The composition of kraft paper tape base paper!

According to the introduction of ECO friendly kraft tape manufacturers, the raw materials of paper tape / non coated kraft paper tape / non coated kraft paper tape / writable kraft paper tape are mainly plant fibers. In addition to the three major components of cellulose, hemicellulose and lignin, there are other components with less content, such as resin and ash. In addition, there are auxiliary ingredients such as sodium sulfate.

 

The chemical composition of the raw material plant fiber mainly includes:

 

1. Cellulose

 

In cotton, the content of cellulose is more than 90%; in wood, reed and Amur reed, 40-50% cellulose is also contained. From the point of view of papermaking, we should try our best to keep cellulose in the process of pulping, so as to improve the yield of pulp and the strength of paper.

 

2. Hemicellulose

 

In plant fiber raw materials, the hemicellulose content of hardwood and grass raw materials can be as high as about 30%; in coniferous wood, only about 20%; in cotton, less. In order to improve the pulping yield and paper strength, some hemicellulose should be retained as much as possible in the pulping process.

 

3. Lignin

 

In coniferous wood, the lignin content accounts for about 30%, while grass materials generally contain about 20%, while cotton and flax do not contain lignin.

 

Chemical pulping is to use chemicals to dissolve a part of the binding substances between cells and separate the fibers into pulp. The more lignin in raw materials, the more difficult it is to pulping, and the more chemicals it will consume.

 

Secondary components: in addition to cellulose, hemicellulose and lignin, there are other components with less content, such as resin and ash. In general, the content of common raw materials is not large, which will not cause too much difficulty in papermaking. But if the content is too much, some paper with special requirements must be removed by corresponding measures.

 

1. Resin and fat are generally less than 1% in raw materials, but they are more in pine wood. Their viscosity is large and they are easy to bond into a group. For example, they stick to copper mesh and roller, which makes it difficult to make paper. Transparent resin spots are formed on paper, which reduces the quality of paper. They are easy to react with alkali to form soap and dissolve in water, so pine with more resin is usually pulped with alkali method to reduce their harm. Fat is generally harmless and can also be saponified and dissolved.

 

2. Starch and pectin starch are the storage materials in the cell cavity, which are not much, soluble in hot water, and have no effect on pulp and paper making. Generally, pectin in raw materials is not much, they are easy to be dissolved by dilute alkali solution. It exists in the form of pectinate in plants and is considered to be the source of ash in plants. The medium of bast fiber such as flax is mainly pectin, which can be degummed only by a small amount of alkali cooking.

 

3. Tannin and pigment are less common raw materials, which are easy to be extracted by hot water. However, if the content is large, it should be extracted in advance, otherwise, the color of the pulp will not be bleached easily.

 

4. Ash ash is the inorganic salt in plant fiber raw materials, mainly the salt of potassium, sodium, calcium, magnesium, sulfur, phosphorus and silicon. The ash content of wood is between 0.2% and 1.0%, and that of grass is higher. Generally, there is no special requirement for ash content in raw materials. But in the production of electrical insulating paper, the ash must be removed to meet certain quality requirements. The high ash content of straw, especially straw, and the high content of SiO2 in ash make it difficult to recover alkali. It is an unsolved problem to reduce or eliminate the interference of silicon in alkali recovery.