What Is Porcelain?
The word porcelain is believed to derive from the Latin word “Porcella”, which means mussel. Porcelain was introduced to Europe primarily by Portuguese merchants, including Marco Polo, who discovered numerous sea routes.
Made up solely of natural raw materials which give it its white color, rather than dyes that preserve whiteness, porcelain is described as a translucent sanitary product that is hardened by firing at around 1,400 Degrees Celsius.
One can define two types of porcelain produced for use in households and hotels. Porcelain for use in households includes products that are translucent when facing daylight, while those produced for use in hotels are thicker in accordance with world standards. When exposed to light, they are seen to be translucent. Today, restaurants first heat the plates before serving the dishes so that they stay hot. If the plate is thick, heat will be preserved for longer, adding to the joy of eating.
Porcelain is divided into two categories, namely soft-paste and hard-paste porcelain, according to its raw materials and the firing temperature required. The most important feature of hard-paste porcelain is the feldspar glaze that is formed at high temperatures such as 1,400 C, and the high amount of kaolinite it contains, which provides surface rigidity and durability on the glaze. The kaolinite ratio of soft-paste porcelain is low, and the glaze formation temperature is also lower. That’s why it is mechanically softer with lower impact resistance compared to hard-paste porcelain.
Why do we Use Porcelain?
Porcelain is used
because it is associated with health and hygiene.
Porcelain does not absorb taste or smell.
Thanks to its hardened structure, it does not host microbes.
Any stains can be removed easily.
It has a hard surface.
It can be washed easily.
It is delicate and visually appealing.
Your dishes become more enjoyable with it.
It preserves the heat of your dishes for longer.
Differences between Porcelain and Ceramics
Both the raw materials and production methods are different for porcelain and ceramics. Such differences are reflected to the product features. Ceramic products are porous, since their firing temperatures are lower than porcelain products. Therefore, crazes are formed on ceramic products in extended use due to water absorption. Moreover, craze cracks may occur upon a hard impact due to lower firing temperatures.
Another difference is that ceramic products do not transmit light, while porcelain products are translucent.
Steps to Consider when using Porcelain
It is not harmful to heat porcelain products in ovens or microwave ovens. However, direct contact with bare flame has a shock effect on the porcelain, causing it to break into pieces. Therefore, they should never be placed upon naked flame.
Porcelains can also be stored safely in deep freezers. However, if porcelain is put in the oven right after storing in a deep freezer, it will break into pieces due to the sudden change of temperature. Therefore, it should be exposed to that temperature only after reaching room temperature.
If you use your porcelain products in an area with lime water, this may lead to white stains over time. However, these can be removed with vinegar.
Metal forks and knives may leave marks on porcelain surfaces. The formation of such marks is normal and not harmful. Porcelain glazes are harder than the stainless metal of forks and knives due to the rigidity achieved through firing at high temperatures, which causes metal erosion and formation of black marks. Specially-formulated non-erosive soft cleaners can be used to remove such unwanted marks.
Borax (porcelain bleaching powder) or bleaching powder can be used for tea and coffee stains.
Things to Consider When You Wash Porcelain
If you handwash your porcelain;
Your washing bowl must not be copper or aluminum.
Avoid putting your porcelains together with non-porcelain objects such as frying pan, saucepan, forks or knives.
Avoid rubbing with hard cleaning substances or wire wool, as well as the use of liquid or creamy cleaning substances for cleaning, and make sure to rinse with a generous amount of water and dry.
Avoid placing too many plates and cups on top of or nested with one another during storage of the dried porcelain in closets. Use of a thin paper between the plates placed on top of one another is recommended. Failure to do so might result in damage to the glaze and golden decorations due to the rigidity of the unglazed bottom side of the plate.
If you wash your porcelains in a dishwasher;
You are recommended to handwash your porcelains if they are decorated with gold. As it is known, gold is precious and delicate due to its nature. Therefore, you must use it with extreme care.
If your porcelains have a glaze or under-glaze decoration, please rest assured that the decorations will never be removed upon dishwashing.
The porcelains must be washed at a warm washing program that does not exceed 60 C degrees.
The detergent used must be tested for glass and over-glaze decoration. Furthermore, it should not contain excessive amounts of alkaline.
Make sure to avoid the use of anti-limescale detergents. Otherwise, whitish layers of lime will form on the porcelains. Caution is warranted especially in the areas where the water contains a high percentage of lime.
Detergents and other rinsing substances must be used at the recommended quantity.
The machine must not undergo any shaking.
The water pressure in the machine should not be too high to cause motion in porcelain and glassware.
Porcelains must be placed with care by observing the placement order in the machine.
It would be better to wash the objects before the leftovers are dried. This is because leftovers might require longer and more careful cleaning, which might cause damage to the decorations.
Which Raw Materials Are Used In Porcelain?
Porcelains are made up of 50% kaolinite; 25% quartz; and 25% feldspar materials.
Kaolinite is the raw material which makes it easier to mould the porcelain paste, giving it its peculiar shape and color. Quartz is the raw material for the skeleton formation, and ensures that the porcelain paste is resistant to hard, vitreous and chemical effects and heat through a significant amount of dissolution in feldspar, which forms the vitreous phase.
As suggested by its name, under-glaze decoration is a method which first involves embossing and firing at 1,400 C through glazing, with limited color applications. It is the most difficult and expensive decoration option due to the embossing technique. It is generally used in ornaments and seldom on tableware. The two basic colors that can be safely used for this application are blue (cobalt compounds) and green (chrome compounds).
Fired at 1,200 C, glaze decoration is a costly decoration technique due to firing challenges. It has more color options than the under-glaze decoration technique. Porcelain decorations utilizing this method are impossible to remove under any circumstances. This is because the decoration is infused into the glaze, since it is fired at an extreme temperature. Products decorated with this technique are no different from under-glaze decorations in terms of protection against external impact.
This is the most common technique, applied at a temperature range of 750 C to 850 C. Decorations produced with gold or dyes suitable for such temperatures are applied upon the glaze of the product. The color range is wider than the other techniques.
How do Under-Glaze and Glaze Decorations Differ from Over-Glaze Decorations?
Both the decorated areas and non-decorated areas reflect light in under-glaze and glaze decorations due to full coverage on the glaze-decorated. When it comes to over-glaze decorations, the decorated areas do not reflect light. Moreover, the difference can be sensed by touch. A rough non-slip surface is felt upon touching over-glaze decorations, whereas under-glaze and glaze decorations have a slippery and smooth surface.