The Difference Between Alkaline Pulping And Sulfate Pulping

 Cellulose is the main component of wood, plants, and waste paper, as well as the main raw material for paper, high-grade pulp, silk fibers, and other fiber products. The pulping process involves separating cellulose from raw materials to form a compressed cellulose mixture. The pulping process is divided into two main types - alkaline pulping and sulfate pulping. Based on their different processes, advantages, and applications, suitable methods are selected for each.
1. Alkaline pulping

     Alkaline pulping is one of the most basic ways to manufacture newsprint and writing paper. Its basic principle is to gradually separate wood or other fiber raw materials into cellulose in an alkaline environment. Alkaline environments can be regulated by chemical substances such as sodium hydroxide or potassium hydroxide. At this time, wood or other raw materials are heated to facilitate the separation of cellulose.

The advantage of alkaline pulping is that it can quickly produce high-quality pure wood pulp. The processing time is shorter, and the components in the raw materials can be more easily cut through alkaline environments, forming a more textured paper. This means that it can produce a more beautiful text, which is particularly important for some high-end paper or printed materials with high texture requirements.

2. Sulfate pulping

      Sulfate pulping is the most commonly used method for producing chemical fiber pulp, high-strength pulp, tough pulp, and recycling pulp using raw materials. Compared to alkaline pulping, it is carried out in an acidic environment, where acidic compounds such as sulfuric acid are added to the raw materials. This chemical treatment focuses on cutting cellulose fibers and quickly separating their components. The raw material process is processed under high pressure to produce higher purity cellulose fibers.

The advantage of sulfate pulping is that the treatment process is simple and consistent, which can form higher surface hardness and density. Due to its more efficient processing, it can better control different chemical reactions from multiple sources of cellulose and produce better quality and texture paper.

Although there are significant differences in the process flow between alkaline pulping and sulfate pulping, the two methods can actually be used in conjunction. For most commonly used paper, alkaline pulping is suitable. The demand for producing high-quality or high-performance paper or other cellulose products is higher for sulfate pulping. In contrast, sulfate pulping has higher time and cost, but it has higher requirements for the efficiency of raw material use and the quality produced, which can produce higher quality products. In the industry, based on different products and purposes, a combination of one or more methods is usually chosen to achieve the best production efficiency and quality results.