Saturday, January 19, 2008

Food packaging

Food packaging is the enclosing of food that requires protection from tampering, whether by physical, chemicals, or biological needs. It also shows the product that is labeled to show any nutrition information on the food being consumed.

Types and weight


Paper is often characterized by weight. The weight assigned to a paper is the weight of a ream (500 sheets) of varying "basic sizes", before the paper is cut into the size it is sold to end customers. For example, a ream of 20 lb, 8½ x 11" paper weighs 5 pounds, because it has been cut from a larger sheet into four pieces. [8] In the United States, printing paper is generally 20 lb, 24 lb, or 32 lb at most. Cover stock is generally 68 lb, and 110 lb or more is considered card stock.

Paper


Paper is thin material mainly used for writing upon, printing upon or packaging. It is produced by the amalgamation of fibers, typically vegetable fibers composed of cellulose, which are subsequently held together by hydrogen bonding. While the fibers are usually natural in origin, a wide variety of synthetic fibers, such as polypropylene and polyethylene, may be incorporated into paper as a way of imparting desirable physical properties. The most common source of these kinds of fibers is wood pulp from