Bag A bag, also known regionally as a sack, is a common tool in the form of a floppy container, typically made of cloth, leather, bamboo, paper, or plastic. The use of bags predates recorded history, with the earliest bags being lengths of animal s ...

s or sacks for

flour Flour is a powder made by Mill (grinding), grinding raw grains, List of root vegetables, roots, beans, Nut (fruit), nuts, or seeds. Flours are used to make many different foods. Cereal flour, particularly wheat flour, is the main ingredie ...

range in size and

material A material is a matter, substance or mixture of substances that constitutes an Physical object, object. Materials can be pure or impure, living or non-living matter. Materials can be classified on the basis of their physical property, physical ...

, from large bulk bags, in

cotton Cotton (), first recorded in ancient India, is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus '' Gossypium'' in the mallow family Malvaceae. The fiber is almost pure ...

or woven

polypropylene Polypropylene (PP), also known as polypropene, is a thermoplastic polymer used in a wide variety of applications. It is produced via chain-growth polymerization from the monomer Propene, propylene. Polypropylene belongs to the group of polyolefin ...

, to smaller consumer packaging, often made of

paper Paper is a thin sheet material produced by mechanically or chemically processing cellulose fibres derived from wood, Textile, rags, poaceae, grasses, Feces#Other uses, herbivore dung, or other vegetable sources in water. Once the water is dra ...

Package types

Bulk packaging

Flour is often shipped from the miller to bakeries, institutions, and other bulk uses. Sizes range from 10 kg to 100 kg. One traditional construction was cheap

bags. These printed cotton bags were sometimes viewed as

collectable A collectable (collectible or collector's item) is any Physical object, object regarded as being of value or interest to a collecting, collector. Collectable items are not necessarily monetarily valuable or uncommon. There are numerous types ...

s; other times the flour sack fabric was repurposed into a variety of household items. Current practices are to use multi-wall paper sacks. Some include a layer of

plastic film Plastic film is a thin continuous polymeric material. Thicker plastic material is often called a "sheet". These thin plastic membranes are used to separate areas or volumes, to hold items, to act as barriers, or as printable surfaces. Plast ...

for barrier properties and insect control. Woven polypropylene bags are also used for high strength; at least one variety ( Purdue Improved Crop Storage bags) also includes inner plastic bags.

Consumer packaging

Consumer packages are often bags or sacks constructed of paper.

Plastic film Plastic film is a thin continuous polymeric material. Thicker plastic material is often called a "sheet". These thin plastic membranes are used to separate areas or volumes, to hold items, to act as barriers, or as printable surfaces. Plast ...

s are also used, sometimes with reclosable features.

Stand-up pouch A stand-up pouch or doypack is a type of flexible Packaging and labeling, packaging that is able to stand erect on its bottom for display, storage, and convenience. It has characteristics of Plastic bag, plastic bags, Water bottle, water bottles ...

es of flour have recently been introduced.

Considerations

A wide variety of

wheat flour Wheat flour is a powder made from the grinding of common wheat used for human consumption. Wheat varieties are called "soft" or "weak" if gluten content is low, and are called "hard" or "strong" if they have high gluten content. Hard flour, or ...

are available. Flour can also be made from other grains, roots, nuts, etc. Packaging engineers and

food scientist Food science (or bromatology) is the basic science and applied science of food; its scope starts at overlap with agricultural science and nutritional science and leads through the scientific aspects of food safety and food processing, informing ...

s need to understand the properties of the particular flour, intended handling and logistics systems, and desired

shelf life Shelf life is the length of time that a commodity may be stored without becoming unfit for use, consumption, or sale. In other words, it might refer to whether a commodity should no longer be on a pantry shelf (unfit for use), or no longer on a s ...

. Package forms and materials can be matched to these needs.

Insects

Insects can be a problem. When available, a suitable

insecticide Insecticides are pesticides used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. The major use of insecticides is in agriculture, but they are also used in home and garden settings, i ...

can be used; care must be used to ensure product safety. Hermetic plastic bags also help. When insect infestation is noted, one method of stopping further growth is to freeze the sacks of flour for several days.

Cultural impact

* Flour sack fabric has been used as a cheap source of fabrics for consumers to create their own textiles. * Printed cotton bags were sometimes viewed as

s. * Various place names were named after flour sacks, since they were so ubiquitous in so many cultures.

Blatobulgium Blatobulgium was a Roman fort, located at the modern-day site known as Birrens, in Dumfriesshire, Scotland. It protected the main western road to Scotland. It was one of the "outpost forts" outside the Roman Empire when the frontier was on H ...

in Scotland, and Pieniężno in Poland, for example, are possibly named after words for ''flour sack'' in different languages. The all-white tower in the old city of

Ravensburg Ravensburg ( or ; Swabian: ''Raveschburg'') is a city in Upper Swabia in Southern Germany, capital of the district of Ravensburg, Baden-Württemberg. Ravensburg was first mentioned in 1088. In the Middle Ages, it was an Imperial Free City and ...

in Germany is called ''Mehlsack''. * Reuel Colt Gridley famously carried a 50-pound bag of flour on his shoulder after losing a political bet in Austin, Nevada. The sack of flour was later auctioned off, then re-donated, then re-auctioned again and again to raise money for the

United States Sanitary Commission The United States Sanitary Commission (USSC) was a private Aid agency, relief agency created by federal legislation on June 18, 1861, to support sick and wounded soldiers of the United States Army (Federal / Northern / Union Army) during the Ameri ...

during the American Civil War. Auctioning this single flour sack eventually raised more than $250,000.Lea, Ralph & Kennedy, Christi (1 October 2005)
Reuel Gridley and a sack of flour
, '' Lodi News-Sentinel''

References

{{Packaging Bags

Sack A sack usually refers to a rectangular-shaped bag. Sack may also refer to: Bags * Flour sack * Gunny sack * Hacky sack, sport * Money sack * Paper sack * Sleeping bag * Stuff sack * Knapsack Other uses * Bed, a slang term * Sack (band), ...