The production of paper pulp is described as chemical pulping. Manufacturers conduct pulp cooking, pulp screening, pulp washing, and pulp bleaching to complete the whole process. So, it is obvious that the Paper Pulp Manufacturers uses multiple machines to complete the chemical pulping process.
There are various machines such as a pulp digester, disc filter, blow tank, vacuum drum, roll press and other machines as well as related parts. All these are used by paper pulp manufacturers to finish the process. These machines have advanced the traditional process of pulp making in the industry of papermaking.
The chemical process turns wood chips or fibrous sources into a pulp of paper. The quality of pulp making decides the quality of papers obtained. This process allows the pulp to contain hemicelluloses and lignin, which ensures high-quality paper.
However, depending on the working mechanisms, you can see two types of pulp making process. They are-
- Continuous process of pulp cooking
- Batch process of pulp cooking
Depending on the chosen mechanism, these machines are necessary to complete the pulp creation process:
1. Pulp digester
Pulp digester looks like a huge vessel, which is used for the steaming of dissolved fibers and chemical pulping. This machine cooks multiple raw materials such as bamboo grasses, wood, and others. A chemical compound is added to react with the raw materials to obtain paper pulp. This pulp contains cellulose mostly.
After the digestion process, the pulp becomes ready for the washing bleaching before the process of papermaking. Manufacturers may choose between horizontal and vertical digester, depending on the required chemical pulping process.
For the super batch style of pulping, a vertical digester is used. This is when the displacement process of cooking is preferred to keep the pulp quality high and keep the costs low.
2. Blow tank
Blow tanks are designed with carbon steel along with an additional inner layer of antiseptic treatment. The outer body of the blow tank contains insulation to maintain the desired temperature inside when keeping the pulp.
3. Displacement digester system or DDS
The DDS machine is a whole system used in the process of pulp digestion. This machine is the latest technology used in pulp cooking. This machine is used when creating wood pulp or bamboo pulp with an annual output of 50 to 300 thousand tons. This machine system contains a storage tank, a separator, a blow tank, a conveyer, a heat exchanger, a digester, a foam breaker, and with filter and pump for black liquor. Along with all that, this system contains four units- heat exchange, cooking, separation of exhaust gas and filter for black liquor.
Here are the benefits of this displacement digester, for which it is used by manufacturers:
- High-quality pulp
- Washing function built-in
- Stable and reliable system
- Great production efficiency
- Flexible processing of pulp
- Less consumption of steam
- Reduced environmental pollution
4. Tubular continuous digester
When it comes to pulp making with non-wood fiber, this machine is prioritized by pulp manufacturers. This machine proves to be useful in chemi-mechanical and chemical pulping both. Sometimes, the same machine is also applied to complete the process of chemi-thermo mechanical pulp making as well as bio-mechanical pulp making process. Wood shaving, non-wood fiber and other materials containing low-density are cooked perfectly in this machine. The process is called the wet-method of material preparation.
Here are the advantages why manufacturers utilize this tubular continuous digester:
- Stable consumption of steam and electricity without any peak load limitation
- High yield of stable and coarse pulp with evenly distributed quality
- Less pollution and flexible adjustment of liquid ratio
- Great level of automation, simpler process adjustments, impressive production efficiency.
- Continuous production with lesser production cost
- Reduction in the consumption of chemicals and energy
All these machines are used in the production of paper pulp and paper packaging board. Manufacturers define the process before choosing the equipment for cooking the pulp. This helps to obtain the desired quality.