Examine individual changes

'{{Refimprove|date=September 2011}} {{double image|right|5450801 m-1-.jpg|160|EatonsShoppingBag1997.JPG|160|<center>Examples of paper bags</center>}} A '''paper bag''' or '''paper sack''' is a preformed container made of [[paper]], usually with an opening on one side. It can be one layer of paper or multiple layers of paper and other flexible materials. A bag is used for [[packaging]] and/or carrying items. ==Single layer== [[File:Two paper bags.jpg|left|thumb|200px|Two small paper bags. Bottom: flat gusseted bag. Top: Square bottom, self-opening.]] Paper [[shopping bag]]s, brown paper bag, grocery bags, paper bread bag and other light duty bags have a single layer of paper. A variety of constructions and designs are available. Many are printed with the names of stores and brands. Paper bags are not water proof. Types of paper bag are: laminated, twisted, flat tap. The laminated bag, whilst not being totally waterproof has a [[Lamination|laminate]] that protects the outside to some degree. ==Multiwall paper sacks== <!-- Deleted image removed: [[File:Charcoal bag.jpg|thumb|left|200px|A multiwall open mouth paper sack of charcoal briquettes]] --> [[File:Portland Cement Bags.jpg|thumb|right|200px|Valve bag containing cement]] Multiwall (or multi-wall) paper sacks or shipping sacks, are often used as [[shipping container]]s for bulk materials as fertilizer, animal feed, sand, dry chemicals, flour and cement. Many have several layers of [[sack paper]]s, printed external layer and inner plies. Some paper sacks have [[polyethyelene]] foil or polyethylene [[coated paper]] layer in between as water-repellant barrier. There are two basic design of bags: open mouth bags and valve bags. Open mouth bag is a tube of paper plies with only one bottom end sealed by the paper sack producer. The bag is filled though the open mouth and then closed by stitching, adhesive, or tape. Valve sacks have both bottom ends closed and are filled through a valve. A typical example of valve bag is the cement sacks. ==Recycling== Paper bags are readily recyclable. Plastic or water-resistant coatings or layers make recycling more difficult.{{Citation needed|date=June 2011}} ==History== [[Margaret E. Knight]] (1838-1914) was an employee in a paper bag factory when she invented a new machine part to make square bottoms for paper bags. Knight can be considered the mother of the grocery bag, she founded the Eastern Paper Bag Company in 1870. On 20 February, 1872, Luther Crowell also patented a machine that manufactured paper bags.<ref>{{cite book | last= Petroski | first = Henry | title = Small things considered | publisher = Vintage | year = 2004 | location = New York | isbn = 1-4000-3293-8 | page = 106}}</ref> ==See also== *[[Bag]] <!--- Do not change the link in any other way, unless the actual title contains "(disambiguation)" in it ---> *[[Sack paper]] ==References== {{reflist}} ===Books=== * Yam, K. L., "Encyclopedia of Packaging Technology", John Wiley & Sons, 2009, ISBN 978-0-470-08704-6 ==External links== * [http://www.pssma.org/ Paper Shipping Sack Manufacturers Association] {{packaging}} {{bags}} [[Category:Bags]] [[Category:Paper products]] [[Category:Domestic implements]] [[ar:كيس ورق]] [[gn:Vosa]] [[br:Sac'h paper]] [[ca:Bossa de paper]] [[de:Tüte]] [[et:Paberkott]] [[es:Bolsa de papel]] [[fr:Sac en papier]] [[ko:가방]] [[hi:थैला]] [[id:Tas]] [[it:Borsa (oggetto)]] [[he:תיק]] [[lt:Rankinė]] [[nl:Tas (voorwerp)]] [[ja:鞄]] [[nrm:Pouque]] [[pl:Torba (worek)]] [[qu:Wayaqa]] [[ru:Бумажный пакет]] [[simple:Bag]] [[sr:Кеса]] [[fi:Laukku]] [[sv:Väska]] [[te:సంచి]] [[vec:Sporta]] [[yi:זעקל]]'