A bottle is a narrow-necked container in various shapes and sizes that stores and transports liquids. It may be sealed with an internal stopper or external closure and is usually molded from impermeable material.
Bottles are manufactured in a number of different ways and from a wide variety of raw materials, including glass and plastics. Plastics go through a manufacturing process to end up as bottles for liquid substances like milk, soda, motor oil and shampoo and containers for dry products such as medications and nutritional supplements.
The most common material for modern plastic bottles is high-density polyethylene (HDPE), which is derived from petroleum, a naturally occurring liquid found in geological formations beneath the Earth’s surface. This material is used because it is economical, durable, resistant to many solvents and provides an efficient moisture barrier. It is also environmentally friendly, recyclable and non-toxic.
Most plastic bottles are produced through blow molding, a process that utilizes a high-pressure air stream to shape the liquid resin into a hollow container. A wide variety of bottles can be made this way, from single-serve beverage containers to large industrial jugs. Bottles can also be decorated with raised lettering, designs and graphics using a technique called embossing. This consists of carving or engraving the inner surfaces of the mold before blowing the liquid into it. Bottles can also be produced from a wide variety of glass materials, and are often sealed with either an internal or external stopper or closure.
The neck of a bottle is the portion that extends from the shoulder to the finish. The neck is shaped to accommodate a specific bottle cap size and can be textured or etched to enhance the appearance of the product it contains. It is also referred to as the “heel” because it is the transition point between the vertical tangency of the body and the base of the neck. The top of the neck is a sealing surface and may be threaded for use with screw-type closures. Bottles can also be made with an elliptical neck that is easier to grip for pouring or carrying.