According to an example aspect of the present invention, there is provided a multilayered fibrous sheet, such as paperboard, having a first layer comprising a first fibrous material, a second layer, spaced apart from the first layer, comprising a second fibrous material, and a third layer between the first and the second layers, comprising a third fibrous material, wherein at least one of the first and the second fibrous materials comprises or consists of a mixture of chemical pulp and mechanical pulp; and the third fibrous material comprises or consists of mechanical pulp.

According to an example aspect of the present invention, there is provided a multilayered fibrous sheet, such as paperboard, having a first layer comprising a first fibrous material, a second layer, spaced apart from the first layer, comprising a second fibrous material, and a third layer between the first and the second layers, comprising a third fibrous material, wherein at least one of the first and the second fibrous materials comprises or consists of a mixture of chemical pulp and mechanical pulp; and the third fibrous material comprises or consists of mechanical pulp.

A bleached softwood kraft pulp fiber with high alpha cellulose content and improved anti-yellowing is provided. Methods for making the kraft pulp fiber and products made from it are also described.

A method for separating cellulose from a wood-based raw material including hemicellulose, cellulose, and lignin as principal components, includes injecting the wood-based raw material into a dissolution reservoir in which ethylene glycol is stored as a separating agent, and heating the separating agent in the dissolution reservoir at atmospheric pressure to a temperature in a range of 260 C. to 280 C., and reacting the wood-based raw material with the separating agent, evaporating a hemicellulose component from the separating agent and condensing the hemicellulose component, and monitoring a pH value of the condensate of the hemicellulose component. A temperature of the condensate is held at the temperature at which a change in the pH value of the condensate decreases, lignin is dissolved in the separating agent, and crude cellulose that floats in the separating agent is separated and collected.

A method for separating cellulose from a wood-based raw material including hemicellulose, cellulose, and lignin as principal components, includes injecting the wood-based raw material into a dissolution reservoir in which ethylene glycol is stored as a separating agent, and heating the separating agent in the dissolution reservoir at atmospheric pressure to a temperature in a range of 260 C. to 280 C., and reacting the wood-based raw material with the separating agent, evaporating a hemicellulose component from the separating agent and condensing the hemicellulose component, and monitoring a pH value of the condensate of the hemicellulose component. A temperature of the condensate is held at the temperature at which a change in the pH value of the condensate decreases, lignin is dissolved in the separating agent, and crude cellulose that floats in the separating agent is separated and collected.

In some embodiments, a method may include treating pulp. The method may include contacting a wood pulp with a singlet oxygen source. The method may include contacting the wood pulp with an alkaline peroxide source. The singlet oxygen source may include a peracetate oxidant solution and generating a reactive oxygen species. The peracetate oxidant solution may include peracetate anions and a peracid. In some embodiments, the peracetate solution may include a pH from about pH 10 to about pH 12. In some embodiments, the peracetate solution has a molar ratio of peracetate anions to peracid ranging from about 60:1 to about 6000:1. In some embodiments, the peracetate solution has a molar ratio of peracetate to hydrogen peroxide of greater than about 16:1. The peracetate oxidant solution may provide enhanced treatment methods of bleaching, brightening, and delignifying pulp fibers involving the use of peracetate oxidant solutions.

The present invention relates to a cellulose paper composite having enhanced ear propagation strength, ratio of tensile strength for cut and uncut paper, tensile strength and tensile modulus. The present invention further relates to a process for the preparation of cellulose paper composite having enhanced tensile strength and tensile modulus.

The present invention relates to a cellulose paper composite having enhanced ear propagation strength, ratio of tensile strength for cut and uncut paper, tensile strength and tensile modulus. The present invention further relates to a process for the preparation of cellulose paper composite having enhanced tensile strength and tensile modulus.

A bleached softwood kraft pulp fiber with high alpha cellulose content and improved anti-yellowing is provided. Methods for making the kraft pulp fiber and products made from it are also described.

A bleached softwood kraft pulp fiber with high alpha cellulose content and improved anti-yellowing is provided. Methods for making the kraft pulp fiber and products made from it are also described.