Printing and Writing Paper
Paper as a medium of communication originated in China around 105 AD and was made from vegetable fibers. The Spanish learned how to make paper around 1150 AD, marking the first paper industry in Europe. The first paper mill in England was created by John Tate in 1490 and shortly following, Johannes Gutenberg invented the printing press. Philadelphia is the home of the first paper mill in the U.S., the Rittenhouse Paper Mill started operations around 1690. Paper from that mill was primarily used for writing and the creation of books.
Today, paper mills produce printing and writing paper products that are found in homes, schools, offices and government agencies, and are part of our everyday lives. The uses for printing and writing paper have evolved over time to meet changing and emerging needs but it remains a function of communication, information, and business transactions in contemporary society. Printing and writing paper has a unique role in everyday life that adds value and creates a connection in ways other forms of communication cannot. From 105 AD, to today and to the future, paper play an important role in society.
What is Printing and Writing Paper
Printing and writing paper refers to a variety of paper types ranging from everyday items such as newspapers, greeting cards and books to specialty items such as special occasion invitations, diplomas and social security cards.
In the United States, printing and writing paper is primarily divided into four major categories: uncoated free sheet, uncoated mechanical, coated free sheet and coated mechanical. The grades differ from one another based on how they are manufactured and their unique properties.
What Kinds of Products are Made from Printing and Writing Paper?
The different grades of printing and writing paper reflect the technical needs of varying products and how they will be used. Products that require greater material strength and long life may use free sheet paper whereas short-lived products that demand less strength may include mechanical paper.
- Uncoated free sheet paper: Uncoated free sheet paper constitutes the largest category of printing-writing paper. It is made using a chemical pulping process to improve the appearance and/or the printing surface. This grade of paper is commonly used for office reprographics (copy paper), books, envelope paper and business form paper. In order to be considered free sheet paper, it must contain 10 percent or less mechanical fiber.
- Uncoated mechanical paper: Uncoated mechanical paper is made of pulp that is produced through mechanical processes. It is materially weaker than and exists as a quality alternative to free sheet paper. Products using uncoated mechanical paper commonly include newsprint, newspaper inserts, directories and paperback books.
- Coated free sheet paper: Coated free sheet paper is produced using a chemical pulping process and contains additives such as clay to improve its quality and printing surface. Examples of products that use this grade of paper are highly illustrated books, high quality posters, magazines and advertising pieces such as catalogs.
- Coated mechanical paper: Coated mechanical paper is created using a mechanical pulping process and contains additives to improve its appearance and printing surface. Products that use this grade of paper include magazines, catalogs and coupons.
Why use Printing and Writing Paper?
Printing and writing papers serve many societal needs across the globe. It supports the needs of business, charity, education and government among a litany of other enterprises. Paper is reliable and secure, practical and sustainable.
Reliability and Security
It’s no coincidence that legal documents such as social security cards and birth certificates are still issued in paper form. Paper offers a level of reliability and security that is unmatched. With paper, security breaches and online hacking are not a concern. There is a level of control over documents, including where sensitive information is stored.
Paper is practical. Paper is essential in everyday life, from households to large corporations. Whether it’s a grocery list before running out the door or negotiating business deals, paper serves as a quick and convenient resource.
Paper is renewable, recyclable and sustainable. Paper is made from a renewable resource – trees that are replanted to ensure a sustainable supply. Paper is also made from recycled paper. It can be recycled and reused, reducing waste in landfills.
The paper industry is also one of the lowest emitters of greenhouse gas emissions as compared to other major industrial industries.
How is Printing and Writing Paper Made?
The first step in the process is to make pulp. Pulp can be made from either virgin fiber, typically from wood, or from paper products recovered for recycling.
Depending on what paper grade is being produced, pulp is produced in one of two ways. Mechanical pulp is obtained by mechanically grinding the fibers under a stream of water, while chemical pulp is obtained by cooking the fibers with various chemicals in high temperatures. Chemical pulp is used to produce higher quality, stronger and bright white materials as the pulp fibers produced are strong and long. Mechanical pulp is lower cost, has high bulk, stiffness, opacity and softness. Mechanical pulp fibers have lower strength and brightness, so it is often used for newsprint.
In the chemical process, wood chips (virgin fiber) are cooked using in essentially a pressure cooker known as a digester. The wood fiber is separated into cellulose fibers, lignin (the wood glue that holds the tree together) and other substances such as sugars. Cellulose is an essential building block in the cell walls of trees and plants, helping to make them strong. The pulp is then washed to clean it and separate it further from the other tree components. After the pulp is washed, it is screened for further cleaning.
In the mechanical process, logs or wood chips are ground through force against a revolving stone, which grinds them into a pulp. The stone is sprayed with a stream of water to remove fibers from the pulp stone and to prevent fiber damage.
Screening the pulp removes oversized and unwanted chunks or pieces from the slurry, leaving the best fibers for paper products. The cleaning process further removes any unwanted particles and debris like any dirt or dust.
The pulp then goes through a series of rollers where the water is squeezed and evaporated out, helping to dry out the pulp. Though lignin is removed during the washing process, some lignin remains together with the fiber and at this stage it has a natural brown color. At this stage, the pulp is bleached, further separating the cellulose fibers from the lignin, increasing fiber strength while creating a bright white color.
After the pulp is bleached, it needs to be formed into a sheet by the paper machine. At the wet end of the paper machine, the pulp flows onto a moving endless belt with a screen to filter out water and form a web. Further down the line, in the press section, the pulp, which looks like a white sheet, goes through several presses to further remove excess water. At this point the web of material still must shed water, so it passes into a dryer.
However, before drying, sometimes additives such as coatings or surface treatments are applied. The coatings and additives may impact the weight, gloss, smoothness and ink absorbency.
The dryer is a large cylinder and uses steam to dry the pulp. The wet web of pulp is pressed against the cylinder tightly to dry it through evaporation, providing a consistent thickness prior to the paper being processed into a giant roll. The resulting product is a large roll of paper that is divided by large rotary blades and packaged for transportation to be sold.