PET

Thermal Properties

The thermal properties of PET plastics are crucial for their versatile applications. PET is characterized by good heat resistance. Its glass transition point (Tg) is typically between 70°C and 80°C. Its melting point (Tm) is typically between 250°C and 260°C, which allows for processing by melt extrusion and injection molding. PET's thermal conductivity is relatively low, typically around 0.15 to 0.4 W/(m·K), making it a good insulator. Its coefficient of thermal expansion is in the range of 10^-5 per degree Celsius, which must be considered when designing components to avoid stresses caused by temperature changes.

Mechanical Properties

PET is a plastic with good mechanical properties, characterized by high strength, stiffness, and toughness. The specific properties can be tailored to the application by selecting the molecular weight, filler, crystallinity, and additives. PET's creep behavior is low compared to other plastics. It is used in components where the shape and dimensions of the material must remain stable over long periods of time. It is important to consider relevant parameters such as tensile strength, tensile modulus, elongation at break, and impact strength to select the optimal PET for the respective application.

Chemical Resistance

PET plastics are characterized by good chemical resistance to a wide range of substances. PET is resistant to diluted acids, oils, fats, and alcohols. However, PET is susceptible to attack by strong bases such as caustic soda and certain solvents such as chloroform, which can lead to swelling and cracking. Resistance to organic solvents varies; while PET is resistant to aliphatic hydrocarbons, it can be attacked by aromatic hydrocarbons and halogenated solvents.

Other Specific Properties

A key aspect of PET is its recyclability. It is highly recyclable and can be reused multiple times. PET is characterized by high tensile strength and stiffness, making it resistant to deformation and stress. PET provides a good barrier against gases such as oxygen and carbon dioxide, making it ideal for packaging food and beverages to extend their shelf life. PET can be processed using various methods, including injection molding, extrusion, and blow molding. It is important to dry the material before processing to avoid hydrolysis.

Packaging and food industry: Crystal-clear PET has established itself in the packaging and food industries due to its remarkable properties. A key application is beverage packaging, particularly PET bottles for carbonated beverages, water, juices, and sports drinks, as PET offers high strength, low weight, and a good barrier against gases and flavors. PET food containers are also used for salad dressings, sauces, oils, and ready meals. PET films and flexible packaging are used for snacks, confectionery, and meat products, where the high tensile strength and barrier against moisture and oxygen extend shelf life. The increasing use of recycled PET also underscores the industry's commitment to sustainability.

Electronics: PET has a wide range of applications in the electrical industry. Due to its good dielectric properties and thermal stability, PET films are often used as insulation material in capacitors, transformers, and cables to prevent short circuits and ensure operational reliability. In addition, PET molded parts serve as housings or components in switches, connectors, and other electrical components because they offer high mechanical strength and resistance to environmental influences. In printed circuit board manufacturing, PET films are used as a carrier material for flexible circuits because of their good dimensional stability and flexibility. PET's ability to be recycled further contributes to this material's growing popularity in the electronics industry, as sustainable solutions are becoming increasingly important.

Toys and Leisure: PET molded parts are often used for housings for electronic toys, model kits, and action figures because of their high robustness and impact resistance. Transparent PET films serve as windows in toy packaging and displays to attractively present the products. In the leisure sector, PET fibers are processed into textiles for sportswear, backpacks, and tents because of their lightweight, durable, and moisture-resistant properties. Drinking bottles and lunch boxes are also often made from PET because it is food-safe and shatter-proof. The use of recycled PET contributes to sustainability in this industry by using it to manufacture new products, thereby conserving resources and reducing waste.