Wood Pulp Tissue Paper Machine

YIDAFA has rich experience in chemical paper pulp making and could provide the whole production line from wood to paper rolls.

Paper is made in two steps: Cellulose fibers are extracted from a variety of sources and converted to pulp. Pulp is combined with water and placed on a paper making machine where it is flattened, dried, and cut into sheets and rolls.

Although many fibers were mentioned above, forestry products (logs from trees) are the source of most fiber in paper pulp. There are three main components, which must all be separated to make pulp.

The bark protects the fibers of the log, which are held together by lignin. The goal is to extract the fibers, and this is accomplished either using a chemical or mechanical process.

Paper mills all work a little bit differently, so please keep in mind that these are generalizations

What is chemical pulp?

As with mechanical pulp, the process starts with a whole log. These logs are cut into small pieces, about 1/2" to 1" long and 1/4" to 1/2" thick. This is done with large wood chippers used by landscaping companies.

Sawdust is put into a giant machine that combines them with real hot water and chemicals. This helps remove air pockets, making it easier for chips to break down into fibers.

Next, move the wood chips and chemical mixture into the pressure cooker. Sawdust spends about two hours in temperatures approaching 350 degrees Fahrenheit. The combination of steam, chemicals and pressure causes the chip to break down. This leaves wood fibers and a liquid called "black liquor" behind.

In the next step, the black liquor is removed. The remaining fibers are cleaned in a number of ways and sometimes bleached to ensure purity.

Much of the waste in the process is black liquor - but these facilities typically operate in "closed loop" systems. The inorganics (chemicals) are recovered and reused for the next batch of paper, while the remaining liquid (natural biomass) is converted into energy to run the mill. In most cases, more electricity is produced than is needed, so this creates an environmentally friendly energy source for the local community.

Paper made from chemical pulp is generally brighter, smoother and of higher quality than mechanical pulp.