Read PET plastic?
PET plastic molecular structure is highly symmetrical, with a certain ability to crystallize orientation, so it has a high film formation and sex. PET plastic has good optical properties and weather resistance, and amorphous PET plastic has good optical transparency.
In addition, PET plastic has excellent abrasion resistance and dimensional stability and electrical insulation. PET bottles have been widely used because of their high strength, good transparency, non-toxic, impermeable, light weight and high production efficiency. PBT and PET molecular chain structure is similar, most of the properties are the same, but the molecular main chain from two methylene into four, so the molecule is more flexible, processing performance is better.
PET is a milky white or light yellow highly crystalline polymer with a smooth and glossy surface. Creep resistance, fatigue resistance, good friction resistance, small wear and high hardness, with the greatest toughness of thermoplastics; Good electrical insulation performance, little affected by temperature, but poor corona resistance. Non-toxic, weather resistance, good stability against chemicals, high moisture absorption, drying before molding is a must. Resistance to weak acids and organic solvents, but not heat resistant water immersion, not alkali resistance.
PET resin has high glass transition temperature, slow crystallization rate, long molding cycle, long molding cycle, large molding shrinkage, poor dimensional stability, brittle crystallization molding, low heat resistance.
Through the improvement of nucleating agents and crystallizing agents and glass fiber reinforcement, PET in addition to the properties of PBT, there are the following characteristics:
1. The thermal deformation temperature and long-term use temperature are the highest in thermoplastic general engineering plastics;2. Because of the high heat resistance, enhanced PET in 250¡æ solder bath impregnated 10s, almost no deformation and no discoloration, especially suitable for the preparation of solder electronic and electrical parts;
3. Bending strength 200MPa, elastic modulus up to 4000MPa, creep resistance and fatigue is also very good, high surface hardness, mechanical properties and thermosetting plastics similar;
4. Since the price of ethylene glycol used in the production of PET is almost half cheaper than that of butanediol used in the production of PBT, PET resin and reinforced PET are the lowest price among engineering plastics and have a high cost performance.
5. Bonding of PET resin: sili-1706 single component room temperature vulcanizate, curing is an elastomer with excellent waterproof, shock-proof adhesive, high and low temperature resistance, because ›q force technology according to the molecular structure of the resin research, so it is specially used for bonding engineering plastics.
use
glass fiber reinforced PET is applicable to electronic, electrical and automobile industry Used in all kinds of coil skeleton, transformer, TV, tape recorder parts and shell, automobile lamp holder, lamp shade, white heat lamp holder, relay, selenium rectifier and so on. PET engineering plastics currently several application areas of consumption ratio is: electrical and electronic 26%, automotive 22%, machinery 19%, appliances 10%, consumer goods 10%, other 13%. At present, the total consumption of PET engineering plastics is not large, accounting for only 1.6% of the total PET.
1. Film sheet: all kinds of food, drugs, non-toxic and sterile packaging materials; High-grade packaging materials for textiles, precision instruments and electrical components; Substrates for audiotape, video tape, motion picture film, computer diskette, metal coating and photographic film, etc.; Electrical insulation materials, capacitor films, flexible printed circuit boards and film switches and other electronic and mechanical fields.
2. Application of packaging bottles: Its application has been developed from the initial carbonated beverage to the present beer bottles, edible oil bottles, condiment bottles, medicine bottles, cosmetics bottles, etc.
3. Electronic and electrical appliances: manufacture connectors, coil winding tubes, integrated circuit shells, capacitor shells, transformer shells, TV accessories, tuners, switches, timer shells, automatic fuses, motor brackets and relays.
4. Auto parts: such as switchboard cover, ignition coil, various valves, exhaust parts, distributor cover, measuring instrument cover, small motor cover, etc., can also use PET excellent coating, surface gloss and rigidity, manufacturing automotive external parts.
5. Mechanical equipment: manufacturing gear, CAM, pump housing, pulley, motor frame and watch parts, can also be used as microwave oven baking pan, all kinds of ceilings, outdoor billboards and models. .
6.PET plastic molding processing can be injection molding, extrusion, blow molding, coating, bonding, machining, electroplating, vacuum gold plating, printing.
Identification method
1, first smell the taste, PET taste is different from general plastic, burn it with a lighter, and then will smell very fragrant and comfortable taste (just burn a bottle to smell), If PET contains other ingredients, the taste is very pungent. One bottle that contains SEBS should not be used.
2, look at the burning part, if it is too black or the oil drops quickly, most of the melting point is not normal, which is often in PET film.
3, wire drawing, burning in the lighter to pull the wire, see the wire is not long, and then pull out of the wire break, see the middle of the break point, the wire is not rolled into a small circle, the more the volume indicates the melting point is high.
But generally if it is a bottle, there should be no big problem. The most critical point is to distinguish whether it contains PVC, which is the fatal injury of PET. First take more samples, and then lay them out in a sunny place. PVC looks pale blue in the sun. If folded in half, there will be white creases. The above is the naked eye identification, the accuracy is limited, mainly to see experience.
There is a more practical and better way to buy an oven to set the temperature to 250 degrees where it is baked for half an hour, if the goods contain PVC, the surface will have a lot of yellow spots; If the melting point is not enough, it will melt quickly.
In fact, there are many varieties of PET to do, such as PET crushed film from foreign factories, pulp block material, rolled film with a length of less than 30 cm, which have different customer groups.
The identification of these goods, strongly require the oven to test. In particular, PET drum in the whole market is a very short supply, the general length of 80 to 120 cm or more, the thickness of 3-5 silk film price is very high (white transparent).