What Are Polyester Chips? Polyester chips, their distinctive features, wide-ranging applications, manufacturing process, and current market status are the focal points of this article.
1. What Are Polyester Chips?
Polyester chips, also known as polyethylene terephthalate (PET), are solid, granular substances. They are synthesized from purified terephthalic acid (PTA) and ethylene glycol (EG). The two primary manufacturing methods for polyester are direct esterification (PTA method) and ester exchange (DMT method). The PTA method is favored for its low raw material consumption and shorter reaction time. It has been the primary choice and preferred production process since the 1980s.
In the market for polyester chips, you might often come across terms like “bright,” “semi-dull,” and “dull,” referring to the titanium dioxide content in the chips. The addition of titanium dioxide in the melt is used to reduce fiber luster. Bright polyester chips contain no titanium dioxide. Dull polyester chips have around 0.1% titanium dioxide. Semi-dull polyester chips contain approximately (0.32±0.03)%. Full-dull polyester chips have a titanium dioxide content of 2.4% to 2.5%.
Molecular Formula: (C10H8O4)n
Categories: Polymer
Appearance: White or light yellow transparent solid
CAS No.: 25038-59-9
2. Types of Polyester
2.1. PET Polyester Chips
PET polyester chips are the most common type. It is known for its excellent mechanical and thermal stability and chemical resistance. They also have outstanding transparency and surface gloss. PET polyester chips find wide applications in plastic, textile, construction, and packaging industries.
2.2. PBT Polyester Chips:
PBT polyester chips offer good insulation and weather resistance properties. It is suitable for applications in the electrical, electronic, and automotive sectors.
2.3. PPE Polyester Chips
PPE polyester chips have high-temperature resistance and toughness. It is useful in the electronics, automotive, and construction industries.
3. Classification of Polyester Chips
Based on composition and structure: blend, copolymer, crystalline, liquid crystalline, cyclic polyester chips, and more.
Based on properties: colored, flame retardant, anti-static, moisture-absorbing, anti-pilling, antibacterial, whitening, low melting point, and high melt (high viscosity) polyester chips.
Based on purpose: textile-grade polyester chips, bottle-grade polyester chips, and film-grade polyester chips (primarily differing in process parameters).
Furthermore, fiber-grade polyester chips can be classified as ultra-bright (full-bright), bright, semi-dull, and (full) dull polyester chips depending on the level of matting agents used.
Additionally, there are cationic polyester chips.
More details can be checked in the Classification of PET Chips.
4. Polyester Chip Specifications
Polyester chip specifications include viscosity, carboxyl end group content, melting point, diethylene glycol content, color, titanium dioxide content, iron content, ash content, moisture, and irregularly shaped chips.
More details can be checked in the Introduction of Polyester Chip Index.
5. Polyester Chip Production Process
The production of polyester chips is a part of the petrochemical industry. The main raw materials are PTA and MEG, with the industry’s source being petroleum. The process begins with petroleum being processed into naphtha. It is then further refined into PX through various processes like catalytic reforming, aromatic hydrocarbon extraction, and isomerization. PX is then converted into purified terephthalic acid (PTA) using acetic acid as a solvent, air oxidation, and hydrogenation purification. MEG is produced by the reaction of ethylene oxide, a derivative of the petrochemical industry.
Currently, the world primarily uses the direct reaction production process with PTA and EG to synthesize polyester. This process involves esterification and polycondensation reactions. The main production steps are:
01 Slurry Preparation: Mixing PTA and EG to create a slurry suitable for esterification.
02 Additive Mixing: Preparing various additives required for production with EG.
03 Esterification: PTA and EG react under certain temperature and pressure conditions to produce the intermediate product, bis(2-hydroxyethyl) terephthalate (BHET), and water. Water is separated by distillation and directed to the wastewater treatment system.
04 Polymerization Reaction: BHET undergoes polymerization at high temperatures, under vacuum, and in the presence of a catalyst.
