PET bottles and PE bottles have outstanding advantages, such as: non-toxic, light weight, high transparency, high strength, not brittle, good pressure resistance, good air tightness and relatively stable chemical properties, therefore, PET bottles and PE The bottle is an aspirational cosmetic packaging container.
 
1. PET layout
PET is classified as an organic polymer compound, which is composed of three elements: carbon, hydrogen and oxygen. The molecular layout is as follows: H—[OCH2CH2—OOC—CO!—OHPET is usually composed of terephthalic acid (PTA) or dimethyl terephthalate (DMT) and ethylene glycol (EG) for direct esterification or esterification The exchange reaction generates PET monomer, which is then formed by solid-phase polycondensation to form polyethylene terephthalate. The chemical reaction equation is as follows: HOOC—COOH+2HOCH2CH2OH”catalyst base HO—CH2CH2—OOC—COO—CH2CH2OH+2H2O
 
2. The physical function of PET
PET is divided into homopolymerization and copolymerization PET according to the polymerization method, and can be divided into textile PET, bottle-grade PET and sheet-grade PET according to its use. The physical functions of bottle-grade PET are shown in Table 1.
 
Physical function of bottle grade PET
Serial number item characteristic value unit
⒈ Density 1.4 kg/cm3
⒉ Average molecular weight 25000~30000
⒊IV value 0.70~0.85
⒋ Melting point 250~260℃
⒌AA content≤3 mg/Kg
⒍Moisture≤0.4 </p>
⒎Particle shape cylindrical or parallelepiped
 
PET is easy to absorb moisture, requires specific warehouse storage, and effective drying before processing. Residues that are difficult to dispose of in the production raw material and injection molding process release acetaldehyde from PET bottles.
 
3. The function of biaxially stretched PET bottle
(1) It has excellent light transmittance and gloss, and the light transmittance is greater than 85%
(2) It has outstanding mechanical function and impact resistance;
(3) Has excellent chemical resistance;
(4) Excellent dimensional stability at room temperature (20~30℃);
(5) Light weight;
(6) It has excellent barrier properties to gas.
 
Therefore, when purchasing plastic bottle products such as PET bottles and PE bottles, you must order according to the purpose of these plastic bottles you use to prevent the pollution of the products you produce due to different functions.