PS resin, that is, polystyrene (Polystyrene), is a thermoplastic resin polymerized from styrene as the main raw material, is one of the five major general-purpose plastics, with many excellent characteristics, widely used in many fields.​
From the point of view of physical properties, PS resin is a glossy, transparent bead or granular solid, density of about 1.04 - 1.09g/cm³, transparency of up to 88% - 92%, refractive index of 1.59 - 1.60 between the appearance of very beautiful. Its melting temperature is 150 - 180 ℃, thermal decomposition temperature of 300 ℃, heat distortion temperature of 70 - 100 ℃, long-term use of 60 - 80 ℃, which makes it in some of the temperature requirements of the scene can play a role in some of the PS resin electrical insulation properties, volume resistivity and surface resistivity are excellent. Volume resistivity and surface resistivity are very high, and is not affected by changes in temperature and humidity, but also not affected by corona discharge, so in the field of electronics and electrical appliances are very useful. At the same time, it also has good processing fluidity, easy to mold, can be injection molding, extrusion, blow molding, foaming, thermoforming, bonding, coating, welding, machining, printing and other methods of processing into a variety of parts, especially suitable for injection molding. In addition, PS resin is easy to color, can be made into colorful products, but also has a good rigidity and chemical resistance, can withstand some mineral oil, organic acids, alkalis, salts, low-grade alcohols and their aqueous solutions. However, it also has some shortcomings, such as brittle and easy to crack, low impact strength, poor heat resistance, not resistant to boiling water, can only be used at lower temperatures and lower loads, poor sunlight resistance, and flammable, combustion will be black smoke and produce a special odor.​
In terms of production methods, there are mainly propriety polymerization method and suspension polymerization method. In this method, styrene monomer is sent to pre-polymerization kettle, adding a small amount of additives and initiators, and pre-polymerization is carried out at 95 - 115 ℃, when the conversion rate reaches 20% - 35%, and then sent to the tower reactor to carry out continuous polymerization, and the temperature of polymerization is gradually raised to 170 ℃ or so in order to realize the complete conversion, and the unreacted styrene is recovered from the top of the tower. The unreacted styrene is recovered from the top of the tower, and the polymer is discharged from the bottom of the tower and extruded for pelletizing. Suspension polymerization method is to use styrene as monomer, water as a medium, add gelatin, starch, polyvinyl alcohol and other protective gum, or magnesium carbonate, magnesium silicate and other insoluble inorganic salts as a dispersant, as well as maleic anhydride - styrene copolymer sodium salt as a co-dispersant, to benzoyl peroxide as an initiator, initiating polymerization at about 85 ℃, but also in the high-pressure polymerization autoclave at 100 ℃. It can also be polymerized at high temperature above 100℃ in autoclave, and finally washed, separated and dried to obtain colorless and transparent fine bead resin.​
According to the differences in performance and use, PS resin is mainly divided into general-purpose polystyrene (GPPS), high-impact polystyrene (HIPS) and evaporable polystyrene (EPS) and other types. General-purpose polystyrene is a thermoplastic resin, showing a glossy transparent, with good electrical insulation properties, processing fluidity, rigidity, and chemical resistance, but it is brittle and easy to crack, low impact strength, mainly used in the manufacture of injection molded parts, audio-visual products, lighting products, transparent stationery, food and cosmetic display containers and other products. High impact polystyrene is added to polystyrene polybutyl rubber particles and other substances to improve the impact strength, but the product is opaque, commonly used in the production of electronic product shells, cassette recorders shells, daily necessities, home appliances and small power tools shells, and other products that require high impact resistance. Expandable polystyrene is a low boiling point physical blowing agent added to PS resin, processed by heat foaming, light weight, heat insulation, sound insulation, shockproof and other characteristics, widely used in the production of fast-food lunch boxes, construction panels, building thermal insulation materials, fragile cushioning packaging materials and other foam products.​
In terms of practical applications, the figure of PS resin can be seen everywhere. In the field of electronic and electrical appliances, due to its excellent electrical insulation, can be used to manufacture connectors, switch parts, small electric cover, etc., to ensure the stable transmission of equipment current; in the field of daily necessities, GPPS easy to process, easy to color the characteristics of the production of transparent cups, tableware, stationery supplies, etc., the ideal material; in the toy industry, PS resin can be made into a variety of lovely shapes, colorful toys; in the field of building materials, EPS can be used for building thermal insulation, reduce building energy consumption, PS resin can also be made into stone, wood-like decorative panels for stone. In the field of building materials, EPS can be used for building insulation and thermal insulation, reduce building energy consumption, PS resin can also be made of imitation stone, imitation wood decorative panels for indoor and outdoor decoration; in the packaging industry, PS resin molding is good, can be made of disposable lunch boxes, food packaging film, packaging containers, etc., to play a role in the protection and display of products; in the medical industry, PS materials in line with health standards can be made of medical equipment shell, disposable syringe parts, etc.. In the medical industry, PS material conforming to hygiene standards can be used to make the shell of medical instruments, disposable syringe parts, etc.​
With the continuous progress of science and technology, PS resin is also constantly improving and innovating, through chemical modification or physical modification, to enhance its performance, expand the scope of application to better meet the needs of various industries, and continue to play an important role in modern life.
