Rigid
polyurethane insulation is manufactured by mixing MDI,
polyols, low boiling point blowing agents and additives
under controlled conditions. An
exothermic chemical reaction takes place between these
base components in liquid form. The heat released
during this exothermic reaction volatilises the blowing
agent(s), and the mixture increases in volume about 30
times.
Manufacture of
polyurethane insulation boards Insulation boards are
produced in a laminator by a continuous process. The process
starts with machine heads designed to mix the isocyanate
and the polyol blend streams.
This mixture is then spread
on the lower facing, which has been heated at the right temperature
to ensure good adhesion.
The blowing reaction takes
place and the mixture bonds with the upper facing. The insulation
boards are then cut to shape and allowed to cool before being
piled and stored.
Manufacture of polyurethane sandwich panels with rigid
facings Polyurethane sandwich panels are manufactured as self-supporting
pre-fabricated construction elements with steel, aluminium
or other rigid facings. They are supplied in widths from 800
mm to 1250 mm and up to 24 m in length. These building components
have relatively low overall weight, but nevertheless display
great stability. They are easy to transport and can be installed
with minimal human resource input.
Polyurethane sandwich panels
can be manufactured in continuous or discontinuous processes.
Continuous manufacture of sandwich panels Polyurethane sandwich elements are manufactured on continuous
laminators. The reaction mixture is applied to a steel or aluminium
sheet being fed in on the laminator belt. In order to increase
rigidity, the metal facings are generally profiled prior to
foaming. Inside the laminator the expanding mass adheres to
a steel or aluminium sheet fed in on the upper belt.
After
running though the laminator, the sandwich panels are
cut to the desired length. The long edges of the sandwich
panels are generally given a tongue-and-groove profile
to facilitate rapid and easy installation of the pre-fabricated
elements. These panels are often factory-manufactured
with seals, making them largely air-tight.
Continuous manufacture of sandwich
panels with profiled metal facings in the laminator – IVPU
brochure
Discontinuous manufacture of sandwich panels In the discontinuous manufacture of sandwich elements, the
facings are fixed in a support mould on a frame and the resulting
cavity is filled with the polyurethane reaction mixture. In
suitable support moulds, several sandwich panels can be produced
simultaneously in this process.
Manufacture of PUR/PIR rigid foam blocks
PUR/PIR rigid foam blocks can be manufactured in either continuous
or discontinuous processes.
Continuous manufacture
of block foam In the continuous manufacture of block foam, the
reaction mixture is applied to a U-shaped paper strip that
is supported at the sides and transported on a conveyor belt.
At the end of the conveyor belt, the expanded block can be
cut to the desired length.
Continuous manufacture of block foam
Discontinuous manufacture of
block foam The base components are mixed in an agitator before
being poured into a box mould. The reaction mixture expands
and forms a rigid foam block.
Discontinuous manufacture of block
foam – IVPU
brochure
After they have reached their final rigidity, the blocks produced
in the continuous and discontinuous processes are cut into
boards (for example insulation boards for either flat or inclined
roofs) or sections (for example attic/garret wedges or pipe
insulation).
Appropriate facings can be glued to the cut boards to make laminated
or sandwich panels of various kinds for diverse applications.
