With the rapid development of Internet shopping, the demand for express cartons is increasing, and the quality of express cartons is also different. In fact, the original paper composition of express cartons determines the quality of the production of cartons, and the good original paper composition is relatively more than that of ordinary ones. Let's take a look at the composition of express cartons.
1、 Trees, paper, and paper paddles can be made from various plants, but trees and non wood materials are still commonly used as raw materials for paper.
2、 The following table shows the typical chemical composition of coniferous and broad-leaved wood. But it is difficult to accurately write the chemical formula of wood, as wood is a complex and uneven natural product composed of multiple molecular compounds. The main components of wood are lignin (40-50), hemilignin (20-35), lignin (20-30), and substances dissolved in solvents (3-3, 5). But it can be said that it is impossible to separate these chemical components without undergoing structural changes and decomposition. If we study the main components of wood, it is mostly composed of polysaccharides, accounting for about 60-80%; If the polysaccharides in wood are decomposed with dilute acid and water, it can be known that they are high molecular weight carbohydrates composed of monosaccharides such as glucose, mannose, and xylose.
The main polysaccharide components of wood can be divided into whole and half elements. When the whole element is treated with dilute alkali (such as 17, 5 NaOH or 10-24 KOH) at room temperature, 15-30% of the dissolved elements in the wood are half elements, and the insoluble elements are elements.
3、 Pulp, the raw material of paper is pulp, which is mainly made from wood. Its manufacturing method is generally as follows: chemical pulp pulp, semi chemical pulp, mechanical (physical) pulp
1. Chemical pulp, chemical pulp is pulp made mainly by chemistry in the process of manufacturing pulp, of course, there are also differences depending on the use and manufacturing method. Compared to the process of removing intermediate layer lignin and cell lignin from raw materials, pulp has the disadvantages of low raw material utilization and high production cost.
(1) Cowhide pulp, also known as kraft pulp, is a type of pulp made by chemical methods. The word Kraft in Sweden means sturdy. Due to the strong strength of the paper made from pulp produced from by-product saltpeter in Swedish chemical factories, it is called kraft paper.
(2) Semi chemical pulp is a type of pulp made by using chemical treatment methods to remove a portion of lignin from wood, and then mechanically crushing the remaining softened wood chips. It also means that chemical treatment and mechanical treatment each account for half of the manufacturing methods. The purity and strength of semi chemical pulp are higher than those of mechanically processed pulp, and the yield is also higher than that of chemical pulp made by chemical methods.
2. Waste paper pulp The so-called waste paper pulp is the used waste paper, which is put into a loosening machine device like a juice grinder, and twisted back and forth to make the coalesced and decomposed into Congee.
The waste paper pulp used for the bottom layer of corrugated cardboard is mainly made of kraft paper and corrugated paper scraps, so its strength is very high.