Wood-free paper

Not to be confused with Tree-free paper.

Wood-free paper is paper created exclusively from chemical pulp rather than mechanical pulp.^[1] Chemical pulp is normally made from pulpwood, but is not considered wood as most of the lignin is removed and separated from the cellulose fibers during processing, whereas mechanical pulp retains most of its wood components and can therefore still be described as wood.^[2][3][4] Wood-free paper is not as susceptible to yellowing as paper containing mechanical pulp. Wood-free paper offers several environmental and economic benefits, including reduced deforestation, decreased energy consumption, and improved waste management.^[5][6] The term Wood-free paper can be rather misleading or confusing for someone unfamiliar with the papermaking process because paper is normally made from wood pulp derived from trees and shrubs.

However, wood free paper does not mean that the paper in question is not made from wood pulp but it means that the lignin in the wood fiber has been removed by a chemical process. Paradoxically, lignin is the complex polymers containing aromatic groups that provide much of the tree strength. In its natural form, it gives rigidity and resilience to the tree, but its presence causes paper to weaken and turn yellow as it ages and eventually disintegrate. The reason for this is that as the paper ages, lignin releases acid which degrades the paper.^[7] Wood is technically a lignocellulosic material and a xylem tissue that comes from shrubs and cambium, the inner bark of trees made up of extractives, lignin, hemicellulose and cellulose.^[8] Pulp consists of wood and other lignocellulosic materials that have been broken down chemically and physically and filtered and mixed in water to reform into a web.^[8][9] Creating pulp by breaking down the materials chemically is called chemical pulping, while creating pulp by breaking them down mechanically is called mechanical pulping.

In chemical pulping, chemicals separate the wood fibers. The chemicals lower the lignin content because chemical action solubilizes and degrades components of wood fibers, especially hemicelluloses and lignin. Chemical pulping yields single unbroken fibers that produce strong quality papers because the lignin that interferes with hydrogen bonding of wood fibers has been removed. Chemical pulps are used to create wood free paper that is of high quality and lasts long, such as is used in arts and archiving.^[8] Chemical pulping processes take place at high pressures and temperatures under aqueous alkaline, neutral or acidic conditions, with the goal of totally removing the lignin and preserving the carbohydrates. Normally, about 90% of the lignin is removed.^[9]

Mechanical pulping, in contrast, converts raw wood into pulp without separating the lignin from the wood fiber.^[9] No chemicals other than water or steam are used. The yield is about 90% to 98%. High yields result from the fact that lignin is retained. Mechanical pulps are characterized by low cost, high stiffness, high bulk, and high yield.  Mechanical pulp has low strength because the lignin interferes with hydrogen bonding between wood fibers. The lignin also makes the pulp turn yellow when exposed to light and air. Mechanical pulps are used in the production of non-permanent papers such as newsprint and catalog papers. Mechanical pulps made up 20% to 25% of the world production and this is increasing because of the high yield of the process and increasing competition for fiber resources. Advances in technology have also made mechanical pulp increasingly desirable.^[8]

Composition

Wood-free paper is made from a variety of raw materials, including

• Tissue pulp: This is the most common type of wood-free paper. It is made from wood pulp that has been treated with chemicals to remove the lignin.^{[10][11][12][13]}
• Balsa pulp: This is a type of wood pulp that is made from balsa trees. It is very strong and lightweight, making it ideal for use in envelopes and other lightweight applications.^[14][15]
• Coniferous pulp: This is a type of wood pulp that is made from coniferous trees, such as pine and fir. It is strong and durable, making it ideal for use in writing and printing papers.^{[16][17][18][19]}
• Non-wood pulp: This is a type of pulp that is made from non-wood materials, such as cotton, hemp, linen, and bamboo. It is often used in high-quality papers, such as those used for art and photography.^[16][18][20]

Wood-free paper has a number of advantages over paper that contains mechanical pulp:

