The company is mainly engaged in the research and development, production, and sales of automatic paper production line equipment, specialty paper, and processing machinery. The company is a technology driven enterprise, and technological innovation is its core advantage. The main equipment of the company is independently innovated and developed, with a leading level of similar equipment in China. The company independently develops a paper machine with a width of 6600mm and a design speed of 3000m/min. It produces 1 million tons of high-end cultural paper annually and is a wide width high-speed paper machine with independent intellectual property rights.

Large paper equipment overview map

What is papermaking machinery

Paper making machinery is an important equipment for manufacturing paper and paper products, mainly including material preparation equipment, pulp making equipment, paper machines, and finishing processing machinery.

Material preparation equipment is mainly used for pre-treatment and processing before steaming or grinding, including grass cutters, reed cutters, peelers, slicers, etc. Pulp making equipment is a key device for separating plant raw materials into fibers, including steamers, wood mills, thermal grinders, pulp washing machines, bleaching machines, pulping machines, etc.

The paper machine is the core equipment that transforms pulp water suspension into paper through processes such as filter dewatering, mechanical extrusion dewatering, and drying. It mainly includes three main parts: forming, pressing, and drying, and is equipped with necessary finishing, winding, and transmission devices, as well as auxiliary systems such as slurry supply, slurry and white water circulation, vacuum, ventilation and exhaust, paper damage treatment and lubrication, and self-control. The width of modern large-scale paper machines can reach 11m, the working speed can reach over 1000m/min, the daily paper output can reach hundreds of tons, and the weight of the entire machine can reach over a thousand tons, with a length of over a hundred meters.

In addition, papermaking machinery also includes some auxiliary equipment, such as crushing conveyors, balers, and specialized equipment for the production of special paper products. These devices play an important role in the papermaking process, greatly improving production efficiency, reducing production costs, and also helping to improve paper quality and environmental performance.

Overall, papermaking machinery is an indispensable and important equipment in the papermaking industry, and its technological level and development status directly affect the development level and competitiveness of the papermaking industry. With the continuous advancement of technology and increasingly strict environmental requirements, papermaking machinery is also constantly being updated and upgraded, developing towards a more efficient, energy-saving, and environmentally friendly direction.

The main production processes of the paper production line

The production of paper includes pulp making, papermaking, and paper processing.

(1) Pulp making
Pulping is the process of separating plant fiber raw materials into natural pulp or bleached pulp. Pulping can be done using chemical, mechanical, or chemical mechanical methods. Except for mechanical methods, both chemical methods and chemical mechanical methods require the addition of chemical raw materials and chemicals.
China mainly uses chemical pulping, and its basic process is: raw material storage → steaming → washing → screening → bleaching. The most critical process is steaming and boiling.
① Steaming and cooking is the process of dissolving lignin and cooking chemicals in raw materials through chemical reactions, making it easier to separate from cellulose. There are mainly two methods: alkaline method and sulfite method.
Alkaline method is to treat plant fiber raw materials with alkaline solution, dissolve the lignin in it, and separate the raw fibers into pulp. According to different alkali materials, it can be divided into lime method, caustic soda method, and sulfate method. Sodium carbonate, sodium polysulfide, hydrogen sulfide, sulfate, etc. can also be used. At present, alkaline cooking is still the main method for pulping in various countries, and most of them use the sulfate method.
② The extraction of waste liquid and the washing of pulp in alkaline pulping cooking liquid are black liquor, while the acid pulping cooking liquid is red pulp, collectively referred to as cooking waste liquid. The lignin, sugars, and fats contained in it must be separated from the pulp as much as possible after cooking to ensure the purity of the pulp. Due to lignin being a water-insoluble network type macromolecule, its molecular chain contains rigid groups such as benzene rings, which are difficult to move and have low flexibility. When the lignin content in pulp is high, it appears stiff and fragile, making it difficult to hydrate during pulping and prone to breakage. The process of extracting waste liquid and washing pulp involves the separation of fiber and non fiber impurities. The treatment of papermaking wastewater involves environmental protection and other issues, which have attracted the attention of various countries. More and more polymer chemicals are being used in this process.
③ Adding bleaching agents to pulp bleaching increases its whiteness.

