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Polyurethane is a polymer obtained by an exothermal reaction between Isocyanate (MDI diphenylmethane-diisocyanate or TDI toluendiisocyanate) and Polyol (polyether or polyester).
Polyurethane's main characteristic: versatility
Polyurethane is the most versatile plastic material.
Versatility as per physical-mechanical characteristics of the polymer:
• rigid
• semi-rigid
• flexible
• expanded
• solid
• closed cells
• open cells
• thermo-plastic
• thermosetting
Versatility as per applicative techniques:
• pour
• spray
• spread
• injection
• extrusion
• lamination
• poltrusion
• rotational moulding
• casting
There are two different types of polyurethanes: expanded polyurethane and compact polyurethane.
Expanded Polyurethane:
A blowing process provided by a suitable blowing agent produces these expanded polyurethanes. They can be rigid, semi-rigid and flexible. DUNA-Group is a specialist in the field of rigid expanded polyurethane and particularly in products suitable for the industrial thermal insulation.
The expanded polyurethane, thanks to its microcellular structure, is one of the best thermal insulators: This characteristic has helped to improve the equipments of the so-called "refrigerated supply chain" appliances. Actually, expanded polyurethane is the main thermal insulation product used for: cold storages, refrigerators, cold shelves insulated trailers and carts and refrigerators.
DUNA's Group has three main product lines: CORAFOAM, DUNAPOL and DUNAPACK
Corafoam is the rigid polyurethane foam produced in blocks with a continuous process. The polyurethane can be manufactured in low-density slabs and high-density slabs. The former are used in the production of sandwich panels core as architectural components or for refrigerated food preservation and transportation. With special fabrication equipment it is possible to manufacture insulation in a variety of shapes for pipes, supports, vessel heads, valves, fittings and accessories for petrol-chemical plants. The CORAFOAMs, in special foams version, are high mechanical performance products, thanks to their structural reinforcement obtained with fiberglass.
DUNAPOL is the line of liquid 1- and 2-components systems used in the production of expanded polyurethane with pour and spray applications and compact polyurethane.
Poured and sprayed polyurethanes (Dunapol C and Dunapol S) are widely used in various civil and industrial sectors. Their characteristic on site application allows a quick laying. Their most significant feature is the on site application that grants quickness and low costs. It's interesting to notice that the expanding polymer perfectly fills the holes and adheres to the supports. These supports act as a barrier against water vapour and can withstand the compression stress.
It is common to use pour application systems in the manufacturing of "refrigerating appliances".
Compact polyurethanes:
Dunapol AD, Dunapol CO, Dunapol PA, are different from the above-mentioned products. During the reactive phase the polymer does not expand, and this is why these polyurethanes are called "compact". They are used mainly as glues,floorings, elastomers, structural adhesives, sealants and castings. DUNA-Corradini is oriented to the development of 1- and 2- components products and their commercial promotion. DUNASEAL products are part of the same range. These are hybrid 1-component sealants (polyurethanes, hybrid and MS) that allow elastic gluing and high performances.
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