Herbold offers custom wash plant configurations

Herbold Meckesheim USA, North Smithfield, Rhode Island, says it can custom configure polyolefin wash plants that can produce high-quality, food-grade recyclate.

While each wash plant is designed around the user’s specific requirements and facility characteristics, they all feature a multistage process usually consisting of preshredding, prewashing and initial separation, granulation, high-density separation and drying.

Preshredding is typically done using a single-shaft shredder, such as the Herbold 60/120. With a 23.5-inch diameter rotor and 60 individual knives, these machines can accept entire bales of plastic scrap, processing up to 13,000 pounds per hour, according to the company.

Washing takes place in a VWE-60 prewashing unit that uses a three-step process of sink/swim to remove heavy materials, a spray wash to loosen and remove embedded sediment and an additional sink/swim to further eliminate remaining sediment, Herbold says.

Further size reduction takes place in a wet granulator, such as the Herbold 80/120. The wet operation provides additional separation of particles and contaminants.

Additional high-density separation of contaminants and recyclate occurs in a Hydrocyclone. The centrifugal force of the Hydrocylcone is designed to provide separation that exceeds conventional methods by a factor of 15, the company says, ensuring purity necessary for food-grade recyclate production.

After final separation, materials are conveyed to a mechanical or thermal dryer for the removal of residual moisture prior to use or storage.

Herbold Meckesheim USA, a subsidiary of Herbold Meckesheim Germany, designs, manufactures and installs size-reduction equipment and wash-line systems for the plastics industry, specializing in the recycling of industrial and postconsumer plastics.