(2) Paper making
Papermaking mainly refers to beating, papermaking, and producing cardboard.
① The pulp after clean washing and screening cannot be directly used for papermaking. It must be processed using physical and mechanical methods to cause fiber cutting, crushing, water absorption swelling, and fine fibrosis, resulting in uniform fiber size, increased surface area, softness, and increased strength.
② Seasoning is the general term for multiple processes such as gluing, filling, coloring, etc.
Glue application is a chemical treatment of pulp, paper, or cardboard to achieve resistance to fluid (primarily water) infiltration. Most paper and cardboard require gluing, which can be divided into in pulp gluing and surface gluing depending on the method.
Adding fillers (such as talcum powder, kaolin, calcium carbonate, titanium dioxide, etc.) and organic polymer chemicals to the slurry to improve the opacity, brightness, smoothness, stiffness, dry strength, wet strength, and other properties of the paper. Adding fillers is crucial for reducing production costs and improving paper quality.
③ Coloring involves adding pigments to pulp to produce the desired color. Colorants are divided into pigments (organic and inorganic pigments) and dyes (alkaline dyes, acidic dyes, and direct dyes, etc.). In addition, paper dyeing can also be achieved through methods such as surface dyeing, immersion dyeing, and coating dyeing.
④ Papermaking is divided into two types: dry papermaking and wet papermaking. The former uses air as the medium, while the latter uses water as the medium. Depending on the papermaking method, equipment, and chemical composition, different varieties of paper can be obtained. Cardboard production is basically the same as paper production, and also requires steps such as pulping, pulping, copying, calendering, coiling, cutting or rewinding.

(3) The processing of paper refers to the production of various processed papers and non plant fiber papers.
① The secondary processing of processed paper after the papermaking process includes coating with pigments (copperplate paper, coated paper, cast coated paper, etc.) and surface treatment with various chemicals (producing pressure-sensitive paper, thermosensitive recording paper, flame retardant paper, release paper, etc. through extrusion, impregnation, bonding, and other methods). According to different preparation methods, it can be further divided into coated processing paper, modified processing paper, impregnated processing paper, mechanically processed paper, composite processing paper, etc.
② Non plant fiber paper includes synthetic fiber paper, mineral wool fiber paper, metal fiber paper, etc. Under the situation of shortage of papermaking raw materials, these non plant fibers have broadened the range of papermaking raw materials, and opened up a new world for the production and application of paper with their unique and new properties.

The main categories of paper production lines

How to choose suitable paper making equipment

Choosing the appropriate papermaking equipment is a process that takes into account multiple factors. Here are some suggestions to help you make a wise choice:

1. Clarify production requirements: Firstly, you need to clarify your production scale, product types, and quality requirements. This will help determine the model and configuration of the required equipment. For example, if you plan to produce a specific type of paper, you need to choose equipment that can meet this production demand.
2. Understanding equipment performance: Equipment performance is one of the key factors in choosing papermaking equipment. You need to understand the production capacity, automation level, ease of operation, difficulty of maintenance, and service life of the equipment. These information can be obtained by communicating with the equipment manufacturer or consulting relevant materials.
3. Assessing equipment quality and brand: Equipment quality and brand are crucial for ensuring production stability and reducing failure rates. You should choose equipment brands with reliable quality and good reputation, and conduct on-site inspections of the equipment before purchasing to understand its actual operation and production efficiency.
4. Consider price and cost-effectiveness: Price is one of the important factors to consider when choosing papermaking equipment. You should evaluate the performance, quality, and brand of the equipment comprehensively based on your budget, and choose the equipment with high cost-effectiveness. Avoid pursuing low prices without considering the performance and quality of the equipment.
5. Pay attention to after-sales service: After sales service is an important guarantee to ensure timely maintenance and upkeep of equipment during use. You should choose equipment suppliers with comprehensive after-sales service to ensure timely resolution of equipment problems.
6. Consider environmental requirements: With the increasing awareness of environmental protection, the paper-making industry has higher and higher requirements for environmental protection. When choosing equipment, you should pay attention to its environmental performance and choose equipment that meets national environmental standards to ensure that the paper produced meets environmental requirements.

In short, selecting suitable papermaking equipment requires comprehensive consideration of multiple factors, including production needs, equipment performance, quality, brand, price, cost-effectiveness, after-sales service, and environmental requirements. By carefully comparing and evaluating the advantages and disadvantages of different equipment, you can find the papermaking equipment that suits your production needs.

Introduction to the Basic Structure of Paper Machines

According to the needs of the copying process, paper machines come in various structural forms, generally consisting of components such as flow, forming, pressing, drying, finishing, coiling, and transmission, as well as supporting equipment such as auxiliary systems.

Forming Department

It consists of a headbox, chest roller, forming net, suction tank, and idler roller. The slurry box distributor evenly sprays the slurry sent by the flow system onto the forming mesh, and the slurry speed should match the mesh speed. Controlling the slurry speed and mesh speed is the main factor in selecting the slurry box type. The fully enclosed hydraulic slurry box is used to adjust the slurry speed by adjusting the slurry pressure of the flushing pump, and is suitable for high-speed paper machines; The air cushion type headbox adjusts the speed by adjusting the air cushion pressure, while the open high-level headbox adjusts the speed by adjusting the height of the slurry inside the box, which is suitable for medium speed paper machines; The open compartment slurry box is suitable for low-speed paper machines. The forming net is an endless circular net, which forms a horizontal or slightly inclined flat net surface between the chest roll and the bottom roll. As the working section of pulp dewatering, it is commonly referred to as a net, and therefore called a long net. If the endless formed mesh is placed on a circular mesh cage to form an arc-shaped dehydration forming working section, it is called a circular mesh. If a steel mesh drum with drilled holes is used to suction vacuum from the shaft end to accelerate the dewatering of pulp on the forming mesh surface, it is called a vacuum circular mesh or vacuum forming mesh. If the pulp is clamped between two long nets and both nets are simultaneously dehydrated and formed, it is called a clamp net former (Figure 2). These forming machines use different forms of dewatering elements to accelerate the dewatering of pulp on the web. There are three types of components: stationary, rotating, and dual-use. Static components such as dehydration plates, curved vacuum boxes, etc., and rotating components such as case rollers, vacuum forming rollers, etc. In addition to using a single form of forming machine to assemble long web paper machines, circular web paper machines, and clamp web paper machines, there are also forming parts that combine multi long web, multi circular web, multi clamp web, and various forms of long web hybrid forming machines.

