How Paper is Made From Trees To Factory 

Paper making involves several key steps, from raw material preparation to the final product. Here is a detailed overview of the process:
Raw Material Preparation:
Wood: The primary raw material for making paper is wood. Trees are harvested and transported to a paper mill.
Recycled Paper: Used paper products are collected and transported to the mill for recycling.
Pulping:
Mechanical Pulping: Logs are debarked and ground into pulp using mechanical grinders. This process retains most of the lignin, resulting in stronger but less durable paper.
Chemical Pulping: Wood chips are cooked with chemicals (like sodium hydroxide and sodium sulfide in the Kraft process) to break down lignin and separate cellulose fibers. This produces a higher quality and more durable pulp.
Recycled Pulping: Recycled paper is mixed with water and broken down into fibers, contaminants are removed through screening and cleaning.
Bleaching:
The pulp is often bleached to produce white paper. This can be done using chlorine, chlorine dioxide, oxygen, or hydrogen peroxide.
Refining:
The pulp is further refined to improve the bonding between fibers. This process can involve beating the pulp to change the fiber characteristics.
Sheet Formation:
The refined pulp is mixed with water to create a slurry.
The slurry is spread onto a moving mesh screen, where water drains away, leaving a mat of fibers.
Pressing:
The wet fiber mat is passed through a series of rollers to remove more water and consolidate the fibers.
Drying:
The pressed fiber mat is passed over heated drying cylinders to remove remaining moisture.
Surface Treatment:
The dried paper may be coated or sized to improve its surface properties, such as smoothness, printability, and water resistance.
Finishing:
The paper is calendered (passed through rollers) to achieve the desired thickness and smoothness.
The paper is then cut into sheets or wound into rolls for distribution.
Quality Control:
Throughout the process, various tests are conducted to ensure the paper meets quality standards for strength, color, thickness, and other properties.
Each step in the paper-making process can vary depending on the type of paper being produced and the specific requirements of the end product.

Хобби