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What is the difference between softwood pulp and hardwood pulp, and the corresponding paper products

The main differences between softwood pulp and hardwood pulp are as follows:

1. The raw materials are different:

Coniferous wood pulp is made from coniferous trees, and the main tree species include pine and so on. Hardwood pulp is made from hardwood trees, and the main tree species include eucalyptus, poplar, birch, etc.

2, the price is different:

Under the same grade, the price of softwood pulp is usually more expensive than that of hardwood pulp.

3. Different meanings:

Softwood pulp fibers are long and thin, the pulp is relatively pure, and there are few impurities. Hardwood pulp fiber is thick and short, and contains more impurities, the paper strength is relatively low, the paper is loose, the absorption performance is strong, and the opacity is high. Hardwood pulp fibers such as birch, poplar, basswood, eucalyptus, maple, etc., hardwood fibers are short, generally about 1 mm in length, and their aspect ratio is more than 60 times.

The differences between the corresponding paper products are:

4. Different performance:

The paper made from softwood pulp has good flexibility, high folding endurance, good tensile strength and good printing performance. Paper made from hardwood pulp has high bulk, high stiffness and good packaging performance.

Characteristics of softwood and hardwood:

For the pulp obtained by the same pulping method for softwood and hardwood, hardwood needs to be beaten to a higher degree of beating than softwood to obtain similar physical strength. However, the fibers of hardwood pulp are shorter, generally 0.8-1.1 mm. It is necessary to improve its beating degree, and try to avoid too much cutting of fibers,

Therefore, hardwood pulp should be beaten with a lower beating specific pressure and a higher beating concentration. The fibers of softwood pulp are long, generally 2-3.5 mm. When producing cement bag paper, it is not advisable to cut too many fibers.

However, when it is used to produce a certain medium and thin paper, such as typing paper, oil seal paper, etc., in order to meet the evenness requirements of the paper, it needs to be cut to 0.8-1.5 mm. Therefore, in the beating process, the beating process conditions can be determined according to the requirements of the paper type.

Earlywood and Latewood:

In the earlywood and latewood pulp, the ratio of earlywood and latewood is different, and the pulping quality is also different when the same beating conditions are used for beating. The latewood fiber is long, the cell wall is thick and hard, and the birth wall is not easily damaged. During beating, the fibers are easily cut off, and it is difficult to absorb water and swell and become finely fibrillated.

Therefore, for pulp with a large proportion of latewood, in medium beating, especially in viscous beating, it should be beating with a lower specific pressure and a higher concentration, and the method of successively dropping the knives or successively reducing the knife spacing should be used for beating. The fiber wall of the early wood is thinner and the fiber is soft.