Additional Craft Information:
Ceramics are part of our everyday lives. There are hundreds of instances where you might've have come across ceramics without ever knowing about them. To give a bit of perspective, let's list all those 'ceramic' things that you might encounter on an average day. Contact lenses, Microwave ovens, dinnerware, knives, porcelain and even our phones as well as computers would be non-existent if not for ceramics.
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DIY Craft Essential #2: Needle nose pliers
But exactly how is a piece of molten clay converted into something that is used to heat our food and then also help us serve it. The traditional process of manufacturing precision ceramics goes through a sequence of processing steps and culminates with one of the many forming steps. The journey of precision ceramics start with a crystalline or a non-crystalline inorganic compound. This compound is then subjected to a varying degree of heat and pressure, And with each of the aforementioned steps, this molten 'clay' starts taking the form of a ceramic product.
The ceramics manufacturing process is broadly divided into two parts – Forming and Sintering. In the first stage, the raw materials go through several processes with the aim of producing a 'green body'. These processes involve batching, mixing, drying, and firing. After the 'green mixture' is achieved, a binder is mixed with to enhance the flow properties of the powder, leading to higher density in the final component. This is where the ceramic mixture is shaped according to the application of the final product which renders the ceramic its characteristic precision. This combination is then dried to extract excess water or binder. The most common method of drying is known as spray drying.
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DIY Craft Essential #4: Spray paint
In Spray drying, the ceramic mixture is pumped to an atomizer which consists of a rapidly rotating disk or nozzle. A rising hot air column then heats this slurry forming small, free flowing granules that result in a powder suitable for forming. The process of drying varies according to the final product that is to be manufactured. Apart from spray dryers, tunnel dryers and periodic dryers are also used. Another method, impulse drying, uses pulses of hot air flowing in the transverse direction instead of continuously in the material flow direction.
The next step involves glazing this dried off mixture. This step is essential for ceramic products that need to be shiny in their final form such as ceramic tiles, fluorescent tubes. Glazing involves spraying a wet (or in some cases dry) particles that render the dried-off ceramic mixture a bright sheen.
Now the sintering process is done in which the mixture is heated at a temperature that is below the melting point of the ceramic. Once a roughly-held-together object called a “green body” is made, the ceramic mixture is ready to be fired into the kiln for the final step of the manufacturing process. The process of sintering introduces various significant changes in the primary micro-structural features of the final product.
Depending upon the desired ceramic product, various refinements can be done to the sintering process such as using organic binders such as Polyvinyl Alcohol; or introducing organic lubricants; or pressing the green body to give the densification a head start and reduce the sintering time needed.
After the sintering is done. The final ceramic product is ready to be packaged and shipped.