As a plastic raw material, PET mainly includes polyethylene terephthalate PET and polybutylene terephthalate PBT. Polyethylene terephthalate is also commonly known as polyester resin. It is a condensation polymer of terephthalic acid and ethylene glycol, and together with PBT. PET is commonly in daily life, but many people do not know how to identify high-quality PET plastic raw materials.
PET is a milky white or light yellow highly crystalline polymer with a smooth and shiny surface. Creep resistance, fatigue resistance, good friction resistance, low wear and high hardness, with the greatest toughness among thermoplastics; good electrical insulation performance, little affected by temperature, but poor corona resistance. Non-toxic, weather resistance, good stability against chemicals, high hygroscopicity, must drying before molding. Resistant to weak acids and organic solvents, but intolerant hot water immersion and alkali.
PET resin has high glass transition temperature, slow crystallization speed, long molding cycle, long molding cycle, large molding shrinkage, poor dimensional stability, brittle crystallized molding, and low heat resistance.
Besides the properties of PBT, PET also has the following identification methods for PET plastics:
the smell of PET is different from ordinary plastics, burn it with a lighter, and then you will smell very fragrant and comfortable (burn a bottle to smell it), if PET contains other ingredients, the smell will be very pungent . If there is a bottle containing SEBS ingredients, it cannot be used.
when it is burning, pull the wire on the lighter to see if the wire is long, then break the drawn wire, check if the wire is rolled into a small circle at the breakpoint in the middle. The more it rolles, the higher melting point it is.
3. Check the burnt part
If it turns black too much or the oil drops quickly, most of the melting points are abnormal, which is often seen in PET film sheets.
But generally if it is bottle flakes, there shouldn’t be any major problems. 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 flat in a sunny place. PVC is light blue in the sun. If there are white creases in the middle of the fold. The above is the naked eye identification, the accuracy is limited, mainly depends on experience.
There is also a more practical and better way. Buy an oven and adjust the temperature to 250 degrees and bake there for half an hour. If the product contains PVC, there will be a lot of yellow spots on the surface; if the melting point is not enough, it will be very fast melt.
Learn to identify PET plastic raw materials, you can easily find good-quality plastic raw materials.Winiber, provides whole bottle production Line. Includes PET bottle blowing machine, PET preform mould, injection machines and its auxliary machines. Click your mouse to contact with us!