herein are capsules for delayed release of an active ingredient contained therein, in particular water-soluble capsules for delayed release of water-sensitive, gas-generating compositions into an aqueous liquid medium. The delayed release capsules incorporate one or more gas-relief pinholes for gas-generating water-sensitive compositions contained in the capsules, such as inorganic bleach or other alkaline compositions intended for delayed release into a wash medium during a laundry cycle. The pinholes permit gas generated within the capsule due to exposure to environmental water vapor to escape from the capsule interior, preventing pressure build-up and capsule deformation during storage. The pinholes are sized to prevent or otherwise substantially limit the passage of liquids when submerged in a liquid medium (e.g., liquid water in an aqueous liquid medium). Related articles and methods for delivering the capsules in combination with a detergent or other laundry composition are also disclosed.