Grouting blank: The above mentioned the production principle of the grouting billet, understand its production process, the grouting billet must be made of mold, and the mold must be two or more pieces, when grouting together, each mold will produce a gap at the contact, which will definitely affect the adsorption performance of gypsum, so that the density of the billet at this position is different from other parts. In addition, because the mold is generally a bottom foot, there is a circle at the bottom of the foot ring corresponding to the foot concave, commonly known as the “grouting line”, that is to say, the grouting porcelain has a prominent outside, because the billet is formed by adsorption gypsum, then the inner wall must have a concave, and the concave can not be filled.
Generally, process marks such as “suture line” have some technical means to cover up, so in identifying whether it is a grouting tire, the more reliable method is to observe whether there is a concave grouting line on the bottom edge of the porcelain, and then carefully look for the suture line and some other grouting traces, such as sliding the stroker body with the hand, the grouting tire is very flat, and the hand-pulled blank is better. It is also inevitable to have a vague undulating feel.
It is worth reminding that there are some porcelain, the mouth is large, the type is relatively short (shallow), this porcelain, after forming easy to turn, grouting deliberately increase the bottom thickness of the blank, and then through the turning method to make the concave “grouting line” disappear, which is the so-called imitation hand drawing blank. For this kind of porcelain such as small incense burner, pen holder, washing, etc., should be extra careful.
On the contrary, the hand-drawn billet is not formed by adsorption on the plaster mold, so the porcelain definitely does not have a grouting line like the grouting billet. Then, it is leaning on the rotating roulette, holding the mud with both hands (the so-called holding is that the mud and the roulette are the same center), by hand to pull the plastic mud into various shapes of the body, so there is no mold line. At the same time, due to manual pulling, the soil can not be drawn into the same thickness, especially the density of mud, and then how to pass the later repair process, it is difficult to achieve consistency, so that the hand pulling billet with the hand slide touch the burned porcelain surface, there will be a vague irregular concave and convex sense. This is also a measure of porcelain body is good or bad an indicator, concave and convex sense is too strong, naturally not so ideal.
Post time: Sep-22-2023