Electronic cigarette product ceramic atomization core is essentially a porous ceramic material, also known as porous functional ceramic, which is a new type of ceramic material.
After forming and sintering at high temperatures, there are a large number of interconnected or closed pores in the body. Not only has the advantages of traditional ceramics such as high-temperature resistance, corrosion resistance, and chemical stability, but also has the characteristics of large specific surface area, low density, and adjustable pore size distribution.
In this case, how is the porous ceramic substrate for electronic cigarette products made?
At present, there are mainly four basic preparation methods, namely the pore-forming agent method, partial sintering method, template replacement method, and direct foaming method.
I. Porous agent method
Pore-forming agent method is the most commonly used method, which is to add volatile or combustible porous agent in the ceramic components, the use of this porous agent at high temperatures is volatile or burned out and leaves pores in the ceramic blank.
The more common porogenic agents are organic resin beads, organic fibers, carbon fiber, carbon powder, starch, wood chips, polymethyl methacrylate, methylcellulose, etc.
Second, the local sintering method
The so-called local sintering method refers to the process of high-temperature, powder particles through the diffusion or evaporation cohesion process connected to each other, but did not reach complete densification, the formation of uniform porous structure between the particles.
The porous ceramics made by this method generally have a porosity of less than 50%, and the particles are 2-5 times larger than the pore size and are mostly used in molecular sieves, water purification membranes, etc.
Third, the template replacement method
Template replacement method is also known as organic foam impregnation method, the production process is to use the prepared ceramic slurry impregnated with organic foam (usually spongy polyurethane), and then the organic material will be burned, sintered ceramic blanks, porous ceramic products.
Sol-gel or colloidal solution can also be used instead of ceramic slurry impregnated with organic foam.
This method is a simple process, easy to operate, without complex equipment and low production cost. It is the production of high porosity (70-95%) porous ceramics, an effective, economic and practical method.
Fourth, the direct foaming method
Direct foaming method is to produce a dispersed gas phase in the ceramic suspension, the suspension is generally composed of ceramic materials, water, binder, surfactant and gelling agent. The process has been used to produce porous ceramics, such as zirconia and alumina, porosity can vary between 20-80%.
As an example, Suellenbarg, a German research technician, dispersed alkanes into a ceramic slurry, added dispersants to form a homogeneous and stable wash of alkanes, and finally made porous alumina ceramic filters with porosity up to 90%.
Relative comparison of the four methods
Among them, the more successful application and more active research and analysis is the addition of volatile or combustible porogenic agents in the ceramic composition, through which the porogenic agents volatilize or burn out at high temperatures, leaving pores in the ceramic blank. Ceramics can be classified by pore size into microporous products ranging from 1000μm to tens of microns, 0.3 to 30μm, and ultra-microporous products ranging from 0.3μm to several nanometers. Porous ceramics can be classified into foam ceramics, honeycomb ceramics and granular ceramics according to the pore-forming method and voids, which correspond to the following porosity.
The preparation technology has different effects on the precise control of the porous ceramic structure, which includes the size, shape and distribution of the pore size. The strength of the connection between aggregate particles determines the strength of porous ceramics, and the relationship between porosity and strength needs to be reasonably coordinated.
Porous ceramics have great thermal resistance and small bulk heat capacity due to their high porosity, low density and low thermal conductivity. Porous ceramic materials have been widely used in metallurgy, chemical industry, environmental protection, energy, biology and other fields. In addition to space shuttle shell insulation, missile heads, filters, etc., they also play a very important role in the field of electronic cigarette products.
Ceramic atomization core is the standard configuration of high quality e-cigarette products nowadays. It uses a porous ceramic structure, and its pore size is generally micron or submicron, generally speaking, it is called microporous ceramic atomization core. In addition to the atomizer core, there is also a ceramic oil guide tube, also using porous ceramic.