So the other day I got this email from Uwell about Ceramic coils. What do you guys think?
The Truth and Science behind Ceramic Coils
Customers have asked why Uwell doesn’t makes ceramic coils since the ceramic coil has a longer life compared with the Crown 2 coil and some ceramic coils even have better taste.
The article followed contains some researches and analysis of how ceramic coils affect vapers’ health and it may help to answer the question.
Uwell realizes the short life of the Crown 2 coil and we are developing coils to taste better and last longer. The latest version has increased life time and is now on the market. The good news is that there is positive response.
Figure 1 shows three kinds of ceramic coils on the market (#1, #2, and #3 stands for three different brands, respectively).
For #1, there is a layer of cotton between the ceramic and the coil. This design is lower in strength and makes the ceramic fragile. For example, the ceramic coil breaks apart when pinched and tiny powders fall off and stick onto the cotton. It is also hard to distinguish the cotton and the ceramic material since they are both white. In the case of #2 and #3, the ceramic material and the coil are heated up together to be made into one piece. However, the melting point of the coil is lower than the ceramic material so this causes the surface of the coil to be loose and porous. This makes the coil have low durability, is fragile, and has powders falling off.
Figure 2 shows partial end surface microstructure of #1, #2, and #3.
All three ceramic coils appear translucent with a glasslike exterior. Visible light can be reflected and scattered by pores inside the ceramic material. This is what makes it a translucent surface. The ceramic coil is made from silica similar to glass. Therefore, the ceramic coil appears as a glasslike surface. Many impurities can be seen at a magnification of 100X from a microscope and they appear as black spots. The glasslike particles are not uniform and appear to be uneven and chaotic. The tiny glass pieces have sharp surfaces that can scratch the trachea and alveoli when used. The black spots could also be unrefined toxic material that could have impurities.
Figure 3 shows partial cross section surface microstructure of #1, #2 and #3.
After breaking the material for the cross section, we can see glasslike particles with sharp surfaces. The glasslike particles are clearly visible at the magnification of 100X.
Figure 4 shows partial edge surface microstructure of #1, #2, and #3.
Some parts have defects and some parts have sharp edges. This comes from two steps in making the ceramic coil. In the first step, the friction causes defects and coarse edges when samples are removed from the mold. In the second step, the surface of the ceramic coil is loose from the friction between the ceramic powders and the mold. The loose powders cannot be heated up and molded onto a dense body. The ceramic powders also stick to the surface of the ceramic coil. This process also makes the ceramic powders fall off easily.
Figure 5 shows ceramic powders falling off microstructure #1, #2, and #3.
When the ceramic powder is touched, the powder sticks onto that surface. All these powders are glasslike pieces with sharp edges mentioned above in the optical microscope. The size of the ceramic powder is distributed between 30120 micrometers which is too tiny to be seen by the human eye.
Figure 6 shows the microscope image on the contact segment between ceramic and coil.
Number #1 does not compare with others since its coil does not come in contact with the ceramic material. Many ceramic powders gather at the position near coil. The first reason is that the coil cannot be easily compressed into a ceramic material when the ceramic material is molded. This is because the cross section of the coil is circular. The second reason is that powders are produced after taking the coil off of the mold. It is impossible to clean the powders stuck to the inner surface of the ceramic coil. There are ceramic powders on the inside of all ceramic coils on the market.
Finally, ceramic coils may cause death. Making the ceramic material
The ceramic coil is made from inorganic porous ceramic material. There are tiny pores inside the ceramic material that cannot be seen. Pores play an important role in wicking. In order to produce a porous ceramic material, raw materials such as silica powders and poreforming materials like starch or other organic polymers are needed. Then they are mixed and put into a mold with high pressure. Samples are obtained with a fixed shape. The samples are put into a furnace and set to a high temperature. Pores are formed while the poreforming agent combusts and escapes. This kind of pore plays an important role by introducing eliquid into your vape. However, to make enough pores, the temperature to stick the materials together is lower which causes low tensile and compressive strength. The powders fall off or crack when the ceramic coil is touched or shaken. All the powders can be introduced into the lung by air which is dangerous (the speed of air can reach 223mph when we are vaping).
Ceramic coils will absorb more eliquid. Eliquid is vaporized and evaporated when the coil is working. High pressure from the vapor will expand and damage the structure of the porous ceramic material. Loose powders will fall off and go into the lung.
Silicosis is a form of occupational lung disease caused by inhalation of crystalline silica dust. Symptoms are inflammation and scarring in the form of nodular lesions in the upper lobes of the lungs. This is a type of pneumoconiosis. Silicosis can be complicated by the development of severe scarring, where small nodules gradually merge together, reaching a size of 1cm or greater. Progressive massive fibrosis is associated with more severe symptoms and respiratory impairment. Silicosis can also be complicated by other lung diseases such tuberculosis, nontuberculous mycobacterial infection, and fungal infection, certain autoimmune diseases, and lung cancer ("Silicosis." Wikipedia. Wikimedia Foundation, n.d. Web.
29 Sept. 2016.)(https://en.wikipedia.org/wiki/Silicosis).
In conclusion, ceramic coils are not healthy. First, a ceramic coil is made from silica similar to glass. Second, ceramic powders or glasslike pieces easily fall off. Finally, silica powders may cause death.
Uwell is working hard to develop a better ceramic coil. However, it is impossible to continue with current technology. Therefore, Uwell will put making a ceramic coil on hold.
Uwell wants to tell customers the truth. Uwell will never produce a product that causes death. Would you buy a coil that lasts longer at the cost of your life?