Corrugated base paper is an important raw material for making packaging cartons

Corrugated base paper is an important raw material for making packaging cartons. In the paper industry, its proportion accounts for more than 20% of the total output of paper and cardboard. With the vigorous promotion and application of corrugated cardboard boxes, the demand for corrugated base paper will also increase day by day. With the continuous improvement of the logistics industry's requirements for the quality of packaging cartons, the requirements for the quality of corrugated base paper itself will also become higher and higher. Generally speaking, low basis weight and high strength are the general trend of corrugated base paper production in the future.

 

From the analysis of the quality and performance indicators required by corrugated base paper, equipment is not the only factor affecting the quality of high-quality corrugated base paper, but the management and control of key processes is important, especially for some small and medium-sized paper-making enterprises. There is a certain "prejudice" in the production understanding of this seemingly low-grade paper type, and the organization of production is not strictly in accordance with the process requirements, which may cause fluctuations and differences in the quality of corrugated base paper products.

 

Reasonable selection and ratio control of raw materials

The main raw material for domestic production of corrugated base paper is recycled waste cartons, and the quality of recycled waste cartons is often uneven.

Imported waste cartons generally have more wood pulp content and better fiber strength, while domestic waste cartons generally have poor fiber quality after repeated reuse.

It has become an unavoidable reality to use a large number of domestic waste corrugated boxes to manufacture recycled corrugated base paper. Therefore, it is necessary to carefully select the raw material waste paper and use it with other high-quality waste paper before pulping in the production process. The key to producing high-quality corrugated base paper.

 

Rational design of production process

Seemingly simple corrugated base paper, the use positioning of the product must also be considered in the process design. The screening and purification process in the waste paper pulping process must be scientifically designed according to the quality of the selected waste paper raw materials.

 

The quality of corrugated base paper is directly affected by the selection of pulper sieve plate sieve openings, the selection and design of rough selection and selection of holes and seams, as well as the screening of tailings at each stage and the rational design of purification processes.

 

Practice has proved that the earlier the removal of non-fibrous impurities in waste paper, the more beneficial the subsequent process and product quality. For example, the use of bulk balers and drum pulpers are effective equipment for removing impurities before waste paper is fully shredded.

 

In the process of producing paper with waste paper as the main raw material, the design of auxiliary processes is also particularly important.

 

Under the premise that the quality of waste paper pulp after a period of screening and purification can meet the requirements, the treatment of tailings is often one of the factors that affect the quality of paper.

 

Considering the production cost, it is impossible for enterprises to discard 15% to 20% of tailings, especially for enterprises with only one paper machine producing corrugated base paper, the key issue to ensure and stabilize paper quality is how to deal with tailings Reuse quality.

 

Some small and medium-sized papermaking enterprises use a large amount of impurities such as tailings in order to save production costs. They do not know that the existence of a large amount of impurities reduces the bonding force between paper fibers, resulting in a decline in the overall quality of the paper. The increase in the rate will actually reduce the plagiarism rate.

 

In the process of producing corrugated base paper, some non-fibrous garbage such as plastic foam particles, sediment, etc. must be removed as much as possible through screening and purification process equipment to avoid the accumulation of non-fibrous impurities in the production process and cause pulping efficiency The decline, and as much as possible to the tailings through beating and other treatment before reuse, which can not only help to control the production cost, but also help to ensure the quality of the paper.

 

Control of key process

The commonly used surface sizing agent for corrugated base paper is corn starch, which is modified, boiled and gelatinized, and then mixed with a water-resistant agent to evenly coat the surface of the paper to improve the ring pressure strength and water resistance of the paper.

 

The self-strength of corrugated base paper before surface sizing, paper evenness and tightness, and the degree of fiber fibrillation play an important role in the strength of corrugated base paper after sizing.

 

The tightness of the base paper is high, the film-forming property of the rubber is good, and the uniformity of sizing on the front and back is stable, so the transverse ring compression strength of the paper is correspondingly high. Especially paper tightness is one of the important indicators that must be controlled during the production of corrugated base paper. Paper with high tightness has good stiffness and correspondingly high ring crush strength. Specifically, it can be obtained by pressing, drying and surface application. Glue is controlled.

 

In order to obtain a high and stable ring crush strength for corrugated base paper, it is necessary to rely on the sizing agent (water-resistant agent) to endow the paper with hydrophobic properties. Because the fiber and starch itself are hydrophilic, if the corrugated base paper "returns to moisture" after strengthening , the paper strength will decrease accordingly.