1. The physical properties of the materials used for plastic bottles are different:
Polyethylene terephthalate (PET) is a colorless transparent substance with a certain gloss (indeterminate), or an opaque milky white substance (crystalline). Difficult to ignite and burn, but once burned, although the flame is separated, it can still continue to burn. When burned, it will melt and burst into fragments, with a yellow flame and early blue edges. There are small droplets falling, black smoke, and a slightly sweet and irritating odor in the mountainous area. The performance of pure PET is very poor, especially in terms of impact strength and heat resistance, but after being reinforced with glass fiber by cosmetic manufacturers, various properties are greatly improved.
Physical properties of polyethylene (PE): Polyethylene is non-toxic, odorless, and milky white in color. A crystalline plastic with a density of 0.91-0.96g/cm3. Polyethylene has a certain mechanical strength, but compared to other plastics, its mechanical strength is low and its surface hardness is poor.
2. Different water resistance:
Polyethylene has excellent insulation properties. At room temperature, polyethylene is insoluble in any known solvent and is resistant to dilute sulfuric acid, dilute nitric acid, and any concentration of other acids, as well as various concentrations of alkali and salt solutions. Polyethylene has high water resistance and its properties can remain unchanged after long-term exposure to water. The polyethylene produced by cosmetics manufacturers has poor water permeability, while it has good permeability to oxygen, carbon dioxide, and many organic matter vapors.
3. Different temperature resistance:
Temperature resistance: Polyethylene will age and become brittle under the action of heat, light, and oxygen. The typical operating temperature for high-pressure polyethylene is around 800C, while for low-pressure polyethylene it is around 1000C. Polyethylene can withstand cold and still has good mechanical properties at -600C, and some flexibility at -700C. PE bottles are relatively soft and have a waxy feel to the touch. Compared to equivalent plastics, they are lighter in weight, semi transparent, and have a blue flame when burned. Common washing products and chemical packaging, such as detergent bottles. The environmental label with a bottom of 2 on the bottle.
PET bottles have high transparency, luster, and a crisp sound when knocked. They are commonly used in beverage bottles, snack food bottles, and peanut oil bottles; The environmental label with a bottom of 1 on the bottle.
