Various Kinds of Paper

paper

Various kinds of paper are produced in different ways. They include Bleached kraft or sulfite pulping, mechanical pulping, and Creping and embossing. They have different types of coatings, and some paper is made from forest products, including paper made from sawdust and paper made from wood chips.

Mechanical pulping

Traditionally, mechanical pulping for paper has been the method of choice for the pulp and paper industry. This is because mechanical pulping provides a relatively low cost way of converting wood into paper. However, this method also has its disadvantages. Paper produced from mechanical pulp tends to yellow with age. In addition, mechanical pulping uses a lot of electricity.

Aside from its cost advantages, mechanical pulping also produces a higher yield of paper. Paper produced from chemical pulping tends to have lower yields.

Bleached kraft or sulfite pulping

Several processes are known for producing a brighter, whiter pulp. However, they all have disadvantages. One process, kraft pulping, has a higher yield. Another, sulfite pulping, has a high residual lignin content. These processes are not suitable for dense hardwoods. During bleaching, residual lignin can discolor products due to chemical changes in lignin structure.

Kraft pulping is an innovative method of producing wood pulp that began in the early 1900s. This process uses a series of steps to reduce the cost of raw materials and minimize environmental impacts. In the 1940s, recovery boilers became available that allowed kraft pulp mills to recycle chemicals.

Creping and embossing

Using different processes, creping and embossing paper can be used to improve some of its properties. The process is used to enhance the mechanical properties of the tissue paper webs, such as tensile strength, liquid absorption capacity, compression, and softness.

Using the creping and embossing process, a number of systems have been developed for bulking paper webs. However, the process has not been well studied. The purpose of this study was to develop a methodology to better understand and quantify the effect of embossing on the mechanical properties and liquid absorption capacity of a tissue paper web.

Coatings

Despite the paper industry experiencing a difficult period, it is still experiencing opportunities to grow in certain sectors. These sectors include food and beverage packaging and publication papers.

The paper industry is responding to the grease challenge and committing funds to developing new grades that have inherent grease resistance. Paper coatings provide the paper with functional properties as well as protection from water, grease, and oil.

The paper coating industry is investing significant R&D resources into reformulating its products to improve productivity and reduce costs. The key ingredients used in paper coatings include biocides, defoamers, wax emulsions, crosslinking agents, and polyacrylates.

Instabilities in forest-products segments

Increasingly, forests are being recognised for their ability to generate income from the sale of forest products. In turn, this has led to an increasing number of stakeholders taking note of the governance of forests. In some countries, forest products have become significant export commodities.

For instance, industrial grade timber is mostly produced from coniferous trees. However, more tropical countries are increasingly relying on plantations to supply industrial lumber. This trend is supported by growing global demand for forest products that are not linked to deforestation.