![]() ![]() However, as soon as you start playing with it, the putty begins to turn cloudy. Liquid Glass Thinking Putty is so clear that you may think we've sent you an empty canister. Stores electricity very efficiently.Like playing with molten glass. Reflects, bends, transmits, and absorbs light with great accuracy. Withstands intense heat or cold as well as sudden temperature changes. %%Resists%% most industrial and food acids. Gives under stress-up to a breaking point-but rebounds exactly to its original shape.Īffected by few chemicals. Surface %%resists%% scratches and abrasions. ![]() Special tempering can minimize surface flaws. Weakened only by surface imperfections, which give everyday glass its fragile reputation. If one area of a piece of glass is thick (staying hotter longer) and another area is thin (cooling down quickly), and that piece of glass is not properly annealed, the steep temperature gradient between those areas causes stress and the piece will most likely crack apart. Immediately after glasses are formed, they are most often annealed, or slowly and evenly cooled, in order to reduce internal stresses (watch: Annealing and Tension in Glass ). Glass cookware and labware are the most well-known applications of this glass (see: ^^96.4.167^^). Glasses containing a large percentage of lead are known interchangeably as crystal, lead crystal, and lead glass (watch: %%Rummer%% with Raven %%Seal%% - Technique ).īoron aids in the production of borosilicate glass, a glass known for its resistance to thermal shock. When added to glass, lead makes glass brilliant, resonant, and heavy. The following elements help to create special types of glass. There are already tens of thousands of workable glass compositions and new ones are being developed every day. Special Types of GlassĬhemical composition determines what a glass can do. Gold - Colors glass deep red, like rubies (watch: Gold Ruby Goblet ). However, in higher amounts, this element can create purple and, in even higher amounts, glass that appears black. Manganese dioxide - Can decolorize colored glasses. ![]() The color of glass may be changed by adding metallic oxides to the batch (watch: Coloring Glass). An imbalance in the batch due to an excess of alkaline flux or too little stabilizer will cause crizzling, a chemical instability resulting in a fine network of cracks and deterioration of the glass. Broken glass, called cullet, is added to the batch to facilitate the melting process. Batch is heated in a furnace to about 2400˚F. The mixture of dry materials used to form glass is called the batch. Calcium oxide in the form of limestone, a mineral, is a common stabilizer. This is usually soda ash or potash, which was traditionally made from marine plant ashes, or by burning bracken or trees, respectively.ģ) Stabilizer - Keeps the finished glass from dissolving, crumbling, or forming unwanted crystals. Silicon dioxide (contained in sand) is the most common former.Ģ) Flux - Helps formers %%melt%% at lower temperatures. Glasses have the mechanical rigidity of crystals, but the random disordered arrangement of molecules that characterizes liquids.įrom bottles to spacecraft windows, glass products include three materials (watch: Raw Materials of Glass ):ġ) Former - This is the main component of glass, which has to be heated to a very high temperature to become viscous. Each molecule occupies a definite position, in a perfectly ordered three-dimensional lattice. They move about, changing from one disordered state to another.Ĭrystalline state: strong attractive forces hold molecules rigidly in position. Liquid state: molecules are held close by attractive forces, but are not held rigidly in position. No interaction between molecules except for collisions with one another. Gaseous state: individual molecules separated from one another by relatively great distances and moving in a chaotic fashion. Being neither a liquid nor a solid, but sharing the qualities of both, glass is its own state of matter. As the glass cools, the atoms become locked in a disordered state like a liquid before they can form into the perfect %%crystal%% arrangement of a solid. Glass is a rigid material formed by heating a mixture of dry materials to a viscous state, then cooling the ingredients fast enough to prevent a regular crystalline structure. ![]()
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