Patent ID: 8658070

Claim:
A process for preparing rotomoulded articles having at least two layers in a robotised rotomoulding machine comprising several separate feeders and several moulds, each mould including ducts designed to be run through by heat-regulating fluid and said ducts being realised by grooves on the external surfaces of the mould, wherein the ducts are closed above and along their extension by metallic strips, said process comprising: providing a first polyethylene composition for layer A comprising from 40 to 99 wt. % of a polyethylene (PE) resin and from 60 to 1 wt % of a functionalised polyolefin (FPO) or of an ionomer or of a polyolefin (PO) grafted to a non-polyolefin (NPO) in the form of a block copolymer (PO)g-NPO) or of a mixture thereof; providing a barrier layer B prepared from 40 to 100 wt. % of a PO that is dissimilar from that of layer A or a NPO or a mixture thereof and from 0 to 60 wt. % of a FPO or a (PO-g-NPO) or of a mixture thereof; optionally providing a second polyethylene composition for layer C prepared from a polymer that is similar to or dissimilar from that of layer A or layer B and is adjacent to layer A and/or layer B and, if present, is characterised in that it has good adhesion to layer A and/or to layer B and is not a blend of layer A and layer B; feeding each resin in a separate feeder of the robotised rotomoulding machine; installing one or more moulds of the same or different shapes and sizes; starting the automatic rotomoulding cycle; and automatically demoulding and retrieving the rotomoulded articles.