Tea Bag Sealing Dies With Zoned Infrared Heating Control

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Solution Overview

Problem

Conventional tea bag sealing systems struggle with temperature control precision, leading to inconsistent seals due to +/- 20°C tolerance and up to 30°C variation along the sealing die, which is critical for maintaining integrity, especially when using eco-friendly bonding agents like polylactic acid.

Innovation Solution

Implementing quartz glass infrared emitters with short wave carbon elements and multiple heating zones, allowing for temperature control within +/- 3°C across the sealing die surface, combined with independent control of heating zones and pressure adjustment to ensure uniform temperature distribution and seal integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional heating drums with ceramic infrared heating elements are used, then the sealing temperature can be maintained, but the temperature control precision is poor with a tolerance of +/- 20°C and temperature variation up to 30°C along the sealing die

Engineering Contradiction:
Improvetemperature control precisionVSAvoidseal integrity
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The heating drum is divided into multiple heating zones (first heating zone and second heating zone) with independently controllable infrared emitters. This segmentation allows each zone to be controlled separately, enabling precise temperature management across different sections of the sealing die and eliminating the temperature variation problem that affects seal integrity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically adjusts the power supplied to each heating zone based on real-time temperature feedback. The independent control of multiple heating zones allows the system to respond to temperature variations along the sealing die, maintaining precise temperature control (+/- 3°C) and ensuring consistent seal quality throughout the production process.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the sealing temperature is increased to ensure proper bonding, then the bonding agent melts effectively, but the agent may leach through the tissue web to the sealing die

Engineering Contradiction:
Improvebonding effectivenessVSAvoidagent leaching
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The system precisely controls the sealing temperature within a narrow range of +/- 3°C across all heating zones. This precise parameter control ensures the bonding agent reaches the optimal melting temperature for effective bonding while preventing excessive temperature that would cause the agent to leach through the tissue web to the sealing die.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If conventional heating systems are used, then the apparatus structure is simpler, but the production rate is limited due to slower heating response time

Engineering Contradiction:
Improveproduction rateVSAvoidheating system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent replaces conventional thermal conduction heating with infrared radiation heating. Infrared emitters directly radiate thermal energy to the sealing die surface, providing rapid heating response and enabling high-speed production (2800 pockets per minute) without requiring complex thermal management systems.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The heating system is segmented into multiple independently controlled heating zones with infrared emitters. This segmentation enables precise local temperature control and rapid response to production demands, achieving high productivity while maintaining manageable system complexity through modular design.

Inventive Principle:
Principle #1Segmentation

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

Achieves high-speed production of tea bags with uniform seals, ensuring effective bonding even with biodegradable materials, reducing leaks and improving production efficiency.

Implementation Method 1

Quartz glass infrared emitters can transfer large amounts of energy at a greater rate than conventional heating sources. This fast response time allows the system to heat up almost immediately from cold with the application of power.

Methodology Applied
Scientific EffectInfrared radiation: Infrared Radiation

Implementation Method 2

The infrared element may have a temperature of approximately 2200°C.

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 3

The heating drums each comprise an array of ceramic infrared heating elements that are controlled to maintain the sealing temperature of the sealing die.

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 4

applying pressure and heat to the tissue around the edges of the tea bag to melt a plastic bonding agent such as polypropylene and create a bond between the two tissue webs

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP4164871B1Packaging apparatus and method
Publication Date: 2026.02.18 TATA CONSUMER PROD GB LTD
  • EP4164871B1 patent drawingFigure 1~2
  • EP4164871B1 patent drawingFigure 3
  • EP4164871B1 patent drawingFigure 4~5

AI summary

Packaging apparatus comprises two counter-rotatable sealing dies for pressing together two tissue webs to produce pockets for containing a substance for preparing beverages and to seal around said pockets, and two heating drums for heating the sealing dies and each being positioned inside a respective sealing die, wherein a first heating zone of each heating drum comprises a first plurality of circumferentially distributed infrared heating elements, and a second heating zone of each heating drum comprises a second plurality of circumferentially distributed infrared heating elements.