Bulk-Heating Graphite for Uniform Air Heating in Tobacco Devices

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Solution Overview

Problem

Current heat-not-burn heating devices experience significant temperature differences in airflow heating due to the proximity to heating sources, leading to unsatisfactory heating effects on tobacco rods.

Innovation Solution

A method for preparing bulk-heating graphite with adjustable resistivity and resistance values, allowing uniform heat generation across the entire graphite body, achieved through specific processing steps including weighing, preheating, kneading, molding, and calcining graphite materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If airflow heating with heating wire or heating needle is used, then the heating source can be easily implemented, but significant temperature differences occur in the heated air leading to unsatisfactory heating effects

Engineering Contradiction:
Improveease of implementation of heating sourceVSAvoidtemperature uniformity of heated air
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The patent replaces the conventional heating wire/needle mechanical heating system with an electric field-based resistive heating system. The graphite material is impregnated with conductive slurry to create distributed heating zones, substituting direct contact mechanical heating with field-based energy distribution throughout the tobacco rod structure

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

Solution Approach 2:

The patent modifies the electrical resistance parameters of the graphite material by controlling the impregnation of conductive slurry. By adjusting the slurry composition, concentration, and impregnation conditions, the resistivity is optimized to achieve uniform heat generation throughout the graphite body, transforming the temperature distribution parameter from highly non-uniform to uniformly distributed

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If heating wire or heating needle is used as heating source, then the structure is simple, but the temperature distribution in heated air is non-uniform

Engineering Contradiction:
Improvestructural complexity of heating systemVSAvoidtemperature distribution uniformity
Core Design Contradiction:
Device complexityVSTemperature

Solution Approach 1:

The patent divides the heating function into multiple segmented zones by creating distributed conductive pathways within the graphite material. The conductive slurry forms discrete heating regions at different positions along the tobacco rod, allowing each segment to generate heat independently and collectively achieve uniform overall temperature distribution

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent creates a composite structure by impregnating conductive materials (silver powder, conductive slurry) into the graphite matrix. This composite approach combines the thermal conductivity of graphite with the electrical conductivity of the impregnated materials, achieving both structural integrity and uniform resistive heating properties

Inventive Principle:
Principle #40Composite materials

3Device complexity

If conventional heating methods are used, then the heating component is simple, but the heating effect on tobacco rod is unsatisfactory

Engineering Contradiction:
Improvesimplicity of heating componentVSAvoidheating effect quality
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The graphite material serves dual functions: it provides structural support as the tobacco rod holder and simultaneously generates heat through its own resistive properties when electric current passes through it. This self-heating capability eliminates the need for separate heating elements while ensuring reliable and uniform heating of the tobacco rod

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The graphite component performs multiple functions simultaneously: it acts as a structural support, a thermal conductor, and an active heating element. By integrating these functions into a single multi-functional component, the system achieves reliable heating effects without increasing overall device complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 bulk-heating graphite ensures uniform air temperature distribution and improved heating effects, providing consistent smoke flavor for tobacco rods by generating heat uniformly upon electrification.

Implementation Method 1

The bulk-heating graphite ensures uniform air temperature distribution and improved heating effects, providing consistent smoke flavor for tobacco rods by generating heat uniformly upon electrification

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP4667439A1Method for preparing body heating graphite, product, and use thereof in heating appliance
Publication Date: 2025.12.24 SICHUAN SANLIAN NEW MATERIAL CO LTD
  • EP4667439A1 patent drawingFigure 1~2
  • EP4667439A1 patent drawingFigure 3~4
  • EP4667439A1 patent drawingFigure 5

AI summary

Disclosed in the present invention are a method for preparing a bulk-heating graphite, a product, and an application thereof in a heating device. The method includes: weighing a powder material and a binder, wherein the powder material is pitch coke, and the binder is modified pitch; preheating the pitch coke; heating the modified pitch to a molten state; pouring the modified pitch into the preheated pitch coke and kneading to obtain a paste; subjecting the paste to hot rolling, cooling, crushing, and sieving to obtain a mixed powder; isostatically pressing molding the mixed powder to form a green body sample; and subjecting the molded green body sample to two calcining treatments to obtain a bulk-heating graphite sample. The method for preparing the bulk-heating graphite, the product, and the application thereof in the heating device provided in the present invention enable a honeycomb graphite as a whole to possess a heatable resistance, generating heat uniformly upon electrification, so as to produce sufficiently heated air with uniform temperature distribution and improved heating effects, thereby meeting the requirement of baking the tobacco rod for smoking, and resulting in excellent baking effects of the tobacco rod and consistent smoke flavor for every puff. There is no need to combine a porous honeycomb diffuser with other heating elements, making assembly more convenient.