Manufacturing process
NPS manufacturing plants are operated in conformance with the stringent health and safety legislation and in consultation with employees and safety professionals.
There are 5 manufacturing stages:
1) Pre-expansion:
Polystyrene granules are expanded by free exposure to steam to form larger beads, each consisting of a series of non-interconnecting cells.
2) Conditioning (Curing):
After expansion, the beads still contain small quantities of both condensed steam and pentane gas. As they cool, air gradually diffuses into the pores, replacing, in part, the other components.
3) Moulding:
The expanded polystyrene beads are moulded to form blocks or customised products. The mould serves to shape and form the pre-foam, and steam is again used to promote expansion. During moulding, the steam causes fusion of each bead to its neighbours, thus forming a homogeneous product.
4) Cutting and Shaping of Expanded Polystyrene Blocks:
Following a short cooling period, the moulded block is removed from the machine and after further conditioning, may be cut or shaped as required using hot wire elements or other appropriate techniques.
5) Post-production processing:
The finished product can be laminated with steel, foils, plastics, fibreboard or other facings to form many and varied building products.