Amut S.p.A. of Italy says it has launched a patented friction washer designed to eliminate impurities from recycled PET (rPET) with a continuous and carefully controlled process that also consumes less water than other cleaning systems.

Amut says its plant reduces water consumption by two-thirds compared to other cleaning systems; the system uses 1 liter of water per kilogram (2.1 pints per 2.2 pounds) of rPET. The final product has high purity levels, Amut says, with levels of organic residues around 20 parts per million.

The friction washer is designed to eliminate contaminants such as labels, glue, residues of organic substances and surface dirt from rPET flakes or bottles.

The machine is fed directly from an external screw conveyor, which transports the material to be processed and discharges it into the entrance mouth. Inside the friction washer, the rPET is washed with hot water and chemicals, soda and detergent. According to Amut, the combined action of the friction generated by the rotor, together with the action of hot water and chemicals, enables a perfect washing of the rPET flakes.

The machine features automatic and continuous operation, in which the same quantity of material enters and exits after being treated for a certain time, which can be set and changed by the operator, the company says.

The water coming out of the friction washer, together with the impurities, is treated with a special vacuum filter and recirculated through a heat exchanger.

System features include: 

• Residence time control (determined by the ratio volume / flow rate);
• Friction coefficient control;
• Automatic temperature control;
• Chemical concentration;
• Flow water recirculation and filtering system;
• Heat exchanger system controls water temperature automatically and recovers residual heat through high efficiency; and
• Customizable plant sizes.