The upstream product chain of cellulose acetate flakes mainly involves multiple chemical and processing procedures from raw materials to cellulose derivatives. The following are the main upstream products and their brief descriptions:

1. Raw materials

Wood pulp (wood pulp): Chemical or dissolved pulp derived from wood (such as coniferous or broad-leaved trees), providing high-purity cellulose.

Cotton short staple pulp: extracted from short fibers on the surface of cotton seeds, with higher cellulose purity, commonly used in high-quality products.

2. Intermediate chemicals

Acetic acid (acetic acid): used in esterification reactions to react with cellulose to produce cellulose acetate. Usually produced by carbonylation of methanol or oxidation of acetaldehyde.

Acetic anhydride (acetic anhydride): a key reagent in esterification reactions, enhancing reaction efficiency, usually obtained by cracking acetic acid or reacting vinyl ketone with acetic acid.

Sulfuric acid or other catalysts: act as catalysts for esterification reactions, promoting the reaction of cellulose with acetic acid/acetic anhydride.

3. Precursor materials

Primary cellulose acetate (or cellulose acetate stock solution): A crude product formed by esterification of cellulose under the action of acetic acid, acetic anhydride, and catalyst, which has not yet been formed into a sheet.

4. Auxiliary materials

Solvent (such as acetone): used to dissolve primary cellulose acetate, form spinning solution or casting film solution, and prepare for sheet forming process.

Plasticizers (such as phthalates): added during the film making process to improve the flexibility of the material.

Stabilizers and additives: used to enhance the heat resistance, weather resistance, and other properties of products.

5. Energy and Public Works

Steam, electricity, water: energy and utilities required in the production process.

6. Equipment and Packaging

Chemical reaction vessels, filtration equipment, drying machines, etc.: used for esterification, precipitation, washing, and drying.

Casting machine or extrusion equipment: Process cellulose acetate solution into sheets.

Packaging materials: necessary for the protection and transportation of finished products.

Overview of industrial chain process:

Wood/cotton short fibers → pulp → cellulose+acetic acid/acetic anhydride (esterification reaction) → primary cellulose acetate → dissolution/addition of additives → casting or extrusion molding → cellulose acetate flakes