Paper bag
A paper bag is a bag made of paper, usually kraft paper. Paper bags can be made either with virgin or recycled fibres to meet customers' demands. Paper bags are commonly used as shopping carrier bags and for packaging of some consumer goods. They carry a wide range of products from groceries, glass bottles, clothing, books, toiletries, electronics and various other goods and can also function as means of transport in day-to-day activities.
Paper bags were first mass produced in 1852 following their invention by Pennsylvania schoolteacher Francis Wolle. Wolle and his brother obtained a patent for the machine that made the bags and soon after founded the Union Paper Bag Company. Square-bottomed bags were soon made afterwards by the English papermaker James Baldwin, who designed an apparatus to made the flat-bottomed bags. Further developments in the size, design, and ease of use for paper bags occurred throughout the 19th century, though bags with carrying handles were only popularized in the 1910s. Plastic bags were introduced in the 1970s and over time replaced paper bags in many stores, though a trend towards lightweight plastic bag bans would cause paper bags to be re-introduced in many places.
Though they take many shapes and can be made from different materials, the paper bag is most often made with a single layer of paper protecting its contents from the outside environment. Bags used in different applications, such as packaging for food, fertilizer, or other dry materials like cement are subject to different quality standards and safety requirements and may be multi-walled or otherwise reinforced. A bag will often indicate its carrying capacity in weight or volume based on performance tests. Some paper bags may be laminated, often with polyethylene, to offer a greater level of protection from moisture and bacteria. As most paper bags are made from fibres extracted from wood, they biodegrade readily and do not have the same ecological footprint as plastic bags.
The term "brown bag" often refers to two specific uses of a paper bag: carrying food prepared at home as a packed lunch, and concealing the label of an alcoholic beverage while in a public area. The former use is often associated with schoolchildren and the working class in the United States, while the latter has been the subject of legislation.
History
The first machine to mass produce paper bags was invented in 1852 by Francis Wolle, a Pennsylvania schoolteacher. Wolle and his brother patented the machine and founded the Union Paper Bag Company.In 1853, James Baldwin, papermaker of Birmingham and Kings Norton in England, was granted a patent for apparatus to make square-bottomed paper bags. Thereafter he used an image of a flat-bottomed bag as his business logo.
In 1871, inventor Margaret E. Knight designed a machine that could create flat-bottomed paper bags, which could carry more than the previous envelope-style design.
In 1883, Charles Stilwell patented a machine that made square-bottom paper bags with pleated sides, making them easier to fold and store. This style of bag came to be known as the S.O.S., or "Self-Opening Sack".
In 1912, Walter Deubener, a grocer in Saint Paul, Minnesota, used cord to reinforce paper bags and add carrying handles. These "Deubener Shopping Bags" could carry up to 75 pounds at a time, and became quite popular, selling over a million bags a year by 1915. Paper bags with handles later became the standard for department stores, and were often printed with the store's logo or brand colors.
Plastic bags were introduced in the 1970s, and thanks to their lower cost, eventually replaced paper bags as the bag of choice for grocery stores. With the trend towards phasing out lightweight plastic bags, though, some grocers and shoppers have switched back to paper bags.
In 2015, the world's largest paper shopping bag was made in the UK by Paper Bag Co and recorded by Guinness World Records. Also in 2015: The European Union adopted directive 2015/720, that requires a reduction in the consumption of single use plastic bags per person to 90 by 2019 and to 40 by 2025.
In 2018, the “European Paper Bag Day” was established by the platform The Paper Bag, an association of the leading European kraft paper manufacturers and producers of paper bags. The annual action day takes place on 18 October and aims to raise awareness among consumers about paper carrier bags as a sustainable packaging solution. It was launched to encourage more people to act responsibly and use, reuse and recycle paper bags. With different activities on local level, the association wants to open a dialogue with consumers and give them revealing insights about paper packaging.
In April 2019, the European Union adopted Directive 2019/904 of the European Parliament and of the Council of 5 June 2019 on the reduction of the impact of certain plastic products on the environment.
Paper sack
A paper sack is a type of paper bag that can be constructed of one or several layers of high quality kraft paper, usually produced from virgin fibre. Paper sacks can also be referred to as industrial paper bags, industrial paper sacks, shipping sacks or multi-wall paper bags or sacks. They are often used for packaging and transporting dry powdery and granulated materials such as fertilizer, animal feed, sand, dry chemicals, flour and cement. Many have several layers of sack papers, printed external layer and inner plies. Some paper sacks have a plastic film, foil, or polyethylene coated paper layer in between as a water-repellant, insect resistant, or rodent barrier.Multi-wall paper sacks are designed to provide strong product protection, with high elasticity and high tear resistance, for products with high demands for safety and durability. Information such as instructions, logos or trademarks can be printed on the resistant outer surface. Plastic films or different dispersions are sometimes used as inner layers or coatings to provide a barrier against moisture, water vapour, grease, oxygen, odours and bacteria. Paper sacks are produced on paper sack converting machines consisting of tuber and a bottomer.
There are two basic designs of bags: open-mouth bags and valve bags. An open-mouth bag is a tube of paper plies with the bottom end sealed. The bag is filled through the open mouth and then closed by stitching, adhesive, or tape. Valve sacks have both ends closed and are filled through a valve. A typical example of a valve bag is the cement sack.
Properties
Paper sacks are usually made of Kraft paper, which has the advantage of being soft and strong at the same time. The stretch or elongation increases the energy required to break the material. They can carry and protect products up to 50 kg, and adapt easily to the nature of their contents and to handling constraints. Depending on the product, the weight ratio of a paper sack to its contents can be up to 1:250. The strength is due to the arrangement of the fresh fibres used in kraft paper production. The bonding together of the fibres during production improves not only the strength, porosity and elasticity, but also the tear-resistance.One of the natural and unique characteristics of sack kraft paper is its porosity. Acting as a filter material, high-porosity paper enables the air used in the filling process for dry powdery goods to escape very quickly, without the need for air extraction systems. This makes it possible to achieve filling speeds of up to 3.5 sec for a 25 kg sack.
Thanks to different paper sack constructions with glue, barrier, layer or surface concepts, paper sacks can also be moisture resistant. All moisture-proof sacks are compatible with regular paper sack filling machines. In especially adverse weather conditions, an extremely thin bioplastic, plastic or other adequate barrier film can be part of the surface layer in the paper sack construction for particularly effective protection.
Added barrier film liners can also extend the shelf life in a range of different conditions. There are many different sack constructions especially designed to offer a good shelf life when paper sacks are exposed to extreme conditions such as damp, moisture, light, oxygen or carbon dioxide. Also, the correct storage and handling of paper sacks along the supply chain extends their shelf life.
Paper sacks also provide a medium for promotional messages and sophisticated printing designs. Due to their natural, non-slippery texture and their construction, paper sacks can safely be handled, stacked, palletized and stored. User-friendly opening systems, such as a tear-open flap, allow quick and clean access to the contents without the use of tools such as knives.
Construction
Standard brown paper bags are made from kraft paper. Tote-style paper carrier bags, such as those often used by department stores or as gift bags, can be made from any kind of paper, and come in any color. There are two different styles of handles for paper carrier bags: flat handles and cord handles. Paper carrier bags made from virgin kraft paper are developed especially for demanding packaging. Paper bags can be made from recycled paper, with some local laws requiring bags to have a minimum percentage of post-consumer recycled content.Paper bags can be made to withstand more pressure or weight than plastic bags do.