Engine covers are both an aesthetic and a NVH part: they absorb engine vibrations and noises. To produce engine covers, PU can be involved in 3 main different ways:
Engine Cover entirely PU made: The process usually involves a stop-and-go carousel (turning table) composed by different stations: one dedicated to removal and mould cleaning, one to release agent spray and/or in-mould spray, and tag placement (the release agent and the spray paint can be applied either manually or automatically), one to open mould PU pouring, and one to mould closing, curing and mould opening
Thermoplastic cover back-foamed with PU: This is a fully automated process where the thermoplastic cover and the back-foaming are carried out within the same injection moulding press. After injecting the thermoplastic cover, the PU is back-injected in closed mould
Thermoplastic cover manually assembled with a PU layer: The PU layer to be positioned on the back of the thermoplastic cover is foamed manually in open mould using a self-equipped tool
L shaped high laminarity and long stroke mixing head
In case fire resistance has to be achieved by adding expandable graphite (fire retardant) to the PU formulation, Cannon has a dedicated solution to achieve this goal. First of all, the graphite, usually in form of a powder or flakes, is blended with part of the polyol using premixing system thus producing a slurry; then the slurry is metered and injected as third component using the Solistream unit and a dedicated FPL AN head or an AX 14/4 (size).