Breakable Capsule Manufacturing via Two-Step Ionic Gelation

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Solution Overview

Problem

Existing methods for manufacturing breakable gel capsules for tobacco products face challenges in controlling gelling time, hardness, and thickness, particularly when using a single ionic bath, which affects the physical characteristics and functionality of the capsules.

Innovation Solution

A two-step process involving a first aqueous solution with a low concentration of multivalent ions for initial gelation and a second solution with a higher concentration for hardening, using iron or calcium ions, to control the gelling time and hardness of the capsules, ensuring they are breakable and maintain crush strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a single ionic bath is used for capsule manufacturing, then the process is simpler and faster, but the control over gelling time, hardness, and thickness is poor

Engineering Contradiction:
Improveprocess simplicityVSAvoidcontrol over gelling time, hardness, and thickness
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The single ionic bath process is segmented into two sequential ionic baths: a first ionic bath for initial gelation and a second ionic bath for hardening. This segmentation allows independent control of gelling time and hardness/thickness parameters, resolving the contradiction between process simplicity and manufacturing precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies parameter changes by varying the concentration and type of multivalent ions in each ionic bath. The first ionic bath uses a lower concentration for controlled gelation, while the second ionic bath uses a higher concentration for hardening. This systematic parameter variation enables precise control over capsule properties while maintaining a relatively simple two-step process.

Inventive Principle:
Principle #35Parameter changes

2Strength

If the capsule shell is made too hard to maintain durability, then the capsule becomes difficult to break for flavor release

Engineering Contradiction:
Improvecrush strength and durabilityVSAvoidbreakability for flavor release
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The capsule shell is designed with local quality variations through the two-step ionic bath process. The inner layer formed in the first ionic bath has different mechanical properties (softer, more flexible) compared to the outer layer formed in the second ionic bath (harder, more durable). This gradient structure provides both durability for handling and breakability for flavor release.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The capsule shell becomes a composite structure with two distinct layers having different mechanical properties. The inner gel layer and outer hardened layer work together to provide both protection and controlled breakability, resolving the contradiction between strength and ease of operation.

Inventive Principle:
Principle #40Composite materials

3Strength

If the gelling time is extended to achieve desired hardness, then the manufacturing productivity decreases

Engineering Contradiction:
Improvecapsule hardnessVSAvoidmanufacturing speed
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The first ionic bath performs the preliminary action of initial gelation, creating a stable gel structure relatively quickly. The second ionic bath then completes the hardening process. This preliminary action approach divides the time-consuming hardening process into two faster sequential steps, improving overall productivity while achieving the desired capsule hardness.

Inventive Principle:
Principle #10Preliminary action

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 process produces capsules with consistent and desirable physical characteristics, such as high crush strength and durability, allowing for controlled release of flavoring or deodorizing agents, enhancing the smoking experience.

Implementation Method 1

introducing the droplet into a first aqueous solution comprising a first multivalent ion selected from the group consisting of iron and calcium, in a concentration of less than about 1 weight %, and allowing the droplet to remain in the first aqueous solution for less than about 30 minutes

Methodology Applied
Scientific EffectGelation: Gel

Implementation Method 2

maintaining the droplet in a second aqueous solution comprising a second multivalent ion selected from the group consisting of iron and calcium, in a concentration of more than about 5 weight %, and allowing the droplet to remain in the second aqueous solution for more than about 6 hours to form the hollow capsule

Methodology Applied
Scientific EffectHardening: Heat Treatment

Data Source

PatentEP3299084B1Process for manufacturing capsules useful in tobacco products
Publication Date: 2019.07.17 R J REYNOLDS TOBACCO COMPANY
  • EP3299084B1 patent drawingFigure 1~2

AI summary

A method for manufacturing breakable capsules that are useful for incorporating into a tobacco product is provided. The method comprises forming a plurality of droplets comprising a core composition and a coating composition. The core composition is enclosed by the coating composition. The method also comprises introducing the plurality of droplets into a first aqueous solution comprising a first multivalent ion, wherein the coating composition gelates in contact with the first multivalent ion in the first aqueous solution to form a plurality of raw capsules, and wherein the first multivalent ion continues to diffuse into the coating composition of the plurality of raw capsules. The method further comprises introducing the plurality of raw capsules in a second aqueous solution comprising a second multivalent ion, wherein the plurality of raw capsules hardens to form a plurality of breakable capsules.