What are the raw materials for the production of polyester fibers
source:
www.wjuafpf.cn | Release time:2025-06-17
The production raw materials of polyester fiber (polyester) mainly revolve around the synthesis of the core polymer polyethylene terephthalate (PET), which can be divided into basic chemical raw materials, auxiliary raw materials, and functional additive materials. The following is a detailed explanation:
1、 Core raw materials: basic chemicals for synthesizing PET
1. Purified Terephthalic Acid (PTA)
Source:
Extracting p-xylene (PX) from petroleum and producing it through oxidation reaction (petrochemical route, the most mainstream).
A small number of bio based routes are used (such as fermenting plant straw to produce terephthalic acid, but the cost is high and it has not yet been widely applied).
Function: As a carboxylic acid component of PET, it condenses with diols to form macromolecular chains.
2. Ethylene Glycol (EG)
Source:
Petrochemical industry: Produced by ethylene hydration (accounting for over 90%), ethylene comes from the cracking of naphtha.
Coal chemical industry: coal to synthesis gas is produced through formaldehyde hydroxylation reaction (with rapid capacity growth in recent years, such as the coal to EG project in northwest China).
Function: As an alcohol component of PET, it provides hydroxyl (- OH) to condense with carboxyl (- COOH) of PTA.
2、 Auxiliary raw materials: additives for polymerization and spinning processes
1. Catalyst
Type:
Antimony based catalysts (such as antimony trioxide Sb ? O3): The most commonly used in traditional PET polymerization, with high catalytic efficiency and low cost.
Titanium based catalysts (such as tetrabutyl titanate): environmentally friendly catalysts suitable for food packaging grade PET (such as beverage bottles) to avoid antimony residue.
Germanium based catalysts (such as germanium dioxide GeO ?): used for highly transparent PET films to reduce yellowing.
Function: Reduce the activation energy of condensation reaction and accelerate the growth of PET molecular chains.
2. Stabilizers
Type:
Heat stabilizers (such as phosphates): prevent PET from undergoing thermal oxidative degradation during high-temperature melting (spinning temperature 280~300 ℃).
UV absorbers (such as benzotriazoles): used for outdoor polyester fibers (such as sunshades) to enhance weather resistance.
Function: Ensure stable fiber performance and extend service life.
3. Solvent (for slice spinning only)
Type: Mixed solvent of phenol and tetrachloroethylene (used for spinning PET slices after dissolution, less common, mainly used for special fibers).
Function: Dissolve PET slices to form spinning solution.
3、 Functional raw materials: endow fibers with special properties
1. Modified additives (added during spinning or post-treatment stage)
Flame retardant:
Phosphorus based (such as phosphate ester) and halogen based (such as bromide): added to PET melt to make flame-retardant polyester (used for firefighting suits and curtains).
Antibacterial agents:
Nano zinc oxide and silver ion powder: attached to the surface of fibers through blending spinning or post finishing processes to prevent bacterial growth.
Colorants:
Organic pigments (such as azo compounds) and inorganic pigments (such as titanium dioxide): added during spinning to make colored fibers (to avoid later dyeing pollution).
2. Functional masterbatch
Type:
Antistatic masterbatch (containing carbon nanotubes and conductive carbon black): improves the disadvantage of polyester being prone to static electricity (used in electronic factory workwear).
Moisture wicking masterbatch (including porous ceramic powder): increases fiber surface grooves to enhance breathability (commonly used in sports fabrics).
4、 Recycled raw materials: the source of environmentally friendly polyester fibers
1. Recycling PET bottle flakes (rPET)
Processing procedure:
Crushing of waste plastic bottles → Cleaning to remove impurities → Drying → Melting granulation → Spinning.
Application: Recycled polyester fibers (such as Adidas marine plastic series) can reduce oil consumption and carbon emissions.
2. Industrial waste recycling
Source: Waste materials from PET production process and textile factories, which are crushed and melted again for spinning.