Pressing department

Further dehydrate the formed wet paper sheet by applying pressure. It consists of two rollers with hard and soft surfaces, such as a stone roller and a rubber roller, matched to form a set of presses. The pressing section is composed of pressing groups of the same or different forms, which traditionally also includes a vacuum suction device. When squeezing, a suitable specification of woolen cloth is used to support the paper sheet. It can evenly distribute the pressure and take away some of the water squeezed out, and enhance the pressure to improve the dewatering ability of the squeezing process. Low speed paper machines often use a line pressure of 20-60kN/m, while high-speed paper machines use a line pressure of up to 210kN/m. When using high impact pressing, such as wet paper machines, the line pressure can reach up to 350kN/m; Making rubber rollers into vacuum pressure rollers, groove pressure rollers, lining pressure rollers, blind hole pressure rollers, etc., to more effectively remove the pressing water from the pressing zone, these are new technologies adopted since the 1950s to improve the efficiency of pressing and dewatering. Afterwards, a compound pressing structure was adopted to form a closed paper feeding system. It is composed of two or three groups of presses combined, with wet paper peeled off from the forming net by vacuum suction rollers, supported by a blanket and sent to the composite press. Afterwards, the paper is transferred between the pressure rollers, eliminating the phenomenon of paper breakage caused by self weight and other factors during the press in the past. Since the 1980s, wide compression zone pressing technology has emerged, with strong and tough rubber belts or rollers that deform under strong pressure, resulting in a line pressure of up to 750kN/m and a wider contact surface, significantly extending the dehydration time and greatly improving the pressing and dehydration capacity. The effect is more prominent on high-speed paper machines. The dryness of the pressed paper can be increased from 30-37% in the past to 43-45%, and some even reach 50%. The number of times the paper comes into contact with smooth hard roller surfaces or rough adhesive surfaces, as well as the amount of dehydration on each surface, will affect the surface quality of the paper. Reasonable handling can significantly reduce the difference in smoothness between the two sides of the paper, and vice versa can also cause a difference in smoothness between the two sides.

Drying department

Several drying cylinders are driven by gears or wool cloth to form a group, and the drying section is composed of several groups of drying cylinders. The linear speed of each group of drying cylinders can be adjusted separately to maintain a slight speed difference between each group of drying cylinders to compensate for the shrinkage of paper sheets during the drying process. The dryness of the paper leaves in the drying section is generally around 92-94%. At the end of the drying section, a cold cylinder is usually equipped to allow water vapor to condense on the surface of the cold cylinder. Condensed water can wet the surface of paper sheets to achieve better surface smoothness during decoration. A drying cylinder diameter of 1.5m is effective. Single sided glossy paper can achieve high single-sided glossiness by using a large-diameter drying cylinder with high hardness and smoothness. The diameter of the large-diameter drying cylinder is generally 3-7.5m.

Surface Decoration Department

Use multiple processes to achieve good surface quality. Most papers undergo mechanical calendering after being processed by a paper machine to achieve a flat and consistent surface. The mechanical calender is made of several cold cast iron rollers, which flatten the paper surface with their own weight or additional pressure. If higher surface smoothness is required, a calender machine should be used for calendering. It is generally composed of paper pulp rollers and cold cast iron rollers arranged alternately. According to different usage requirements, some varieties require surface gluing to improve surface quality; Some require surface coating to improve appearance or printing quality. Surface gluing and coating can be processed on paper outside the paper machine using glue and coating machines, or by combining glue and coating equipment inside the paper machine for in machine processing.

drive system

Connect and synchronize the various parts of the paper machine to form an integrated mechanical and electrical system. It is composed of mechanical deceleration device, speed regulation and stabilization device, and sub transmission device, all of which use electricity as the power source.

White water system

It is a recycling, processing, and reuse system for the dewatering of the paper machine forming section. The entire system includes equipment for collecting, transporting, filtering or precipitating white water, air flotation, etc., to separate and recycle fibers and fillers for reuse, as well as to recycle clean white water in the papermaking process.

Auxiliary system

It consists of electrical system, vacuum system, lubrication system, workshop steam supply and exhaust system, paper damage treatment, compressed air system, steam supply and drainage system, etc. that are matched with the paper machine.