APR Design Guide for PET rigid packaging<\/a> explains how labels, adhesives, colors, barriers and closures affect an established PET recycling process.<\/p>\nIndustrial PET bottle recycling process<\/h2>\n1. Collection and bale receiving<\/h3>\n
Bottles arrive from deposit-return, curbside, commercial or other collection systems. The plant records supplier and bale grade, weighs the load and inspects moisture, non-PET items, fines and prohibited material. Feed variation must be included when the line is sized.<\/p>\n
2. Bale opening and whole-bottle sorting<\/h3>\n
A bale breaker and metering conveyors separate compacted bottles. Screens and air systems remove loose fines and light material. Manual and optical sorting remove metals, non-PET bottles, PVC, PETG, opaque colors and other contaminants according to the product specification.<\/p>\n
Whole-bottle sorting is especially important for PVC. PVC and PET can both sink in water, so a later float-sink tank is not a reliable primary PVC-removal step.<\/p>\n
3. Label and closure removal<\/h3>\n
Label removers, screens and air separation reduce sleeves and loose labels. Some caps remain until after grinding so their PE or PP can be separated from PET flakes by water density. Adhesive performance, label polymer and ink affect how cleanly the components separate.<\/p>\n
4. Wet granulation<\/h3>\n
A granulator cuts bottles into flakes suitable for washing and separation. Water can cool the cutting chamber and begin removing loose soil. Knife condition, clearance and screen size affect flake distribution and fines.<\/p>\n
5. Washing<\/h3>\n
Prewashing, hot washing, friction washing and rinsing remove beverage residue, dirt, labels, adhesives and chemicals. The wash temperature, chemistry, residence time and mechanical action should be a validated recipe for the actual feed. More chemical is not automatically better; poor rinse control can leave residue.<\/p>\n
6. Density and other separation<\/h3>\n
In water, PET flakes normally sink while unfilled PE and PP closures float. This helps recover a PET fraction and a polyolefin fraction. It does not remove every sinking contaminant, and trapped air, fillers or bonded components can change behavior. Additional flake sorting and metal removal may be required.<\/p>\n
7. Dewatering, drying and flake sorting<\/h3>\n
Mechanical dewatering removes surface water, followed by thermal or other drying when needed. Moisture limit and test method come from storage, transport and downstream processing requirements. Flake sorters may remove remaining color and polymer defects before packaging.<\/p>\n
8. Optional extrusion and pelletizing<\/h3>\n
Clean dry flakes can be melted, vented, filtered and cut into pellets. This step improves feed form and can homogenize a qualified stream, but it does not correct all contamination or create food-contact authorization by itself.<\/p>\n