• It is more resistant to yellowing. This is because the lignin, which is the main cause of paper yellowing, has been removed from the pulp.^[17][21][22]
• It is stronger. This is because the cellulose fibers in wood-free paper are longer and more uniform than the fibers in mechanical pulp.^[10]
• It is more durable. This is because wood-free paper is less likely to tear or crease.^[10]
• It is smoother. This is because the surface of wood-free paper is smoother than the surface of paper that contains mechanical pulp.^[10]

Wood-free paper is used in a variety of applications:

• Writing and printing papers: Wood-free paper is the most common type of paper used for writing and printing.^[23] It is available in a variety of weights and finishes, making it ideal for a variety of applications^[17]
• Envelopes: Wood-free paper is the most common type of paper used for envelopes.^[24][25] It is available in a variety of colors and finishes, making it ideal for a variety of occasions.
• Art and photography papers: Wood-free paper is the most common type of paper used for art and photography.^[23] It is available in a variety of weights and finishes, making it ideal for a variety of projects.
• Other applications: Wood-free paper is also used in a variety of other applications, such as packaging, labels, and currency^[16][26]

Cotton paper texture

Hemp paper

Bamboo paper

Advantages and benefits of wood-free paper

1. Conservation of Forests: One of the key advantages of wood-free paper is its ability to reduce the demand for wood pulp derived from trees. This conservation of forests persevering valuable ecosystems and biodiversity. Wood-free paper production significantly contributes to the conservation of forests by reducing deforestation and protecting natural habitats.^[27][28]
2. Harder to Warp: Another key advantage of wood-free paper is its lesser likelihood to warp or curl.^[29]
3. Decreased Deforestation: The use of alternative fibers in timber-loose paper reduces the stress on forests, minimizing the need for big-scale deforestation. This helps protect touchy and ecologically valuable regions.^[30][31][32]
4. Decreased Carbon Footprint: wooden-loose paper generally has a decreased environmental effect as compared to standard wood-based total paper. The manufacturing system emits fewer greenhouse gases, consumes less strength,^{[clarification needed]} and requires less water.^[33][34] Additionally, it frequently includes fewer chemical treatments.
5. Usage of Agricultural Residues: Wooden-free paper can be made from agricultural residues like wheat straw, rice straw, and bagasse. Making use of those by-products of agriculture reduces waste and presents an extra source of revenue for farmers.^[35]
6. Advertising of Sustainable Farming Practices: The cultivation of opportunity fiber crops for paper manufacturing encourages sustainable agricultural practices. although vegetation frequently requires fewer insecticides and fertilizers as compared to traditional crops, lowering environmental impacts.
7. Waste discount and recycling: wooden-unfastened paper is often crafted from recycled materials. This supports recycling projects and reduces the demand for brand new raw materials. moreover, it emitted from landfills.
8. Diversification of supply Chains: depending completely on timber pulp can result in overexploitation of unique tree species and wooded area ecosystems. Incorporating alternative fibers diversifies the assets of uncooked materials for the paper industry, decreasing strain on precise varieties of timber.
9. Energy efficiency: wood-free paper manufacturing often requires much less electricity compared to conventional timber-based totally paper manufacturing.
10. More advantageous Soil health: utilizing agricultural residues for paper manufacturing can enhance soil fitness by returning organic count to the soil. This may lead to better fertility and a normal soil structure.
11. Help for Rural communities: The manufacturing of timber-free paper using agricultural residues can create economic possibilities for rural communities. This will lead to improved livelihoods and sustainable improvement in areas where these resources are plentiful.
12. Monetary Viability and market demand: The demand for environmentally sustainable products, including wood-free paper, is on the rise. This presents economic opportunities for businesses that choose to invest in and produce eco-friendly paper products.
13. Alignment with Sustainability desires: the use of wood-loose paper aligns with global sustainability dreams, together with the ones outlined within the United Nations Sustainable Improvement Goals (SDGs). It contributes to desires related to accountable consumption and production (SDG 12) and existence on land (SDG 15).

See also

• Coated fine paper
• Cotton paper
• Woodfree uncoated paper
• Tree-free paper