What is the process of making ceramics?

Eating pulp is the mold adsorption of moisture in the mud, the process of forming a blank.

Pulp release, also known as empty pulp, is the process of discharging excess mud when the blank forms a certain thickness. The slurry released back to the slurry pool (or tank). Back to the slurry in the following ways: (1) artificial end bucket back to the slurry: (2) natural pressure back to the slurry, the use of the slope of the pipe, so that the slurry flow back to the slurry pool; (3) the use of slurry pumps to pump back to the remaining slurry: (4) negative pressure back to the slurry, that is, the use of the downward pressure slurry injection pipeline, the formation of a negative pressure with a vacuum pump, to the mud back to the slurry tank. In the above various ways, in addition to the first, all belong to the pipeline back slurry.

Consolidation: after the release of slurry billet is very soft, can not be immediately demolded after a period of time to continue to discharge the billet moisture, increase its strength. This time is called consolidation. Consolidation is one of the main processes of grout molding, and its duration is about half of the time of eating pulp.

During the consolidation process, as the model continues to absorb water, the water content of the billet continues to decline, the billet due to water discharge mountain and gradually shrink. When the water content of the body fell to 19-20% or so (that is, the point of demolding), the consolidation process is over, this time the body is easy to take the mountain from the model.

Demolding: the process of removing the rough from the model. The mastery of the demolding point is a key. Demolding too early, the billet rest is not strong enough, demolding is difficult, and after demolding the billet is easy to collapse; demolding is too late, the billet will be cracked.

Trimming and bonding: including a trimming, eyeballing and bonding process. The traditional grouting method, after demolding the body of the blank inside and outside the surface are very rough. Generally need to go through several times to repair the blank, and the workload of bonding is also very large. Modern high-strength gypsum mold or resin mold, pressure grouting and other means to repair the sticky workload has been greatly reduced. Trimming, eyeballing and bonding these jobs need to be carried out manually, easy to waste products, must master the water content of the blank.

Drying: pre-drying (also known as semi-dry), that is, the water content of the blank from 15% to 17% (the water content of the bonding) down to about 8%.

In the traditional pouring method, the pre-drying of the blank is done naturally in the grouting shop. In the 16 hours after the workers work, the grouting workshop to maintain a high temperature (33 ~ 40 ℃), high humidity (40% a 60%), so that the blank slowly dry. After pre-drying, the moisture content of the wet billet Hugh from 15% to 17% down to 8% 10%. Be careful to prevent too rapid drying or uneven drying, resulting in waste products.

Modern grouting methods generally use hot air directly on the billet Hugh forced drying, glass porcelain billet pre-drying shrinkage rate of 4%, clay billet pre-drying shrinkage rate of 2%.

Second repair blank (brush): is the last process of grouting forming, will ultimately determine the size of the blank. Brushing the body should be less water content, brush the body with less water, can not have oil. After finishing the brush, the blank is stored in the room at 28-35 ℃, ready for glazing.

2 Grouting operation process

(1) grouting, to wipe off the model of the mud on the strands, into the grout should not be too fast, so that the model of the air with the injection of mud and discharge, to avoid the air mixed into the mud, as well as to avoid making the surface of the blank to produce defects.

(2)When pouring large products, in the corners and other parts of the contraction of the corners, before the injection of grout, can be in the model of the corresponding places in the silk cloth, so that all parts of the speed of moisture movement as much as possible balanced, in order to prevent cracking.

(3) need to be formed on the core of the product, beforehand, sprinkle stone powder on the core to help demolding.

(4) Master the length of time to eat pulp to ensure the thickness of the blank.

(5) before putting pulp should be open air eyes, the speed should not be too fast, so as not to produce negative pressure in the model, so that the blank prematurely out of the model caused by deformation or collapse.

(6) repair adhesion, parts billet should be slightly lower than the main billet moisture content of 2% to 3%.

Ceramic grouting forming mold manufacturing process

1 mold manufacturing process

Sanitary ceramic mold manufacturing is both a complex and detailed work, requiring high skill. In order to make a working mold for grouting, it needs to go through a series of rigorous work. Its general manufacturing process can be divided into the following five steps:

The first step: the production of prototypes prototype dimensions with the finished ceramic sanitary ware. According to the design drawings (or samples) made. If there are physical samples to be imitated, the first step can be omitted.

The second step: the production of the original tire original tire, also known as mold species, its size and sanitary ceramic blank consistent. According to the prototype is made after the size (increase the total shrinkage of the drying and firing process). In some cases can also be directly based on the design drawings or physical samples, made after the release of feet.

The third step: the production of concave tires concave tires, also known as mold species, is made from the original tire turned into.

The fourth step: the production of convex tires convex tires, also known as the mother mold, is made from concave tires. It usually consists of a base mold and a mold surround or a core and a mold surround.

Step 5: make the working mold The working mold, also known as the sub-mold, is made from convex tires for grouting and forming.

2 mold materials and classification

(1) traditional casting of gypsum mold

The manufacturing process: the standard β-type half-water gypsum powder, made of gypsum slurry with water, after mixing, vacuum degassing and other treatments, injected into the mother mold, gypsum hardening, demolding, and then after appropriate trimming, assembling, drying at 50-60 degrees Celsius for 5 ~ 7 days. 7 days to become.

(2) low-pressure fast-draining casting with gypsum mold

with microporous pipe network and without microporous pipe network of two kinds. With microporous pipe network of gypsum molds and the previous difference is: before pouring in the mother mold in the corresponding parts (from the pouring surface of 2 centimeters), into the pipe network through the stereotypes, the interface of these pipe networks, can be connected with the forming line of the vacuum and compressed air pipeline, in order to pour the drainage, demolding and dehydration of the mold.

Materials for the manufacture of microporous pipe network are: microporous glass fiber hose, tube diameter φ = 7.5mm; weaving grid with nylon wire φ = 9.5um: net with resin impregnation solution (from the resin, catalysts, initiators, talc, etc., and other formulations). These netting materials in another specially made auxiliary master mold woven into the pipe network and curing, after removing the mold, for the production of