Shampoo PET Bottle

2026-01-30

When we pick up a commonly used shampoo bottle, there will be a PET label at the bottom of the bottle, indicating that this product is a PET bottle. PET bottles are mainly used in the personal care industry and are mostly large-capacity. PET bottles are plastic containers obtained by processing PET plastic materials through one-step or two-step methods. PET plastic has the characteristics of being lightweight, highly transparent, and resistant to impact and shattering.

PET, or polyethylene terephthalate, is also known as polyester. Its English name is Polyethylene Terephthalate, which is produced by the polymerization reaction (condensation) of two chemical raw materials: terephthalic acid (PTA) and ethylene glycol (EG). Preforms are injection-molded items. As an intermediate semi-finished product for subsequent biaxial stretching and blow molding, the neck of the preform is shaped during the injection molding stage, and its size will not change during heating and stretching/blow molding. The size, weight, and wall thickness of the preform are factors that need to be paid close attention to during the blow molding process of the bottle.

When preparing blow-molded bottles, PET chips are first injected into the preform. It is required that the proportion of recycled materials should not be too high (less than 5%), and the recycling times should not exceed two. The molecular weight and viscosity should not be too low (molecular weight 31,000 - 50,000, intrinsic viscosity 0.78 - 0.85 cm³/g). According to the National Food Safety Law, recycled materials are prohibited from being used for food and drug packaging. The injection-molded preforms need to be stored for more than 24 hours before use. Unused preforms after heating must be stored for more than 48 hours before being reheated. The storage time of the bottles should not exceed six months. The quality of the preform largely depends on the quality of the PET material, so it is necessary to choose materials that are easy to inflate and form, and to develop a reasonable preform molding process. Experiments show that preforms made from imported raw materials with the same viscosity are easier to blow mold than those made from domestic raw materials. However, for the same batch of preforms, different production dates may require different blow molding processes. The quality of the preform determines the difficulty of the blow molding process. The requirements for the preform are purity, transparency, no impurities, no color, appropriate injection point length, and a halo around it.

PP and PE material bottles are mostly solid colors, while PETG, PET, and PVC materials are mostly transparent or colored transparent with a clear and translucent appearance, and solid colors are used less frequently. PET material bottles can also be spray-painted. There is a convex point on the bottom of the blow-molded bottle, which is brighter under light. The bottom of the injection-blow molded bottle has a bonding line. The main accessories for blow-molded bottles include inner stoppers (commonly used for PP and PE materials), outer caps (commonly used for PP, ABS, and acrylic, and also available in electroplated, electro-galvanized, and spray-painted finishes, often used for toner bottles), pump head covers (commonly used for essence and lotion), flip caps, and snap caps (mostly used in large circulation daily chemical lines).