What Are the Pros and Cons of Ceramic Coils in E-Cigarettes?

What are the pros and cons of ceramic coils in e-cigarettes? In recent years, new materials that emphasize surface and interface properties have gained increasing attention. Porous ceramic materials are a type of new material that utilizes physical surfaces, created through high-temperature sintering, with a large number of three-dimensional interconnected pores, forming a three-dimensional network structure. This type of porous ceramic material plays an extremely important role in the atomization process of e-cigarettes.

RELX is the first in China to use the Microwell FEELM heating element in its small devices. The atomization core used by RELX is a ceramic atomization heating element, characterized by stability, high-temperature resistance, and safe oil conduction, providing a finer taste and leak-proof advantage. Currently, the microporous ceramic atomization core is standard for e-liquid e-cigarettes, in addition to RELX, there are also MK e-cigarettes, NRX, MT, and other brands. How is this three-dimensional network structure of porous ceramics manufactured?
There are many types of porous ceramic materials, and due to different purposes, their performance varies. Therefore, many different preparation techniques have been developed in recent years. The general preparation process for porous ceramics includes granulation, mixing, forming, and sintering.

The methods for creating pores in porous ceramics mainly involve the formation of pores during the sintering process. Methods include adding pore-forming agents, foaming processes, organic foam impregnation processes, and sol-gel processes.

1. Adding pore-forming agents

By adding pore-forming agents to the ceramic mixture, these agents occupy a certain space in the green body, and during the sintering process, the pore-forming agents leave the matrix, thus forming pores and resulting in porous ceramics. The forming methods mainly include pressing, extrusion, rolling, isostatic pressing, injection, and slip casting. The products are generally referred to as honeycomb porous ceramics.

2. Organic foam impregnation

Organic foam is impregnated with ceramic slurry, and after drying, the organic foam is burned away, resulting in porous ceramics. This method is suitable for preparing porous ceramics with high porosity and open pores. The products are generally referred to as mesh porous ceramics.

3. Foaming method

Foaming agents are mixed with clay materials, and under pressure, the clay particles bond together. When sufficient heat reaches the clay particles, the material foams and expands to fill the mold, cooling to form porous ceramic materials. Various pore sizes and shapes of porous ceramics can be prepared, generally referred to as foam porous ceramics.

4. Sol-gel process

Ceramic particles are mixed with organic gel, washed through ion exchange, and then sintered to form porous ceramic materials. The sintering temperature can be adjusted to change the structure, porosity, and pore size of the porous SiO2 material. The sol-gel method is mainly used to prepare microporous ceramic materials, especially microporous ceramic films.
Advantages

1. Different forming methods can produce complex-shaped products

2. Various pore structures can be created

3. High porosity products can be produced

4. Good strength of samples

5. Particularly suitable for producing closed-pore products

6. High porosity and strength

7. Suitable for producing microporous ceramics

8. Suitable for producing film materials

9. Uniform pore distribution

Disadvantages

1. Poor uniformity of pore distribution

2. Not suitable for producing high porosity

3. Cannot manufacture small-diameter closed-pore products

4. Product shape is limited

5. Product composition density is difficult to control

6. High requirements for raw materials

7. Difficult to control process conditions

8. Limited raw materials

9. Low productivity

10. Product shape is limited

Among the successful applications and active research, one method involves adding volatile or combustible pore-forming agents to the ceramic mixture, utilizing these agents to vaporize or burn off at high temperatures, leaving pores in the ceramic body. Depending on the pore size, ceramics can be classified into coarse products with pore sizes from 1000 μm to several tens of micrometers, microporous products with pore sizes from 0.2 to 20 μm, and ultramicroporous products with pore sizes from 0.2 μm to several nanometers. Based on the pore-forming methods and voids, porous ceramics can be divided into: foam ceramics, honeycomb ceramics, and granular ceramics, with corresponding porosity as follows:

The preparation technology allows for precise control of the structure of porous ceramics, including different influences on pore size, shape, and distribution. The bonding strength between aggregate particles determines the strength of porous ceramics, and it is also necessary to reasonably coordinate the relationship between porosity and strength. #p#分页标题#e#

Due to their high porosity, low density, and low thermal conductivity, porous ceramics have significant thermal resistance and small volumetric heat capacity. The applications of porous ceramic materials have spread across metallurgy, chemical engineering, environmental protection, energy, and biology. Besides the well-known applications in aerospace, missile heads, and filters, they also play a significant role in the e-cigarette field.

Ceramic atomization cores are currently standard for high-quality e-cigarette devices, utilizing a porous ceramic structure with pore sizes generally at the micron or sub-micron level, commonly referred to as microporous ceramic atomization cores. In addition to atomization cores, there is also a type known as ceramic oil conduction tubes, which also use porous ceramics.

This article is sourced from "Preparation Technology of Porous Ceramic Materials" and edited by Aibang.