Ceramic characteristics
? "Ceramics, tea and silk" are three major inventions besides "printing, compass, gunpowder and papermaking". Since ancient times, ceramics have had the reputation of "sound like a chime" and "sound like nature". Ceramics bear the culture of China for thousands of years, with smooth glaze, crystal clear, soft luster and jade-like. We hold a well-made porcelain, and when we flick it, we will hear a crunchy sound of "dong", just like the wonderful sound of an instrument, which is exciting-this is bound to be related to ceramics and music.
"Pottery" has soft texture and good sound absorption effect, while "porcelain" has hard texture and poor sound absorption effect. To produce ceramic speakers, we must first understand the influence of different ceramics on the sound: when we know the data such as the thickness or local thickness of ceramics, the rate of porcelain output, the combination of ceramics and porcelain, whether it is glazed or partially glazed, and whether it leaves lines, then we can avoid many detours in the process of sound cavity matching. A good ceramic speaker can output bass effect even if the cavity is not sealed. This is the effect of careful cavity matching by electronic engineers with the cooperation of ceramic technicians who know the sound box and structural engineers who know the ceramics. This effect can not be achieved by traditional wood and plastic speakers under similar conditions. We can call it the * * * vibration effect between sound and ceramics.
? As long as we master this vibration law, ceramic speakers will become a dark horse in the field of speakers. At present, the enterprises with this database are still in the initial stage, and for the sake of technical confidentiality, enterprises are even reluctant to apply for invention patents.
Production difficulty
? Since there is a certain relationship between ceramics and sound, ceramic speakers should have been popularized long ago. Why can't you find a ceramic speaker with a certain appearance and professional level until 20 12? This is related to the kiln changing properties of ceramics. The so-called kiln change is because the ceramics are in a semi-molten state during the firing process of 1000 degrees, so there are many uncontrollable factors, such as deformation, shrinkage, glaze effect, etc., which can not be controlled and can not achieve the effect of constant volume. Therefore, it is almost impossible to realize industrialized electronic products made of ceramics. If ordinary mud glaze is directly produced, the rejection rate is almost 100%, that is, the formula mud glaze is used. According to the data fed back by Shenzhen Daci Technology Co., Ltd., the scrap rate is still around 30%.
? In order to make the tolerance of ceramics in self-burning state less than 50 lines (error less than 0.5 mm), the use of wet mud will be affected by shrinkage and kiln position. As long as the shrinkage is different, the tolerance must be large, and the electronic part cannot match the ceramic. If the kiln location is different, the firing temperature of ceramics is different, which will also affect the shrinkage rate. Therefore, to make ceramic speakers, we usually use semi-clinker dry pressing technology. In order to keep the secret of key technologies, the following are some common steps:
1, making semi-cooked porcelain powder at a certain temperature;
2, adding substances into the porcelain powder, grinding, sieving, atomizing and selecting materials;
3, adding water into the porcelain powder with a certain fineness to reach a certain humidity, and dry-pressing and molding;
4. Burn vegetarian food to a specific temperature;
5, porcelain selection, defective products discarded;
6, laser leveling, until all porcelain tolerance is consistent;
7. Glazed porcelain;
8, porcelain selection, defective products discarded;
9, laser leveling;
10, burning the bottom fire to a higher temperature;
1 1, porcelain is selected, defective products are discarded, and those with slight errors are leveled and returned to the furnace;
12. Apply formula glaze and burn to a specific temperature;
13, porcelain selection, defective products discarded;
14, decal and fire according to the temperature of decal paper;
15, glazing and firing to1130℃;
16, porcelain selection, defective products discarded;
17, electronic equipment.
? It should be noted that in the seventh and twelfth links mentioned above, the shrinkage rate of ceramics will be affected due to the large temperature error in the kiln (usually the error can reach 40- 100 line), so it is recommended not to repair the kiln, and the vacant position is where the temperature can not be controlled, and it can be emptied or other ordinary porcelain can be made.