05 Vacuum Pumping: Steam from the esterification tower generates a vacuum to remove EG efficiently, ensuring normal polymerization.
06 EG Recovery: The EG produced throughout the process is purified, with approximately 95% being recycled and mixed with PTA to form a slurry.
07 Pelletization: The dried and crystallized polyester chips are processed into specific-sized chips (granules) through filtration and pelletization.
08 Solid-Phase Polymerization: Polyester chips (granules) undergo solid-phase polymerization in a nitrogen atmosphere at a specific temperature, where polymer chains undergo further reactions to improve chip polymerization and viscosity. Simultaneously, low-molecular-weight byproducts like EG and acetaldehyde are released.
The overall process from petroleum to textile manufacturing is described as follows:
Petroleum → Naphtha → Xylene (MX0) → Terephthalic Acid (PX) → Purified Terephthalic Acid (PTA) → Polyester Chips (also known as PET) → Production of polyester fiber or, alternatively, processing polyester chip grades into staple fibers.
6. Difference Between Polyester Chips and Polyester Fiber
6.1. Composition
Polyester fibers are composed of polyester compounds, primarily terephthalic acid and ethylene glycol. The primary raw materials for polyester fibers are purified terephthalic acid (PTA), dimethyl terephthalate (DMT), and ethylene glycol (EG).
6.2. Polymerization Method
Polyester chips are produced through direct esterification (PTA method) or ester exchange (DMT method). In contrast, polyester fibers are formed by esterification or ester exchange and condensation reactions. It creates high-polymer PET. This PET is then processed into fibers after spinning and post-treatment.
6.3. Applications
Polyester chips are mainly used in polyester molding, injection molding, and thermoplastic resin applications. It can enhance material hardness, wear resistance, ductility, and impact resistance. Polyester fibers find diverse applications in textile and industrial product manufacturing. It includes clothing, furnishings, and industrial materials.
7. Advantages of Polyester Chips
7.1. Versatility
Polyester chips can be tailored to meet specific requirements. So it is used in a wide range of industries, from textiles to plastics, electronics, and automotive manufacturing.
7.2. Cost-Effectiveness
Polyester chips offer a cost-effective solution for various applications, especially in the form of non-woven fabrics. It reduces production expenses.
7.3. Durability
These chips are known for their durability and resistance to corrosion. It is a suitable choice for construction, home goods, and automotive components.
7.4. Environmental Friendliness
Non-woven fabrics produced from polyester chips are eco-friendly and recyclable. It contributes to sustainability efforts.
7.5. Safety
Polyester fibers are used in safety applications, such as airbags and safety belts. Because their flame-resistant properties are good.
7.6. High Modulus
High-modulus polyester industrial yarn is replacing other materials in tire manufacturing. It has improved performance and cost-effectiveness advantages.
7.7. Advanced Materials
Polyester chips can be used to create advanced materials like liquid crystal polymer fibers. In some specialized applications they are widely used, such as airbags for space exploration.
7.8. Customization
The ability to produce differentiated polyester chips allows manufacturers to create tailored materials. they materials can meet specific market demands.
8. Specific Applications of Polyester Chips
Polyester chips can be used in various industries, such as the textile industry, film industry, automotive, electronics, packaging, and so on.
8.1. Textile Industry
Polyester chips find extensive use in the textile industry. It can produce breathable fabrics, air filters, and non-woven materials. Non-woven fabrics are a significant application of polyester chips. They are cost-effective, friendly, and have excellent strength and durability. They are commonly used in packaging, bedding, medical supplies, and environmental protection.
Common types of PET textile fabrics include pure polyester, polyester-cotton blends, and CVC fabrics. Fabrics like chiffon and organza are primarily composed of 100% polyester. Other materials like georgette are also popular choices.
8.2. Plastic Industry
Polyester chips are vital for the production of diverse plastic products. It can produce bottles, pipes, wires and cables, and luggage. They can also be used on a large scale in engineering plastics, agricultural films, etc.
