A bottle is a narrow-necked container made of an impermeable material in various shapes and sizes that stores or transports liquids. The mouth of the bottle can be sealed with an internal stopper, an external bottle cap, or a closure. Bottles are typically manufactured from glass or plastic but can be made of other materials as well. Bottles can be blown, injection, or extrusion molded and may be decorated or colored by the manufacturer. Bottles are also used to store and transport products that require special storage or handling such as pharmaceuticals, cleaning products, and automotive fluids.
Glass bottles are usually shaped with smooth sides, a curved shoulder, and a neck that can be plugged or corked. This design is useful for catching sediment and allows for stacking, which reduces the space needed to store or ship the bottles. Plastic bottles are lighter and more economical than glass ones, and they are also easier to transport because they do not break as easily. In addition, many consumers prefer the taste and appearance of a beverage in a plastic bottle over a glass one.
Plastic bottles are made from a variety of polymers. One of the most common is high-density polyethylene (HDPE). HDPE can be made into a wide range of bottles, including those for carbonated beverages and water. It is available in a range of translucent and opaque colors, including clear and green. It is also resistant to odors and can be sterilized in a steam autoclave. It is one of the most popular plastics for bottling drinks and household chemicals, such as cleaning and laundry detergents.
Another type of bottle is made from low-density polyethylene (LDPE). This plastic is more flexible than HDPE and can be shaped into a wide variety of containers. It can be made with a transparent or opaque color, and it is resistant to odors and some chemicals. LDPE is less expensive than HDPE and is a good choice for bottles for food and cosmetics.
A third kind of plastic bottle is made from polycarbonate. Polycarbonate has excellent strength and optical qualities, making it ideal for bottles that display their contents. It can be produced with a wide range of colors and finishes and is easy to decorate. It is used for baby bottles, beer bottles, and some pharmaceuticals. Polycarbonate can be made with or without bisphenol A (BPA), an ingredient that is believed to be harmful to human health.
Other kinds of plastic bottles include PET and styrene butadiene (SBR). Both are recyclable. PET is made by reacting petroleum hydrocarbons with ethylene glycol and terephthalic acid. This process is called polymerization, and it forms long molecular chains that are the building blocks of PET bottles. It is a popular choice for carbonated beverages, water, and some foods because it can be made to look like glass.
A fourth kind of bottle is made from a renewable resource such as cornstarch or wheat straw. This type of bottle is called a biodegradable or biocompostable plastic and can be recycled with other renewables. It is also more affordable than a PET bottle and can be produced with or without BPA.