A glass bottle is a container for holding liquids. Bottles can be made of many materials but glass is particularly suitable because it combines strength and durability with good optical transparency. In addition, glass can be manipulated and refined to a large degree to satisfy specific functional requirements. As a result, bottles have been produced in many shapes and sizes with a wide variety of closures, all of which are designed to seal the contents securely and to prevent leakage. Bottles can be manufactured by various processes but the most common is blow-molding, a method that allows for the production of high volume bottles at low cost. Plastics have also been used for bottles, but glass remains the material of choice in most applications due to its superior properties.
The term “bottle” can refer to any container that contains a beverage or other liquid such as milk, water, juice or alcohol. The bottle can also refer to a container for industrial, pharmaceutical and personal care products. Glass is the primary material used for manufacturing bottles, although metals can also be employed. A wide variety of chemicals are added to glass during its manufacture to give it the desired physical and chemical characteristics. Glass is a complex compound composed of many different elements and compounds including silicates, oxides, hydroxides and halides. Bottle glass is a highly refined version of glass that requires a higher percentage of silicates and oxides to produce than does window glass or sheet glass.
Applied color label (ACL) – A technique of marking, lettering and decorating a bottle by applying mineral or organ pigments with a very low melting point that are baked in a furnace to fuse the colors to the surface of the glass. This process is sometimes also referred to as pyroglazing, pyro, enameling, fire-fused and painted labeling.
Base plate (baffle plate) – A plate that forms part of the blank or parison mold on an automatic and semi-automatic bottle making machine that causes an off-center, incised baffle mark on the bases of some machine-made bottles. This feature is much better illustrated by a picture than by description – see the Bottle Bases page for an example.
Full sized bottle mold – A glass bottle mold that is the exact size and shape of a finished bottle. An inflated gather is placed into the full sized mold and expanded until the outside surface of the gather conforms to the inside surfaces of the bottle body, shoulder and heel or neck/finish areas. A full sized mold usually forms most or all of the bottles base, body, shoulder and sometimes neck/finish. A full sized mold can also be referred to as a “full rim” or a “standard bottle” (Tooley 1953).
Lehr – A kiln or furnace where newly blown bottles were gradually reheated and cooled to enhance their strength and reduce cooling breakage. A lehr was often tended by a person who was known as a lear tender.