8.3. Bottle Grade Market
Polyester chips are primarily used in the production of bottle-grade polyester, a material widely used in beverage packaging, especially for carbonated drinks.
8.4. Construction and Home Goods
Polyester chips are utilized in the manufacture of construction and home goods such as flooring, wall panels, and furniture. It has features of excellent durability, resistance to corrosion, and a wide range of available colors. So it has become a popular material in the home decor industry.
Especially those made from polybutylene terephthalate (PBT) and its copolymers, they are valued for their high standardization, low volatility, and mechanical strength. They are extensively used in the manufacturing of automotive components and household appliances.
8.5. Packaging
Polyester chips are essential in the production of various packaging materials and containers.
8.6. Electronics
Polyester chips play a crucial role in manufacturing electronic materials and components.
8.7. Automotive Sector
Polyester chips are used to produce a wide array of automotive parts.
8.8. Textiles for Transportation
Transportation textiles include items for road vehicles, railways, ships, aircraft, and spacecraft. Direct applications of polyester fibers include seat covers, safety belts, carpets, and more. Indirect applications include composite materials for inflatable boat bodies, tire cord fabrics, airbags, automotive interior fabrics, sound-absorbing insulation, hoses, hose reinforcement fibers, filters, and firefighting hoses for ships.
Notably, approximately 90% of automotive seat fabrics worldwide use polyester fibers. These fabrics need to be flame-resistant. It can be achieved through fabric finishing methods or by using flame-resistant fibers, such as a blend of polyester and aramid fibers in a 50/50 ratio.
Polyester industrial yarn is used in airbags. It accounts for about 30% of the airbag’s cost, significantly reducing production costs compared to using polyamide fibers. It has a competitive advantage in this regard.
High-modulus, low-shrinkage (HMLS) polyester industrial yarn is replacing some spandex filament yarn due to its higher modulus, improving the “flat tire” phenomenon. As a result, it’s gradually gaining a share in the production of semi-steel radial tires.
Global demand for fiber used in safety belts exceeds 550,000 tons per year. PET chips with a specific viscosity of 1.12 dL/g, spun at 291°C with a quenching air speed of 0.5 m/s and a total draw ratio of 5.9, produce industrial yarn with a strength of 8.21 cN/dtex and an elongation at break of 14.2%, meeting the requirements of high-performance safety belts.
Liquid crystal polymer (LCP) fibers are used to manufacture various airbags, airships, and other inflatable materials. For the Mars Exploration Rover airbag systems, which face extreme temperature fluctuations from -50°C to 100°C on the Martian surface while maintaining airtightness, the innermost layers of the landing airbags are made of 220 dtex Vectran long filament fabric, coated with silicone. In the envelope structure of Lindstrand’s stratospheric airships, the primary load-bearing layer also employs Vectran and PBO fibers.
For luxurious synthetic suede fabric composed of polyester and polyurethane, is used in interior design and luxury car interiors. PVC-coated woven fabrics made from polyester industrial yarn have gradually replaced textiles processed from cotton, viscose, and short polyester fibers, making them ideal for long-haul side-curtain trailers in Europe and North America. The use of these materials has helped reduce vehicle weight by approximately 4 tons. It results in fuel savings and increased carrying capacity.
9. PET chips Industry Status
In this section, we will discuss the status of the polyester chip market in China from 2016 to 2021:
9.1. Basic Industry Overview
The demand for PET chips in China is divided into domestic consumption and exports. From 2016 to 2021, domestic consumption increased from 4.56 million tons to 7.12 million tons, with a compound annual growth rate of 9%. Due to the strong price and quality advantages of domestic companies, the export volume of PET chips also saw rapid growth, rising from 2.16 million tons in 2017 to 3.18 million tons in 2021, with a compound annual growth rate of 10%.