PET resin, polyethylene terephthalate, is a linear thermoplastic polymer produced by polycondensation of terephthalic acid and ethylene glycol. It has excellent physical and mechanical properties, such as high strength, good rigidity, impact resistance is outstanding in thermoplastics, but also has good chemical resistance, in addition to a few strong solvents, most of the acids, alkalis, salts have good resistance. In addition, PET resin has good high temperature resistance, long-term use temperature can reach 120 ℃ or so, and excellent electrical insulation properties, light transmission is also more outstanding, these characteristics make it in many areas are widely used.
In the field of packaging, PET resin is one of the main materials for making plastic bottles. Many of the common mineral water bottles, beverage bottles, edible oil bottles, etc. in our daily life are made of PET resin. This is because PET bottles are characterized by light weight, high transparency and good sealing, which can clearly display the products inside the bottles, and at the same time effectively prevent the contents from leaking and deteriorating. Moreover, PET bottles are strong enough to withstand a certain amount of pressure during transportation and storage, and have a high recycling rate, which is in line with the trend of environmental protection. In addition to plastic bottles, PET resin can also be used to make food packaging film, this film has a good barrier, can effectively block oxygen, water vapor, etc., to extend the shelf life of food, commonly used in meat, pastries and other food packaging.
In the textile industry, PET resin is the core raw material for the production of polyester fiber. Polyester fiber has the advantages of high strength, good elasticity, wear-resistant, light-resistant, corrosion-resistant, etc. It is widely used in clothing fabrics, home textile products, industrial fabrics and other fields. Clothing made of polyester fiber is stiff and wrinkle-resistant, not easy to deform, and easy to dry after washing; home textile, polyester sheets, curtains, etc., strong durability, bright colors; industry, polyester fiber can be used to make filter cloth, conveyor belts, etc., to give full play to its high-strength and wear-resistant properties.
In the field of engineering plastics, reinforced PET resin (such as glass fiber reinforced PET) is widely used. By adding glass fibers and other reinforcing materials, PET resin mechanical properties have been significantly improved, strength, rigidity and heat resistance have been greatly improved, can be used for the manufacture of automotive parts, electronic and electrical enclosures and so on. In the automotive industry, reinforced PET can be used for the production of door handles, dashboard components, engine peripheral parts, etc., not only light weight, can realize the car lightweight, but also to meet the use of the mechanical properties of the process requirements; in the field of electronic and electrical appliances, reinforced PET can be used for the production of printers, photocopiers, and other equipment such as shells and internal structural parts, with good dimensional stability and temperature resistance.
In the film field, in addition to food packaging film, PET resin can also be used to make electrical insulation film. This film has excellent electrical insulation properties and high temperature resistance, can be used for electrical equipment such as motors, transformers and other insulating materials, to ensure the safe and stable operation of equipment. In addition, PET film can also be made after stretching treatment stretch PET film, its strength is higher, better toughness, can be used for the production of magnetic tapes, optical discs, such as the base film.
With the continuous development of technology, PET resin applications are still expanding. For example, in the medical field, some special modified PET materials can be used to make medical equipment components, with good biocompatibility; in the construction field, PET resin can be used to make sound insulation materials, thermal insulation materials, etc., to take advantage of its certain barrier properties and mechanical properties. At the same time, PET resin recycling technology is also advancing, after the recovery of PET can be processed through chemical or physical methods, re-used in the production of plastic bottles, fibers and other products, further promoting the recycling of resources.
If you have PET material purchasing needs, please contact us, Ningbo Chaohe Plastic will be happy to provide you with high quality materials and first-class customer service. We are looking forward to cooperating with you and creating a bright future together!