The shredded rubber fractions from the precleaning stage are milled and flattened into thin sheets with a Dry Rubber Content of approximately 65–70%. This microblending stage aims to facilitate maturation and reduce water content. Milling is performed with creper machines consisting of two iron rolls with narrow gaps, producing rubber blankets 7–8 mm thick. Milling may be carried out for up to 8 passes (on inline systems), with the roll gap wider in the early stages than in the later stages, to achieve gradual and even flattening.