From 2016 to 2018, domestic PET chip prices experienced fluctuations. Because crude oil prices rise and the suspension of production by some large PET chip manufacturers overseas. In 2019 and 2020, prices declined due to the gradual recovery of overseas production capacities and falling raw material prices. In 2021, PET chip prices saw a significant rebound. It is driven by rapid increases in upstream raw material prices and increased domestic and international demand.
Additionally, PET chip products exhibit some seasonality. It is influenced by the demand from the beverage industry during significant holidays such as New Year and summer. They are peak seasons for beverage sales. So bottle-grade PET chips are in large demand.
9.2. Industry Development Trends
The PET chip industry in China has a high capital and technology threshold. In recent years, the industry concentration has been continuously increasing. Leading companies enhance their capabilities. It is expected that the concentration of production capacity in the PET chip industry will further increase in the future. The trend toward larger and more centralized enterprises is a significant development in China’s PET chip industry.
Production through continuous copolymerization modification demonstrates some differentiation. Functional polyester (PET) is also encouraged by the National Development and Reform Commission. These are all conducive to the development of the polyester industry chain. New types of polyester materials are expected to create new growth opportunities for the industry.
In recent years, most of the new demand has been for differentiated varieties. These varieties include low viscosity, low melting point, and cationic differentiated varieties. Differentiated slice production is already profitable. It has led to many factories changing spinning stations. Some others add new stations to increase differentiated production.
In recent years, composite elastic fibers have appeared on the market. Prominent examples are PET (polyethylene terephthalate) and T400. These fibers are characterized by a parallel composite structure. One of the ingredients is a low-viscosity PET with a viscosity range of 0.47-0.65, while the other ingredient is a high-viscosity PET with a viscosity range of 0.82-1.05. These parallel composite PET fibers were created by utilizing PET slices of different viscosities and adjusting the temperature of the spinning assembly. The resulting composite fiber exhibits excellent elasticity and strength. Making it an ideal choice for polyester stretch thread products. Also, they have good chemical stability. Can enhance the elasticity and feel of polyester fabrics while maintaining chlorine resistance.
9.3. Future demand trends for world polyester chips
The global supply of polyester chips will continue to increase in the coming years. This capacity expansion is mainly concentrated in Northeast Asia, India and Pakistan, Southeast Asia, and the Middle East. The upward trend in supply is driven by several factors:
9.3.1. Investment in polyester fibers continues to grow:
The continued growth in demand for polyester fibers, especially in emerging markets, is an important driver. This is due to the versatility and cost-effectiveness of polyester materials.
9.3.2. Diverse end uses:
Polyester chips are not only in increasing demand for textile applications. And demand for non-fiber uses is increasing. Industries such as plastics, electronics, automotive, and construction are increasingly incorporating polyester chips into their manufacturing.
9.3.3. Environmental Concerns:
The trend is towards eco-friendliness. It has prompted a shift toward the use of polyester chips. So recyclable and sustainable materials will be more and more popular.
9.3.4. Safety and Durability:
In sectors such as automotive manufacturing and safety applications, the flame-resistant and high-strength properties of polyester chips have elevated their demand.
9.3.5. Specialized Applications:
The development of unique products like liquid crystal polymer fibers for applications such as aerospace and space exploration is expected to further drive demand for polyester chips.
The polyester chips market continues to grow year by year. Industry players should focus on the specific needs of different regions and industries. Polyester chips offer a variety of applications in various industries. making it an integral part of the global manufacturing process. The polyester chips industry will expand further in the coming years. We can provide solutions for a wide range of modern needs. These needs are from textiles and plastics to advanced materials and sustainability initiatives.
The rise of specialty polyester chips, such as PET and T400 composite fibers, demonstrates the industry’s commitment to innovation and adaptability in response to changing market demands. The polyester chips industry is expected to boom as demand continues to grow, especially from emerging economies. Northeast Asia, India, Pakistan, and the Middle East remain the focus of growth.
