Because of its low price and strong thermal stability, cordierite baking slabs have shown explosive growth in recent years, defeating competitors such as ceramic slabs and volcanic slabs, and becoming the first choice for home and commercial pizza and bread baking.
“Slate” is passed on by word of mouth among baking enthusiasts, but most people don’t know how to distinguish it. Some are much cheaper, but they are quite heavy to pick up, and you think the quality is good. In fact, as long as you look at the appearance carefully, you can see a lot of differences.
How do you Identify High-Quality Cordierite Baked Slabs?
There are certain processes in the manufacture of cordierite slabs, from raw material processing and mixing to pressing, drying, firing, and later grinding packaging, and other processing. The differences in processing in these aspects by different manufacturers determine the different costs. RS manufacturers provide high-quality cordierite slabs for wholesale sales. The price is fair.
Differences in raw material quality and mix ratio
The main raw material content of cordierite slabs is of course cordierite, and some clay mineral soils are also mixed to form and improve properties. Cordierite with a very low thermal expansion coefficient plays a vital role in the thermal stability of the slab. Therefore, the quality and amount of cordierite largely determine the refractoriness of the slab.
The raw material cordierite needs to be sintered. The higher the sintering temperature, the higher the cost, and it will look whiter after firing.
After mixing with other materials (usually colorants are added), pressing and sintering, the color of cordierite can no longer be distinguished. Moreover, the impact on refractoriness is not as obvious as reducing the content of cordierite. Simply put, the addition of additives will not directly affect the refractoriness of cordierite slabs.
Generally, the temperature used by home users is limited and the frequency of use is not high. Therefore, some manufacturers will reduce costs by reducing the amount of relatively expensive cordierite. This will directly lead to a decrease in refractoriness, easy cracking during rapid cooling and heating, and faster aging of the slab.
Raw material processing process
Before mixing various raw materials, some processing is required. For example, one step that has a greater impact on the appearance of the finished product is to remove the larger iron impurities in the raw materials. Because iron impurities have a greater impact on the appearance of the finished product, it is difficult to completely remove them using a simple process, and generally the larger particles are isolated.
Since iron impurities are difficult to completely remove, even if the surface of the product is relatively clean after iron removal, it is inevitable that there will be some black spots after high-temperature firing. Therefore, some manufacturers will skip the iron removal process to save some time and labor costs. However, if large iron impurities are not removed, dense iron particles will appear on the surface of the product after firing.
Firing is a very important process in the manufacture of stone slabs, which has a great impact on the quality of the product. Sufficient firing time and appropriate firing temperature (generally 1200 degrees Celsius) can make the stone slab fully sintered, harder, and more refractory.
The surface of the fully sintered stone slab is firm and flat.
The powder on the surface of the unsintered stone slab will fall off, and the particles on the surface seem to fall off easily. The so-called powder loss is the foreign dust accumulated on the surface, which will disappear after washing. However, the powder loss caused by insufficient sintering is the shedding of the material of the stone slab itself.
Some unsintered products have particularly serious powder loss.
Shortening the firing time and lowering the temperature can reduce fuel consumption. More finished products can be fired in the same time, which can naturally reduce costs. That’s why some stone slabs can be sold at very low prices. The cordierite slabs of RS manufacturers are of reliable quality, factory direct sales, and guaranteed after-sales service. Contact RS for free samples and quotes.
Subsequent grinding and packaging
Mineral powder is very soft and needs to be stamped into shape with a large-tonnage press. Different shapes and sizes require different molds. The mold consists of several parts. The upper and lower mold cores and the frame form a closed shape. There is a certain gap between the frame and the core, so the edge of the stamped embryo will be rough. The embryo is very soft before firing and is inconvenient to grind. It can only be done after sintering and forming with hardness. Whether it is semi-automatic machine grinding or manual grinding, it is a time-consuming and labor-intensive process.
Of course, not grinding can also save some costs. Some manufacturers will not grind at all to save labor costs.
Through the above description, I believe that you will soon find out whether the cordierite slab you bought is the one with the highest cost performance. Identifying the differences and differences in the quality of cordierite slabs will also understand the difference of “you get what you pay for”. I hope you can buy a product that suits your taste.
