HDPE Milk Bottle Recycling Washing Line

1. Feeding & Size Reduction System

Pre-treatment:
The materials are first loosened using a debaler (or bundle breaker) to separate compressed bales. The loose materials are then conveyed to a pre-washing tank or manual sorting table for initial washing and sorting. A metal separator is used to remove metallic impurities, and a label remover strips off bottle caps and labels.

Crushing:
The containers are directly fed into a crusher for size reduction. The crusher is typically designed with wear-resistant components to ensure long-term stable operation.

2. Hot Washing System

The materials, after friction washing, are further conveyed into a hot water washing tank (sometimes with added alkaline solution). This stage uses high temperatures, steam, and chemical agents to dissolve oil stains and stubborn contaminants. A circulating water system is typically integrated at this stage to maximize water efficiency and ensure continuous operation.

3. High-Speed Friction Washer

The crushed flakes are conveyed to the friction washer, where high-speed rotating paddles and circulating spray systems thoroughly scrub the HDPE flakes, effectively removing residual glue and label traces adhered to the bottle surfaces.

The friction washer and high-speed centrifugal washing system can be adjusted according to the material characteristics, allowing fine-tuning of the rotation speed and blade force to ensure optimal cleaning performance.

4. Sink-Float Separation Unit

Since HDPE has a lower density than water, it floats after washing, while heavier impurities and other plastics (such as PP and PVC) sink and are separated. Through multiple rinsing and repeated sink-float separation cycles, the purity of the HDPE flakes is further improved.

5. Dewatering & Drying System

After rinsing in the rinsing tank to remove residual detergents and impurities, the material is transferred to the dewatering equipment. A centrifugal dewatering machine is commonly used for mechanical dewatering, which can significantly reduce the moisture content of the plastic flakes.

Drying:
Finally, the material is processed by a hot air dryer to further remove residual moisture, ensuring the HDPE flakes reach the target moisture content (e.g., less than 3%). After cooling, the flakes pass through air separation and optional optical (near-infrared) sorting to remove trace impurities and different-colored plastics, resulting in clean, high-quality HDPE final products.

6. Bagging & Packaging Unit