Forming specific pieces
With polyurethane nearly every form can be poured. It is just a matter of the mould being technically capable of handling the piece to foam. A heated mould is nearly always necessary for a good curing. There is a wide range of production methods concerning the forming of specific pieces. Roughly we make a distinction between three types:
End product after demoulding
With a mould, formed pieces can be poured that can be used immediately after demoulding, so without needing a further finish. Open celled foam, to create flower bouquets are for example poured in moulds which rotate on a carousel passing the dosage unit. After injecting, curing and demoulding the end products which are formed in the shape of a ball, an aureole or a heart can be used immediately. Poured elbows pieces, jacket pipes or pipe shells for service pipes are other examples. When a hard top layer or skin is needed, like casing for electrical appliances or armrests, an integral foam can be used.
Semi-finished products after demoulding
Pieces that have been created by pouring into a mould, are also available as a semi finished product. In that case, after demoulding, the formed piece is finished with a layer of polyester resin, metal or composite. Final products which have been created this way are rudders for polyester yachts, insulated escape hatches on roofs or pieces used in the automotive sector.
Pouring system used as cavity filling
A mould in which is poured can also be used as an end product itself. The poured system will, after its reaction, not be demoulded but be used as a filling of the cavity between the inside part and the outer shell. Floating devices like demarcation or life buoys, cooling devices like beer tanks and heating systems like pre insulated pipes are examples of forms with an insulated cavity.