Fire polishing, also known as flame polishing, is a method of

polishing Polishing is the process of creating a smooth and shiny surface by rubbing it or by applying a chemical treatment, leaving a clean surface with a significant specular reflection (still limited by the index of refraction of the material accordin ...

a material, usually

glass Glass is a non- crystalline, often transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling (quenchin ...

thermoplastic A thermoplastic, or thermosoft plastic, is any plastic polymer material that becomes pliable or moldable at a certain elevated temperature and solidifies upon cooling. Most thermoplastics have a high molecular weight. The polymer chains associate ...

s, by exposing it to a

flame A flame (from Latin '' flamma'') is the visible, gaseous part of a fire. It is caused by a highly exothermic chemical reaction taking place in a thin zone. When flames are hot enough to have ionized gaseous components of sufficient density the ...

or heat. When the surface of the material briefly melts,

surface tension Surface tension is the tendency of liquid surfaces at rest to shrink into the minimum surface area possible. Surface tension is what allows objects with a higher density than water such as razor blades and insects (e.g. water striders) t ...

smooths the surface. Operator skill is critical with this method. When done properly, flame plastic polishing produces the clearest finish, especially when polishing

acrylic Acrylic may refer to: Chemicals and materials * Acrylic acid, the simplest acrylic compound * Acrylate polymer, a group of polymers (plastics) noted for transparency and elasticity * Acrylic resin, a group of related thermoplastic or thermosett ...

. This method is most applicable to flat external surfaces. Flame polishing is frequently used in acrylic plastic fabrication because of its high speed compared to abrasive methods. In this application, an

oxyhydrogen torch Oxyhydrogen is a mixture of hydrogen (H2) and oxygen (O2) gases. This gaseous mixture is used for torches to process refractory materials and was the first gaseous mixture used for welding. Theoretically, a ratio of 2:1 hydrogen:oxygen is enough ...

is typically used, one reason being that the flame chemistry is unlikely to contaminate the plastic. Flame polishing is essential to creation of the glass pipettes used for the

patch clamp The patch clamp technique is a laboratory technique in electrophysiology used to study ionic currents in individual isolated living cells, tissue sections, or patches of cell membrane. The technique is especially useful in the study of excitabl ...

technique of

voltage clamp The voltage clamp is an experimental method used by electrophysiologists to measure the ion currents through the membranes of excitable cells, such as neurons, while holding the membrane voltage at a set level. A basic voltage clamp will itera ...

ing.

Equipment

Various machines and torches/

gas burner A gas burner is a device that produces a controlled flame by mixing a fuel gas such as acetylene, natural gas, or propane with an oxidizer such as the ambient air or supplied oxygen, and allowing for ignition and combustion. The flame is ge ...

s are used in the flame polishing process. Depending on the heating requirements for an intended application, different kinds of gases are used including but not limited to: natural gas, propane and oxygen, oxygen and hydrogen. A specially designed machine called the hydro flame is commonly used in flame polishing. The hydro flame is a gas-powered generator that uses distilled water and electricity to create oxygen and hydrogen for its flame. The size, shape, and chemistry of the flames used in fire polishing can vary widely based on the type and shape of the material being polished.

References

Glass production Plastics industry {{Industry-stub

Equipment

See also

References